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Oral History Transcript — Dr. David Latham

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Interview with Dr. David Latham
By David DeVorkin
In Harvard, Massachusetts
October 8, 2006

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David Latham; October 8, 2006

ABSTRACT: In this interview David Latham discusses: his family background and early education; going to Massachusetts Institute of Technology (MIT) for his undergraduate degree; decided to study astronomy as his post graduate degree at Harvard University; Sputnik satellite; finding work at the Smithsonian Astrophysical Observatory; working with Charles A. Whitney, Owen Gingerich, Eugene Avrett; taking courses from Cecilia Payne-Gaposchkin on stellar spectroscopy; Oak Ridge National Laboratory; George Field; Leo Goldberg; equipment he worked with; Bart Bok; Donald Menzel; Harvard College Observatory; James Baker; Fred Whipple; stellar spectra; Kitt Peak Observatory; Don Hayes; Mt. Hopkins Observatory; Gerry Kron; Fred Chaffee; high-resolution spectroscopy; helping build telescopes for new observatories; Agassiz station; making cathodes; Herb Gursky; Marc Davis; American Astronomical Society (AAS); red shift survey; John Huchra; binary stars; Tsevi Mazeh; International Astronomical Union (IAU); stellar velocity measurements; Search for Extraterrestrial Intelligence (SETI); Paul Horowitz; extrasolar planet research; space interferometry mission; atmospheric extinction; Chuck Lundquist; optical and infrared astronomy; Andrea Dupree.

Transcript

DeVorkin:

This is a tape-recorded interview with Dave Latham at his home in Harvard, Massachusetts. The interviewer is David DeVorkin, and the auspices are the Smithsonian and the American Institute of Physics. This is funded by a National Science Foundation grant. Letís start out by having you talk about your family. Where did the Lathamís come from and where were you born?

Latham:

On my fatherís side, the family is from New England. His father grew up in Thetford, Vermont right across the river from Dartmouth. Thereís the Latham Library in Thetford as well as the Latham House and Latham Road and so on. My father grew up in Connecticut, went to MIT, and then the Sloan Business School. My motherís family was from Ohio. They met through friends in West Virginia soon after my father graduated from MIT. I was born in Boston on March 19, 1940.

DeVorkin:

What did your father do? You said he went to business school.

Latham:

He was an inventor, and he was quite successful at commercializing his inventions. He worked for many years at Arthur D. Little. He was the Executive Vice President. The Smithsonian Astrophysical Observatory is just about to move a large part of its operations into Cambridge Discovery Park, as itís now called, in West Cambridge. I still think of that as Acorn Park because my father purchased the land and named it Acorn Park when he moved Arthur D. Little from down in the heart of Old Cambridge to the outskirts of West Cambridge. After he retired, he decided to work on something heíd been tinkering with in our basement as I grew up. This was medical technology — blood fractionation equipment. The company that he founded for that work is called Haemonetics.[1] Its headquarters is in Braintree. I think business now earns a billion dollars a year and has about 1,000 employees, but you can check those numbers. In some ways, I think he was proudest of the work that he did after he retired. He continued to work until just a few years just before his death at age 95. He always liked to tinker. He wanted to invent things.

DeVorkin:

Was he typically in medical technology?

Latham:

Yes, after he retired in medical instrumentation. For example, he developed a machine that would collect shed blood in a triage unit. If an accident victim came in bleeding, the machine would suck up the shed blood, clean it, remove the bone particles and foreign material, and return the blood to the patient. This is now very heavily used in open-heart surgery. Typically in the old days, it would require 25 to 50 pints of blood. With the Cell Saver, you only need a pint or two, which makes it practical for the patient to pre-donate his or her own blood, which is really important in these days of AIDS because you know youíre getting your own blood. So there was a variety of developments at Haemonetics that basically centered around a centrifuge for cleaning the blood or separating the components. It was the centrifuge that was really the key idea, and that was his invention.

DeVorkin:

Did your mother have a career?

Latham:

She taught at Mount Holyoke College. She had a junior faculty position. But then, as was traditional in the Ď40s and Ď50s, she became a housewife. She brought up the four kids.

DeVorkin:

What number are you?

Latham:

Number three. Number three is always the best, isnít it?

DeVorkin:

Of course. Iíve read books about that. What about one, two, and four? Who are they?

Latham:

My older brother is suffering from Parkinsonís, and heís retired. His name is Nichols, William Nichols, but everybody calls him Nick. William Nichols was my motherís father. I think thatís where the name came from. He has an MIT degree and had a career in engineering for many years. He also ran a summer camp. My sister, Harriet Latham Robinson, is Director of Primate Studies at the Yerkes Institute in Emory University. Sheís working very hard on AIDS vaccines. She has one that works pretty darn well; theyíre just starting human tests now. She has a degree from MIT as well. My younger brother is a lawyer. We all have degrees from MIT. It was a great concern to my grandfather, Allen Latham, Sr., that none of his offspring went to Harvard. He was very proud of his Harvard degree. He died before the next generation started going to Harvard. Two of my sons went to Harvard, so we broke the string of MIT degrees there.

DeVorkin:

What was your life like before college? Where did you live in Boston?

Latham:

We lived in Jamaica Plain and we went to the Roxbury Latin School, which is a semi-private school, although it prides itself in taking students from the inner city as well with the admissions requirement. When I went to Roxbury Latin, it was quite small; there were 21 students in my graduating senior class. I think nine or ten of them went to Harvard, and three of us went to MIT, kind of rebelling against the Harvard tradition. There was no good reason why I chose MIT over Harvard. Ignorance is probably the best answer I can give for that.

DeVorkin:

Did you consider Yale?

Latham:

No.

DeVorkin:

Columbia?

Latham:

No.

DeVorkin:

Anywhere else?

Latham:

I applied to one school.

DeVorkin:

That was it?

Latham:

Yes.

DeVorkin:

Okay. What roles did academic or intellectual pursuits have in your family? Did everybody read?

Latham:

Oh, yes. It was the most important thing. We were expected to excel at school. We were expected to work hard at it. We were expected to go on to excellent schools for our college educations. I guess we were half-expected to get advanced degrees.

DeVorkin:

So this was not unusual for your family.

Latham:

No. Well, maybe not so much in the generation before, although they all had either Harvard or MIT degrees. MIT degrees on my fatherís side. The whole family went to MIT. But not the women, though. See, that had to wait for our generation.

DeVorkin:

Thatís right. Your mother taught at Mount Holyoke.

Latham:

She had an advanced degree, but I think only a masterís.

DeVorkin:

Where did she go to school?

Latham:

Oberlin. There was certainly an academic tradition and high expectations in our family.

DeVorkin:

What about the development of interests in the family? What did the family do as a family?

Latham:

We took trips together. We took trips in the car around the country, went camping together, and went hiking together. We did not play sports together. My father was not an athlete. He wasnít interested in that.

DeVorkin:

Were you?

Latham:

Again, I rebelled, so I got very interested in athletics. That was my way of expressing my rebellion. [Laughs]

DeVorkin:

What athletics did you prefer?

Latham:

In high school, I wrestled and played soccer. Tennis in the spring was the easy sport. At MIT, I was the captain of the wrestling team. Virginia.

Latham:

You were New England champion.

Latham:

Well, can you believe I wrestled 130 pounds my senior year?

DeVorkin:

I know that the weight ranges are very carefully set up. Yes, 130 pounds, thatís not bad.

Latham:

Iím not 130 pounds anymore.

DeVorkin:

[Laughs] No. I canít say that, either. How about your schooling? Could you point to a few teachers or class experiences that may have been influential in your life? Where did your idea of a career in life come from?

Latham:

I think it was always going to be science or mathematics because I loved mathematics in high school. I went to MIT thinking it would be physics of some kind or other, and then I discovered about the end of my junior year that you didnít have to write a thesis in mathematics. That sounded good to me, so I shifted from physics to mathematics. I got a degree in mathematics.

DeVorkin:

That was the reason?

Latham:

I donít know what the real reason was. Thatís what I tell people. I think maybe because a couple of the mathematics teachers at MIT struck me as my favorites. My favorite was Edwin O. Thorpe. Heís a memorable character because he is the fellow who figured out how to win at black jack, and was the very first that went out and made big bucks for a while until he became recognized and got thrown out of every casino that he tried to walk in.

DeVorkin:

He knew how to beat the game.

Latham:

He developed the original system for beating black jack, yes. He did it on hand calculators, on the old Monroe and Marchant machines. So he had a system where he counted the deck, and towards the end, heíd start making his big bets when the odds were in his favor.

DeVorkin:

What attracted you to that?

Latham:

Iím not sure if thatís what attracted me to him. Itís just that that was a sideline for him. I didnít learn about that until later. All I know is that he disappeared a couple of times for a week or two in the spring of my senior year, when I was taking some advanced calculus class, and one of his buddies taught the class in his place. I only learned after I graduated that he was off in Las Vegas, breaking the bank.

DeVorkin:

So did he become a benefactor at MIT?

Latham:

I doubt it. What comes also goes. I think that he ended up losing a lot of his winnings in some way or other. But you always hear about the winnings, not the losingís!

DeVorkin:

Do you have any other insights into your choice of MIT in terms of your career?

Latham:

No. It just seemed to be the family tradition, and it seemed like a perfectly good place to go, so I didnít even visit Harvard. I probably should have. Since I graduated from MIT and worked many years teaching at Harvard, I think Harvard probably would have been a better choice.

DeVorkin:

In what way?

Latham:

It has a much broader range of students and interests. I think it probably wouldíve been a better educational experience. MIT in the Ď60s was very focused on academics and choosing the very best students and working their butts off. The attitude of most students at MIT from that era is that they survived The Institute, but it was considered your enemy. Youíre doing battle with The Institute and the goal is to survive.

DeVorkin:

But you say that with a smile.

Latham:

Yes.

DeVorkin:

Was it a pleasant experience for you?

Latham:

I actually enjoyed it. I liked the challenge, and I think that was a common characteristic in many MIT students. They liked the challenge.

DeVorkin:

As you switched from physics to math, did you have thoughts of what you would do beyond MIT?

Latham:

No, but I got married my senior year. Weíve been married 45 years.

DeVorkin:

What is your wifeís name?

Latham:

Virginia Tullis Latham.

DeVorkin:

Where was she a student?

Latham:

She was a student at Duke. She moved to Boston when we got married and finished up at BU.

DeVorkin:

How did you meet her?

Latham:

She sent me a letter inviting me to be her escort to the Thanksgiving dance that follows up the cotillion. She was a debutante, and she didnít have an escort. Her friend, who I had dated once or twice, suggested, ďWhy donít you ask Dave Latham?Ē So she did, with a letter. In those days, you always did it with letters.

DeVorkin:

And she was at Duke?

Latham:

She was at Duke.

DeVorkin:

And you were here.

Latham:

I was here, but the Thanksgiving assembly, I think that is what they call it, is in one of the big hotels in Boston. She was coming back for Thanksgiving and needed somebody to escort her to this dance.

DeVorkin:

So sheís from a Boston-based family.

Latham:

Yes. Her father was in medicine based in Boston, although her motherís side was from the South. Thatís why she headed south. She was actually born at the Duke Hospital the year it was built. I couldnít figure out her handwriting because she said, ďCall my mother if you can do this.Ē I had a hell of a time figuring out what her last name was, so I went through the phonebook under all the Iís, looking for I-u-l-l-i-s. That wasnít it. Eventually, I got to the Tís, and there was a Tullis.

DeVorkin:

What compelled you to respond positively? You had never heard of this woman.

Latham:

I wasnít busy that weekend.

DeVorkin:

[Laughs] Thatís sort of an interesting and fateful thing to have.

Latham:

I think thatís the reason I bothered to tell the story. The reason I decided to go to MIT wasnít based on any deep thought or logic; it just kind of happened. The way I met my wife just kind of happened. Young people worry as much about making these important decisions. Maybe they shouldnít worry about it so much. Just do it.

DeVorkin:

Do you rationalize why you donít worry about such things?

Latham:

No.

DeVorkin:

Would you say you come from a comfortable background?

Latham:

I would say so.

DeVorkin:

Is that part of it? That you know that you always felt supported?

Latham:

I always felt supported. It wasnít always comfortable in terms of material resources.

DeVorkin:

How so?

Latham:

The family was like everybody else during the war, and soon after the war, not wealthy by any means. We wouldnít always drive the car to church; weíd walk a mile and a half to save the gasoline after the war.

DeVorkin:

You didnít mention church as something your family did.

Latham:

My family did, yes.

DeVorkin:

So did you continue on in church?

Latham:

No. Well, I went to a church when I got married. I conceded that.

DeVorkin:

So you had stopped going to church even then.

Latham:

Yes.

DeVorkin:

What is your religious background as far as family is concerned?

Latham:

New England Congregational.

DeVorkin:

Is there any explanation for why it didnít become a larger part of your life?

Latham:

I didnít think the logic of it was compelling.

DeVorkin:

Did the family compel you in any way?

Latham:

Oh, sure, when I younger. Until I went off to college, they controlled what happened on Sunday.

DeVorkin:

So until you went to college, you went to church.

Latham:

Yes. I found various ways to rebel, and that was one of them.

DeVorkin:

What about your siblings?

Latham:

My sister still goes to church fairly regularly. My younger brother, I donít think so. My older brother, I know he doesnít. Itís not something we discuss, though.

DeVorkin:

So itís an individual choice.

Latham:

Yes. Entirely.

DeVorkin:

The decision, as youíre moving into your senior year at MIT, for what youíre doing afterwards, are you still saying that you didnít plan ahead? You mustíve been at some point.

Latham:

Iím not sure youíre going to believe this story. My wife was very good about not nagging too much, but long about January, she said, ďWhat are you going to do next year?Ē Weíre just finishing up college, both of us. And I said, ďOh, I donít know. I suppose I could continue in mathematics.Ē I may even have applied to schools in mathematics; I donít remember. Then it just came to me: ďOh, maybe astronomy would be interesting.Ē I donít know why it came to me.

DeVorkin:

When was this?

Latham:

Probably the last day of January 1961. So where did one do astronomy in the Boston area? ďI bet you do astronomy at Harvard.Ē So I went over to the admissions office at Harvard because I didnít have any of the materials, got the catalog, and went, ďYup, they did astronomy.Ē ďOkay, how do you apply to graduate school?Ē ďWell, those applications are due tomorrow.Ē ďOh. Well, give me an application.Ē I sat down in Byerly Hall and filled out the application, wrote my essay in long hand like that, handed it in. Lo and behold, I got accepted.

DeVorkin:

So that essay would be somewhere in your records.

Latham:

No, not my records. I didnít keep a copy.

DeVorkin:

No, I mean at Harvard.

Latham:

Oh, gosh, I wouldnít know. Harvard keeps everything?

DeVorkin:

Yes, they do. And they donít let anybody see it, either.

Latham:

Oh, thatís probably a good thing.

DeVorkin:

Did Sputnik have anything to do with it?

Latham:

Oh, totally. It had an enormous impact on the whole psyche of our country.

DeVorkin:

Do you remember how you reacted to Sputnik and how people around you did?

Latham:

Not really, but Iím sure we were very excited. Just like I was very excited the first time I saw a 707 flying overhead on its way to Logan. I know exactly where I was when I saw that.

DeVorkin:

Where were you?

Latham:

I was walking across the Killian Court at MIT, and it was on the landing path to Logan. It was probably 1959. I donít know when they first flew. ďWow, look at that!Ē

DeVorkin:

Do you remember where you were when you heard about Sputnik?

Latham:

October í57?

DeVorkin:

So you donít remember the moment.

Latham:

No, I donít remember. I remember reading the papers with a lot of interest, but no, I donít remember exactly.

DeVorkin:

Did you know anything about the Smithsonian or Moon watch?

Latham:

Not a thing.

DeVorkin:

What magazines did you subscribe to or read?

Latham:

We were too busy dealing with the Institute to read magazines.

DeVorkin:

Not even in high school? You didnít keep up with anything?

Latham:

No, just what the family had.

DeVorkin:

What was that, typically?

Latham:

Life.

DeVorkin:

So not Scientific American?

Latham:

No.

DeVorkin:

Definitely not Sky and Telescope.

Latham:

No. I was never exposed to any of that.

DeVorkin:

No epiphany upon seeing the sky on some camping trip?

Latham:

Well, maybe, but it was in a small planetarium at Mystic Seaport the summer of 1960.

DeVorkin:

So you do remember that as an experience.

Latham:

I remember thinking, ďWell, this is kind of neat.Ē I may even have mentioned it to my wife for a month or two. It just kind of happened. Well, who knows what was going on in my subconscious?

DeVorkin:

So thatís about as far as we can get.

Latham:

Yep. I decided astronomy sounded neat, and Iíve never been sorry I chose it.

DeVorkin:

How would you typify your student years at MIT? Were you a successful student?

Latham:

I did okay. I had my ups and downs. Sometimes I got interested in other things.

DeVorkin:

Like what?

Latham:

Motorcycles.

DeVorkin:

Did you have one?

Latham:

Oh, sure.

DeVorkin:

What did you have?

Latham:

Started with Triumphs; British. But eventually, I went on to a career of international competition in motorcycles.

DeVorkin:

Oh, really? Did you just ride them or did you work on them?

Latham:

I worked on them, too. That was part of the fun.

DeVorkin:

Did you modify them?

Latham:

Sure.

DeVorkin:

In what way?

Latham:

I built machines for specific forms of competition. Although by the time I got really serious, I was a factory rider, so a factory was doing all that.

DeVorkin:

You were a factory rider? For what?

Latham:

Ossa and Yankee Motors. Yankee Motors was the U.S. importer.

DeVorkin:

I take it your family was absolutely thrilled and delighted that you were doing this.

Latham:

I told you, every now and then, I rebelled.

DeVorkin:

Do you see that as a rebellion?

Latham:

My wife says it was a form of rebellion, but I thought it was just something I wanted to do.

DeVorkin:

It explains the posters in your office. Those are also rather sophisticated posters.[2]

Latham:

Yes.

DeVorkin:

Well thatís very interesting. Did you ever have any serious accidents?

Latham:

I had a rule of thumb: If I didnít get off at least once a day, then I wasnít going fast enough. Yup. I call it ďgetting off.Ē[3] You know how I knew it was time to quit? I wasnít falling off anymore. It meant I wasnít going fast enough. It meant Iíd lost my nerve, so it was time to quit. In the Italian six days in í74, I didnít get off one time the whole week.

DeVorkin:

í74? You were riding through the Ď70s while you were here at Harvard.

Latham:

Yes.

DeVorkin:

Do you know any other astronomer in the world who races motorcycles?

Latham:

No.

DeVorkin:

Very interesting.

Latham:

There may be, but I havenít run into him.

DeVorkin:

Letís remember that as we keep going, because itís about taking risks, and Iím very interested in risk, in all its forms.

Latham:

I hear you.

DeVorkin:

Okay, excellent. So then you ended up saying, ďWell, Iím going to Harvard,Ē in the fall of í61?

Latham:

Yes.

DeVorkin:

So, you had no time out of school. You had the usual summer, and then you went right into Harvard.

Latham:

Actually, I found work at the Smithsonian Astrophysical Observatory the week after I graduated in June of í61.

DeVorkin:

So thatís when you came to the Smithsonian.

Latham:

Charles A. Whitney took me on, yes.

DeVorkin:

What compelled you? Did you have to take a job?

Latham:

I had a new wife, and we had to buy groceries.

DeVorkin:

So your living wasnít assured. The family was not that well off.

Latham:

We were on our own by then. Well, except we werenít, really. My father was always a great believer in education. So for example, when my wife decided that she wanted to go back to medical school after our five sons were born and the youngest was four or five years old, my father actually paid for her education at Harvard Medical School.

DeVorkin:

Thatís wonderful.

Latham:

At the time, she was the oldest woman ever admitted to Harvard Medical School.

DeVorkin:

Did you live out here at that time?

Latham:

We did, but we moved into Concord so sheíd be closer to medical school.

DeVorkin:

Thatís a whole fascinating story in itself. Well, youíve established that your first work was for Charles Whitney. What did you do for Charles?

Latham:

That was the time when computers were being applied to stellar atmosphere calculations, and SAO was a leader in that field. Charles A. Whitney was the leader of that group. There were several others working with him or in related areas. For example, Owen Gingerich, Iím sure you know, was working closely with Chuck. There were several other graduate students, some of whom are still around. Wolfgang Kalkofen and Gene Avrett working both with Chuck, and Max Krook, and several others that you donít hear of anymore.

DeVorkin:

You mentioned one other name just before Gene Avrettís name that I didnít catch.

Latham:

Wolfgang Kalkofen. Heís still on the staff at SAO now. This was a hot topic. New computers that the Smithsonian Astrophysical Observatory was getting access made it possible to calculate stellar atmospheres in detail in a way that hadnít been possible before. Chuck Whitney wanted me to incorporate convection into the computer codes for calculating model atmospheres. So that first summer, I actually worked with Owen Gingerich as my immediate supervisor, installing some convection code in a model atmosphere program that Owen had developed. That was the year that Owen got his thesis and finished his Ph.D.

DeVorkin:

What did you see you could contribute yourself? You were a math major. Were you attractive as a math major?

Latham:

No. I donít know why. I probably wasnít attractive. I didnít have any computer skills. I had never used a computer before. I had seen that punch card machine in the hallways at MIT and wondered what it was for.

DeVorkin:

Thatís fascinating.

Latham:

Well, mathematics wasnít computation at MIT. It was really theoretical. So I jumped into the deep end of that pool and learned by doing how to code in FORTRAN.

DeVorkin:

Did you teach yourself FORTRAN?

Latham:

I used Owenís codes as examples of how to do things. That was probably the most efficient way to learn. Of course, I got books and read them and all that. I taught myself. I didnít take any courses. I learned on the job.

DeVorkin:

What was the machine you were using?

Latham:

When I first arrived, I think it was an IBM 704. That pretty quickly evolved over the next year or two to a 709, and then the transistorized version, the 7090.

DeVorkin:

Did you have direct control over the computer? Or was there always an operator? Was it a batched system?

Latham:

It was completely batched. You had to read the decks of cards in. It was probably an 1801. It was a stand-alone computer to read the cards in, and youíd run the program, and sometimes it would take more than one pass. I think the compiler took three passes. I canít remember now. So you stood there feeding the deck through, two or three times.

DeVorkin:

But you did it yourself.

Latham:

It depended on what time of day it was. During the day, there were operators, but at night, they were happy to let you run things through.

DeVorkin:

They were happy, as you say. Did grad students then have direct access?

Latham:

Yes, I think so.

DeVorkin:

1961.

Latham:

I think so. SAO did have operators on duty, but if you were there doing it all the time, pretty soon, theyíd know who wasnít going to drop the decks and so on.

DeVorkin:

So it was that informal.

Latham:

It was reasonably informal, yes.

DeVorkin:

At other institutions, it was nowhere near that informal, and the turnaround was as much as 24 hours.

Latham:

Yes. On a good evening, you could get several turnarounds in our center when it was in the basement. But then that changed after we had to use computers down on campus, and so you were lucky to get a couple of turnarounds a day.

DeVorkin:

Okay, so having the dedicated computer for the SAO.

Latham:

I think that was really important.

DeVorkin:

Did you, at that time, wonder what the Smithsonian was doing at Harvard? Or even recognized it as a second entity? Was there any distinguishing characteristic for being an SAO employee as opposed to a Harvard employee in your mind?

Latham:

I was pretty much oblivious to that. The paychecks came. They were green federal paychecks. They werenít Harvard paychecks. I noticed that. Everyone seemed to be one big, happy family as far as I could tell.

DeVorkin:

So no other graduate students looking at you saying, ďWell, Iím working on a Harvard project and youíre working on a Smithsonian project.Ē

Latham:

If we had those conversations, Iíve forgotten.

DeVorkin:

I donít want to induce anything in your memory, but thatís an issue that I know is very clear at the much higher levels.

Latham:

Oh, Iím sure. It didnít trickle down to first-year graduate students that I remember. I certainly knew that Chuck Whitney was leading an SAO group, but he was a professor at Harvard as well. I donít think I understood how that worked. In other words, that there were Smithsonian employees with professor positions at Harvard.

DeVorkin:

Had you, by then, gone to Washington and actually knew what the Smithsonian was?

Latham:

No. Not that I remember. I donít think I had ever been to Washington, no. Iím sure I knew of the Smithsonian. I must have. How could you grow up and be 21 years old and not have heard about the Smithsonian? So I must have heard about it.

DeVorkin:

This summer of work, did that work then continue with Charles Whitney? Or did you have a completely open choice once classes started?

Latham:

I had an open choice, but I was having a lot of fun and I was learning a lot, so I worked part-time, continuing on the model atmosphere code development primarily with Owen,

DeVorkin:

Letís talk a little bit about the first-year courses. What courses did you have?

Latham:

I canít remember.

DeVorkin:

Let me name a few names. Anything from Cecilia Payne-Gaposchkin?

Latham:

Oh, yes, but that was later. That was í63. Best course I ever took at Harvard was with Mrs. Gaposchkin. ďMrs. G.,Ē we used to call her. The students — amongst ourselves, anyway — we called her ďMrs. G.Ē She taught a course on stellar spectroscopy, and I think I have to say thatís why I consider myself a spectroscopist, because I thought that was so neat. She had such a command of the material that I said, ďAll right, this is who I want to emulate.Ē

DeVorkin:

But there must have been some general courses for you to become aware of astronomy.

Latham:

Sure. My only memory of that is that I didnít know anything compared to most of the other students, so I had to learn all the astronomy because I had no background whatsoever in astronomy.

DeVorkin:

Did you consider that, at first, an impediment?

Latham:

No. Itís just like MIT: Itís a challenge.

DeVorkin:

Was there a point where you were exploring? Or was there a point where you made a commitment?

Latham:

I was exploring. I was finding out what was going on in astronomy, and I think maybe it took me two years to decide, ďHey, observational astronomy is the thing for me.Ē

DeVorkin:

Because you came from a very theoretical background.

Latham:

I came from a mathematics and theoretical physics background. Very little laboratory experience. I canít tell you exactly why I decided observational astronomy intrigued me. Iíd like to say itís because I saw there was going to be a great future for observational astronomy, but that probably is not true.

DeVorkin:

When is the first time that you came out to Oak Ridge to work?

Latham:

1963.

DeVorkin:

So you spent at least a full year on campus, two years on campus almost, before you came out here.

Latham:

Yes. It was just about then that I decided, ďOkay, observational astronomy looks really intriguing.Ē Bill Liller was organizing a summer intern program, based at the Agassiz Station, as it was called in those days. I signed up for that, and it was great.

DeVorkin:

On campus, there were some telescopes. Did you use them?

Latham:

I donít think so. Not before Iíd come out here. After that, I started using the telescopes on campus. The 15-inch was still operating in those days, and I would run that for the open nights.

DeVorkin:

That must have been quite a contrast. Or was that the kind of thing that you had in your mind? It was an astronomical telescope.

Latham:

No. It was quite a challenge to get that old telescope to work. Not a very good telescope. The optics are not Alvin Clark optics.

DeVorkin:

No, theyíre not. But they were fraunhofer uts-Schneider Utschneider.

Latham:

Yes.

DeVorkin:

What Iíve noticed from your publication history is that, your first participation was on convection in a conference on stellar atmospheres that took place in 1964.

Latham:

See, in those days, there wasnít the same pressure on graduate students to publish. Maybe it was partly the Sputnik fallout that there was such generous and united supported for anything connected with space, and astronomy had some connection. You werenít fighting for a career in this field. Anybody that got into it was almost guaranteed a career at that time.

DeVorkin:

Do you know how you were supported? Did you have a fellowship?

Latham:

I was teaching and being paid by Harvard to teach. I think I had a part-time position funded through the Smithsonian. But Iíd have to look it up; I canít remember.

DeVorkin:

So you werenít aware of, letís say, NASA fellowships or where your money was coming from.

Latham:

I was completely unaware of all those important details. I wasnít worrying about it.

DeVorkin:

Your first three publications were part of a large conference that I wanted to ask you about. And then work on limits of photographic spectrophotometry?

Latham:

Yes. See, I got interested in the detection of light because that seemed so fundamental to observational astronomy. My introduction to the detection of light was photography since that was the traditional detector of choice in astronomy. I actually got sidetracked into some pretty fundamental work on photographic detection, so youíll see kind of a theme for a while there.

DeVorkin:

Yes, I was wondering about that. Was that something that was self-driven by you?

Latham:

Completely.

DeVorkin:

So no one at the Smithsonian or Harvard was concerned in this.

Latham:

No, I had to completely bootstrap all that, and I did it because I thought it was important. When I was young, I tackled problems because I thought they were important, not because I thought I could solve them. Later on, I learned that maybe you ought to also consider whether you can solve the problem.

DeVorkin:

How did you learn that?

Latham:

Probably when I realized I needed to publish.

DeVorkin:

Yes, but there must have been some stimulus. Did somebody come to you, like Goldberg or Whipple, and say, ďYouíre not producingĒ?

Latham:

It was George Field, actually.

DeVorkin:

So it was after í72.

Latham:

Yes. I just coasted along.

DeVorkin:

You got away with everything for a good while! [Laughs]

Latham:

Yes, I was just riding on the coattails of Sputnik. I took a long time to finish my degree because I was teaching two-fifths and three-fifths because I had a family to support, and I had a job, too. So I wasnít taking a full course load, and I took a long time to finish the thesis because I kept getting distracted by doing things because I thought they were important.

DeVorkin:

You even had some spoof on taking Mizar ďSiriusllyĒ (itís a bad pun)

Latham:

Yes, I was a bit irreverent too.

DeVorkin:

Was that kind of irreverence appreciated around Harvard?

Latham:

No, it was not. I got myself into trouble.

DeVorkin:

Can you give me a few examples?

Latham:

I built an instrument. I got into building things already, working with my hands.

DeVorkin:

Yes, I wanted to get to the origins of that.

Latham:

One of the things I built was a device to do really careful calibrations of the performance of photographic plates. It had a great, big cylinder on it for an integrating sphere, which worked great. So when I published the description of that, I called it the ďWhite Elephant Tube Sensitometer.Ē Leo Goldberg was not happy with that. He objected. But by then, it was too late; it had already been published. So he called me on the carpet for that one, because I guess ďWhite ElephantĒ had some kind of connotation that he didnít appreciate.

DeVorkin:

Was this after your thesis or before your thesis?

Latham:

That was halfway through my graduate career. That probably would have been í64 or í65.

DeVorkin:

Yes, it didnít come up on ADS.[4]

Latham:

No, that was published in the AAS Photo Bulletin, which probably doesnít show on the ADS.

DeVorkin:

It should. That means they just havenít scanned it yet. You were writing quite a few papers, actually. I was impressed with how many papers you had by the time you got your degree.

Latham:

No, not very many.

DeVorkin:

Well, in comparison to others. Letís put it that way.

Latham:

I didnít start publishing until I realized that people who only build instruments donít get recognition in the same way that people who publish lots of papers get — advancement.

DeVorkin:

Thatís true. Thatís also an extremely important thing to discuss in a little length, if you donít mind.

Latham:

Oh, yes. So I decided, ďOkay, Iím going to put less effort into building instruments and more effort into using them.Ē

DeVorkin:

Was that after George Field?

Latham:

Yes. That date was probably 1974. I said, ďOkay, George. Iíll stop racing motorcycles, which has been absorbing about 60 or 70 days of my life a year and Iíll show you what I can do.Ē

DeVorkin:

So itís a challenge.

Latham:

Yes.

DeVorkin:

How serious was hisÖ?

Latham:

Not that serious. He asked me to resign my position, so it wasnít that serious.

DeVorkin:

Oh, no. [Laughter] No, I would say thatís moderately importantÖ Letís go back to tool making. Now, you already gave me a great big hint with your dad, but I want to take you way back and say a lot of fathers get into all sorts of stuff. Even though the family may know about it, they canít touch. What about your dad?

Latham:

Could I touch his stuff?

DeVorkin:

Yes.

Latham:

Of course.

DeVorkin:

Could you mess with it?

Latham:

Yes.

DeVorkin:

Did he have tools?

Latham:

Oh, yes, all kinds of tools.

DeVorkin:

Did he have an actual shop?

Latham:

Yes.

DeVorkin:

How big was your house?

Latham:

Not that big, but the shop was in the basement.

DeVorkin:

Lathe?

Latham:

Not when I was in high school. We couldnít afford it. Later on, when he built his new home in the Ď80s, he built it with a shop. A Bridgeport, lathe, saw, press, grinder. Those tools are in my shop now, of course.

DeVorkin:

So you inherited them.

Latham:

Yes.

DeVorkin:

Was there any competition from your brothers or your sister?

Latham:

Not really.

DeVorkin:

Did he dabble more than in mechanics? It sounds like it was optical or electronic.

Latham:

Yes, he would dabble in a lot of stuff. He wasnít really an expert in modern solid-state electronics, but he could make things work.

DeVorkin:

Did he have a welder?

Latham:

Yes.

DeVorkin:

What about an oscilloscope?

Latham:

No. That tells you a lot!

DeVorkin:

I was just asking. [Laughter] But as far as what he had to design or build a simple circuit or something, to make something like a servo?

Latham:

Yes.

DeVorkin:

So you got your hands on all this stuff.

Latham:

No, this was after I had gone off to college that he was doing that at home.

DeVorkin:

Can you sort of typify what you had access to by the time you, went to MIT?

Latham:

Any of the junk in the shop, if I wanted to go play with it, I could.

DeVorkin:

Did you build anything?

Latham:

Motorcycle engines.

DeVorkin:

So thereís no telescope hanging around some place.

Latham:

No.

DeVorkin:

Iím devastated! [Laughs]

Latham:

Well, it doesnít always work that way.

DeVorkin:

I know. Well, it worked with Gerry Kron.

Latham:

Yes, Iím not surprised.

DeVorkin:

Yes, and various others, but mainly Gerry. Did you carry this tool-building, inventiveness thing through, and did it express itself in any way at MIT?

Latham:

No.

DeVorkin:

Or did your contact with your dad continue through that time, since you were here in town?

Latham:

Yes, some. I was living on campus. But I didnít really start building things until í64, I guess. í63, í64, someplace in there I started building things. Because I came out for that summer here at the observatory. We lived in the cottage on the observatory grounds, and my responsibility was to make some new things work. So finally I had a charge. I could start using Larry Carron, the machinist, and Peter Crawford, the electronics guy, and we could start doing stuff.

DeVorkin:

Was there a staff out there?

Latham:

Yes. That was the old way of doing it. There was a staff of three people. There was a caretaker, there was a machinist in the shop, and there was an electronics technician.

DeVorkin:

There were also certainly shops down in the Smithsonian.

Latham:

Yes, but we were living out here, so this was a natural place to do it.

DeVorkin:

When did you actually move out here then?

Latham:

The fall of í63. We moved into the cottage on the grounds.

DeVorkin:

Oh, so that wasnít temporary; you actually moved.

Latham:

We lived there for a year. I think it was the fall of í63. Then the next year, we found a small house here locally, lived there a couple of years, and I commuted in so we could be close to the observatory. We just fell in love with the town. When we were living at the observatory, my wife would walk around with the kids in a stroller and walk past this place and think what a fantastic place that is, never dreaming sheíd ever live there.

DeVorkin:

When did you move in here?

Latham:

That was í92, so we had moved back to Concord. She finished medical school. Very active practice. Then one day, we heard this place was for sale, and had been for two years. So we bought it at the bottom of the market.

DeVorkin:

Thatís fantastic.

Latham:

I knew I was in trouble because I arrived back from a trip at Logan Airport, and there was my wife, meeting me at Logan Airport. She never met me at the airport. And her first words were, ďI lust.Ē [Laughs] Okay. No, no. ďI lust. We are going to buy the Henry place.Ē And I said, ďOkay.Ē Literally, thatís what I said. A week later, we had a purchase and sale agreement.

DeVorkin:

She was a practicing physician?

Latham:

Yes, an internist. We made it work.

DeVorkin:

No, I mean she was more than an important addition.

Latham:

Oh, yes, sure. Making more than I made. Although, doctors donít make so much anymore.

DeVorkin:

Not good doctors who actually like medicine?

Latham:

Yes, and sheís one of those.

DeVorkin:

Letís talk about the first instrumentation projects and what challenges you had. See, I take your first experience facing instrumentation, dealing with photographic emulsions and their limitations. When can you first recall feeling frustrated with photography, looking for an alternative? Or was that not the area of instrumentation you were going to go into at first?

Latham:

ďFrustratedĒ — thatís a pretty strong word. I tried to cope with it and understand how it worked and do the job. The observatory here was rather backwards in terms of modern instrumentation because Bart Bok left and went to Australia when Menzel took over, and that was the doom for any real development in optical astronomy at Harvard for a decade or more.

DeVorkin:

When Bok left.

Latham:

Yes. Menzel became the new director of the Harvard College Observatory. So, observational astronomy was essentially nonexistent at Harvard when I arrived.

DeVorkin:

Was James Baker a force at all here then?

Latham:

He may have been, but I was oblivious to Jim. Menzel actually used James Baker for his solar eclipse equipment. I might even say ďabused.Ē

DeVorkin:

Thatís an interesting observation. Goldberg has said similar things about Baker, only he said that Shapley abused. He didnít use the term ďabused,Ē butÖ

Latham:

But you got a sense of that, did you?

DeVorkin:

Yes, very strongly. Could you amplify that a little bit?

Latham:

Menzel dabbled in solar astronomy and would go off to eclipses and would decide he needed such-and-such, a spectrograph. Jim Baker would design and be involved in the building of an instrument that would be the best of that type in the world, as far as I would know, and then Menzel would go do something useless with it. In other words, Bakerís instrument deserved better. But youíre now getting some of my prejudice against Donald Menzel

DeVorkin:

Iíve interviewed Darrit Hoffleit and others, and Iíve gotten some very strong views about Don Menzel. Iím still trying to figure this out, but he may be the person who actually did bring SAO up here behind the scenes.

Latham:

Maybe. He seemed to work behind the scenes a lot.

DeVorkin:

How active a presence was he when you were here as a grad student?

Latham:

We never ran into him in a teaching environment. I donít remember learning any astronomy from him. He was the director. He had the big corner office where I now sit, only itís not as big. Itís been divided up. He was the only person with a reserved parking spot. It said ďMenzelĒ on it. It was the one right next to his office. You were in trouble if you parked in his spot.

DeVorkin:

Iím sure. [Laughter] Menzel was there, and Whipple was in one of the other wings?

Latham:

Yes, he was in the new buildings. That was 1960 or 1961. He got one of the offices over in the new building.

DeVorkin:

Thatís right. You also had Goldberg coming in.

Latham:

Yes.

DeVorkin:

In fact, Goldberg came just as you arrived.

Latham:

Yes, but he was pure Harvard. He brought Bill Liller with him, I believe, as his fair-haired young star.

DeVorkin:

But how about your Atmospheres Group?

Latham:

We were over near Fredís office.

DeVorkin:

Did you interact at all with Goldberg?

Latham:

No. Very little interaction with Goldberg because he was basically solar physics.

DeVorkin:

You didnít do anything beyond that. Because I know that L. H. Aller who came to UCLA, left Michigan for UCLA pretty much the same time as Goldberg left for Harvard. Aller was doing all stellar spectroscopy at that point. I imagine you would have read his textbooks and that sort of thing by the early Ď60s.

Latham:

Yes, I think so.

DeVorkin:

So there was very little overlap.

Latham:

Right. I donít remember ever taking a course from Goldberg. I donít know whether he was teaching or not.

DeVorkin:

I should have generated a list of the Harvard teaching staff and we could have found names, but I can also get it from your transcripts. But of all those teachers, Cecilia stands out?

Latham:

Yes, definitely.

DeVorkin:

What problems were you trying to overcome as you built your first instruments?

Latham:

I wanted to get stellar spectra, which I could then do simple things like classify, because that was an important topic back in those days in the early Ď60s. The MK, the Morgan-Keenan, classification system was brand new. It was much better at classifying luminosities of stars, distinguishing giants from dwarfs, than the old MKK — the Morgan-Keenan-Kelle scheme. This was, a long tradition at Harvard, stellar classification, and it was a course that I had taken in the fall of my first year. Which was, all new to me, this kind of taxonomy, coming from a math background into classification. But I got really interested in that issue of stellar spectroscopy with Mrs. Gaposchkinís course in the spring of í63, and then I went out to the observatory — largely because of her course — to learn about it. I discovered there was hardly any capability for doing spectroscopy at the Agassiz Station. There were a couple of instruments that had objective prisms. The one I had access to was the 12-inch Metcalf. That was an old refractor, probably a four-element refractor that was built by Reverend Joel Metcalf. He probably did the lenses back before 1920. It had been in Cambridge for a while, and it was moved out here as one of the supporting instruments when the Agassiz Station was built in the Ď30s. That was the thing that I could do spectroscopy with, so I started trying to use that instrument. What I discovered was that when you trail the telescope in right ascension to broaden the spectra, so that you get a nice, wide spectrum, the periodic errors in the drive made it streaky. The signal would build up in one place, and then it would speed up, and then the signal would be a terrible looking spectrum. So one way you could solve this problem was with your eye glued to the eyepiece and pushing buttons and trying to generate a smooth motion. But that was not right either because the crosshair didnít move. So then I had an idea for building an instrument that would go on the guide telescope so you didnít have to sit there with your eye glued to it. It had a refraction block in it and a stepper motor that drove the refraction block, so it moved the image of the star smoothly and gradually with time over a ten- or twenty-minute exposure, however long the exposure was, and then a photo detector. It would feed back into the drive motor, and it would do automatic widening. So I built an automatic widener stet the objective prism spectra. So that was probably the first instrument where it went from me to concept, to design, to building, to use.

DeVorkin:

This is for the objective prism?

Latham:

This is for a telescope that had an objective prism on it, a 12-inch telescope with a great, big 12-inch diagonal prism.

DeVorkin:

So you moved the entire plate then.

Latham:

No, you moved the telescope. You moved the telescope gradually so the stellar spectrum trails across the dispersion on the plate.

DeVorkin:

And you did that out here at the shop.

Latham:

Yes, Larry Carron built the parts.

DeVorkin:

Now, did anybody pay attention to what you were doing?

Latham:

No, nobody knew what I was doing.

DeVorkin:

So you didnít have to go to a design stage and get it past by somebody. This was not a project, so to speak.

Latham:

How did I pay for it? I scrounged. Larry had all the stock that he needed. I may have had to pay a few dollars for a prism or a piece of glass from Edmund Scientific. I canít remember how I did that. I may have gone to the department and gotten 100 bucks or something. It would be interesting to see if I did.

DeVorkin:

Where is that widener?

Latham:

I donít know. It was used for two or three years, and then it was replaced by a new spectrograph that was procured completely independently of me by the Harvard College Observatory, I believe, for the Wyeth reflector - the 61-inch telescope. So there was a new Cassegrain spectrograph, and, I was given the responsibility for making it work. I did a research exam on that. Did I ever publish that? I donít think I ever published that study. That was before my thesis.

DeVorkin:

Yes, itís not here, because between í68 and your thesis in 1970, you had basically stellar atmospheres work. You have spoken about Merak in a AAS meeting. Then you were still calibrating Kodak plates, doing that sort of thing.

Latham:

Yes. You see, I was trying to do high-quality quantitative spectroscopy with photography; thatís what this new spectrograph was doing. Then by the mid-Ď60s, I gave up on using this spectrograph here for a variety of reasons and went to the National Observatory, so I got time at Kitt Peak. I was well-prepared to go to Kitt Peak because I had learned photographic techniques here and knew what I wanted by the time I went, and could write a proposal that got time and so on.

DeVorkin:

Your thesis does include instrumentation and techniques. The observations were at Kitt Peak. High-dispersion spectra.

Latham:

Right.

DeVorkin:

But what was the instrumentation there? Because I havenít read your whole thesis.

Latham:

I built an instrument to measure spectral energy distributions.

DeVorkin:

From photograph spectra?

Latham:

No, I had given up on photography for that, so this was photoelectric. That eventually led to fundamental calibration work, the calibration of Vega. See, I was still doing projects because they were important.

DeVorkin:

And you worked with Don Hayes. Don Hayes and Seth-Ann Howard-Hayes.

Latham:

Thatís right.

DeVorkin:

I definitely want to get to that because some of that work is the highest-cited work youíve done.

Latham:

Yes. Itís still cited.

DeVorkin:

You have, as of now, 651 citations to the 1975 paper, ďRediscussion of the Atmospheric Extinction of Vega."[5]

Latham:

Thatís right.

DeVorkin:

I know Don Hayes had been working on fundamental calibration stuff for some time since the late Ď60s. But weíll get to that once we get a little more into the spectrophotometry, or after that, because photoelectric spectrophotometry was being done mainly — I mean, everyone thinks Wisconsin. Were you aware of what Wampler was doing?

Latham:

Not Wampler, but Code. It was Codeís work that we were most aware of.

DeVorkin:

Did you interact with them at all and get ideas?

Latham:

No. We read, and I had an idea of how I thought it ought to be done.

DeVorkin:

This was a much more demanding, precise kind of thing to get across.

Latham:

Oh, yes.

DeVorkin:

From what I know about scanners at Lick, these were temperamental, to say the least.

Latham:

Wampler was not trying to do very accurate, absolute spectrophotometry. His main goal was to get spectra, faint objects, galaxies, for example. Coming out of the Stellar Atmospheres Group, we were trying to test the model stellar atmospheres and calculations of what the emergent spectrum should look like. We were limited by the quality of the observations of spectral energy distributions. Steve Strom, who was also in the Stellar Atmospheres Group, and I identified the need for very accurate spectral energy distributions. We realized we werenít going to do that from here, and the instrumentation at the National Observatory wasnít suitable for that work either. So in 1964, Steve and I talked about how we could build our own capability. We decided to go see Fred Whipple. We prepared a proposal, I typed it up myself — and we went in and made a presentation to Fred Whipple (I could get the exact date, but Iím pretty sure it was the summer of í64) about how we would like to establish a capability to measure absolute spectral energy distributions, and we thought it would require a new instrument, perhaps on a new telescope at a good site, perhaps in the Southwest. We were not prepared for Fredís reaction. Fred grabbed this idea and ran with it. The only conclusion I can draw is that Fred mustíve been thinking about building his own observatory for some time, and suddenly, he saw an opening; he saw a couple of young people who had a need, a burning desire, for a capability, and he was going to try to harness some of that. So itís remarkable how fast things developed after that. We made presentations to Richard Perkin down at Perkin-Elmer. The project did not get supported by Perkin, but Fred set that meeting up. Richard Perkin was the top guy, and certainly a friend of astronomy in Cambridge for many years. We made a presentation to him; we were talking about a 24-inch telescope with a new scanner on it. We didnít need that big a telescope; you just need to have good skies and the right instrument. I have a whole book on this in my office where I put notes of all the things that we did. That was certainly one high point.

DeVorkin:

So, Perkin did not support this.

Latham:

As far as I know, he did not support it.

DeVorkin:

But you remember Whipple as being this enabler.

Latham:

Yes.

DeVorkin:

And he kept you in it. He didnít run it all by himself.

Latham:

No. Itís amazing that he took a fourth-year graduate student and let me do things that I wanted to do. Simply amazing.

DeVorkin:

I will agree with that. Where were the faculty between you and Whipple in this?

Latham:

Supportive. Chuck Whitney and Owen said, ďYes, thatís a great idea. Go see Fred.Ē

DeVorkin:

So thatís how it worked. There was access for a fourth-year graduate student.

Latham:

Yes. We made an appointment, we marched in, and he listened. About every 15 minutes, heíd sneak into the next room and get a cigarette. He didnít keep them on his desk; he kept them in the next room so that he could dole them out, and heíd smoke.

DeVorkin:

Oh, yes. Now, this was you and Steve Strom.

Latham:

Yes.

DeVorkin:

By the way, did Steve Strom have any cachet because of his famous brother?

Latham:

I donít think so. I donít think it helped Steve.

DeVorkin:

Well, he did okay.

Latham:

Yes.

DeVorkin:

All right, back to this. You lacked support from Perkin.

Latham:

Yes.

DeVorkin:

Where did you go then?

Latham:

Iím a little bit fuzzy about the exact sequence of events, but the next thing that I remember clearly is that Fred decided that he would look at the Tucson area, or certainly the Arizona area, as a place where he might build an observatory. He kept me involved. We went and talked to people in Arizona. He also got Fred Franklin involved, so you can talk to Fred and find out the various sites that Fred drove around and looked at. This all happened, I think, that fall, two or three months later. Sometime, in that fall, we ended up in Gerard Kuiperís office. I gather Fred and Gerard were old buddies. Gerard Kuiper said, ďMount Hopkins. Thatís where you want to go, Fred. I fly all over Southern Arizona.Ē He was an avid pilot. ďThe air over Mount Hopkins is the smoothest of any of the mountains I fly over. For example, Mount Wrightson, right next to it, has very bumpy air. But Mount Hopkins has smooth air, and that means the seeing is going to be great there.Ē

DeVorkin:

What a way to do a site survey. I never heard of such a thing. Is that documented anywhere? Thatís wonderful. I see ďMan points to head.Ē

Latham:

I wrote a description of that, in my diary, because I was struck by it, that this was the way the observatory site was going to be chosen.

DeVorkin:

I can see an article in Air and Space magazine already!

Latham:

We paid some lip service to doing some more serious site testing. We put together some systems to measure seeing diameter with Questar telescopes, and we built little facilities, little shelters at three places on Mount Hopkins, but we only did it on Mount Hopkins. We didnít go test a whole bunch of other sites, and we only did it for half a year or something like that.

DeVorkin:

I mean, if it was sufficient for your needsÖ Thatís fascinating.

Latham:

So I built those things, and Bob Noyes got involved in helping out. Bob had just arrived, and this Australian graduate student, Don Hall, who ended up being the director of Mauna Kea Observatories, and then got the can because of his associations with C2H5OH.

DeVorkin:

Alcohol?

Latham:

Yes. Ethyl.

DeVorkin:

Oh, I didnít know. But Don Hall?

Latham:

Don Hall was a graduate student and he worked on the site testing, too. We found that the seeing looked like it could be pretty good on Mount Hopkins, although we didnít have an absolute scale for the seeing. But we could see from the star trails when the seeing was really tight and when it was blowing up, and it looked pretty good. We had one at the summit of Mount Hopkins. We had one on the ridge, if I remember correctly.

DeVorkin:

Was there a road up there at the time?

Latham:

No, the road went partway. It was a mining road. But the first time we went to the ridge, we had to hike the last mile or two. But pretty soon, Fred had organized people to get in there. Chuck Tougas, probably, came on very early. He came out of satellite tracking like many of the people that Fred put to work on this. He picked his best people out of the satellite tracking network, people that got things done, and he brought them in. Next thing you know, weíre building an observatory at Mount Hopkins.

DeVorkin:

Was there a Baker-Nunn station?

Latham:

A Baker-Nunn station was moved from New Mexico to Mount Hopkins. Why was it moved? Iím sure there was a reason given. Itíd be very interested to see what the documents say. But the real reason was to allow satellite tracking money to be used to pay for the infrastructure. That was the real reason. This is how Fred funded it, is my speculation. I was a graduate student. What did I know about all these things? Nothing. But itís pretty transparent, isnít it? And there was Smithsonian money to pay for the 16-inch telescope, which was the first major instrument up there. But the satellite tracking, I think, had been built and was operating already before the 16-inch, because that was a new instrument.

DeVorkin:

But of course, that all didnít happen until you did a site survey.

Latham:

It didnít start happening till we had some numbers from the site survey, is my memory. But all this kind of stuff, of course, could be verified from materials that I have. But Fred kept me involved. Simply amazing.

DeVorkin:

That is amazing. As he was planning this whole activity, did you have to keep it secret? Or did everybody know about it?

Latham:

I donít think there was any secret. I canít remember him ever saying this was secret. No, he was having a great time. Pissing Leo off, for sure.

DeVorkin:

How is that? Why?

Latham:

Because Leo, who was the big person at Harvard College Observatory, couldnít just go out and spend money and hire people to do things because he didnít have the resources. But this was the time of growth at the SAO, and there were resources kicking around, and Fred could do all kinds of things. I think this really rubbed Leo the wrong way, and eventually, it came to a head.

DeVorkin:

When was that?

Latham:

I think the thing that really kind of blew up is when Fred could hire serious academics without consulting with Leo or Harvard. Sometime in the late Ď60s. í67, í68?

DeVorkin:

Oh, that late?

Latham:

Maybe. I donít know. Iíd have to dig around and remind myself when it was. Iím sure lots of people, like Owen, will know for sure.

DeVorkin:

Yes. Iíve gone through the Harvard College Observatory Council records about the status of Smithsonian employees, and surely through the Ď50s and early Ď60s, they were second-class citizens.

Latham:

Yes.

DeVorkin:

Also, these were not autonomous hires. These were things that had to be approved by Harvard.

Latham:

The things that were Harvard professors, anyway.

DeVorkin:

No, even if it was a Smithsonian.

Latham:

Okay. Well, that changed, eventually. [Laughs]

DeVorkin:

Yes. Thatís what Iím trying to track down. It isnít as clear as Iíd hope. By the time you would have become aware of these things, that watershed had already come and gone.

Latham:

So when did Leo go to Kitt Peak? It would have been the year or two or three before he went to Kitt Peak when this all came to a head, I think.

DeVorkin:

Right, exactly. And still well before í72.

Latham:

Oh, yes.

DeVorkin:

So you were a fourth-year graduate student doing this sort of thing. Essentially, building an instrument and a new telescope for the observatory. Were you involved in the building of that telescope itself?

Latham:

Oh, yes. I sat in on all the meetings and reviewed all the proposals from Tinsley.

DeVorkin:

So thatís a Tinsley telescope. Is there a reason why it was a Tinsley and not a Boller and Chivens?

Latham:

Yes, price. It was all we could afford. The original proposal that Steve and I had made was for a 24-inch telescope, and Fred said, ďNope, itís got to be at least 60 inches.Ē To get up to a 60-inch, we had to cut some corners. It couldnít be a classical Cassegrain. It had a spherical primary. It was on stet axis only. We looked, definitely, for the lowest bidders.

DeVorkin:

Did you ever ask him why it had to be at least 60 inches?

Latham:

Why even argue with him? I have a memo, which I saw when I was preparing for the symposium last fall in his memory, where I was arguing strongly that we should push ahead with something smaller and not overextend ourselves. Well, what did I know? I was a fifth-year graduate student. I was wrong. He was right.

DeVorkin:

Did he listen to your arguments at all?

Latham:

I donít know.

DeVorkin:

In other words, did he allow you to argue?

Latham:

Well, I sent him the memo. [Laughs]

DeVorkin:

And youíre still in the project.

Latham:

Oh, yes. He was right.

DeVorkin:

Tell me why he was right.

Latham:

Because a 60-inch was big enough to do some real work, and weíre still using it very productively now.

DeVorkin:

You say itís a spherical primary?

Latham:

It now has a corrector.

DeVorkin:

But what was it at first?

Latham:

It was a spherical primary. Still is.

DeVorkin:

So what did you call it? Is it a Schmidt?

Latham:

No, itís just a kind of classical Cassegrain configuration, except it didnít have a parabolic primary. So it has a lot of spherical aberration.

DeVorkin:

So you didnít correct it initially? You didnít correct the spherical aberration?

Latham:

Nope. It was a spectroscopic instrument. You used it for one object at a time, on axis where the images are fine.

DeVorkin:

Iíve never heard of that as a cost-cutting measure. Would you say thatís rare or unique? Or Iíve just been missing it?

Latham:

Well, it was the first 60-inch I was involved in, so what did I know?

DeVorkin:

So this was a dedicated spectroscopic instrument.

Latham:

Yes, and still is.

DeVorkin:

Thatís the instrument that the Z-Machine went on.

Latham:

Thatís right.

DeVorkin:

Well, I want to know as much as I can about it.

Latham:

[Laughs] Yes.

DeVorkin:

It has a full aperture corrector?

Latham:

No. It now has optics near the focal plane that gives good images over, I donít know, a big enough field. 20 minutes of arc yes.

DeVorkin:

Oh, itís a small corrector.

Latham:

Yes. Small lens correctors.

DeVorkin:

Did anybody come to you from the Hubble Space Telescope project and say, ďYouíve been dealing with spherical aberration for a long time. How did you fix it?Ē

Latham:

No. Sorry. I didnít move in those circles.

DeVorkin:

So, you were building a dedicated spectroscopic instrument.

Latham:

Yep.

DeVorkin:

Chuck Whitney was building the Atmospheres Group. Iím trying to get a sense of this. Thatís why Iím interested in the Atmospheres Group; for many reasons, but beyond the intellectual, what you were doing is that institutionally, it was the largest deviation from the traditional Smithsonian mission.

Latham:

Although, there was some solar physics. Spectra of the sun are useful for solar physics. But my main motivation was to make observations of stars that could be used to test the new theoretical models.

DeVorkin:

Of course. But Iím talking about Leonard Carmichael and Dillon Ripley saying, ďWhereís the traditional program going?Ē Because that was part of the deal.

Latham:

I have no idea how Fred sold this new observatory he was building to Smithsonian Institution. I can imagine all kinds of things he might have used to sell it. ďNew Mexico is just not the right place for this satellite tracking station. I need to transfer it to a new site in Arizona.Ē

DeVorkin:

Was he good at that sort of thing?

Latham:

I donít know. I never saw him in action.

DeVorkin:

And he didnít share this.

Latham:

No. He didnít talk about strategy with me that I remember.

DeVorkin:

To your knowledge, did he talk about strategy with anybody?

Latham:

Thatís an interesting question. I donít know. Maybe with Chuck Lundquist.

DeVorkin:

Iíd love to know.

Latham:

I donít know. Iíll bet he didnít talk about it to Leo. [Laughter]

DeVorkin:

And he was very reticent to talk to me. Iíve interviewed him in a few occasions, and he was interviewed by a Smithsonian historian as well, and I can imagine by others that we donít even know about yet and Iím trying to find out. He was very, very careful about it.

Latham:

Fred wanted his own observatory, and he found a way to build it. Thatís my interpretation.

DeVorkin:

That is a nice way to put it. I will work on that. Thereís another element about Fred Whipple that Iím trying to develop in my celescope work, and Iíll be asking Richard McCrosky about that tomorrow. I have a suspicion that Fred was competing to become NASA. His model was not first centralized by the agency to handle space, but for a decentralized academic base of which different large institutions would take on very large chunks of NASA. I donít think, even in Fredís mind, that he believed that he could be all of what NASA had to be, but he wanted to be a good chunk of it, certainly in the tracking, data acquisition, and instrumentation.

Latham:

Yes, and he tried to compete in space. Celescope was a failure, and Iím sure that was a great disappointment for him.

DeVorkin:

Yes, in his oral history. But he also is angry because it wasnít what he had initially wanted — at least he says after the fact. Iím wondering if you knew anything about that or if you were aware of that.

Latham:

Only what I could guess. But I can guess that that was a point of tension between Leo and Fred, because Leo was doing the solar satellite series and having a fair measure of success, and the only thing that Fred tried to do just didnít cut it.

Redacted portion of transcript is CLOSED to researchers without permission from David Latham.

DeVorkin:

Iím going to try, yes. Itís a very tough operation. Now, youíre an instrument man. I donít know how much you were into electronics in the Ď60s.

Latham:

Oh, heavily. That was my introduction to cathodes. Thatís how I learned about semiconductor cathodes. I came out of a background of photographic emulsions, but I needed to know about more modern detection. I did my apprenticeship with Gerry Kron and the Kron camera.

DeVorkin:

Thatís not recorded anywhere.

Latham:

We never got very many publications out of it, but I learned a lot over a period of two or three years. Fred Chaffee and I worked together first to bring high-resolution echelle spectroscopy to Mount Hopkins. We built the first echelle spectrograph together. It is still in operation. That was probably í68, í69. And then we needed not just photographic detectors. We wanted really high-quality quantitative detectors, so we started working with Gerry Kron. I spent a fair amount of time in Flagstaff, set up our own cathode-making lab, and made cathodes.

DeVorkin:

This is in í60? í69.

Latham:

í69? He was in Flagstaff.

DeVorkin:

Yes, he moved to Flagstaff. So all of thisÖ

Latham:

Into the early Ď70s. Then we used a Kron camera and we got some science out of it. Not a lot.

DeVorkin:

Yes, I didnít see any publications that reflect that.

Latham:

Nope. I donít think I ended up being an author on any of those.

DeVorkin:

Everybody at Lick was crazy about Gerry.

Latham:

Sweetheart of a guy.

DeVorkin:

Amazing guy. But also, his instrumentation. Talk to me about Gerry Kron as an instrument person.

Latham:

Well, he innovated a lot of interesting, detailed technical solutions for the electrographic camera, the Kron camera. Not big money. I mean, they were relatively inexpensive solutions. The rolling coin valve, for example, I donít think Iíve ever seen anything like that elsewhere. That was how he protected the cathode from the back end when you broke the vacuum to get the electrographic plates out. And optics expertise! A sapphire corrector window in the front of the camera. A lot of quite capable technical solutions. Iím not sure he was driven so much by the science; I think he was more interested in the technology of making the camera work.

DeVorkin:

Is he an example of what you think about when you made that statement before about instrumentation?

Latham:

Yes, I think so. He would be one of several examples, but my own example was the most obvious.

DeVorkin:

Well, sure. That was the one that was most poignant to you.

Latham:

Yes.

DeVorkin:

To know him is to watch him interact with his detector. It seemed to me like he was an epicure, in a way. He could see way beyond anything that I can understand. You spent a good enough amount of time with him. What were your impressions of how he thought through problems?

Latham:

Technical problems, he thought through very carefully. I donít think I can judge his approach to scientific problems. We never really discussed scientific problems that much. It was always detection of light.

DeVorkin:

Thatís really what Iím asking.

Latham:

Oh, I think he was a real master at thinking things through.

DeVorkin:

Did he think from physics? Or did he think from some other direction?

Latham:

There was a certain amount of hands-on stuff there, too.

DeVorkin:

For the record, Iím not sure what to say this is, but youíre fiddling with your fingers.

Latham:

I think of Gerry Kron working with his hands as much as anything.

DeVorkin:

Yes, okay. Last time I saw him, he wanted to show me the latest steam engine he built.

Latham:

I see.

DeVorkin:

Iíll just ask one more question about Celescope. The big problem, as I understand it, was stabilizing the Uvicons, making them work, and making them reliable over a period of time.

Latham:

And getting good photometry out of them. The relative brightnessís were not very good. And the dynamic range wasnít very good, either.

DeVorkin:

Right, as it turns out. But did anybody know that before it launched in í68?

Latham:

I donít know. It was a technology I was completely oblivious of.

DeVorkin:

There werenít a bunch of people sitting around saying, ďThe contractors are getting away with something.Ē

Latham:

No, I never had any interaction at all with Celescope. None whatsoever. I was only vaguely aware of it.

DeVorkin:

Whom could I ask who might have been watching it a little closer?

Latham:

Ask Bob Davis, who was watching it.

DeVorkin:

Perhaps McCrosky pay attention? It doesnít seem like he would.

Latham:

Iíd be amazed. I think Richard was involved in meteorite stuff entirely, which was all photographic.

DeVorkin:

Right and he started very early on that. But he was in an initial definition of Celescope, and I have to ask him those questions.

Latham:

Yes, he may have been.

DeVorkin:

This is í58 weíre talking about.

Latham:

Thatís interesting.

DeVorkin:

A group of four or five people involved, and you were not one of them.

Latham:

No, not at all. Thank God.

DeVorkin:

Well, I had hoped to see your name there, darn it, so I could ask you questions, but no.

Latham:

It got going before I arrived on the scene, and I think the team was all set by the time I got there.

DeVorkin:

This brings up a question that will jump back a bit, but it deals with instrumentation. The atmosphere at Harvard-Smithsonian, because you didnít really separate out the two, so Iíll just say ďHarvard-Smithsonian.Ē

Latham:

No, I didnít.

DeVorkin:

You didnít. Okay. Throughout your graduate years.

Latham:

Thatís pretty much true, although it became more and more obvious that the Smithsonian was where the resources were for what I wanted to do towards the end of my graduate career. í67, í68, weíre building telescopes for a new observatory.

DeVorkin:

Thatís the case. When you first came there in í61, would you typify the place as being occupied by people who knew how to build things and were constantly building things?

Latham:

No. Quite the opposite. The only person who was dabbling in optical astronomy was William E. Liller, and he was playing at it. He built spectrographs out of plywood, and for insulation, he stuffed in some of his wifeís yarn. Then he went and tried it one night a week. He used to come out and observe at the Agassiz Station, as it was called.

DeVorkin:

So when Bok left and Menzel took over, instrumentation kind of died.

Latham:

Well, not completely. Menzel tried to show that his heart was in the right place. There was a long tradition of patrol cameras here at the Agassiz Station. If you go into the plate stacks, youíll find, I suppose, decades of plates from those patrol cameras. Menzel shut them down, and I gather that there was a reaction against that. This is all guesswork. I havenít seen any paperwork or anything.

DeVorkin:

Doritt Hoffleit has confirmed that in spades, yes.

Latham:

Okay. There was probably uproar in the council. So Menzel said, ďAll right, I will reestablish a patrol program, but I will do it with modern instrumentation.Ē He got his friend, James Baker, to design inexpensive patrol cameras. Jim Baker started with the Golden Dagger, a very high-quality lens of the time, and did design work on how he could make three different color versions of it; discovered that it was going to be far too expensive or difficult to have somebody commercially modify the lens element, so he took the lenses apart and ground them and polished them himself in his kitchen. Theyíre beautiful lenses for the time. They make images out to the edge of a 15-degree field that are really quite good. So then Menzel took on somebody named Hector Ingrao to be his engineer/instrument guy, and Hector designed the rest of the camera around these lenses. One of my very first jobs here at the Agassiz Station that first fall and winter that I was staying over was to help make these new patrol cameras work. Donald Menzel also hired Michael Snowden to come and learn how things were working here, and then take the three southern cameras down to the Boyden Station and install them there. So Michael and I worked together to learn how to make them work here, and then Michael went to South Africa to install them there. They worked for a few years, but they never did much science. It was kind of typical Menzel.

DeVorkin:

Thatís the extent of MenzelísÖ

Latham:

Well, that was one thing that I can think of that he did in observational astronomy. They were F7, I suppose. Something like that. F5, F7. We couldnít quite figure out what these patrol cameras were supposed to do. We just got the job to make them work, so Michael and I decided weíd go into Menzelís office — we made an appointment — and try to understand a little bit better what he was trying to accomplish with these new patrol cameras. He started to explain what he was doing. He was going to get nice wide-angle pictures of the sky, and youíd map out the nebulosity. I looked at Michael, and he looked at me, and Michael said, ďF7?Ē I just shut up after that. I decided Menzel didnít know what he was talking about. He didnít know why he was doing these patrol cameras. But we made them work anyway.

DeVorkin:

But not too good with nebulosity, I would take it.

Latham:

No.

DeVorkin:

Well, itís pretty impervious to the sky brightness, too.

Latham:

Yes. This just amazed me that he thought that was the reason for building these patrol cameras.

DeVorkin:

What about on Whippleís side of the house? Was there more tool-building going on there? I mean, there was the Baker-Nunn. That was operational by the time you were there.

Latham:

Yes.

DeVorkin:

But did that translate to an internal cadre of instrument people who were available to lend a hand for technical development and technical innovation?

Latham:

Not that I was aware of. Those were all done outside.

DeVorkin:

They were all outside contracts.

Latham:

Yes.

DeVorkin:

Because everything was done pretty much on an outside contract basis.

Latham:

I assume, yes.

DeVorkin:

Iím trying to better understand the growth of it because in contrast to, letís say, other departments that entered into space astronomy in a major way, such as WisconsinÖ

Latham:

For example, yes. They had a lot of in-house stuff.

DeVorkin:

Exactly. Any thoughts about how important this kind of lesson is?

Latham:

[Laughs] Well, I think youíve got to be able to build things — Let me think for a minute how Iím going to answer this. I think thereís a risk in relying completely on contract work when youíre building something. I think you have to have people that have built instruments themselves to be involved, but thatís just based on my own personal experience, of course, and my own prejudices.

DeVorkin:

Thatís an observation that certainly can hold water in many places. Did Bob Davis ever gain instrumentation capability?

Latham:

I donít think so.

DeVorkin:

Thereís no evidence of that.

Latham:

No. He is an observer; he can use a telescope just fine. But I donít think of him as somebody that would be effective at fixing a problem when an instrument stopped working or building an instrument on his own. I donít think of him as having those aptitudes.

DeVorkin:

Letís go back to electrographic then and center on your experiences, developing alternatives to photography.

Latham:

The Kron camera was my opportunity to learn about vacuum systems, and about making cathodes, and measuring the performance of cathodes.

DeVorkin:

Would you say that Kron was the person to go to for this stuff?

Latham:

In this country, yes. Of course, there were centers of interest in electromyography in Europe. The Lallemand camera, for example, and in France especially. I made cathodes out of raw materials like with antimony beads, cesium, andÖ

DeVorkin:

How did you make them?

Latham:

You have to get the vacuum just right, and then you have to evaporate the materials so that it spreads uniformly on the inside surface of the front window. Gerry developed all this stuff. Very hands-on. Trial and error. We stood beside Gerry and watched him make a couple, and then we tried it on our own.

DeVorkin:

Can you describe the process?

Latham:

From memory?

DeVorkin:

Just from intuition or feeling. Could you even say that youíre going to bed at night somewhere up in Flagstaff, knowing that this your project for tomorrow?

Latham:

Oh, sure. The main trick was to achieve the vacuum that you needed. You need a good, high vacuum to make a cathode. You have all this stuff inside thatís going to apply the materials to the window. I donít remember the sequence of events, which came first. I think the antimony came first for the S11ís. There was a cookbook that we learned from Gerry on how you do that.

DeVorkin:

A written cookbook?

Latham:

No, we took notes.

DeVorkin:

And youíve got those notes.

Latham:

Oh, probably.

DeVorkin:

What was the biggest technical hurdle in making it a good cathode? Was it getting an even coating?

Latham:

Yes. And having the right thickness.

DeVorkin:

How did you measure that? By the amount of antimony put in there to evaporate?

Latham:

I believe we monitored the sensitivity of the cathode — the amps per lumen we were getting out of the cathode as we applied the material, and we stopped before they got to the magic number. Thatís my vague memory.

DeVorkin:

A real-timeÖ

Latham:

I believe so.

DeVorkin:

That sort of sounds like cut-and-try to me.

Latham:

Yes.

DeVorkin:

That was Gerry?

Latham:

It was very empirical. Doesnít it sound like Gerry?

DeVorkin:

Of course, youíre not making 10,000 of these things.

Latham:

No. So I had a proper appreciation of photocathodes when it came time to make my first detector system that really worked. Thatís the photon-counting reticons where I stole key ideas from Steve Shectman, but did it my own way. [Laughs] But Sheck was critical for all the signal processing. That part, I pretty much adopted straight over from Steveís design in the first version. This was a team with Marc Davis and John Tonry, of course.

DeVorkin:

Right. You have this dual-author paper, ďPhoton-Counting Reticon,Ē with Marc Davis.

Latham:

Early on?

DeVorkin:

Thatís already í79.

Latham:

Thatís about right. That was the first time we got one running.[6]

DeVorkin:

But when did all that work start?

Latham:

The year before. We did that in, I think, almost exactly one year, when Herb Gursky took over. Marc Davis came in, and Marc and I started working together on projects. Then Marc told me what he really wanted to do was a galaxy redshift survey because heíd come out of Princeton, and the whole tradition of James Peebles to look for structure. That was all in the cards, and that was probably í77 or í78 that we started talking about it. So finally, I went to Herb and said, ďThis is what I think we ought to do.Ē Herb had already decided that I was going to be his guy in terms of guidance for instrumentation.

DeVorkin:

This is already ten years after being with Kron.

Latham:

Close to it, yes.

DeVorkin:

Werenít you with Kron in í68, í69, kind of?

Latham:

And then into the early Ď70s.

DeVorkin:

Were you out there in residence for that length of time? Or youíre just visiting?

Latham:

No, just visiting.

DeVorkin:

How did the infrastructure develop? Did Whipple play any part in that at all?

Latham:

He supported it. We built the high-resolution spectroscopic capability, the echelle spectrographs, and tried to get quantitative detectors. The electrographic cameras. So that wouldíve been the mid-Ď70s. The other thing I was busy doing was teaching because Owen invited me to join him teaching in a natural sciences general education program. I started in í71, so I got distracted to teaching as a main activity for a while. For 28 years.

DeVorkin:

By the way, were all of those your graduate students there last night?

Latham:

A lot of them. Post-docs. Well, I have two new post-docs and two Ph.D. students, Gabor and Cullen. A couple of undergraduates. So I have maybe six people working with me. Thatís more than enough. It keeps me busy.

DeVorkin:

Again, going back to working with Kron, this was something Whipple supported?

Latham:

Yes.

DeVorkin:

Was he looking to import this expertise?

Latham:

No, I think he was allowing Fred Chaffee and me to pursue this because we wanted to. It was support of the stellar atmospheres, doing quantitative spectroscopy, doing abundance analyses. We argued that we needed this capability in-house, and that photography wasnít good enough. ďWhy didnít you go to the National Observatory and use Coudť photography?Ē My argument was it wasnít quantitative enough. Thatís the sort of thing Laurence Oliver was doing, and others like that. They were sticking with photographic plates and worrying constantly about calibrating each plate and all of that sort of thing. I had seen, through my experience, all the shortcomings of photography, and I knew we had to do better. The most important thing is we had to get better quantum efficiency. In some ways, one of the most important of my early papers is in a physics volume. ďMeasurements of the Detective Quantum Efficiency of Spectroscopic Emulsions Used in Astronomy.Ē First time it had been measured properly.

DeVorkin:

When was that?

Latham:

í74, maybe? I have a copy of that book, in my office. I forget exactly when it was.

DeVorkin:

In a symposium that, you and Dave Philip organized?

Latham:

Yes.

DeVorkin:

Or Don Hayes and Dave Philip did. ďAdvances in Instrumentation for Stellar PhotometryĒ?

Latham:

Yes, I may have reported it at a conference, too.

DeVorkin:

You definitely reported on that.[7]

Latham:

But for the first time, I had detective quantum efficiency measurements of photographic emulsions with different kinds of sensitizations, and it came out half a percent or 1%. I knew with cathodes we could do at least 10%, so we had to go to the cathodes. We needed that sensitivity.

DeVorkin:

So that was your push.

Latham:

You bet. The same push came later with CCDs, right? You go from 10% to 70% or 80%.

DeVorkin:

Yes, exactly. But you were never thinking at this point of solid-state stuff. You were looking at vacuum tube technologies.

Latham:

No, it had to be vacuum tubes because that was what was practical. What we ended up doing with the Z-Machine is taking advantage of the night vision image intensifiers that were developed for the Vietnam War. We had a very good working relationship that we developed with Varo in Garland, Texas where we got to select the best of their tubes out of the thousands they were making. So theyíd send us a dozen of the very best that they had, and then weíd test them further in a way that they couldnít to get the best of those.

DeVorkin:

This kind of relationship is not unique in astronomy.

Latham:

No, there are several good examples of it. Kodak had that same relationship, for example.

DeVorkin:

Thatís right. C. E. Kenneth Mees and various astronomers.

Latham:

Yes, and then Al Milliken after. Al Milliken was very important in the Ď60s, for example with the development of mono-dispense emulsions.

DeVorkin:

Were these intensifiers classified when you used them?

Latham:

Not by the time we used them. Anybody could buy them.

DeVorkin:

But they selected out the best ones for you.

Latham:

Yes. Well, they had tests they did. There was just cathode sensitivity, no wavelength sensitivity, and we were really interested in the wavelength sensitivity. Sometimes we might want extra blue sensitivity; others, we wanted good red sensitivity. Weíd measure all that in a lab. I set up a lab to make all those measurements.

DeVorkin:

Who is your contact at Varo?

Latham:

What was his name? Iíd have to go look it up.

DeVorkin:

Okay. So you built the lab at Harvard.

Latham:

At the Smithsonian. Everything I did then was Smithsonian, for research. Harvard was the teaching. But I want to get back to detective quantum efficiencies. I was heavily involved in trying to understand how light was detected with photography. That was my main reason for working with photography experimentally. I was frustrated because the way that astronomers tended to evaluate the performance of photography seemed not to be fundamental. It tended to look at the output that you got in a photographic plateóthe density or the contrast. I thought this through and decided that what really mattered was how accurately you had measured the amount of light coming in, how accurately you determined the number of photons. But you just canít count photons on a photographic plate, so the only way you can get at that is to measure the uncertainty in the determination of the exposure level, and see how much you variation you get. If you get a lot of variation, thatís a lot of noise for the same signal. So I developed signal to noise ideas, and I developed an idea — I donít even remember what I called it, detective quantum efficiency. I had even drafted the paper on this when I discovered, to my dismay, that somebody else had already had the idea. A guy named Peter Felgett had published it. I came up with the concept of detective quantum efficiency completely on my own, independently.

DeVorkin:

Was that the first time you felt scooped?

Latham:

But heíd done it ten years before. Actually, I felt, more confirmation that this really was the right way to do it. Itís a more natural way to do it when you move from photography, say, to photon counting, where you can think of terms of quanta and the Poisson statistics of detecting photon arrivals and so on. So all that work I did in photography was worth it in the end, although it sure was the hard way to do it.

DeVorkin:

You characterized your work in photography as something that just — at first, it was a distraction because you were interested in it. You simply were pursuing it for its own sake.

Latham:

No, I was pursuing it because I needed to make better observations. The early work on photographic detection did get some notice, and so when the American Astronomical Society decided to start a new small journal called the AAS Photo Bulletin, they chose me, a graduate student, to be the editor. I worked with Jack Brown at Kodak to put together these occasional, small journals that describe practical stuff about photographic detection. But to step back and look at the big picture, all that work I did with photography and then with electronography was an essential part of my education. So when I got to building the Z-Machine, I had a much better idea of what I was doing and how to do it. It wasnít something where I couldíve gone and taken courses. I canít imagine that thatís something you could learn except by doing it.

DeVorkin:

In moving to that progression, and thatís a very good point, the staff was still building. Who was hiring the staff at that time in your area? Such as Marc Davis andÖ

Latham:

Well, Marc was a Harvard hire.

DeVorkin:

Oh, I see.

Latham:

I think George Field by then was the director of both the Harvard College Observatory and the Smithsonian Astrophysical Observatory. I think that there was much better uniformity in the plan for where the CfA was going to go. For example, bringing the X-ray effort into the newly founded CfA clearly was very important, partly because it brought in the leaders of the field, who were just about to have great successes, but partly because they also brought a lot of money in, too, and overhead. So it built on Fredís tradition of having big projects that would supply overhead so that he could do the things he wanted to do, like build his own observatory.

DeVorkin:

But before that, during Fredís latter years, was there a sense that these two organizations were not working close enough together? That there was friction? Did you ever sense it as a grad student or just after, as you were doing your instrumentation?

Latham:

Yes, I probably sensed it.

DeVorkin:

Did you have a feeling of what the solution was or what the problem was?

Latham:

No, I donít think I had a good view of the big picture. I think I was driven by the idea that we were building a new observatory in the American Southwest. We dreamed of the day when we would be as good as Kitt Peak. I remember Fred Chaffee and I sitting — and this didnít happen just once how our goal was to become as good as Kitt Peak. This was a very distant goal. The ironic thing is that I think now, in some ways, weíre better than Kitt Peak. Really kind of amazing.

DeVorkin:

How so? Give me some indicators.

Latham:

I think scientific productivity at Mount Hopkins is excellent for the dollar. We have to take into account the two budgets. The innovation, I think, with the MMT and a lot of the instrumentation that has been built in the last few years is more state-of-the-art; in some ways, more risky. We as an institution have been able to push into areas where thereís more risk that the National Observatory might not be able to do. [Laughs]

DeVorkin:

Okay. Whipple, as you said, he would assign or allow a certain person, a junior person, to pursue a certain project and then give them a lot of room.

Latham:

Yes. And he had the resources so he could support them. And very little administrative or bureaucratic hassle. If I needed a bit or piece, I didnít have to write a proposal for it. If it wasnít very much money, Iíd just go down the hall and see Derry Miller, and sheíd make sure we got it.

DeVorkin:

Who is Derry Miller?

Latham:

Once she got married, her name was Derry Miller Allen. If we needed more money, a little more resources, we checked in with Chuck Lundquist, and if it was a big deal, Fred got involved.

DeVorkin:

What would be a dollar amount for a big deal?

Latham:

$10,000 or $20,000. I think Fred actually watched most of the purchase requisitions. I think they went across his desk. I think he kept track of what was going on that way.

DeVorkin:

That would be a pretty big chunk.

Latham:

In those days, yes.

DeVorkin:

Where did the idea of the Z-Machine come from?

Latham:

It was Marc Davis who wanted to do a galaxy redshift survey, and talking about how you would do that at Mount Hopkins and my opinions about what the instrument should look like. We talked about whether we should do the Wampler scanner, and I was not impressed by the limitations of the Wampler scanner because of all the persistence in the phosphor. They could not take comparison exposures — the emission lines to get the wavelength calibration — regularly during the night because then the ghost of all the calibration exposures would hang in there for tens of minutes. So you had to be very careful about the sequence of exposures.

DeVorkin:

What were the technical goals then? You wanted to take as many galaxies as you could.

Latham:

We wanted to be very efficient with the observations of galaxies. The most important thing in my mind was to have it computer-ready; to have it come directly into computers so that you could work with the data immediately with the software systems. This was a very strong opinion also of Herb Gursky. His vision was that we take advantage of the computer expertise in the Cambridge area; that we would apply computer technology to spectroscopy in a way that you enhance how quickly you look at the data and what you do with it. In many ways, the most important thing we did with the Z-Machine was to support it with the computer technology, and especially the software development, so that we got good results and we got them quickly. We avoided all the issues with electronography where you have put the plate on a micro photometer and digitize it and all that stuff.

DeVorkin:

So with the Z-Machine, you were way beyond photography.

Latham:

Yes.

DeVorkin:

You were not going to have any photographic records, but you still had to get radial velocities.

Latham:

Yes.

DeVorkin:

Now, that means you have to get the absolute position of a line.

Latham:

Youíve got to have those calibration lines on there.

DeVorkin:

So where do they come from?

Latham:

They come from, in the case of galaxies, helium-neon lamps.

DeVorkin:

So you have lamps in the Z-Machine.

Latham:

Thatís right. Before and after every exposure, you take a calibration exposure for 15 seconds or 90 seconds.

DeVorkin:

And thatís scanned or sensed by —

Latham:

By the same machine.

DeVorkin:

But this is a scanner.

Latham:

No. This is simultaneous readout of a diode array. But the key is it has high-speed signal processing. So it looks at the flash of light on the diode array that you get from the last phosphor, and then it only counts it once. That decays away, but it knows about it and keeps track of it, and it only counts the big flash once. Furthermore, its centroidine, so it gets very accurate positioning for these big, fat flashes of light.

DeVorkin:

If itís a diode array, is it a reticon?

Latham:

The reticon was the diode array that we used to read out the flashes of light at the phosphors of a high-gain intensifier package. Three-stage intensifier package. This whole idea was pioneered by Steve Shectman, and heíd gotten one running. We heard about Steve and we talked to him, and he agreed to help us out. Marc Davis actually went out to Pasadena and built the first version of the signal-processing electronics in Steveís lab. John and Tonry Marc spent a couple months out there.

DeVorkin:

So thatís the pipeline. You didnít do that; Marc Davis did that.

Latham:

I was busy doing intensifiers and the spectrograph. That was my job.

DeVorkin:

So you had the intensifiers and spectrograph, and Marc Davis did the electronics and the software.

Latham:

The other part that I was responsible for was the guys that did the software systems. Tom Stephenson and Jim Gettys, and most important of all, John Tonry. John did the analysis software. He did the correlation software that gave us the redshifts. John was critical to this project. Of course, he was a graduate student at the time.

DeVorkin:

He had an affiliation other than the Smithsonian at one point?

Latham:

He was Harvard physics, as far as I know.

DeVorkin:

So you have the photon-counting reticon, and then you have solid-state imagers for astronomy ďstellar speedometer.Ē

Latham:

Well, thatís the same Z-Machine detector, only put on a stellar spectrograph.

DeVorkin:

So that is not the Z-Machine.

Latham:

No, but the part that counts, the detector and the software systems, were the same.

DeVorkin:

Okay. And there you have colleagues such as Robert Stefanik, Tsevi MazehÖ

Latham:

And many others. You see, the idea is that you do galaxies when the moon is not bothering you. What do you do the other half of the month when the moon is up at night? Well, you look at bright stuff. So you do stars. After we got the redshift survey going, a lot of the telescope time was not in demand, and so we gave up on the Kron camera and we brought a version of this system into operation on the echelle spectrograph that we had built for the Kron camera.

DeVorkin:

So you brought a Kron camera design back here.

Latham:

Oh, yes. We had them in operation at Mount Hopkins for a couple years. Two or three years.

DeVorkin:

To your knowledge, how many places adapted Kronís technology?

Latham:

Very few. We may have been the only one that actually got it to work.

DeVorkin:

It was considered to be more practical than the Lallemand.

Latham:

Yes, but it still wasnít very practical.

DeVorkin:

How important are stages like that — the Lallemand and the Kron — in your way toward a practical instrument? Was there another way to do it?

Latham:

It was an important step for us, because I learned that there are some approaches you just canít use and be productive. We had to have a better way of getting the spectrum off of the detector than off an electronographic plate. That was one of the main limitations, reading the electronographic plate.

DeVorkin:

Would Gerry ever say, ďWhere are the detectors?Ē Or was he wedded to the plate in his mind?

Latham:

I think by the time CCDs came along, he was too late in his career to make a change. But that was clearly the way to go because CCDs give you data directly into the computer. The light sensor is silicon instead of a cathode, so there is another of five improvements. Now youíre pushing towards the limit of what you can do except for area coverage. People solve that by putting many CCDs together in a big array, like the 36 CCDs in megacam.

DeVorkin:

Oh, I see. Is the megacam operational now?

Latham:

Yes.

DeVorkin:

The photon-counting reticon did you call it a photocon?

Latham:

No, photocon was something else. I worked on that a little while, but I gave up on it pretty quickly. It was not a solution. That was Gethyn Timothyís machine, I think. I did that only to humor Herb. I got far enough on that to know that it wasnít the place I wanted to put my effort. So the intensified reticon photon-counting machine was where I put the effort, and then gradually, the CCDs came and I put much more effort in that. Thatís where all my recent effortís gone.

DeVorkin:

Understood. Letís go back to the CfA Redshift Survey. Everyone remembers or thinks of it in terms of Margaret Geller and John Huchra. What were the dynamics in the group? How did they come on board? Because Margaret was also a Peebles student. Where did John come from?

Latham:

It depends on who you ask.

DeVorkin:

Well, Iím asking you. [Laughter]

Latham:

We got the Z-Machine running, and we started getting good redshifts of, back then, relatively faint galaxies almost immediately.

DeVorkin:

And by ďgood redshifts,Ē you mean what?

Latham:

25 kilometers per second.

DeVorkin:

Accuracy.

Latham:

Yes.

DeVorkin:

That was an issue, of how accurate they had to be?

Latham:

That was one of the issues. We could do emission-lined galaxies beautifully because we had a detector with no persistence. See, with the Wampler machine, youíd get those emission lines still ghosting in the next exposure an hour later if it was a strong emission line. So the Z-Machine was just terrific with emission-line galaxies. Huchra had been trying to gather redshifts. He had an interest in redshift catalogs quite independently of Marc. He noticed that we were getting results, and so he joined the team. When did he join the team? I canít tell you exactly, but he became an important member and he started helping out a lot with organizing the observations, doing a lot of the observing.

DeVorkin:

Heís very much the observer.

Latham:

I would say so. Heís not an instrument-builder. Not at all. About at that time, I ended up being Associate Director. Margaret Geller was having some trouble in the division she was in. She and I talked about how we could secure a better position for her at CfA where she could do what she wanted to do and wouldnít be harassed, so I set it up for her to move to OIR. Basically, I hired Margaret.

DeVorkin:

What is OIR?

Latham:

Optical and Infrared. To be honest, although John doesnít know this, I also hired John because Herb Gusky wanted to get rid of him. I argued with herb over that, and we ended up getting a position for John. In some ways, I didnít do it by myself, but in some ways, I hired both John and Margaret during the first year or two when I was Associate Director. I saw it as support for this large-scale structure work, which I thought was a hot field, a very important field, and I was trying to strengthen the team. Margaret would bring the theoretical analysis to that team, which she did. From the point of view of the publications and the visibility, it was a great success, bringing John and Margaret into the effort.

DeVorkin:

Oh, absolutely. But Iím wondering the dynamics of the group, how it is that we think in terms of Margaret Geller primarily. Sometimes Geller-Huchra, but de Lapparant not too often. But never Marc Davis, never Dave Latham. Or very rarely.

Latham:

Personalities.

DeVorkin:

Yes? [Laughs] Was there ever any intention?

Latham:

[Laughs]

DeVorkin:

I take it thatís a yes.

Latham:

Those were unpleasant times. I learned the hard way what some people are like. Until then, I had always assumed the best of everybody. My solution to that was to let some people take full credit and involvement for the redshift surveys, and I would focus on the stellar spectroscopy, which they were not interested in, and I would do something new and different, which is what I did. Marcís response to that was to leave. Paul Schecterís response was even quicker. Paul didnít have as much patience, and he left after a year for the same reason.

DeVorkin:

Was it because of Margaret alone, or Margaret and John?

Latham:

It was Margaret.

DeVorkin:

Fascinating.

Latham:

You probably arenít going to get much more out of me.

DeVorkin:

Iíll try a little bit here and there. Iíve interviewed her, of course, as you can imagine, extensively. Obviously, quite fascinating with her career path and that sort of thing. What was she doing originally in Bill Pressís division, to your knowledge?

Latham:

Iíd have to do a little research to give a good answer to that. I think it was much more theoretical and modeling. Was it large-scale structure? I donít think so. Iím not sure. John Huchra was certainly a very close collaborator with her in those days. John was her champion. He came to me first and he said, ďMargaret is really not appreciated and is suffering and is being harassed in her present division. Is there any way we could bring her into OIR? Iíd love to work with her.Ē I said, ďJohn, Iíll see what I can do.Ē

DeVorkin:

Thatís very important to know. I didnít know that.

Latham:

So then Margaret and I got together and spent a whole afternoon talking about the situation and what we might do with it. I found a way to bring her into OIR, give her support, give her a proper office, and all those things she wanted that she wasnít getting.

DeVorkin:

This is consistent with her continued frustration and feeling unappreciated or not treated equally for a person of her attainments.

Latham:

Well, that was the theme of our initial interactions, how everybody had been unfair to her, even George Field.

DeVorkin:

Any truth in that from your direction?

Latham:

At the time, I assumed it must be true. I felt this was not right and we should try to fix the problem.

DeVorkin:

Did it have anything to do with her being a woman?

Latham:

I think, in her mind, it had a lot to do with it.

DeVorkin:

In her mind, of course, yes. But would other people — you, particularly — look at it at the time?

Latham:

In retrospect, itís hard for me to imagine that George Field took into account the fact she was a woman in any of his dealings with her. I think George, treated her like any other scientist.

DeVorkin:

From there, you moved into stellar spectroscopy, as you said. But this was back to atmospheres and things like that to a certain extent, wasnít it?

Latham:

Nope.

DeVorkin:

Or you did binaries for a while.

Latham:

Well, still do. [Laughs] I became interested in the fundamental astrophysical characteristics of stars, and the way you learn that is through binaries, especially through double-line eclipsing binaries. But the technology of the photon-counting reticon applied to stellar spectroscopy opened up all kinds of new possibilities using the same software, except measuring the radial velocity of stars instead of galaxies. And measuring them in large quantities and measuring them with very good accuracy. For the time, it was very good accuracy — better than a kilometer per second. We could study all kinds of things. We could look at the motions in clusters of stars that hadnít really been studied. We did a fair amount of that. We could look for binaries in globular clusters. The conventional wisdom in those days was that globular clusters had no binaries. That was a great puzzle. The conventional wisdom was also that the very first generation of stars, the metal-poor, high-velocity stars that formed even when the galaxy was collapsing, had no binaries. What we ended up showing is the oldestÖ we have just as many binaries as the stars in the solar neighborhood.

DeVorkin:

Because you had a new way to find them.

Latham:

Because we had a much better way of measuring velocities of stars with weak lines.

DeVorkin:

That was your motivation, though. Fundamental characteristics, stellar statisticsÖ

Latham:

Yes. Measuring very accurate masses and radii of stars so that you could test the stellar models.

DeVorkin:

So it wasnít what you eventually started applying it to — extra solar planets.

Latham:

This is why your attitude should be, ďWhat, me worry?Ē All this work to learn how to get orbits for stars and understand the characteristics of stars was a necessary and important apprenticeship for moving into extra solar planets. Because itís the same approach; itís just that the velocity amplitude is 50 times or 100 times smaller.

DeVorkin:

So this was not premeditated.

Latham:

No, it was not premeditated. I wish I could say it was, but it wasnít. In fact, I will prove to you it was not premeditated, because in 1984, I was approached by an Israeli, Tsevi Mazeh, who called me from Lick Observatory where he was visiting Steve Vogt. As it turns out, he was trying to get Steve Vogt interested in looking for extra solar planets using radial velocity techniques. Steve Vogt apparently wasnít that interested. I wasnít his first choice, apparently; I was at least his second choice.

DeVorkin:

Who was his first?

Latham:

Steve Vogt, presumably. So he called me, and on his way back to Israel, he stopped off in Cambridge. We had an appointment on a Friday afternoon. At the last minute, I had to ask him if we could postpone the appointment to the next day because I was busy putting out one of my fires. I was Associate Director in that day. Not unconnected with the previous topic we discussed. And he said, ďSure,Ē although he told me afterwards he was a little bit put off that I hadnít honored my appointment. ďSo when could we meet?Ē ďWell, Iíll come in tomorrow.Ē He was busy. ďCould we meet tomorrow evening?Ē He was going to be busy during the day. ďSure.Ē So I made a point of coming in and working all afternoon, and he came over and we met at night. Eventually I learned about Shabat, but at the time I was oblivious He had this idea that we could look for short-period planets around solar-type stars with radial velocities. And I said to Tsevi, ďBut there arenít any big planets with short periods. Youíre not going to measure 12 meters per second with my equipment. We can only do 500 meters per second. And besides, thatíll take ten years,Ē you know, like Jupiter. He said, ďNo, actually, Iím thinking we might detect things that are Jupiter-sized in shorter orbits.Ē I said, ďItíll never work. There arenít any planets like that. And besides, the velocity precision I get with my machines isnít good enough.Ē He said, ďWell, you can average lots of points together and beat down the errors.Ē I said, ďNo, Iím sure Iíve got systematic errors that are not statistical.Ē But you know, he struck me as a nice fellow. I said, at the end of the two-hour discussion of all this, ďOh, what the hell. Letís try it.Ē So in 1984, we set up a program to look at M dwarfs, because theyíre low mass, and so the signal will be bigger. Youíd gain a factor of two or three. We started a project looking for extra solar planets.

DeVorkin:

You knew about Van de Kampís work with astrometric binaries.

Latham:

Oh, sure, because I had been lecturing in Nat Sci 9 for years, so I was tuned into all this. I knew this was an important question because of my teaching to undergraduates. Tsevi Mazeh and I started an observational survey of a sample of low-mass stars, M dwarfs, looking for evidence of short-period, massive planets, which is all we could detect.

DeVorkin:

But you still didnít think that any of them existed.

Latham:

No. The standard wisdom was that giant planets could only form out in the condensation region, out where things were cold enough to make ices and collect together enough material out of the disk, just like Jupiter in our solar system. The only thing youíd get in close to resfur in short periods would be terrestrial planets, things like the Earth or Venus or Mercury.

DeVorkin:

Itís curious, given that as received opinion, how you still went ahead with this.

Latham:

Tsevi thought it was a good idea to look for something that nobody thought would exist, because if you found it, that would be pretty exciting.

DeVorkin:

Well, yes. But people say that about UFOs, too. [Laughs] I guess you weighed the odds.

Latham:

I agreed because I thought Tsevi seemed like a nice chap and I wouldnít mind working with him. And also because Iíd done enough teaching to undergraduates that I knew this was an important issue. We only know about one planetary system; we need to find some others around other stars and see what kind of common characteristics they have.

DeVorkin:

But was there an instrument component here? Something that you saw you could develop?

Latham:

No, it was an application of our Z-Machine detector on our stellar spectrograph to making the best measurements we could. You have to make precise measurements of velocities with the smallest errors if youíre going to detect a very low amplitude variation.

DeVorkin:

Right, but you were talking about 25 kilometers.

Latham:

But with a stellar instrument, the echelle spectrograph, the dispersion is much higher, so you can go to a much better velocity precision. Typically, we were getting under a kilometer per second, and so a challenge would be to see if we could improve that by a factor of two or three. We worked on that. And one of the things we did as part of understanding how to make very good velocity measurements was to observe standard stars. The International Astronomical Union had a set of standard radial velocity stars. We and some good friends that we met at about the same time from Geneva, A young fellow named Michel Mayor. We agreed that since we had two systems making lots of stellar velocity measurements, we would do a service to the community. We would agree on a set of stars that we would observe, and weíd observe them a lot and try to establish the absolute velocity system. It wasnít the first time Iíd worked on absolute calibrations. You know, the photometric calibration of Vega was another thing.

DeVorkin:

Weíll get back to that, but letís continue there.

Latham:

Okay. So, we started, long about the same time, monitoring, more or less every night, certain stars. We learned about how stable our velocity system was, how well we could reproduce from night to night, week to week, month to month.

DeVorkin:

So you already built the machine?

Latham:

Oh, yes. That had been in operation since í79. This was five or six years later.

DeVorkin:

You were out at Hopkins.

Latham:

No, right across the street.

DeVorkin:

At Oak Ridge?

Latham:

Yes.

DeVorkin:

Of course. You donít need a great sky.

Latham:

All the standard stars are bright, it turns out, so it was something that we would naturally do from here.

DeVorkin:

The first publication that I found on this (although Iím sure there must be an earlier one) was in the International Astronautical Congress in Malaga, Spain in 1989. Did you publish on this earlier than that? The speedometer.

Latham:

Oh, sure.

DeVorkin:

ďThe Spectroscopic Searches for Low-Mass Companions of Stars.Ē That was you, Robert Stefanik, and Tsevi Mazeh.[8]

Latham:

Yes. We had a paper in Nature just about the same time, in 1989.[9] It talks about the first example of a very low-amplitude orbit with a relatively short period, about the same as Mercury is, 84 days. That implied a companion with a mass of about ten Jupiterís. That ended up being published May í89. Let me tell you the fun part of the story. We were working on the standard stars. It was one of those standard stars where we noticed that there was a wobble going on, and not in the project of M dwarfs. That was the unseen companion of HD 114762, which we interpreted as being something about ten times the mass of Jupiter. That is the minimum mass, of course; you donít know the orbital inclination. In the paper, we said it looked like it was probably a brown dwarf companion, although we explicitly said it could even be a giant planet. But there were three strong prejudices at the time against something like this being a giant planet. First of all, it was much too close to its parent star. Everybody knew that giant planets like Jupiter had to form way out in the cold regions, and this would be in the hot inner region of that stellar system. It was too big; the theoreticians didnít know how to make anything much bigger than two times the mass of Jupiter. And it had an elongated eccentric orbit, and everybody knew that planets had to have circular orbits. Got three strikes, youíre out.

DeVorkin:

Well, at the time.

Latham:

We now know of many more planets in much closer orbits, and much more eccentric orbits. It was unexpected that we didnít dare say in that paper, ďThis is the first extra solar planet,Ē because we didnít have proof; we didnít know the inclination. It couldíve been face-on, almost. For several years, when it was the only example of a short period, eccentric, large giant planet, nobody wanted to believe it because it just didnít fit the standard picture. People just dismissed it as probably an accidental alignment effect: Itís nearly a face-on orbit, and thatís why you see projected velocity amplitude thatís so small. Itís only when you start getting lots of them that, ďOh, maybe thatís interesting after all.Ē We found a planet candidate amongst the standard stars; not where we were looking for it among the M Dwarfs

DeVorkin:

And the bright standard.

Latham:

Yes, the bright standard. But, we were tuned into the idea of looking for extra solar planets. I wouldnít have bothered to test my standard star observations for an extra solar planet orbit with such a short period if I hadnít been tuned in by Tsevi to the idea that this would be fun to find. So I had developed the tools, and I applied them routinely to all the stars where there were lots of observations, and lo and behold, this one popped out. I sent an email around to my collaborators as soon as I had discovered this. It was work that I had started on the 31st of March, 1988. So by the time I ended up composing the email, it was time-stamped 1st of April, 1988.

DeVorkin:

Oh, no! Did they think this was another Latham joke?

Latham:

I donít think so because the email was too serious.

DeVorkin:

Who did you send it to?

Latham:

I sent it to Michel Mayor, Tsevi Mazeh and Robert Stefanik, who was a collaborator because he was making the Oak Ridge Observatory run. I sent it to a couple of other people, actually. The reason I sent it to Michel Mayor was to find out his observations of the same target.

DeVorkin:

Because he was looking.

Latham:

Because we had agreed that this would be one of the standard stars. His initial report back was that no, they only had two or three observations and they couldnít help us. Then about a month and half later, I got an email from Michel saying, ďGuess what? With our other telescope at CORAVEL in Chile, we have 30 observations, and guess what? We see the same orbit.Ē So then we published together.

DeVorkin:

But the interpretation was still iffy.

Latham:

Sure. We didnít know what the inclination of the orbit was. But Tsevi and I pushed the interpretation that this was a very low-mass companion, and might even be a giant planet. We didnít push the giant planet part; we said ďbrown dwarf.Ē But fortunately, we mentioned the giant planet possibility. We argued about that amongst ourselves. Tsevi argued we should be much more definite, I was more cautious, and Michel was strongly against the planet interpretation because of the eccentric orbit.

DeVorkin:

How do you feel about that?

Latham:

Itís the way the chips fall.

DeVorkin:

In this case, you accept the historical legacy.

Latham:

Yes.

DeVorkin:

Essentially everybody thinks in terms of Marcy and Butler.

Latham:

Thatís a mistake. They should think in terms of Didier Queloz and Mayor.

DeVorkin:

Yes, and Iíd like to have your story on that. How did that happen?

Latham:

Which part of it? Well, Iíll tell you how it happened. This interpretation of the low-amplitude orbit for HD114762 as a really low-mass companion, maybe even a giant planet, opened Michelís eyes. He had not been thinking in these terms before. The Swiss didnít have any programs to look for extra solar planets, and he immediately reshaped some of the main research they were doing to start looking for evidence of extra solar planets around other solar-type stars. They even built a new instrument with the main goal being to search for extra solar planets. It was called ELODIE, on the 72-inch at the Observatoire de Haute-Provence in France. ELODIE was designed from the beginning to make very precise velocity measurements. Maybe even as good as ten meters per second.

DeVorkin:

So his program for doing the radial velocity standards was not to search for extra solar planets.

Latham:

It was a service to the community. So in í88, when the internal excitement in the team of finding this very low-mass companion was being written up in the paper and all that, Michel realized, to his credit, ďThis is a hot field, and Iím going into it, whole hog.Ē So they built a new instrument to do it, got a graduate student to work on this — that was Didier — and they had the effort underway. It took a couple years to build the instrument, maybe three, so that by 1995 finally, seven years later, they noticed they had a Jupiter-like planet with a really short period of 4 days, in 51 Pegabi. Again, it was not something they expected. So they announced that at a Cool Stars meeting off the coast of Italy. There was a meeting and they announced it there, but they had an embargo because it was published in Nature. But this was a 4.2-day period, so Marcy and Paul Butler, who had been gearing up with their iodine cell technique to look for similar velocity precision around solar-type stars, were able to go back and commandeer or negotiate access to their telescope where they could make observations several nights in a row for a week or two. Since the period is only 4.2 days, they got it within a couple of weeks. They had no embargo, so they announced it on this side of the ocean.

DeVorkin:

So they knew of the work of —

Latham:

Oh, absolutely. Itís the only reason they looked at this star. So in this country, people have lost sight of the fact that 51 Peg was discovered, was submitted for publication, and eventually got accepted by Nature long before Marcy and Butler observed the same star and saw the same orbit.

DeVorkin:

By people in this country, you mean astronomers?

Latham:

I think most astronomers know. But the public, of course, got the word that it was an American discovery. It was on Nightline with Ted Koppel.

DeVorkin:

Oh sure. All over the place.

Latham:

I was actually on that program. I know why they picked me. The science editor or whoever it is that put together the program was local, and he came over to Harvard looking for people that knew about extra solar planet. He ran into me. I told him about what was going on, and all of a sudden, he decided he was going to make a program out of that. This all happened in one day. So, at 9:00 in the morning, I was minding my own business; and at 7:00 at night, we were out here, getting ready to film at the telescope. Yes. With the trucks in the driveway with satellite antennas and all that stuff.

DeVorkin:

Do you have a tape of that? Do you have a copy?

Latham:

No. Iím sure you can get the transcript.

DeVorkin:

Yes, but Iím interested in the tape. Iíll see if I can get that.

Latham:

Right. Thereís a very interesting story that goes along with all this, but Iím not sure Iím going to get into that.

DeVorkin:

At that point, do you recall that you had a chance to say something about your work?

Latham:

Yes, Iím sure. I decided not to try to blow our own horn. I knew very well that Marcy and Butler were ignoring HD114762. They were even misquoting the results in the literature.

DeVorkin:

Really?

Latham:

Sure. They were giving the wrong number for the minimum mass so that it would look much too big. They said 14 instead of 11.

DeVorkin:

Thatís a sizable difference.

Latham:

But itís the whole idea that youíre trying to stretch things to make it look less important.

DeVorkin:

This is Marcy and Butler?

Latham:

Well, it was mostly Paul. Paul is the most competitive one in that crew. Weíre getting into a very controversial area here, where there are some remarkable stories that have never been told.

DeVorkin:

He is so unassuming. Paul Butler. He appears that way.

Latham:

Heís super-competitive.

DeVorkin:

Fascinating. Well, I would like to record this other stuff.

Latham:

Iím going to have to think about this.

DeVorkin:

Sure. You have control over it. I would get back to you with it. But you can well imagine that this would be something Iíd like to preserve.

Latham:

All right. Thatíll take a better part of the day, though. [Laughs]

DeVorkin:

Let me ask some more general questions. Mayor had one technique. You had a second technique.

Latham:

Well, we were doing very crude velocities. We had a spectrograph that was on the telescope, so it was vulnerable to the gravitational environment changing as you point to different directions. The detector was not built for super stability; it was vulnerable to changing magnetic field orientations. So we did things at the level of maybe 500 meters per second. They designed equipment to do 50 times better.

DeVorkin:

ďTheyĒ beingÖ?

Latham:

The two independent groups, namely ELODIE and the Swiss, and the California group with this iodine technique on the Hamilton echelle at the Lick Observatory.

DeVorkin:

But yours was capable.

Latham:

Only of finding a really big planet and in a short period orbit. So we found one of the easiest ones. Not quite, but almost the easiest one of all the ones that has been found, thatís what we found. I guess we were lucky. But we were also tuned into looking for it. So were we lucky that we happened to observe that star? No, we were observing a lot of stars and staying up with the data reduction. You know the story that the Californians soon discovered that they had two or three others that had been sitting in their data, but they hadnít fully analyzed their data yet because they just assumed the periods would be so long. They were able to get 70 Virginis, for example, and Tau Bootis within weeks by rushing their reductions through and finding more of them. So they get credit for those discoveries, as they deserve, and many since then.

DeVorkin:

Their technique of using the iodine filter, which gives you, as I understand it, just thousands of lines.

Latham:

No, hundreds of lines.

DeVorkin:

Hundreds of lines against which you can reduce your error. It takes a lot of computation time, apparently, to sift through them.

Latham:

The way they do it, yes.

DeVorkin:

They would describe to us, basically, that this was a major amount of effort that was the reduction time.

Latham:

Thatís probably true.

DeVorkin:

If yours was a conventional echelle, youíre looking at one spectrum with a traditional set of lines, how many observations can you take before you see that kind of shift? That would be much more of a conventional sort of issue. What about Mayor? How would you describe hisÖ?

Latham:

His reductions were more conventional. They did not involve modeling the iodine spectrum or the line profile of the spectrograph.

DeVorkin:

But did they have a special type of filter, like the iodine filter?

Latham:

No, they use a thorium-Argon hollow cathode lamp for the wavelength reference, and their emphasis was to make a stable spectrograph rather than remove the instabilities in the reductions. The line profile changes subtly depending on the guiding of the star in the slit, for example, and the focus and the alignments. The iodine cell allows you to model that and remove that effect. Mayor made a spectrograph thatís very stable and fed with an optical fiber, so he did not have to worry about those effects so much.

DeVorkin:

So where in the discovery process would you place the iodine cell? How critical was it to the discovery of planetary companions around other sets?

Latham:

It was a way of doing it, but it was not the only way of doing it. The proof is that the one that everybody recognizes, the unseen companion at 51 Peg, was discovered without iodine. About half the ones that had been reported since then had been discovered without iodine. Roughly half.

DeVorkin:

So iodine is not essential.

Latham:

No. In my opinion, itís a hindrance.

DeVorkin:

How so?

Latham:

Because you can only use the wavelength region that has iodine lines, and thatís about 1,000 angstroms, from about 5,000 to 6,000 angstroms. ELODIE uses the full spectrum, so it has a factor of three or so more wavelength coverage, more lines — especially the blue, where thereís lots of lines. Number two; the iodine cell itself absorbs some of the light. So thereís another factor of something like two. Just those two factors together mean that the iodine cell technique pays a penalty of at least a factor of five. Thereís some evidence that itís more like a factor of ten by the time the smoke clears because of what you have to do to make the reductions work. So if youíre trying to go faint and get very good velocity precision on faint objects, like the ones weíre identifying with Kepler, then iodine cells are probably not the most efficient way to do it.

DeVorkin:

Is it still debated as to what kind of instrumentation will go up on Kepler?

Latham:

This is follow-up instrumentation on the ground. After Kepler identifies the candidates, we have to figure out what they really are. The most important thing we can do is get a spectroscopic orbit for the parent star so we can figure out the mass of the planetary companion. It turns out there are lots of ways that you can make a dip in the light curve that looks like a planet, only itís really stars that produce the light curve. I can tell you about some of those.

DeVorkin:

Yes, Iíd be interested. I know youíre on the Kepler team, and this is already answering why youíre on the Kepler team. Kepler is one of the TPF proposals, right? Terrestrial Planet Finder.

Latham:

No. Terrestrial Planet Finder is a separate flagship class mission to look for rocky planets. You can say Kepler is related. It was originally capped at $400 million, I guess, but the final price ended up around $640 million. Itís designed to find Earth-sized or Earth-like planets in habitable zones around Sun-like stars. Weíre very heavily involved in that as a co-investigator. Weíre developing the Kepler Input Catalog, which will be used to choose the 150,000 best targets, and we will be involved in the follow-up once Kepler finds good candidates, which is where the scientific payoff will be.

DeVorkin:

By ďwe,Ē do you mean your group?

Latham:

Yes, me and my team, plus a lot of other people.

DeVorkin:

Is that Bill Borucki?

Latham:

Bill Borucki is the PI.

DeVorkin:

Yes, we had him come to speak about this only in general terms about a year and a half ago. Itís very exciting.

Latham:

Well, I believe within five years, we will know if there are Earth-like planets where water is liquid and life could be comfortable orbiting other stars. Right now, we donít know.

DeVorkin:

Itís a huge step.

Latham:

Donít you think thatís an exciting question?

DeVorkin:

Yes, enough so that people at NASA are beginning to worry about the social reaction to it, knowing that. How about you? How do you feel about it?

Latham:

I think itís remarkable that I have the opportunity to work on such a big question in my lifetime. Hereís the wonderful part about it: Itís almost as if my whole career has prepared me for this opportunity.

DeVorkin:

You stopped being religious, I take it. [Laughs] You stopped going to church.

Latham:

Well, if we donít find any other Earth-like planets, I may have to reassess my position on this point.

DeVorkin:

[Laughs] Iíd love to get you to explain that statement, if you could.

Latham:

If weíre alone, then itís a lot harder to dismiss the idea that somebody chose to make us specially. However He chose to do it, of course. Or she.

DeVorkin:

Thatís a very interesting point.

Latham:

If intelligent life is common, weíre just like everybody else; nothing special about us. Isnít it fundamental to most religions that somehow weíre special and unique?

DeVorkin:

Quite right. Do you see this as a service, maybe?

Latham:

Iíve never really thought of it that way. I just thought of it as one of the most interesting questions of our time, and I have an opportunity to contribute to the answer.

DeVorkin:

But it fundamentally changes who we are.

Latham:

Or how we think of ourselves, anyway.

DeVorkin:

Exactly.

Latham:

Well, I have a long history of being involved in SETI for the same reason.

DeVorkin:

I didnít know that.

Latham:

Oh, yes. Weíve been very active in SETI searches. Itís a very long shot, but the impact communications with another technical civilization would be profound. Thereís no doubt about that.

DeVorkin:

Was your participation at all on the radial velocity side? Or was it looking for G-type stars?

Latham:

I was involved in the NASA SETI project before it got defunded by Congress on October 12, 1993.

DeVorkin:

You remember that date.

Latham:

Itís easy to remember.

DeVorkin:

Why?

Latham:

Because I was counting on the funding for that for the next ten years! So I was at Arecibo when Carl Sagan threw the switch for the targeted search with Arecibo. Just exactly the year before, it was the 500th anniversary of Columbus in 1492. Isnít that right? That wouldíve been October. I think Columbus Day was coming up on the 12th or something? It was almost a year to the day before Congress decided to defund this. Pig in a poke. Since then, I have, until last April, been participating with Paul Horowitz on an optical SETI search here at the Oak Ridge Observatory. Paul, with his students, made a system that could detect nanosecond laser pulses. It turns out we have the technology now to make laser pulses that outshine the Sun by a factor of several for a nanosecond.

DeVorkin:

I recently read something about that in Science News, I think it was. Thatís extraordinary.

Latham:

Well, maybe in the ApJ because we published an ApJ paper on this with Paul about six months ago.[10]

DeVorkin:

Then itís gotten into the popular press.

Latham:

It probably has. We had this collaboration with Paul Horowitz at the Oak Ridge Observatory. Paul, of course, had been operating his beta SETI on the radio telescope at Oak Ridge for many years. But when it was clear that optical SETI was feasible even for us, that we could create a laser pulse that would last a nanosecond and we could aim it with a big telescope at a nearby star and it would outshine our Sun for a nanosecond to anybody looking for it from that stellar system.

DeVorkin:

So we are sending, in this case.

Latham:

No, we are not sending, but we now have the technical capability for doing it. The biggest lasers can now do it. So you just turn it around and say, ďWell, maybe theyíre doing it to us.Ē They would have to purposely target us. The reason it can be so bright compared to the Sun is that they concentrate the optical light into a very narrow beam. It just includes the orbit of our planet. Itís not radio, where defraction would limit you, so you can really concentrate the laser light. We would have to be the target of another civilization, pointing their laser at us and flashing it in some coherent way that we would recognize.

DeVorkin:

So this would have to be another civilization in, what, 50 light years?

Latham:

Yes. Actually, it can reach out pretty far.

DeVorkin:

Iím thinking in terms of how long it would take for another civilization to catch this. I mean just our radio broadcast or something.

Latham:

Sure. Thatíd be about 50 years ago.

DeVorkin:

50 or 60 years, yes.

Latham:

So the whole idea here was that we were observing a sample of solar-type stars every night for a big survey of the characteristics of binaries around solar-type stars. We had an observing list of 3,000 of these, just the kind of star that our SETI colleagues would like to look at. So they put their instrument piggyback on ours, and we gave them about half the light that didnít go into the spectrograph; it was being reflected off for guiding. Whenever we observed a solar-type star, they would watch for these nanosecond pulses. For close to five years, we collaborated with Paul Horowitz on that optical SETI experiment, and didnít find anything. Otherwise, you would have read about it in the New York Times.

DeVorkin:

Absolutely. Looking for the nanosecond burst?

Latham:

Yes, looking for laser pulses from a technical civilization that had targeted us. So we were looking at stars like our own, at G dwarfs.

DeVorkin:

Were you doing other things with these stars at the same time?

Latham:

Oh, sure. Our scientific motivation was a characterization of the binary population around solar-type stars, which weíre still working on, actually. After a while, Paul began to get a little bit bored because we didnít find anything, so we decided it was time to write up the paper for publication, and now the optical SETI is not working anymore. This is partly because the observatory got closed down, but mostly they had obviously lost interest. They were moving on to their next technological toy, which is a facility that would search the whole sky, not just point at individual targets, looking for optical pulses. The technological challenge is signal processing, so the effort from Andrew Howard, the graduate student, is to produce a very highly customized silicon device that will process the signals in a way equivalent to a supercomputer.

DeVorkin:

Is that a dedicated program? Or is that going to be piggy backing?

Latham:

Fully dedicated. They built their own telescope.

DeVorkin:

And they can get funding for that at this point.

Latham:

They have funding from a variety of sources, including the Planetary Society, and they will continue to operate. They are a tenant at the Oak Ridge Observatory.

DeVorkin:

So they will continue.

Latham:

Yes. And so will the seismograph, which is also a very sensitive instrument. Iíve heard it described as one of the two best seismograph stations — the most sensitive — in the world. But that was by Harvard people from the project, so you never know how biased they are about their own work.

DeVorkin:

Did you ever have any contact with the atomic clock people at SAO?

Latham:

No. Do you mean Bob Veso?

DeVorkin:

Yes.

Latham:

No, I just knew of his work, but not very much.

DeVorkin:

None of that timing work was needed out here?

Latham:

No. Not for us.

DeVorkin:

I know that, as you say, there are some sensitive parts of this extra solar planet aspect of your work. Is there anything youíd like to go into? Maybe we can come back to it.

Latham:

Yes, I donít want to get started on it quite yet. I have to think about just how much Iím going to say in the whole story.

DeVorkin:

Give me some tips. What should I be looking for? What should I be asking other people? I havenít interviewed Marcy or Butler, and I donít even know if thatíll become one of my projects. It would be very interesting to interview the Europeans as well.

Latham:

Well, there has been an ongoing competition. I would hesitate to call it a friendly competition, between the team headed by Michel Mayor — based primarily in Geneva, although there are French collaborators as well — and Marcy, Butler et al. In the ďet al.,Ē I include Debra Fischer, Steve Vogt, and a bunch of graduate students, so itís a pretty big group. Some of that group from California, although Paul is now in Washington, is more open than others in that group. The ones that have an agenda, which is to win a Nobel Prize, are less open. The Swiss have the same agenda. The Swiss are being strongly supported by Swiss interests; which is to say, government support and private support, generating the history, the story. Films for consumption in Europe, books relating the true story, conferences in honor of the discovery of the first planet, which happened in August, and so on.

DeVorkin:

That was in Europe?

Latham:

That was at the Observatoire de Haute-Provence, where they say the first planet was discovered. Itís pretty obvious to me that thereís a competition and agenda for positioning these individuals for being recognized by Nobel Prize, which may happen sooner or later.

DeVorkin:

Are we saying all four of them?

Latham:

It canít be four; thereís only three. I think thatís the limit.

DeVorkin:

Oh, I see. I donít know enough about the Nobel Prize. That puts an interesting twist in the situation. Do you feel these conferences are a conscious campaign?

Latham:

Absolutely.

DeVorkin:

Whoís leading it?

Latham:

A variety of people. I donít even know who they are, but people that have influence in Switzerland. I have an idea of who some of them are.

DeVorkin:

Can you give me a few names?

Latham:

I think Iíd rather not.

DeVorkin:

So how would I find out? What literature do I read?

Latham:

I donít think itís recorded anywhere. But I am just putting pieces of evidence together and putting my own interpretation on whatís going on.

DeVorkin:

I would look at citation patterns; I would look at who is sponsoring conferences, who is making the welcoming remarks, who is buying into it. And of course, the Nobel Foundation has its own archives, and we have always learned a lot from that about Nobel Prizes in the 1930s, anyway. Weíve never done anything thatís recent. The Carlo Rubia stuff is, of course, famous.

Latham:

I suggest that you consider interviewing Tsevi Mazeh, because he has already written a book on this, but itís only in Hebrew.

DeVorkin:

Well, thatís helpful.

Latham:

Iím not sure if itís published yet. He addresses, some of these issues in full candor. Tsevi is much more outspoken than I am, and I think more speculative than I am about peopleís motives and agendas, and a fascinating person to talk to, so if you have the opportunity, you really ought to talk to Tsevi.

DeVorkin:

Does he visit the United States?

Latham:

Yes. He will be visiting here six to eight months from now.

DeVorkin:

Thatís a reasonable time frame.

Latham:

You might even be able to get access to his book. I donít know where he is in the publication plans. But there are a couple of incidents here that Tsevi would probably not hesitate to tell you about.

DeVorkin:

The book is published?

Latham:

I donít think itís published yet.

DeVorkin:

I definitely would like to write to him. I take it heís online. Is he a member of the AAS, to your knowledge?

Latham:

He may be.

DeVorkin:

How might I get in touch?

Latham:

If you need his email, I can give it to you, mageh@post-tau.ac.il since heís a longtime collaborator. In fact, the interesting thing is that we are continuing to collaborate closely with Michel Mayor and his team.

DeVorkin:

Excellent. Now, the most successful person, to me, is Butler, and Iíve been planning to interview him down the road.

Latham:

You may get an earful from Paul about me.

DeVorkin:

I see. Thatís very interesting. Do you have any suggestions for what types of questions I should be asking him?

Latham:

No, just be yourself.

DeVorkin:

That I can do. Are there certain things I should ask him about? Like, ďHow did you learn about this?Ē

Latham:

I believe that he will be very upfront about 51 Peg. He has to be because the timing is well-documented when they learned about 51 Peg at that meeting and then came back.

DeVorkin:

They were at the meeting.

Latham:

Oh, sure. They came back and immediately got to work on it.

DeVorkin:

But they had been looking at that point.

Latham:

Oh, sure. Longer than Michel. Michel didnít get started until HD 114762, and that just went like a light switch. All of a sudden he realized this is what he wanted to work on.

DeVorkin:

Thatís a very interesting dynamic. Somehow, you were the instigator.

Latham:

I like to think I was. Michel might not agree to that, or he might. Iím not sure. Michel is mostly honest, but he has an agenda, too. Would he admit this to an outsider? I donít know.

DeVorkin:

Interesting question. In the case of Marcy and Butler, were they aware of your work?

Latham:

Oh, yes.

DeVorkin:

How do you know that?

Latham:

Yes, sure. They knew about it. They had been at a conference where I reported it. Itís hard to believe they didnít know about it. But they chose to treat it as not the same. The excuse they gave for several years is that it didnít count because the velocity precision that I had was 50 times worse than their velocity position, and so they only count the orbits that are detected with very high precision. It doesnít matter what the characteristics of the orbit are; it was the instrument that was used that counts. What a specious argument. They went back and measured 114762 with their instrument and confirmed my orbit. So what do you think? Once itís been measured with that instrument, itís okay to be considered a candidate?

DeVorkin:

[Laughs] Now, you said that you were brought to this by your NatSci 9 lecturing.

Latham:

I certainly was sensitized to the importance of the issue by my teaching at Harvard.

DeVorkin:

And you were in a possession of a certain technology.

Latham:

Yes.

DeVorkin:

In the case of Marcy and Butler, Iím not sure. Iíll have to ask them, of course. Iím sure itís written down; I just havenít read it.

Latham:

They set out to detect these things.

DeVorkin:

Yes, from the get-go.

Latham:

As did the real pioneer, who was Gordon Walker. You need to talk to Gordon Walker if you want to pursue this issue. But thereís half a dozen books written on all this.

DeVorkin:

Yes, and I havenít read them yet.

Latham:

Well, you donít miss that much. You see, none of them know the real story. [Laughs]

DeVorkin:

Thatís the whole point. From my experience, itís very hard to get at the real story when itís this fresh. But what is absolutely essential is that we record as much of it as possible, and then let it, in a way, ripen.

Latham:

Maybe I will make available my email archives on this whole story someday.

DeVorkin:

Put them on a disk. That would be great. In some retrievable format.

Latham:

Yes, thatís not so easy.

DeVorkin:

Some searchable format.

Latham:

Right.

DeVorkin:

Your stuff is straight Internet.

Latham:

Yes, ASCII.

DeVorkin:

Great. Thatís searchable. Any aspect of the extra solar planet stuff that we havenít covered? Or should we go back to the standard photometry?

Latham:

The most important development, in my opinion, in the field of extra solar planet research is the discovery of transiting planets, because there you get the inclination of the orbits, and now you have the actual masses, not just lower limits. You get the size of the planet. Actually, itís the planet relative to the star, but you can guess at the size of the star, and so you get information about the density, about the surface gravity. Then beyond that, quite an amazing variety of experiments to detect light from the planet itself. The observations during a transit, when the light of the star shines through the atmosphere of the planet, has allowed the detection of one or two constituents — the sodium and the hydrogen in the atmosphere. And the recent detection of infrared radiation with Spitzer that must come from the planet. You look for the slight drop during the secondary eclipse, when the planet goes behind the star. So weíre doing astrophysics — weíre learning about the atmospheres of planets from the transiting planets. This is what TPF was going to do for how many billion dollars, and transiting planets have gotten us there a decade or two sooner. Maybe we wonít learn everything that TPF will learn, but transiting planets are a window into this whole area of research.

DeVorkin:

Whatís the key technology here?

Latham:

The key technologies are making very accurate photometric light curves, and getting very high-quality, very precise radial velocities so you get the orbital motion. So both of those are technologies that are well in hand.

DeVorkin:

Can you point to any particular technology? To me, the iodine filter still stands out.

Latham:

No. Thatís just one of two ways, and I think itís not the best way.

DeVorkin:

Exactly. But in the case of the photometry, is there any oneÖ?

Latham:

CCD photometry. Silicon detectors are the important breakthrough. If youíre really interested, Iíll show you some examples. For example, a light curve I did last Wednesday of a new transiting planet, which may have been announced this week, actually.

DeVorkin:

Here? Youíve done that here?

Latham:

ELODIE was used to get the spectroscopic orbit. We did the really high-quality photometric follow-up at Mount Hopkins with a new CCD camera that went into operation last month, in September. We call it KeplerCam, a camera which I built to help generate the Kepler Input Catalog. Thatís a whole other story. We have a very major effort to generate the Kepler Input Catalog, which involves ground-based, high-quality photometry of 10 million stars.

DeVorkin:

I saw some of the abstract information on that, and that places that in your work. Thatís CCD-based.

Latham:

Thatís all CCD. So this is a new state-of-the-art camera. Itís terrific.

DeVorkin:

Thatís wonderful.

Latham:

With the help of some friends, like John Geary, who I hired in 1978. And Andy Szent-Gyorgyi. They worked with me on Kepler Cam

DeVorkin:

He is fun to listen to.

Latham:

Heís a good guy. Thereís a Nobel Prize winner. Itís his uncle who is the Nobel Prize winner. But he pronounces it ďSt. Georgie.Ē Itís Hungarian.

DeVorkin:

Part of my questioning may be futile, but Iím trying to direct my attention to things that I should collect, objects that I should collect, to remember this extremely important era in the history of astronomy and the history of humanity, Iíd say. Iíve already made a commitment to get the iodine filter.

Latham:

Just an iodine cell?

DeVorkin:

The original one, when theyíre done with it.

Latham:

Thereís a bunch of them. Nothing special. Itís just a glass bottle with iodine gas in it and a heater to keep it at constant temperature.

DeVorkin:

Right, but there are certain characteristics to that particular one that theyíre used to. As long as they donít destroy it.

Latham:

Sure. It may break on its own, of course.

DeVorkin:

We collect for two reasons: historical and technical. What youíre saying to me — and of course, I would pursue it — is that it still fits the historical, but not necessarily the technical.

Latham:

It wasnít the invention of the absorption cell technique. That was done by Gordon Walker. He chose hydrogen fluoride. It turns out that probably iodine was a better choice because it has more lines over a broader wavelength window. But the idea of using an absorption cell was pioneered by Gordon Walker ten years before Marcy and Butler got started. Their innovation was to find a better molecule that was much easier to handle and better suited, and to develop software that allowed them to work with the iodine and go fainter. The Canadian team, Walkerís team, while they worked on really bright stuff, they chose a sample of 17 dwarf stars; altogether, there may been have been 26. When they started, they fully expected to find several extra solar planets the size of Jupiter in relatively long periods. Everybody knew they had to be long periods.

DeVorkin:

But you were the only one who thought of short period?

Latham:

No, no. Give credit to Tsevi. Tsevi convinced me.

DeVorkin:

Did he have any theoretical understanding that gave him this insight?

Latham:

No. He didnít know about migration. It turns out the idea that planets might migrate much earlier had been published. But that was completely ignored. I was completely unaware of it.

DeVorkin:

Who was that?

Latham:

I guess it was Peter Goldreich, but let me check that.[11] I havenít even bothered to read the paper because Iím willing to accept that planets mustíve migrated. [Laughs]

DeVorkin:

Peterís one smart cookie.

Latham:

Yes, isnít he? I should double-check what the sources are. The point is it had been thought of, it had been published, and as I understand it secondhand, the basic conclusion of the paper was puzzlement over why there was no evidence for migration in the Solar System because it shouldíve happened.

DeVorkin:

Thatís fascinating.

Latham:

But Iíd be amazed to learn that Tsevi was aware of it. No, I just think that Tsevi liked to think a little outside of the box. He appreciated that if we found short-period giant planets, it would set a few theories on their ears, or a few conventional ideas. Iím not sure. Iíll call them theories.

DeVorkin:

What is the status of the echelle spectrograph that you used for this?

Latham:

Itís sitting right up there. Hasnít been used since April, when Charles shut us down.

DeVorkin:

Here at Oak Ridge?

Latham:

Yes, itís there.

DeVorkin:

Is that a Smithsonian instrument? Or is that a Harvard instrument?

Latham:

I have a confession to make. We built three of them here. The first one was built with State of New York funds because they were collaborating with us in Mount Hopkins. They couldnít pay us money, so they bought instruments, and that was built by Optics for Industry. That oneís still in Arizona and weíre still using it there. Then the next one was built with Agassiz money, and it went to the MMT and was used for many years at the MMT. So we took the instrument that was in operation at Oak Ridge and put it on the MMT, but we wanted to replace that, so the third one was built with Smithsonian money with the idea it was going to go to the MMT. It was on the MMT budget. But did I actually swap the two spectrographs? No, I just didnít tell anybody. I left the Agassiz one out there and I put the new one up here. So the one up here actually was built with Smithsonian money, but you would not be able to find documentation of that unless you talk to me.

DeVorkin:

Well, I am!

Latham:

[Laughs] That is Smithsonian property, yes.

DeVorkin:

Are you on that committee, by the way, on the disposition of the Oak Ridge?

Latham:

No, Iím not on that committee.

DeVorkin:

Donít you think you should be?

Latham:

No. Iíve got better things to do. I want to look ahead; I donít want to look back.

DeVorkin:

Well, my charge, looking back. I lobbied Charles Alcock to put Sarah Schechner on that committee?

Latham:

Sarah Schechner? Oh, she is the historical instruments.

DeVorkin:

Yes. Iím not sure whether Owen Gingreich is, but I was going to talk to Owen.

Latham:

No, I donít think so. Bob Kirshnerís in charge?

DeVorkin:

Yes, Kirshnerís in charge, and so is, David Aguilar. And then various other people, right?

Latham:

Well, that spectrograph is in excess to our needs. Itís retired. In fact, there are two of them here. The MMT one we brought back for spare parts.

DeVorkin:

Would you be the one then who would write me an email with the closing that itís in excess to your needs?

Latham:

Itís available, yes. Of course.

DeVorkin:

Would you do that?

Latham:

Of course.

DeVorkin:

Then I will act on it. Do you feel thereís a lot of other stuff out there that needs to be saved that would be Smithsonian?

Latham:

No, not much. The interesting, old instruments would belong to Harvard. The ones that Metcalf did the optics for, theyíre kind of interesting.

DeVorkin:

Iíve been digging up those things. Sarah and I have been working on that, and we made a very clear agreement that Iíve got no problem if she gets all that stuff.

Latham:

Yes. You donít need it. But the echelle spectrograph, which someday might be recognized as detecting the first extra solar planet, that might actually be of interest. It is not recognized as such right now. Everybody talks about 51 Peg as being the first. We will have the answer by 2015. SIM, the Space Interferometry Mission. SIM can measure the inclination of the orbit, and then weíll know what the true mass of that companion is. If, as I expect, itíll turn out to be 10 or 15 Jupiterís, then the documentation can only be interpreted one way: it was the first extra solar planet. And it predates the pulsar planets, too.

DeVorkin:

Yep. People every so often bring those up, which, to me, is kind of irrelevant.

Latham:

Maybe not entirely.

DeVorkin:

But in the case of the Space Interferometry Mission, how can that get an inclination? What am I missing here?

Latham:

SIM does extremely precise astrometry. So you get the astrometric orbit on the sky, and you get the orbital inclination. Thatís in the back of my mind, that weíll know eventually. I can wait.

DeVorkin:

Yes. I expect to be around here, too. And so will you.

Latham:

I hope.

DeVorkin:

We were at the point where I had asked you about what was lingering, and you went to the photometric stuff, which is very important.

Latham:

Oh, yes. Transiting planets, and thatís why Iím investing so heavily in transiting planets now as the final stage of my career.

DeVorkin:

Kepler.

Latham:

Kepler is the most important project over the next five or ten years, I think, for extra solar planets. But in the meantime, weíre trying to do as much as we can from the ground. So there are wide-angle surveys with ten-centimeter telescopes that stare typically at eight-by-eight-degree squares on the sky, and watch for giant planet, hot Jupiterís, to transition stars and cause dips that are 1% or 2% deep, lasting two to three hours. Then we have to follow them up, because it turns out that the vast majority of them actually are stellar systems. A common astrophysical false positive is an eclipsing binary diluted by the light of a brighter star. So instead of being 30% or 50% deep, itís 1% deep. Another very common false positive is an F star, one and half solar radii or two solar radii, being eclipsed by an M dwarf, which is almost as small as a planet. So you get down to the bottom of the main sequence into something thatís about a tenth of the size of the Sun, and then matter goes degenerate; the whole structure of less massive objects changes, and they more or less all have the same size. So, Jupiter has the same size as the smallest star burning hydrogen within 10% or 20%. It turns out there are lots of M dwarfs eclipsing F stars. I have maybe 30 of them that we have orbits for. I followed up 250 candidates from four different ground-based surveys, which is very interesting in itself. Only one of them, so far, has proven to be a transiting planet, thatís ďTRES 1.Ē We did all the spectroscopic follow-up on that one. Not only did we weed out all the false positives, but we actually got the spectroscopic orbit with NASA time with HIRES on Keck I. So other people have been using HIRES on Keck, and we have been a user right from the beginning. We have, about a, half dozen spectroscopic radial velocity planets that weíve announced. Most people donít recognize that weíre a player in the game, but itís because we donít get a lot of telescope time.

DeVorkin:

But are you building robustness with your techniques?

Latham:

We are trying to learn how to confirm and characterize. The planet candidates dissolved by Kepler. It will be a very difficult job, and something we donít talk about too much, but weíve got to do it very carefully with Kepler.

DeVorkin:

Why donít you talk about it?

Latham:

Because itís a little discouraging that weíre going to have to sort out all these false positives. Weíre not just going to make detection and thatís it. We have to be absolutely sure we know what weíve got.

DeVorkin:

Yes, but thatís the case for just about anything.

Latham:

Sure, but itís worse than we thought when we wrote the proposal for Kepler.

DeVorkin:

I see. Is Kepler in competition with other proposals at this time?

Latham:

No.

DeVorkin:

Or are they all approved?

Latham:

Kepler is approved. We still have hurdles to pass. Weíve got a critical design review coming up at the end of this year. We have to pass that. Then we have a flight readiness review that we have to pass at the end of Phase C. But it is an approved project, and I think itís got a solid position at NASA headquarters. That didnít keep them from stealing $30 million that had been allocated to the Kepler mission in January. We got a budget for the fiscal year in October or November, and then in January they took $30 million back, which postponed launch by six months.

DeVorkin:

When is the launch now?

Latham:

June 2008 is the schedule.[12]

DeVorkin:

Whoís the prime contractor?

Latham:

Ball Brothers.

DeVorkin:

Do you have any contact with Ball yourself in this?

Latham:

Yes. Iím involved in kind of the inner core of the science team. Iím happy to let Ball do their job, though. I donít worry about managing that. Thatís all done out of Ames.

DeVorkin:

Now, Kepler — Iím trying to recall from Borukiís talk at the Museum — uses a very sophisticated way of masking and creating some sort of a defraction pattern. How does it work?

Latham:

Very simple. You simply stare at the same area of the sky for four years, continuously, and you look for stars that blink by as little as 50 parts per million. The ultimate photometric precision that we get for the best situations, 12-magnitude stars, is 20 parts per million. Thatís the design. In order to get the photometric precision, you have to accumulate a lot of photons. To cover a wide arc on the sky with a finite number of pixels, the pixels end up being rather large. The images are 8 arc seconds across. Thatís a little bit of a problem because you can get contamination of the images by a nearby star that isnít separated by enough. This is why we have to worry about eclipsing binaries being blended with brighter stars and looking like a planet when it isnít really.

DeVorkin:

If I recall, he was talking about how you canít choose a field thatís too dense.

Latham:

Because of the same reason. A year ago the mission managers finally agreed that we had to move the field off of the galactic plane a little bit because we were being overcrowded. That was one of several issues that I battled for.

DeVorkin:

You wanted to move it all.

Latham:

Yes. We had to move, even though it made trouble for me, because I had already started to observe the original Kepler field with the ground-based photometry. Most of that is no longer in the field. [Laughs]

DeVorkin:

Whatís the Kepler field now?

Latham:

Itís in Cygnus and Lyra. Itís at 19 and a half hours right ascension and plus 45 degrees declination roughly.

DeVorkin:

Whatís the field of view?

Latham:

The footprint is 160-some square degrees. The actual area on silicon is 108 square degrees. There are gaps between the CCDs.

DeVorkin:

So this is a wide-field photometric?

Latham:

Kepler will be a Schmidt telescope. Weíre doing a wide-field photometric survey. 1,600 pointings in the field with our 48-inch telescope, because our Kepler Cam only covers 23 arc minutes in a side, so to cover the whole field is 1,600 pointingís in four filters.

DeVorkin:

If you were able to commandeer the Sloan telescope, would that give you that kind of field? Or even farther away?

Latham:

To do photometry for the Kepler Input Catalog?

DeVorkin:

You have to change the CCD.

Latham:

There was an initial discussion with the Sloan project about whether they could do the classification, and they wanted too much money, so I volunteered to do the work.

DeVorkin:

At Mount Hopkins?

Latham:

With a telescope that I built, so thatís kind of fun.

DeVorkin:

Yes. Is this a gratifying new use? You said before that itís uncanny how so much of your career leads to this.

Latham:

The 48-inch telescope, that weíre using, was something that I identified as a useful capability for us at Mount Hopkins. I wrote the proposal, I got the money, I saw the construction and all that through, and then I ended up not using it. It was just something that I felt was needed for the user community. Now, ironically, Iím coming back and using it, and Iím the heaviest user. So thatís kind of fun. This is funny. After doing the calibration of Vega with Don Hayes (we got that publishing back in í75), I decided this photometry business is too difficult. Iím going to do something easy. Iím going to do spectroscopy. So I focused on spectroscopy for 25 years. Now for Kepler, I have to do photometry, so Iím back to doing photometry of the toughest kind, an All-sky, absolute photometry. So I guess it took 25 years to forget how hard it was. Over the last two and a half years, I have been relearning how hard it is.

DeVorkin:

I remember Donís struggling with standard lamps.

Latham:

You were at Lick, werenít you?

DeVorkin:

I was at Lick when he was doing his thesis.

Latham:

Oh, yes.

DeVorkin:

Is this a good time to move onto that?

Latham:

Well, we went on to using a black body. In our case, we couldnít afford a gold black body, so we used copper. Don made an oven that melted copper, and it glowed nice red, ruby red, orange-red. Then weíd turn off the power and weíd gradually let it come down to its melting point. It sits there, and then it freezes and it drops further. The temperature of the melting point of copper is very well determined, so you know what the black body spectrum is, and that was our fundamental calibration against a copper black body.

DeVorkin:

This is what you did in this paper with Don in í75?

Latham:

Yep. Basically, it was Don. I provided the telescope and the photoelectric scanner.

DeVorkin:

The only note here in í75 is Don Hayes and David Latham, ďA Rediscussion of the AtmosphereĒ.[13]

Latham:

Yes, thatís the key one.

DeVorkin:

You have 651 citations to that paper. Now, this is atmospheric extinction.

Latham:

Thatís right. You have to understand the extinction of the Earthís atmosphere in order to figure out how bright Vega is outside the atmosphere. It turns out that that was the important thing that we did. We really got to the point where we understood how to work with extinction. Although the technology of making copper melting-point black bodies was kind of interesting too.

DeVorkin:

Whoís responsible for that?

Latham:

Don mostly did that, following a recipe from somebody at NBS, as it was called, at the time. We had been doing site testing for the MMT, which wasnít in existence. And we had a test tower up on the summit where we located the black body.

DeVorkin:

This is well before í75.

Latham:

This is something like í72, í73. We had a 12-inch telescope, which we had set up for this purpose, down on the ridge. We could point it at the summit. There was a hole on the side of the shelter that we had been using for site testing and we set up the black body and we monitored the melting curve with our telescope on The Ridge. Then weíd observe stars all over the sky to derive the nightly extinction for that night and then transfer the calibration to Vega.

DeVorkin:

How did you get involved in this?

Latham:

Stellar atmospheres, again. If youíre trying to understand the atmosphere of Vega and interpret the observed spectral distribution, youíve got to have an absolute calibration in ergs per square centimeter per angstrom as a function of wavelength. It turns out the absolute calibration was the limit, especially going into the ultraviolet. The Balmer discontinuity was wrong by several percent. Also, the absolute brightness is an important constraint because thatís how you set the luminosity. So much energy is coming out of each square centimeter of the surface of Vega, and you have a very good distance, of course. You have to know the absolute level of the energy coming from the stars, so thatís the two things you did: looked at the wavelength dependence and the absolute level.

DeVorkin:

I could see the application, but how did you and Don get together?

Latham:

Well, I got to the point where the comparisons with the model atmosphere predictions were limited by the absolute calibration. I must have contacted Don first because he wouldnít have known about me. But I canít tell you how that happened. I donít remember.

DeVorkin:

Was he at Rensselaer?

Latham:

He was at RPI by then, and somehow, we got in touch. We may have run into each other at a meeting.

DeVorkin:

Do you spend a lot of time reading the literature?

Latham:

Not as much as I used to when the journals were in paper. Theyíd come across my desk and Iíd look at them. But I donít have subscriptions anymore. I find that I just donít look at the literature as much because it doesnít come across my desk. I read things as I need to read them, but not out of curiosity in general.

DeVorkin:

So you donít do a keyword search on ADS to see whatís up?

Latham:

No. Iíll look at the references as needed when I am working up results for publications.

DeVorkin:

So you donít routinely see a paper copy of the object.

Latham:

No I donít, and I donít have the discipline of watching astro-ph to see the new postings. Now, the young people do. They read stuff as it gets posted. But Iíve never gotten in the habit of doing that.

DeVorkin:

Thatís an interesting observation, and I can appreciate it. But itís a very interesting transition to how we get our information.

Latham:

Yes. Now Iím much more focused on what I need as I write the next paper.

DeVorkin:

Do you worry about that sometimes?

Latham:

Yes, very much. Iíll tell you another thing. Owen and I donít teach anymore, but when I was teaching, both Owen and I would watch the literature, especially the secondary literature like Science, Scientific American and American Scientist. We would watch that in all the areas that might have something to do with a topic in the course, always looking for new material for a lecture, always trying to make sure we were on top of things. So I read much more widely when I was teaching. Now when I get Science, I donít bother to follow up all those topics, such as anthropology, where I know I wouldíve been very interested in that because of the three lectures that we had in the spring term on the way humans evolved. I donít bother anymore. I donít have time. I have other things to do.

DeVorkin:

Whoís teaching that?

Latham:

Nobody.

DeVorkin:

Whatís in its place?

Latham:

Nothing. Other courses. There are courses in astronomy.

DeVorkin:

Wasnít it a core course for Harvard undergraduates?

Latham:

For a long time, yes.

DeVorkin:

What changed?

Latham:

Owen retired, and so did I, from teaching. It would have been very hard to do it the same way that Owen and I did it. Really, it was Owenís interest that established the way the course was set up, but I certainly agreed with it, and I liked to think that I contributed to it.

DeVorkin:

While weíre talking about that, the course teaching is a very important part of your life.

Latham:

I taught for almost 40 years.

DeVorkin:

Owen, I guess, along with Whitney, could be regarded as yourÖcould I say mentors in astrophysics?

Latham:

Certainly early on, but I gradually moved into other things.

DeVorkin:

Understood. But at the beginning?

Latham:

Certainly, yes. Especially Owen.

DeVorkin:

Iíll be interviewing Owen, of course, and thatíll be a very different experience for me, as you can imagine, because I talk to him about this a lot. I see youíre smiling. What is your take on Owen?

Latham:

Let me preface it by saying heís one of my good friends. Iím not sure heís my best friend. But certainly, we have been friends for many, many years and have worked together closely and warmly. Iím not sure just anybody could work closely with Owen, but I have always managed to.

DeVorkin:

Now, you see him as an astronomer.

Latham:

Not really. Iíd say I see him as an interested and highly skillful expert observer of humanity in general, but of the way science works in particular.

DeVorkin:

When he made the transition from astronomy to history, you mustíve been aware of this.

Latham:

Sure.

DeVorkin:

What were your feelings about that?

Latham:

It was his choice. He was addressing fascinating questions and finding new insights, which I also found interesting. I certainly wasnít going to redirect my career in that direction, but I always enjoyed learning his latest insights.

DeVorkin:

Harvard astronomy has an interesting history of people being here and going off in some directions and not doing too well. I mean, achieving world fame like Carl Sagan, but not getting tenure. Letís put it that way.

Latham:

Well, he didnít get tenure at Harvard.

DeVorkin:

Right, he went to Cornell. But thereís always been this question. You know, Harvard really lost out or wouldnít tolerate him or whatever. In the case of Owen moving to history, was this any of this issue? Or did he already have tenure? Iíll ask him.

Latham:

He already had tenure.

DeVorkin:

Okay. Makes a big difference.

Latham:

Yes. But he also was remarkably productive if you measure in terms of publications and international recognition. So I donít think anybody complained, but you better ask him.

DeVorkin:

I will. The issue was, this is a position for an astronomer in an Atmospheres Group, and we need the job done kind of a thing. Did you look at it as a team? Was the Atmospheres Group a team where everybody had a role?

Latham:

Yes, more or less.

DeVorkin:

So Owen is not continuing on in atmospheres, but heís taking up a slot

Latham:

It didnít bother me. There seemed to be plenty of slots.

DeVorkin:

That might be the key. As long as there are plenty of slots.

Latham:

It was back in the post-Sputnik era when there were lots of resources.

DeVorkin:

What about Charles Whitney?

Latham:

Interesting case. Everybodyís acknowledged that Chuck was the leader of the science end of the team. He was going places, and then it came to an abrupt end.

DeVorkin:

I understand that there was a very serious falling out with Fred. Iím certainly going to ask Charles Whitney about that, but any insight? It happened while you were there.

Latham:

Well, there was some development that implied a change in resources. The end of the honeymoon after Sputnik, you might even view it as. It was going to mean cutting here and cutting there and deciding where the resources would go, for the first time in our memory.

DeVorkin:

Itís a very interesting observation.

Latham:

Chuck Whitney started open discussions of what was important. To my memory, Fred was not part of these discussions. It started, I think, in the Model Atmospheres Group, and then maybe got a little wider. Chuck may even have been a department chairman about that time. My guess is that Fred viewed it as a palace revolt, and that Chuck had stepped over the line of what was his responsibility or his role. I kind of think Fred called him on the carpet for it, and I kind of think Chuck said, ďScrew you,Ē and basically disappeared.

DeVorkin:

But not continuing to do stellar atmospheres work.

Latham:

Yes, he pretty soon (I canít remember how quickly) phased out and did his own thing, but didnít take a leadership role anymore.

DeVorkin:

Because he started doing historical work as well.

Latham:

He did some of that. He wrote an interesting enough book on the discovery of the Galaxy. Rather well-written book, actually.

DeVorkin:

Yes. It was the first one I read of the specialist books, of the specialist histories, or narrow or thematic histories. He also took a very strong interest in education. I know that one of his students was Dick Berendzen.

Latham:

Yes. I rolled my eyes.

DeVorkin:

Well, an interesting thing. Did you interact with Dick at all?

Latham:

Oh, yes.

DeVorkin:

So why did you roll your eyes?

Latham:

Just because of subsequent history and the trouble that Richard got himself into.

DeVorkin:

At American University.

Latham:

Yes. Well, Richard had to pass his research exam. Let me put it this way: I helped him a lot on that.

DeVorkin:

I see. I started working with him in the early Ď70s when he was at BU on education and history stuff.

Latham:

Right, and he even had a contract to do something.

DeVorkin:

Oh, yes, he did. He was one of my local advisors for my Ph.D. even when I was in history and doing the history after the astronomy. But Iíve always regarded him as a very focused and driven person and a better organizer of things. Really quite extraordinary. But he did his thesis under Chuck Whitney.

Latham:

Is that right? Iíd forgotten.

DeVorkin:

Yes. ďThe Professional Development of Astronomers in the United States.Ē

Latham:

You know, Dick wasnít really cut out to do real scientific research is my conclusion.

DeVorkin:

Thatís interesting. What was he cut out for?

Latham:

What he ended up doing — being a president of a university, organizing things.

DeVorkin:

Thatís right. Should I get into?

Latham:

Your choice.

DeVorkin:

Well, I donít know if weíve covered completely your association with Don Hayes and how that continued, because you worked with him for a good while. I know from knowing Don that it was a very compelling thing to do because it had to be done, but boy, itís messy.

Latham:

And demanding. You have to worry about all the possible things that would go wrong.

DeVorkin:

Right. And when he was doing it with these standard lamps from Europe that was heartache.

Latham:

They were fundamental enough standards. Nowadays, you have much more fundamental standards. But the thing thatís really fundamental, of course, is the melting point of something like gold. Thatís the way Bev Oke and Rudy Schild did it. The reason that you donít hear about the Oke-Schild calibration and it hasnít got 600 citations is they didnít understand atmospheric extinction. They didnít understand the difference between horizontal extinction and vertical extinction. The atmosphere is layered, and so you have to use a different way of treating the horizontal extinction. Thatís where they messed up.

DeVorkin:

What I remember Don doing was one of his lamps would be up on the parapet at Lick, headed up to the 120, and heíd be observing from the crossley. What youíre doing was very much the same thing. But that was at a specific angle, and all of that has to be figured in.

Latham:

And itís far enough away that the horizontal extinction is significant and youíve got to calculate it directly.

DeVorkin:

And Oke?

Latham:

No, he got it wrong. But he had a gold black body.

DeVorkin:

He could afford it?

Latham:

Apparently.

DeVorkin:

How much gold do you need?

Latham:

You donít need that much. But itís a higher melting point, which is an advantage. One of the disadvantages of the copper is that itís a lower temperature, so youíve got to be much more careful how you block the leaks because itís so red. You canít have red leaks.

DeVorkin:

We havenít talked, to my knowledge, about the image stacker.

Latham:

That was just a technical gizmo to accommodate the light from six individual telescopes at the MMT, which was unique. So it was a way of improving the through put onto our echelle spectrograph, the one that I built with Agassiz money and then shipped out to the MMT. We took the light from the six telescopes and managed to put that down the slip, so we called it an image stacker. That was collaboration with Fred Chaffee.

DeVorkin:

Is that an instrument that was used throughout the six mirror system?

Latham:

Yes, until a conversion came along, and then it was no longer needed. We decided not to bring up the echelle on the converted MMT. In retrospect, we shouldíve because the replacement instrument was delayed by four or five years. But under the original schedule, there was no need for it. It was going to have a replacement instrument.

DeVorkin:

We did an extensive video history of the group of people, like Nat Carlton and others, Meinel and Ray Waymann. The only person we couldnít get to was Frank Low about the building of the MMT. Should we have included you?

Latham:

Well, Iíll tell you that story from my point of view. I finished my degree, and that was almost simultaneous with the notion from Arizona, I think really from Aiden Meinel, that maybe these Air Force blanks could be used in some kind of novel telescope. They approached the Smithsonian because Fred had his observatory in Southern Arizona by then, and Iím sure that we were viewed as a source of resources. I think Fred got kind of excited about it and he put Chuck Lundquist to work on it to organize things. The initial reaction amongst the astronomers was they didnít want anything to do with it.

DeVorkin:

Astronomers at SAO?

Latham:

Yes. They thought, ďThis is kind of a wacky idea, and why do we want to get involved in that?Ē For whatever reason, I counter-reacted. I said, ďWhatís wrong with it?Ē So I went into Chuck Lundquist and I said, ďI will volunteer to work on this project. What can I do?Ē Chuck and Fred said, ďYou can help us write the proposals and you can go to Arizona and do some site testing because the U of A, especially Frank Low, wants to put it on Mount Lemmon.Ē We, of course, wanted to put it on Mount Hopkins, so we moved to Arizona for nine months and I organized site testing, mostly at Mount Lemmon and Mount Hopkins. Night sky measurements, seeing measurements at the summit. When would that have been? í70 or í71, I guess. My fifth son had just been born, so maybe it was í71. Anyway, we went down there, and I got heavily involved in all the initial groundwork, especially the site testing. You can read my site testing reports and all that. I think Fred may even have called me the project scientist at the time, although Iím not sure of that. Then when I came back and the first round of funding was secure, Nat Carlton got interested. Iíve heard other people describe this transition, Nat becoming the project scientist, as if it was some nasty thing where Nat moved in. So about a year into the MMT project after I first volunteered to help out, there was a transition. Nat formally took over as the SAO project scientist. Of course, I stayed very interested in the project and I was involved in an awful lot of the technical work as part of the team, but Nat was the person leading the effort for Fred.

DeVorkin:

I take it he was on staff before then, or was he at MIT.

Latham:

Yes, he was one of these SAO positions shared with physics.

DeVorkin:

Thatís right. He was in physics.

Latham:

But he moved up to the Observatory Hill and essentially began spending all his time on the MMT project.

DeVorkin:

If it was a smooth transition for you and Nat, why were you happy to let him take over?

Latham:

Thatís just the way I was. I had plenty of things to do.

DeVorkin:

So youíre saying, before, that you volunteered to it.

Latham:

Yes. I was a brand-new Ph.D., and I probably decided that Fred was looking for a more experienced, a more senior person; somebody that could deal with the big egos at the U of A.

DeVorkin:

Compete with them, so to speak?

Latham:

I guess. Hold their own with them.

DeVorkin:

And Nat was more senior.

Latham:

A lot more senior.

DeVorkin:

Itís an interesting thing, because in a way, you would be in almost the same position as Bob Davis in í58, í59 — thrown into something that was just huge.

Latham:

Yes.

DeVorkin:

Did you know about that experience at that time? That didnít factor in at all?

Latham:

No, I donít remember thinking about it that way.

DeVorkin:

But as you just said, you really did think at that time that you had more immediate things to take care of.

Latham:

I had discovered international motorcycle competition.

DeVorkin:

So it was a purely personal thing about priorities.

Latham:

I was very gung-ho about that.

DeVorkin:

Were you ever gung-ho enough to think that that would be your career, and that you would leave astronomy?

Latham:

No. No way.

DeVorkin:

You had already married and had kids. What did your wife think about all this?

Latham:

After a while, she told me enough is enough.

DeVorkin:

But she tolerated it for a while?

Latham:

Yes, for three or four years.

DeVorkin:

What was the worst accident you ever had?

Latham:

I messed up some vertebrae once. I had to lie on my back for a while.

DeVorkin:

Iíve heard far worse.

Latham:

Well, you know, I got a bunch of stitches here and here. I can show you scars. That one right there, that was painful.

DeVorkin:

So Nat took over, but you stayed involved.

Latham:

Sure, I stayed involved and worked hard on teaching. I was doing teaching by then.

DeVorkin:

So you got your degree in 1970. Did you ever think of going anyplace else? Did anybody ever encourage you to?

Latham:

They should have, but they didnít.

DeVorkin:

Isnít that the normal thing to do?

Latham:

Itís the wise thing to do, because instead of being the same, old graduate student, you come in as the new champion — you come on a big white horse, gallop in as the hero.

DeVorkin:

So there was no thought of you going anywhere else?

Latham:

I thought about it a little bit, but didnít pursue it. There were so many exciting things going at SAO, I saw no reason to move. I looked at an opportunity in Australia, for example, and decided not to go. Decided thatíd be too disruptive. It wouldnít be anywhere near as exciting as SAO.

DeVorkin:

Was there a question of the stability for your family?

Latham:

Yes, a little bit. Not much.

DeVorkin:

Did you, in any way, make yourself indispensable at SAO by then?

Latham:

Of course, Iím the wrong person to ask. I was certainly building instruments, if you have a new observatory; you need people to build instruments for the telescopes.

DeVorkin:

So you chose at a time, though, when you had just been hiredÖ

Latham:

Actually, I was hired back in í65 or í64. While I was a graduate student, Fred hired me on as half-time or something. A civil servant.

DeVorkin:

You were talking about getting your federal check.

Latham:

Yes. Itís one of the reasons it took me so long to finish.

DeVorkin:

But did you have a slot? Or were slots not even an issue at that time?

Latham:

I really donít know. I didnít worry about those things in those days. It was only after I became an Associate Director that I had to learn how the system really worked.

DeVorkin:

And you did that under George Field?

Latham:

Yes. Of course, I had to learn in great detail how things worked, because then I was in charge of hiring.

DeVorkin:

Yes, but weíre not quite ready to go there yet. Iím trying to straighten out this decision that you made.

Latham:

Like a lot of decisions in my life, it just seemed to happen.

DeVorkin:

As a motorcycle rider, you take risks. Would it have been more risky to stay with the MMT project or move off on your own?

Latham:

I donít think I ever thought of it that way.

DeVorkin:

Did you talk with your wife about it? What the options would be?

Latham:

Probably not.

DeVorkin:

You just did it.

Latham:

Yes.

DeVorkin:

Okay. What about talking about your associate directorship. What were the circumstances that put you in this position?

Latham:

Well, letís see. Nat Carlton was Acting Associate Director for a couple years, í74, í75, something like that. Apparently, that wasnít working out as well as George had hoped. I donít know how long after George came in, but at some point, he went to the high energy group and picked out Herb Gursky to be the Associate Director of Optical and Infrared Astronomy. I donít know whether Herb went campaigning for that job or what. Thatís my guess, because there was a kind of rivalry between Riccardo and Herb. Riccardo was in charge of High Energy, and so Herb wanted to be in charge of something, too. I am oversimplifying it, but Iím sure there was some of that. So Herb came over to Optical and Infrared Astronomy and managed things in his own inimitable style.

DeVorkin:

Thatís interesting. I mean, heís an X-ray guy.

Latham:

Yes. That was when we were seriously building the MMT, and we had to think about the first light instruments. So long about a year into his associate directorship, I had become, in Herbís eyes, the guy that was going to lead the instrumentation effort. He made no bones about that. He came to me for the decisions; I did all the budgets, I did all the planning for the instruments we were building on the ridge. All the CCD cameras and new hires. Thatís when I hired Geary. Thatís when I hired other people in the lab. Herb took my suggestions on that. Then when Riccardo moved on to Space Telescope, Herb had to match his move, so he became Director of something or other at NRL. I did not go out of my way seeking to be associate director, but my guess is that Herb mustíve gone to George and said, ďYou know, Daveís really been doing this part of the job.Ē I was young at the time 42 or something. No, younger. This would have been í81. 41? Anyway, George came by and had some discussions with me. He asked me if I would be interested in taking on this job. Seven years before, he asked for my resignation. Thatís when I stopped riding motorcycles and turned my attention to doing science and publishing.

DeVorkin:

Seven years earlier?

Latham:

Yes.

DeVorkin:

Itís not the associate directorís.

Latham:

No, no. í74, so it took me seven years to convince George, I guess.

DeVorkin:

You had Civil Service protection.

Latham:

Yes.

DeVorkin:

Did you have a Harvard appointment?

Latham:

Yes, a teaching appointment, but not a faculty appointment.

DeVorkin:

So that threat from George FieldÖ

Latham:

It came at the right time. I was ready to move on from the motorcycles to something more serious.

DeVorkin:

But he could not have gotten rid of you.

Latham:

Well, he wouldíve had a hard time. There wouldíve had to been some kind of a RIF or adverse action.

DeVorkin:

But that can be devastating. Certainly a wake-up call.

Latham:

Yep. Well, my interpretation of that meeting with George was that it had come from Nat. Nat wanted to get rid of me, and Nat had asked George to see what he could do. Thatís my interpretation.

DeVorkin:

What was Natís reasoning, do you think? [Pause] You donít know.

Latham:

I think Nat viewed me as a threat.

DeVorkin:

Thatís very different from productivity, so I see what you mean. Were you a threat?

Latham:

I didnít think of myself as a threat at the time.

DeVorkin:

How could you have been a threat?

Latham:

[Chuckles] Because I was better at the things he was supposed to be doing.

DeVorkin:

Well, weíve gone a really long way here. I mean, youíre my first formal interview for the SAO research, so itís quite likely that Iíll be coming back to you from time to time.

Latham:

Iíve been an observer and Iíve been involved in a lot of things. You wonít too many people that have been involved in so many different things during those years when Fred was building his own observatory and the MMT. I was involved in all of that.

DeVorkin:

I do have a few general questions about Fred Whipple, about the observatory. Iíll start it by saying: Was his retirement amicable all the way around? Or was there a force?

Latham:

I was not in those circles. I was not consulted, so I donít know. But now that you pose that question, maybe there was some pressure.

DeVorkin:

I donít know of any at this point. Iím sure that it existed.

Latham:

Yes, I canít rule it out, and I can imagine where it couldíve come from, too.

DeVorkin:

Could you point me in some directions?

Latham:

I think the conflict between Leo and Fred was something that cooler heads thought, ďWe ought to try to fix this problem so it doesnít happen again.Ē The way you fix this is you bring in some new hero to be director of both arms, and it canít be somebody whoís on one side or the other of the previous administration. It has to be somebody new. It has to be somebody like George Field. Big reputation. So I can imagine that there couldíve been discussions, talking about the wisdom of a fresh start or a new organization. How old was Fred at the time he retired? Was he ready to retire?

DeVorkin:

Thatís what I was trying to remember.

Latham:

When did he retire?

DeVorkin:

í72. But he stayed, of course, well through the Ď90s.

Latham:

Yes, and he did his own research. He kept writing papers.

DeVorkin:

Still quite active.

Latham:

Yes, teaching too. Maybe not so much teaching after that. He was still teaching in the Ď60s, but not big courses. Tended to be one or two students. But just knowing what was going on, it wouldnít surprise me if there was some discussions about the wisdom of changing things.

DeVorkin:

I asked Fred and other people asked him about his relationships with the central Smithsonian. They were, in fact, quite rocky from time to time.

Latham:

Really? Because he was going off in directions that they didnít necessarily approve of?

DeVorkin:

No, it was management issues, really. Accountability and management issues and stuff like that.

Latham:

Oh, yes. Well, that was the golden age, from my point of view. If you wanted to get things done, you got them done. The layers of reporting and accountability and hoops you have to jump through to get things done now are just amazing.

DeVorkin:

Did you experience this bureaucracy directly with the Smithsonian during your time?

Latham:

No, maybe after Fredís time. Fred was pretty good at protecting us against that somehow.

DeVorkin:

So itíd be after his time.

Latham:

Yes.

DeVorkin:

That, by the way, fits nicely. Of course, the Smithsonian changed a lot as well.

Latham:

The Smithsonian has changed maybe even more. It wasnít just changing from Fredís style to somebody elseís style; itís this whole new layer of management. Well, multi-layers, the ultimate evil of which is PeopleSoft.

DeVorkin:

Youíre right!

Latham:

I have a new employee. He started a week ago. Iím scheduled on three telescopes next week. He is going to be at one of the telescopes because I canít be at all three. I need to buy him an airline ticket. He started work last week. ďCan we please purchase the airline ticket?Ē ďNo, we canít purchase it yet.Ē ďWhy not?Ē ďBecause he isnít in PeopleSoft.Ē ďWhy isnít he in PeopleSoft?Ē ďWe donít have his home telephone number.Ē ďWell he doesnít have a home telephone yet. Heís waiting for it to be installed!Ē But fortunately, they have a reservation and itís a government fare, so the ticket wonít go away. I sure hope he has a ticket by the time he needs to leave next Thursday. This is the kind of stuff we end up dealing with now. What a waste of time and effort.

DeVorkin:

Oh, sure. I traveled here on NSF money. Completely independent of the Smithsonian. Itís money that is administered by the American Institute of Physics.

Latham:

Plus, you just bought gas, and youíll send in your receipts when youíre done.

DeVorkin:

Iíll eventually do that, but the Smithsonian sees none of that. I still have to go through PeopleSoft to get an authorization.

Latham:

And then fiscal had to approve that the funds are actually done. See, it used to be we could just buy tickets, and the next day, you went. Now it takes a week and a half, two weeks just to get all the processes done.

DeVorkin:

Thatís right. It was just hilarious for no-cost travel to the Smithsonian. Itís extraordinary.

Latham:

Itís much harder to do things now for some reasons, but for other reasons, so much easier. This whole computer revolution and the way we work has completely changed. But some things have gotten much more difficult.

DeVorkin:

I can tell. You already identified the CCD as revolutionary technology. How did you first start hearing about the CCD? Was it something that you had hoped to exist before it actually happened? Was it a surprise when it came on?

Latham:

No, I think, that knowledge probably came with John Geary. I interviewed a lot of people, six or seven people, for that job, looking for somebody that would lead detector development at SAO, which he has done admirably now for 30 years. Part of the interviewing process was to discuss the future of detector technology, so that was part of the discussions. But we also talked about CIDs and other technologies. Charge-induced transfer.

DeVorkin:

Iíve never even heard of those.

Latham:

It turns out they have not come along like CCDs, perhaps because they are not so well suited for handheld cameras.

DeVorkin:

That made a big difference, of course. Weíve been following the history of the Hubble Space Telescope and its transition, especially the wide-field planetary camera, when CCDs were brought on. Were you working with CCDs by then?

Latham:

By í76 or í77, I guess.

DeVorkin:

Right.

Latham:

Because when we brought John Geary in, that was one of his areas of responsibility. But there was some development where at SAO, Herb Gursky was insistent that we had to move to CCD technology because he recognized it as the future. Nobody really argued with him, thatís for sure. He had a graduate student that was working on building electronics for cameras, Bob Leach. You can still buy Leach cameras. Heís at San Diego State. Bob Leach is the chap that Herb wanted to hire permanently instead of John Huchra. Fortunately, I convinced him otherwise.

DeVorkin:

Fortunately?

Latham:

Fortunately, yes. Bob Leach wouldnít have had anywhere near the impact Huchra has had. Come on. No way.

DeVorkin:

Yes, I donít know.

Latham:

I mean, Bob has always been an instrument guy, and Huchraís one of the most cited astronomers in the world.

DeVorkin:

Your second-most cited paper, by the way, is the ďSurvey of Galaxy Redshifts: Large-Scale Space Distribution.Ē Thatís Davis, Huchra, Latham, and Tonry, 1982.[14] You have virtually no paper in here with Margaret, I believe.

Latham:

Only the mysterious one with Tim Beers.[15] I never understood why she put me on that paper until later. She was buying me off.

DeVorkin:

She works that way?

Latham:

Yes. That way I would not have to be an author on the famous large-scale structure papers. Itís very important for Margaret that her advancement was clearly on her own merit. You know she doesnít talk to John, and hasnít for more than ten years.

DeVorkin:

Yes. You know, when I was designing the gallery, and thereís that one picture of them working together, they were no longer working together at all. But I said, ďDamn it, Iím going to put that in there still.Ē First of all itís a good picture. Second of all, I want them together.

Latham:

Why not? Itís history.

DeVorkin:

The other thing that I was going to do was get you and the instrument in there. I canít remember where I got that picture. Maybe I got it from you?

Latham:

You got it from me. Owen took that picture.

DeVorkin:

Thatís great. Because my whole point was to show the relationship of the observer to the machine and how it changed. In this case, of course, I understand when it was really operating, nobody was standing in there; it was all remote. But this had the chance of having somebody in it.

Latham:

Well, not at the beginning. Before we got the intensified TV guiders, we had to run out there all the time. But that didnít last but a few months. One of the most important parts of that instrumentation development was the remote viewing and TV guiding.

DeVorkin:

Exactly.

Latham:

It wouldíve taken all kinds of room. I like the idea.

DeVorkin:

Iíd like to be able to walk around it. But anyway, thatís another story. So you didnít have much contact with the central Smithsonian?

Latham:

I had essentially none.

DeVorkin:

Should we talk any more about your associate directorship? Or is there anything remaining in your career that, we should be aware of so we can come back to you and develop it further sometime?

Latham:

Yes, the future. [Chuckles]

DeVorkin:

The future will happen, and we can come and talk to you again. Is it Kepler that is most exciting to you at this point?

Latham:

Yes, thatís what Iím putting effort into. The one capability that we donít have as a country is spectroscopic follow-ups of candidates for Earth-like planets because we donít have good enough velocity precision to get an orbit for something the size of the Earth, pulling on something the size of the Sun. The orbital motion of the Sun is nine centimeters per second in response to the pull. The state of the art for most observations these days is three to five meters per second. So thatís more than an order of magnitude cruder than you need to see something the size of the Earth.

DeVorkin:

How do you envision solving that problem?

Latham:

Technology.

DeVorkin:

What kind?

Latham:

Our friends in Geneva have pioneered the next generation of instrument. Itís in operation. Itís came into operation in the last year and a half on a dedicated telescope in Chile at La Silla with the European Southern Observatory. Itís called HARPS. They are now achieving a performance at the level of better than 50 centimeters per second. Itís not nine, but itís clearly better than a meter per second. The iodine cell on high res is presently limited to a meter per second. Well, they claim that. They canít, really. The best that Iíve seen that theyíve done is two or three meters per second.

DeVorkin:

Still, that sounded like science fiction not so long ago.

Latham:

Itís pretty damn good, but I think that theyíre reaching the limits of the stability of the high res spectrograph and the iodine technique on that.

DeVorkin:

Does this use some sort of an image feed to a stable instrument thatís completely isolated?

Latham:

The HARPS uses a fiber feed, but the main thing is the instrument was designed for ultra-stability from the beginning. The measured temperature stability on the main optical element, the diffraction grating, the echelle grating, is one or two milli-Kelvin over weeks. Thatís achieved by having an outer room that is controlled to a couple of tenths of a degree centigrade, and then the spectrograph itself is in a vacuum chamber, which is temperature-controlled. The optical design is optimized for stability, like pupil design and so on. This is the state of the art, and maybe can be made even better. The problem is for Kepler is itís [HARPS] in the Southern Hemisphere. The Kepler field is at plus-45 degrees. There is no capability for this kind of velocity precision in the North. Now, I donít think weíre going to achieve nine centimeters per second. We wonít be able to see an Earth-sized planet, Earth-mass planet in a one-year orbit. But we can push towards that by almost an order of magnitude compared to the present state of the art. That is something Iíve been working on for the last six months.

DeVorkin:

What is your part of it? Youíre developing this as a Northern Hemisphere?

Latham:

Mostly, itís been political so far. I have negotiated collaboration with our Swiss friends. They have agreed enthusiastically to work with us to build a copy, maybe even a slightly better version, of HARPS in the Northern Hemisphere. The straw man is that itís going to be on the MMT, although it might not end up being on the MMT. There are a lot of users at the MMT, and theyíre unhappy about somebody coming in with an instrument thatís going to demand 25 or 50 nights a year.

DeVorkin:

Thatís a lot of telescope time.

Latham:

Yes. The amazing thing is that it looks like weíre going to get Harvard to fund this. We do not have a definite final commitment, but weíre hoping to get that. This is almost $12 million now. Not Smithsonian money. Harvard money. In some ways, Harvard money is the best kind because there are no strings attached. You get a job, you go do it. Thatís the good news. The bad news is once they decide how much theyíre going to give you, thatís all you get. Period. So you better be right with your estimates up front. So my goal is to have HARPS in operation soon after the launch of Kepler — a machine that will allow us to derive the mass of the, Earth-like things that weíre detecting more or less. So maybe itíll be two or three times the mass of the Earth. Maybe itíll be in a three-month orbit around a K dwarf, which is cooler, and therefore water is liquid closer in with a shorter period.

DeVorkin:

Sure. Su Shu Huangís habitable light zones, I remember how it changed, yes.

Latham:

Weíre going to push an order of magnitude better, I hope, in the velocity precision that we can achieve on the stars that are as faint as the best Kepler targets. See, thatís the other problem. You need a lot more photons, and this sensitivity penalty that you pay with the iodine that I mentioned earlier becomes critical. You just canít do 20-centimeter-per-second velocities with a ten-meter Keck telescope with the iodine technology. You just canít do it.

DeVorkin:

Something like OWL.

Latham:

Youíre no dummy. So thereís a progression here. This is an area that is going to continue to blossom, extra solar planets. If we ever want to do true Earths, things at the centimeter-per-second level, we need those photons. Youíll only get those with the really giant telescopes. So thatís the long-range vision, but the step towards that long-range vision is this next step with Harvard support.

DeVorkin:

And these steps are needed. Thinking of the future, how do you know what is the right size to take?

Latham:

Tough call. I think this is the right-sized step because it is intimately connected with Kepler and so you have an immediate scientific goal. Therefore, you can convince people that this is the right thing to do; you can convince donors that they want to be part of the confirmation of the first Earth-like planet in a habitable zone.

DeVorkin:

Yes. So itís a gamble. It canít be so big that you canít get any science out of it for a long time.

Latham:

Right.

DeVorkin:

But itís got to be enough so that you can get some science and you make progress.

Latham:

Right.

DeVorkin:

Itís an interesting equation. Do people sit around and speculate about this? That there should be a certain kind of a model that works for technological things?

Latham:

You mean the Thomas Kuhns of the world?

DeVorkin:

Yes.

Latham:

Iím not aware of anything like that.

DeVorkin:

Thereís this whole question of a technological curve.

Latham:

Iíd say it depends. In certain areas, youíve got to go in reasonable steps, like the computer industry. Except maybe all of a sudden, youíre going to have this breakthrough that uses a completely new technology that enables the several orders of magnitude. Who knows?

DeVorkin:

Can you envision what that breakthrough would be?

Latham:

In astronomy? No, not in this field. I think we have to go by steps. One of the problems is that we are now beginning to run into the limits set by stars themselves. You get velocity oscillations and jitter in the atmospheres of stars, and we see that already at the 50-centimeter-per-second level and a meter-per-second level. Itís going to get harder and harder as you try to get down to better and better velocity precision, and we may simply not be able to ever see Earth simply because stars are not stable enough.

DeVorkin:

Youíve got to integrate for longer amounts of time?

Latham:

Do lots more observations. Youíve got to sample all the oscillations of the star and take them out to see the orbital motion.

DeVorkin:

Exactly. Itís a whole new area of science fiction in my mind from what I remember, but itís extraordinary. Let me ask you about another stepwise sequential project that, of course, you were intimately involved in. Going back to the large-scale structure project, the CfA Survey. That, to my knowledge, was the first large-slice radial velocity survey. Am I right about that?

Latham:

Yes, there had been surveys that gave strong hints that this was an important thing to do.

DeVorkin:

Right, the deep pencil surveys and things like that.

Latham:

For example, in catalogs that had been drawn together of velocities from here and there. An Eastern European, Jan Eimasto, had noticed that there seemed to be structures in the way the redshifts mapped out the distances to galaxies. I think I give him credit for the first coherent proposal, that there would be voids and walls and stuff. He gave papers at conferences that Huchra went to and Davis went to. This, I think, kind of energized them to get going and actually do the next step, which is to do a proper wide-angle survey.

DeVorkin:

That does sound familiar. Iíll look that up. But in the case of the CfA Survey, were you around when Valerie de Lapparent did this?

Latham:

Oh, certainly. She was the right person in the right place at the right time, but she wasnít anything special.

DeVorkin:

Interesting statement. What does that mean?

Latham:

What have you seen from Valerie since then?

DeVorkin:

Nothing.

Latham:

She was handed a plum.

DeVorkin:

So this is not like the case of Jocelyn Bell, letís say, who was excluded.

Latham:

Quite the opposite. Hereís an interesting question: Would it have happened if she was male? Valerie. Margaret chose her.

DeVorkin:

Chose her specifically because she knew she wouldnít go anywhere?

Latham:

No. My guess is that part of the choice of Valerie as the graduate student to be involved in this is that she was a woman.

DeVorkin:

Let me now ask about the follow-on to the CfA Survey. Can you rightly say that the CfA Survey and the results as announced started something of a gold rush?

Latham:

Yes.

DeVorkin:

Thatís good. The Sloan Survey. There are various other things, too.

Latham:

The Australian surveys. The Southern Sky Survey, which we organized with Nico Da Costa.

DeVorkin:

Right, all of these surveys. Where has Margaret been in this whole time? In retrospect, was that too much of a leap? Would buying in on the Sloan or cooperating with other institutions made more sense? Because the AAT stuff is just spectacular.

Latham:

I have an opinion, but youíre not going to hear it. SAO has not kept up in this field.

DeVorkin:

Can you tell me why the Hectospec took longer than expected to build?

Latham:

Well, I wasnít really part of that effort. That was really Dan Fabricantís project. Supported, I guess, by Margaret, although again, I wasnít part of those deliberations. So I donít even know what the schedule was or whether it was behind.

DeVorkin:

Is it possible Irwin got into the mix with his other priorities, such as the sub millimeter instrument?

Latham:

The worst mistake SAO has made in recent history.

DeVorkin:

To be continued, then. Does that sound okay?

Latham:

Yes. We never shouldíve done that submillimeter project. I had felt so at the time; I expressed my opinion since I was part of management at that point. I didnít pull any punches in expressing my opinion, but they went ahead anyway.

DeVorkin:

The Smithsonian put a lot of money into it.

Latham:

And whatís it got out of it? Almost nothing. So far. Maybe thatíll change.

DeVorkin:

One final project: VERITAS. Any thoughts about VERITAS?

Latham:

Herb wanted to fire Trevor, too.

DeVorkin:

No kidding?

Latham:

He even tried to make it happen by ordering Trevor what he was to do, which is not gamma-ray astronomy anymore, but CCD imaging. It was pretty clear to me that that wasnít working. So when I took over as associate director, I assured Trevor that I would support him for any money that he could raise on his own. He could go back to his beloved gamma-ray astronomy, and Iíd support him as much as I could. He didnít have to do anymore CCD photometry.

DeVorkin:

Why would Gursky not want to support gamma-ray?

Latham:

I guess he thought it wasnít going anywhere. I donít know.

DeVorkin:

Your take on VERITAS so far?

Latham:

Itís the natural evolution of what Trevorís always wanted to do in his career. Is it going to go anywhere scientifically? I donít know. The ground rules that I had with Trevor for the eight years that I was associate director were that if he could find resources, if he convinced DOE or somebody else to pay for his gamma-ray astronomy, thatís fine. He had a home at Mount Hopkins, and weíd support him with the infrastructure. He took it forward, and as far as I can see, he is viewed as one of the fathers of the field. If the next logical step in the field is VERITAS and they can find people to fund it and it doesnít siphon off a lot of SAO resources, itís okay with me.

DeVorkin:

Gamma-ray astronomy has become more important.

Latham:

But not because of ground-based.

DeVorkin:

No, in Compton. Is there a question that the discriminating techniques between gamma-rays and cosmic rays, you know, looking at the Ceren Kov patterns and something like that, that this is maybe overly ambitious?

Latham:

Iím not in a good position to have an opinion on that. Itís not a field that I would personally choose to work in. I donít see the excitement of it.

DeVorkin:

Could it be the same sort of thing as, ďItís a long-shotĒ?

Latham:

Well, maybe.

DeVorkin:

As you said, when you chose the extra solar planet stuff, going in with Tsevi, thatís a long-shot. You didnít even know that the candidates would exist.

Latham:

Yes, but it sounded like fun, and we had the right equipment to do that job.

DeVorkin:

And you gave Trevor the freedom to follow his dream.

Latham:

If thatís what he really desperately wants to do, thatís almost more important than anything else because people have got to desperately want to do something to be successful, usually.

DeVorkin:

So how is that different than Shapiroís submilliter array?

Latham:

I saw it drawing off the Smithsonian resources that I thought could be better used. Thatís what itís done.

DeVorkin:

Oh, yes. Big time.

Latham:

Capital equipment, and most important, positions. Positions have been diverted. People have been hired for the sub millimeter effort, and we havenít hired rising superstars to replace the most productive people who were hired during George Fieldís tenure and before. Our most successful SAO scientists are Gray,[16] and thereís no obvious next generation that is coming up in Shapiroís tenure as Director. I think part of the explanation for that is because the positions, as they became available, were used for his pet project.

DeVorkin:

Do you begrudge him the project? I mean, does he possess the same passion as Trevor Weekes?

Latham:

Yes, maybe. But weíre competing for the same resources. The rules with Trevor were, as long as weíre not competing for the same resources, itís okay.

DeVorkin:

So itís the expense and what itís doing to the institution.

Latham:

Yes. The investment made in optical astronomy during Irwinís directorship was not what it couldíve been, and was begrudging. Evidence for that would be new hires. He has had essentially no new hires for almost ten years there in Optical and Infrared Astronomy. Now, we had fresh, new people coming through. We were very popular — the most popular division for the CfA post-docs. People came from all over the world and the country. Iíd be very interested to look at the numbers, but I bet you we had more than our share by most measures. They wanted to come in; they wanted to be part of the action. But they come and go, and after three years, theyíre gone.

DeVorkin:

Andrea Dupree is one of your senior members

Latham:

Yes. Sheís in Solar and Stellar Physics. Solar, Stellar, and Planetary, itís now called. Kept the same three letters, but the ďPĒ changed to ďPlanetaryĒ because the Planetary Division was absorbed into SSP.

DeVorkin:

Now that youíre searching for extra solar planets, do you have the sort of turf fights where the planetary people say, ďNo, thatís our bailiwickĒ? Thatís never happened?

Latham:

Maybe itís happened, but we ignore them.

DeVorkin:

Thereís a lot of autonomy within the divisions?

Latham:

Sure. You do what you want if you have tenured position and people are willing to support you with resources. If you write proposals to NASA and they give you money, you get to do it.

DeVorkin:

Thatís the value of having an outside source of support.

Latham:

You see, for a long time, my only source of resources was Smithsonian federal funds. But after Owen and I decided weíd been teaching long enough, I decided it was time to look for new resources, so I wrote three NASA proposals thinking maybe one of them would come through. Well, all three of them came through, so now I have NASA support.

DeVorkin:

You got three NASA proposals?

Latham:

Yes. One of the projects that I became part of, FAME, got canceled, so Iím really only active in two.

DeVorkin:

What were you doing on FAME?

Latham:

Irwin asked me to be the Smithsonian project scientist. I wrote major sections of the scientific requirements document, and was always involved in the presentations of the science to be done with FAME at the various reviews. It was actually something that I was quite excited about. It would have been a blockbuster for star formation region work, for example. I went to all of the technical interchange meetings, so I was doing that once a month. Involved in the weekly telecoms. So that was half-time for me for two years.

DeVorkin:

Wow. Thatís a lot of work.

Latham:

Yes, it was. Didnít come to anything because it got canceled.

DeVorkin:

Why, from your perspective?

Latham:

NASA headquarters chose to withdraw its support of the FAME mission because of lack of confidence in the potential for success of the mission. The reasons they gave were non-availability of the CCDs because there were long delays in the delivery of suitable CCDs, cost overruns, and schedule delays. A possible translation of those last two items would be poor management.

DeVorkin:

I was going to ask.

Latham:

That was at the bottom of it. They didnít trust Ken Johnstonís ability to pull it off.

DeVorkin:

Are you willing to say it was justified or unjustified?

Latham:

It was a good decision.

DeVorkin:

Why?

Latham:

FAME couldnít possibly have succeeded the way it was being run. Its budget was nominally $180 million. The Kepler budget is $440 million right now. The Kepler budgetís about right for an instrument that is a lot simpler than FAME would have had to be. It couldnít be done for the price.

DeVorkin:

Was that a calculated risk on Johnstonís part?

Latham:

Well, Ken was a very optimistic guy, and he was overly optimistic, I think. Terrific mission scientifically. Got very high grades on the scientific presentations, which is where I was focusing my effort intentionally.

DeVorkin:

Yes, it was really great. I was really bummed out. Of course, I always wondered why the Navy didnít support it itself.

Latham:

Ken was trying to parlay some of that, but they didnít have $200 million to put into it.

DeVorkin:

Right. The Naval Observatory is hurting right now, so Iím worried about it, for my own purposes. [Chuckles] Anyway, thanks so much. This has been a terrific session.

[1] Haemonetics Corp. Braintree, MA 02184

[2] Can you describe one or even more of them? My favorite is an ad for OSSA. I am at a speed in a dirt trade special test. There is nothing fake.

[3] "getting offĒ means falling off the MC.

[4] Astronomy Data Service

[5] Hayes, D.S. and D. Latham, ďA rediscussion of the atmospheric extinction and the absolute spectra-energy distribution of VEGA,Ē APJ 197 (1975), 593-601

[6] Davis and Latham, ďPhoton-counting Reticon Detector,Ē Instrumentation in Astronomy III (SPIE, 1979) pp 71-81

[7] Advances in Instrumentation For Stellar Photometry,Ē Dudley Observatory Report, 1975 (A.G.D. Philip and D.S. Hayes, eds)

[8] BAAS 21 (1989), 1224

[9] Nature 339 (May 4, 1989), 38-40

[10] "Search for Nanosecond Optical PulsesÖ.Ē APJ 613 (2004), 1270H

[11] Goldreich and Sari ďEccentricity Evolution for Planets in Gaseans Disks,Ē APJ 585 (2003) 1024-1037 (see refs therein for earlier papers)

[12] Launched March 7, 2009

[13] Hayes and Latham APJ 197 (1974), 593-601

[14] APJ 254 pt. 1 (Feb 15, 1982), 423-445

[15] APJ 283 (Aug 1, 1984), 33-49

[16] as in ďoldĒ