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Interview of John C. Mather by David Zierler on May 26, 2020,Niels Bohr Library & Archives, American Institute of Physics,College Park, MD USA,www.aip.org/history-programs/niels-bohr-library/oral-histories/XXXX
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In this interview, David Zierler, Oral Historian for AIP, interviews John Mather, senior astrophysicist at NASA Goddard Space Flight Center and senior project scientist for the James Webb Space Telescope. Mather recounts his childhood in rural New Jersey and the benefits of pursuing a physics education at a small school like Swarthmore. He discusses his research at Berkeley and the value of pursuing dissertation research based on an unsuccessful research experiment. Mather describes his work at the Goddard Institute for Space Studies and the decisions that led to his participation at NASA in the COBE satellite team that measured the heat radiation of the Big Bang. Mather narrates what it was like to learn he won the Nobel Prize for this work, and describes his current work and excitement about the James Webb Telescope.
This is David Zierler, oral historian for the American Institute of Physics. It is May 26th, 2020. It is my great pleasure to be here with Dr. John Mather. John, thank you so much for being with me today.
Happy to join you!
To start, please tell me your title and institutional affiliation, or affiliations, as it were.
I am at NASA Goddard Space Flight Center, primarily. I have a couple of titles there. One is senior astrophysicist. One is senior project scientist for the James Webb Space Telescope. I am also a rather inactive but officially a member of the faculty at University of Maryland. I'm what they call a College Park Professor, which is a kind of honorary version of an adjunct professor. I thought when I accepted that position that I was going to be having graduate students and visiting the university, and then the James Webb Telescope turned up. So I didn't actually get to do very much with that, but I'm still happy to use my connections when I can.
Let’s take it right back to the beginning. I want to ask you first a little bit about your family background. James Cromwell Mather, right? It seems like you might have a long lineage that goes back in this country.
Yeah. So John Cromwell Mather, yeah. There are a lot of Mathers that are famous in this country, and my family branch is not one of them, as far as I know.
We're not connected, that I'm aware of, to the ones from Massachusetts, or even the ones from Ohio. So I don’t know. So, I'm not aware of any connections to other famous Mathers.
What about any famous Cromwells?
Maybe. Maybe not. The genealogy has not been done to find out if I'm connected to the famous British ones. I did have an umpty great uncle whose name was Oliver Cromwell.
But I have no idea. Nobody knows. On the other hand, just a little story—when we got to Ireland once, and we rented a car, they looked at my passport, and it says John Cromwell Mather. And of course, when you drive around Ireland, every village has a sign that says Cromwell’s army came to this place and killed a lot of people.
So it’s interesting to have your potential family member remembered so widely.
Where are your parents from?
They grew up in the Midwest. My dad was from Indiana, and my mother grew up in Illinois, just in the suburbs of Chicago. But my dad was actually born in Portuguese East Africa and spent his first 9 years in Southern Rhodesia. My grandfather was an educator and Protestant missionary there. But I hardly knew him; he died shortly after retiring back to the US.
Where did they meet?
I think they met at the University of Wisconsin. I'm not quite sure. Maybe before that.
They were both pursuing undergraduate degrees at Wisconsin?
No, my mother had already graduated by then, so maybe they met before. My mother went to Miami University in Ohio, and my dad went to several schools as an undergraduate—Lafayette College, and then he went to Purdue, for his undergraduate degree. He went to Maryland, here, to get a master’s degree, in agriculture, in dairy science. Then he was in Wisconsin to get his doctorate, in Madison, Wisconsin, in animal husbandry. So he was a scientist. He was a statistician, primarily, studying dairy cows. And my mother’s father was a bacteriologist. A long time ago, I looked up his thesis. He did a thesis in 1922, which is the same year my mother was born. He did his thesis at Johns Hopkins University, and it was about immunology of what happens if you put blood from a guinea pig into a rat, or vice versa. And of course bad things happen.
I wonder, growing up, if you felt that science was sort of the family business?
Well, I didn't really know my grandfather well, but yes, I sort of was aware. Because we lived, when I was a little kid—well, for a long time, we lived in the agricultural research center of Rutgers University, in northwestern New Jersey, near Sussex.
Now, you were born in Roanoke?
I was born in Roanoke. When I was about a year old, my parents moved to New Jersey. I guess my dad had just been a postdoc or something at Virginia Tech, what they call it now. So he got his permanent job at Rutgers. It was a remarkably isolated place. Sussex County was pretty nearly empty compared to what it is now. There were 50,000 cows and 50,000 people in the county. We lived on the farm, which was about a mile downhill from the Appalachian Trail. So it was really country. And if you're a kid and you live at the top of the hill, you really don’t want to go anywhere, because it’s a long walk back uphill.
Even with a bicycle, it’s a long walk back uphill. So it was pretty isolated. I had lots of time to read and think, and the public library bookmobile started coming around when I was maybe sixth grade or something like that. So I got all the science books you could get from the public library bookmobile. Anyway, what I remember isn’t very clear, but I do sort of have a memory of when I was, hmm, kindergarten or first grade—probably first grade—being aware of the idea of infinity, and covering a page with zeroes to sort of experience that you cannot get the largest number. There is no such thing. I knew that.
You came up with the idea of infinity by yourself? Somebody taught you the concept of infinity?
No, no. Somehow I had read about it. I'm sure I had read about it. In fact, I would say that’s true of almost everything I've ever done; I thought I thought of something by myself and of course you find out later, somebody did that before. Including the projects that I'm working on now, too. By third grade, we had been down to the Museum of Natural History in New York City at least once, maybe more than once, seen the planetarium show, seen the bones. That’s how I remember it. Can’t quite be right. But at some point maybe I was 11 or so, maybe we went down and saw the planetarium show and heard about Mars, which was going to get really close. My dad went to Sears Roebuck and bought a tiny telescope and you couldn't see a thing with it. Anyway, I was really interested in reading everything I could get, beginning around third grade. I do remember that my parents read out loud from biographies of Darwin and Galileo, and I had a book about George Washington Carver, a great Black scientist who studied peanuts. Anyway, I was aware that science was a cool thing, and that also it was so important that people wouldn't like you when you did it, sometimes, that I used to have even nightmares occasionally of teaching evolution in the schools and having to defend that.
Anyway, so I sort of bought into the controversy and the excitement of science when I was quite young. So, read everything I could. By around fourth grade, I was the science kid in my class. That’s what I spent my time doing—reading, and thinking. And I could do my science projects. So yeah.
How big was your school?
It was a consolidated school, so grades kindergarten through eight had about 600 people.
And then you stayed in the same area for high school?
Yeah, sort of. The family knew that the local high school wasn’t great. We knew, however, that if we moved to another house that belonged to the ag center, we would be in a different school district, so I would be able to go to the school in the big city, which is 5,000 people—Newton, New Jersey. So that was a much bigger school and had a good science program. About 1,200 students. So that school served half the county. So we did move, and so it was about an hour’s bus ride to get to school from there. I even had a good buddy that rode on the school bus with me. His father also worked for the ag center. And I still am in touch with that guy. He’s a really sweet and bright guy.
Anyway, by fifth grade, I think I had a radio kit from Heathkit to make a short wave radio. I think after sixth grade, I went away to summer camp—a local one, just day camp—to hear about science from the high school biology teacher. After seventh grade, my parents found a summer camp in the Poconos where they said they had a science program. Well, they didn't, really, but I went. So I was entering science fairs and doing a lot of things that there were to do, if you were a kid. So I got to high school, ninth grade, biology class. My ninth grade biology project was feeding baby rats. I had eight of them. They lived in cages under the kitchen table. And so my father showed me how to set up an experiment with them.
Your mom tolerated this? Rats under the kitchen table?
Yeah, they were a little smelly, but yeah. It wasn’t a big house, so what else are you gonna do?
Anyway, so my dad showed me how to design an experiment with a nested Graeco-Latin square for statistics, so I learned statistics in ninth grade, at least an elementary form of the old fashioned that you would have done, with analysis of variance. So I learned that some kinds of food are better for you than others and that corn flakes is a completely inadequate source of food. Never did like ‘em, anyway.
So anyway, that was ninth grade. Ninth grade biology wasn’t so easy for me, though, because of course I wasn’t that keen on memorizing things, and there was an awful lot of memory required to really learn biology. Tenth grade, chemistry, and tenth grade also included geometry class. So by then I had already decided it was time for me to learn a lot more math than my friends had already learned, because I wanted to understand radios. And I got this handbook for radio amateurs from the AARL. You might remember this. The Radio Amateur’s Handbook, I guess. Anyway, I studied everything there was in this book about how to design electronic circuits. And, well, you need to know math to do that. So OK, better learn some.
So then after tenth grade, my parents somehow found this out—there was a place I could go take a summer course in math. NSF was sponsoring these things, and this was at the Assumption College in Worcester, Massachusetts. So I got to go there and rub shoulders with astonishingly smart young people, a large fraction of whom were from Bronx High School of Science, a real powerhouse in those days. I think they're not quite so much of a leader now as they were then, but that was a remarkable experience. I saw that there were kids that were far, far, far ahead of me in math. They knew stuff I had never dreamed of.
Did you have to take an entrance exam for this program?
I don’t think so. Anyway, it was still exciting to learn what they had to teach us. I learned about infinities and about various kinds of algebras and rings and sets and commutativity of operators and things like that in tenth grade. So this was really cool, but I could also see there was no way I was ever going to beat these kids at math. So, OK, I liked physics anyway, so after 11th grade—I did have physics in high school—I had a summer course in physics at Cornell, which was absolutely fabulous. Really bright young people as teachers for us, and I got to play in the lab with Geiger counters and interferometric equipment. You could see the Young’s double-slit experiment and start to really get into this. And I learned relativity and a little quantum mechanics in 11th grade, summer. So that was super. This is something I really, really, really want to do. This is the greatest, most exciting thing you could ever imagine finding to work on. So this is me. I'm going to do this.
In the summer of tenth grade, when you determined that you had reached your limitations in math, was that because of how abstract math can get at a certain level? Was that part of it?
No, it was much more that these kids were just ahead of me. They were also terrors about chess. They could beat you with their eyes closed.
Yeah, OK, well, I'm not good at chess. So this is a whole other category of people. And besides, I liked physics. So as it turned out, when I got to a summer course at Cornell, the other kids were not ahead of me. They were more or less with me. OK, I can do this. I can be good at this.
Who were the instructors in the Cornell program? Were they Cornell professors?
Yeah, they were Cornell professors. I don’t remember all their names. There was a graduate student named Michael Nieto, who was super wonderful and exciting. I liked him a lot. Michael Nieto, N-I-E-T-O. But here I am in this ancient laboratory of wonderful tools to play with, equipment to play with, and so I'm going to do this. So somewhere along the way—I don’t remember if it was 11th grade of 12th grade—there was a statewide quiz on physics, and I aced it. I was the number one winner in New Jersey.
So I was pretty pleased with that. OK, maybe I really do have a chance to keep on going on this, and do something. Somewhere along there was also a nationwide math contest. I don’t remember everything about it, but I think I was number seven in New Jersey. So OK, so maybe these kids from New York can beat me, but I'm not too bad. So anyway, then time to go to college. So OK.
John, when you're thinking about college, are you thinking specifically about physics programs that you want to work in?
Oh, yeah. Physics. I forgot to mention that in senior year of high school, the science program offered us advanced chemistry, but I thought the teacher had gone senile, so I think I'm going to spend my time doing something else. I got my father’s calculus book, and I did all the problems in it. So when I got to college, I found that I had aced that one, too. I knew a lot more than the people who took advanced placement math. So OK, this really can work. I'm pretty good at this. Have ambition, have confidence that this is going to pay off. So I did apply to college, and I think I applied to six and got into all six. Not quite sure what the list was, but at MIT and Harvard and Swarthmore, where I went, and Rutgers, where my dad was a professor, and probably Caltech and Chicago. Those might have been the six, but I'm not sure. Anyway, I got in all six.
The decision to go to Swarthmore is an interesting one, because clearly you have most of the major powerhouse departments there in that list. So Swarthmore—a clear difference there is that it’s a small school, and it’s a primarily undergraduate school. So I'm curious what your decision-making was there.
Well, a couple of things. One was, I visited the big city—Boston, Harvard and MIT—this is pretty intimidating for a kid from the country. Besides, I was pretty aware that they were going to be filled with the very best talent from New York, so I’d have plenty of competition. I didn't know where I stood in the world. So we visited Swarthmore College, and I got a very personal tour and attention from people, and it just felt small and comfortable. And so, well, OK, this would be a good place to do my physics and math and astronomy. And so it was.
On the other hand, after I had been there for about two or three weeks, I thought, “Where are the other physics students? Am I the only one here?” Physics I was a class where I knew everything they were teaching already. What am I going to do now? So I went around—and after I couldn't sleep for several nights, I thought, “I’d better ask for help.” So I asked the faculty, “What do I do now?” They said, “Well, would you like to try jumping ahead?” And so they handed me the sophomore physics book for first semester. “Well, take this and see what you can do with it.” So I took it home over Christmas, and I did all the problems, and I aced the exam when I got back. Oh, OK, I can do this too. I beat the other kids that were taking the class, and I just did it from the book. So OK, twice I can do something from a book and do really well. So, OK, have courage. So I jumped ahead and I took sophomore physics in the freshman year. That was actually harder than I expected, because I had no experience yet with vector calculus and electricity and magnetism.
Uh-oh. We cut out.
—yeah, you can do a lot of hard things. Might as well try.
John, hang on a second. We cut out for a second there. The last thing I heard you say was it was harder than I expected.
Yeah. So I don’t think I said anything important after that—
—but basically I concluded, “Yeah, I can do hard things, and I can do this. So have courage. Try hard things.”
I want to ask you about the faculty at Swarthmore. You clearly wouldn't have known this at the time, but looking back, I'm curious—perhaps one of the benefits of going to a place like Caltech or Harvard is that the professors are engaged in research in addition to teaching. Was that the case at Swarthmore, or were the professors there mostly engaged in teaching?
They were mostly engaged in teaching. In fact, one of the promises made by the college was, “You will not be taught by graduate students. You will be taught by professors.” So they did that.
And on balance, would you say that that was advantageous for your education?
It’s hard to know. To tell the truth, I don’t learn well from lectures. I do well from doing problems. And college had an honors program for junior and senior years, and I thought, “OK, I'm in that.” So the faculty were thinking, “Well, this is so much of an honors program, the students will just propel themselves.” Well, students came back to them and said, “No, this doesn't work. You gotta give us some help. You gotta show us what to do. You gotta tell us to do these problems. Then we'll come together.” And that worked. Anyway, so the working through things yourself is a model that I like. Anyway, it was an interesting place to be. I took advantage of what I knew and took extra math and extra astronomy, as compared with really taking full advantage of the liberal arts college that it was.
Did you have summer internships in physics and astronomy related areas?
Let’s see. Not really. I think one summer at Swarthmore I had somebody who gave me some time, and I tried to learn Fortran to do a molecular orbitals calculation, but it was when the computer was pretty rudimentary. It was an IBM 1620 with a clock speed in the kilohertz range. So, I didn't get very far. But I did start to learn Fortran in the summer. That was one.
So anyway, finished up college with highest honors. As it happened, the honors exams included David Wilkinson from Princeton, who was one of the examiners. I don’t really remember much of the questions, but it was interesting to go through them. One that still sticks in my mind—somebody asked, “What is a daily observable effect of relativity?” And the answer I would have given was magnetism, because a moving charge has got a magnetic field, and we have all of that from relativity. So I was sort of aware of that.
I was also interested in a little bit of quantum statistics. And this is sort of the foolish naiveté of a young person, to think, “I'm going to build a correlator and measure the correlation of photons coming from two photomultiplier tubes.” Well, it was hopelessly difficult for one undergraduate with a soldering iron. But I got to read about it and think about it. And this is when the Hanbury Brown and Twiss correlation interferometer was in public, and it was a huge surprise for people. So OK, I'll think about that. So anyway, that was college. I really liked college.
John, how well-formed was your identity as a physicist by the end of your college years? In other words, when you were thinking about graduate programs to apply to, were you thinking specifically in terms of the kinds of physics that you wanted to specialize in? Did you have well-formed ideas about theory and experimentation and cosmology? Or it was all still wide open for you?
Yeah, it was pretty wide open for me. In fact, there’s a story there. I applied for graduate school, and I got in where I applied. And so I chose Princeton, because that’s close by. It’s not a big jump to go there. And I went up to visit my friends there, and they said, “We don’t like it here.”
You had friends in the physics department?
Yeah, some graduate students who had been at college. So, OK, I'll go up and see them. “We don’t like it here. Why don’t we like it here? Because there are not any women.”
“We have to go travel a great distance to find a future partner.” They kept saying, “If you're not married, don’t come here.” “Oh, man.”
I've heard it said that in the physics department building, they didn't even have women’s bathrooms until a certain point later on.
I wouldn't know, but anyway, it was a pretty off-putting place to me at the time. So I got to go off—I had a summer job at Berkeley after my senior year in college, and drove out there in a little red car with a college friend. And I worked at the Lawrence Berkeley Laboratory, with Henry Frisch—
—who was a graduate student—you might know him.
And anyway, this was really exciting. Oh, this is something—particle physics. This is the coolest thing. So Richard Feynman, he was my hero. I want to be like Richard Feynman. So I took a couple of years of courses, and I was pretty good at them, too. I want to be a theoretical physicist.
You took courses at the lab or at Caltech?
No, at Berkeley. Oh, I forgot to tell you the story. After the summer job, I said, “Can I stay? I want to transfer here from Princeton.” So they said, “OK.”
So I went to Berkeley instead of Princeton. I did well at that, too.
John, where did you interact with Feynman?
I didn't, actually. Just through his red (lecture) books. He was my hero. Be like that. At a certain point, though, I'm thinking, “What do I do for a thesis?” And I said, “I want to do that.” And they said, “Are you independently wealthy?”
Because there’s no jobs for those people. OK, no, I'm not independently wealthy. So I started asking around, faculty, “Well, what have you got that you're doing that’s interesting?” So, I came across Paul Richards and Charles Townes and they had a project to go measure the cosmic microwave background radiation, which had only been discovered a few years before that. It was discovered in ’65, and this was 1970, and I'm looking for a thesis. OK, we're going to go measure. OK, I'll try that. Because I was getting tired of just being in the library, and struggling with math problems.
Were you aware as an undergraduate at Swarthmore about this discovery in 1965, or this is all new to you at this point?
No, I was quite aware. In fact, I had read that it should be there, in a little book by Gamow—One, Two, Three…Infinity or something. I was pretty aware that there should be the Big Bang, and it should have been hot, and then there should be the heat radiation. So what’s the big deal? Why is everybody surprised? But people were surprised because they weren’t paying attention. It had been perfectly well-shown to them in 1948 that they should be looking for this, and they didn't.
So what happened in 1948?
That’s when Alpher and Herman published their paper, starting with the Big Bang idea and calculating temperature. I talked to Alpher and Herman, and they tried to persuade people to go measure it. Nobody would do it.
On the basis that it was measurable?
Yeah. I don’t know whether it was easily measurable, but it could have been done. I think it could have been done. It wasn’t that far from possible. By then, the world was filled with surplus radar equipment. And if a person really, really tried, they might have succeeded. Another story there—Joe Weber called me up many years later and said that NASA should go look for the neutrino background radiation. He burnt my ears for quite a long time about this. And he asserted that he had now been deprived of two Nobel Prizes because of gravity waves, and because when he was a young man, the people told him, “No, you cannot possibly measure this cosmic microwave background radiation.” So he didn't try. So he had a real chip on his shoulder at that time. He was a smart guy, but I thought, “I cannot bear to listen to this man any longer.” [laugh] So no, NASA did not fly a neutrino mission. There was no point in it whatever.
At any rate, so anyway, this was in—in 1965, I heard about the discovery, and I thought, “Oh, that’s interesting. No problem.” In 1970, it was still an interesting question whether it was really cosmic or not. And so my thesis project that I latched onto was to measure the spectrum of it. So the first attempt was a measurement from the ground at White Mountain. There’s a research facility at 12,000 feet in California. So I went up there with Mike Werner. He was the postdoc, and I was the graduate student, and we built ourselves a little Fabry–Pérot interferometer so we could tune in between the atmospheric water lines and see, well, what’s the temperature of that particular wavelength? It was about right. Then the next step was, OK, Paul Richards went off on his sabbatical to Britain and came back with the idea, “Well, let’s build a balloon apparatus that will carry a Michelson interferometer into the upper atmosphere.” And we would use that to measure the spectrum. So OK, so we sketched it out, and we all worked on it—me, along with David Woody, who was another graduate student with me, and another grad student who ended up in medicine. That was Norm Nishioka. And we had an engineer from the Space Science Laboratory, uphill from the campus, and that was Henry Primbsch.
Anyway, the five of us built this apparatus, and we sent it up. In late ’73, we took it to Texas. David Woody and I drove the big yellow university truck full of cryostats and equipment, all the way from Berkeley to Palestine, Texas. You ever been there, to Palestine? You know what it is?
I have not been there.
OK. Well, you know, it’s the national balloon facility for—now, NASA runs it. At the time, the National Science Foundation did it. NSF. Anyway, so we drove this apparatus down there. We launched it. And as you know, it did not work properly.
What happened? What was the problem?
Well, there were three. Two of them had to do with the electronics that don’t like to be that cold. It’s minus 70 C way up there. And the third one was—of course, you could have found those two if you had tested the apparatus at home. The third was one that you never would have guessed to try. Because the humidity is never 100% in Berkeley, but it is in Texas.
And in the evening, when you're about to launch. So here we've got this liquid helium in the cryostat. It’s boiling up. And the top of the cryostat is below the condensation temperature of water, as anything would be below the condensation temperature of water. So, water gets into the motor. There’s a little stepper motor that rotates the screw that moves the interferometer mechanism, and it gets rusty. So by the time it got up to altitude, it wouldn't turn at all. That was quick. So anyway, third reason. So our original reasoning had been, well, there are a lot of things you can’t test, and a lot of things you could be surprised about, so maybe we should just go try. And so I think that was a sound decision, because you never would have—no matter how many times you thought of testing something at Berkeley, you never would have thought of 100% humidity in Texas.
So anyway, we brought it home. I wrote my thesis about the failed project. And David Woody continued. I got out. David Woody continued. He fixed it. He made a big dry ice box of plywood and Styrofoam, to cool everything down, and sure enough, you can see clearly enough what the problem is. So he fixed it, and so it worked the next time. By then, I was a postdoc at the Goddard Institute for Space Studies in New York City, trying to become a radio astronomer. But I did go back to Texas to join the Berkeley team for the flight.
John, I want to ask, before we move on to that, about your research style and your intellectual approach beginning with your dissertation. Was your sense, looking back—was there an overall research question that you were trying to answer? Or did you see it mostly as just collecting the data and trying to make sense of whatever it was that you were going to find?
I always felt that the job of the experimenter was to measure and not to jump ahead into the—have a pre-determined theory you were supposed to test.
I'm asking specifically in terms of the narrative of the discovery in 1965, and your interest in sort of pursuing what exactly was going on.
OK. Well, my approach to this one was just really simple. I liked these people at Berkeley. I liked Paul Richards. I liked Mike Werner. I liked Charles Townes. I wanted to work on their project. So it was not just because of the idea of the measurement that we would make; it was that I liked these people. They're working on something that’s really important. I don’t know enough yet to know why it’s important, but—I trusted them. And by the way, there were some other people that I did not like at Berkeley, and I thought, “I’d never want to work with those people.” So no need to go into depth, but to me, people make the biggest difference. The conversations you will have with people, the support they will give to you, the authority they will give to you, the opportunities they will give to you. The people make more difference than the topic, practically. So that’s the way I look at it. So when they were working on this, I knew that’s important.
The other question I wanted to ask during your time at Berkeley is—you were there during a very significant time in recent American history, the late ‘60s and early 1970s. I'm curious if you were involved in the many sorts of student activities that were going on with regard to antiwar protests, civil rights, women’s rights. What was your participation or lack thereof with all of these things that were going on, on campus, during those years?
Oh my goodness. Well, I was aware of them, and they were happening all around me. And I thought, “Try not to get in the middle of this; you'll get your fingers crushed.” The protests were the most obvious sort of thing you could see, and I thought, “This is really disorganized. You can be upset and angry, but that doesn't mean anything good is going to happen.” So anyway, a lot of faculty were participating in these protests, too, including a guy—I think it was John Schwartz from the physics department, quite well-known for leading some of the activities, the antiwar parts. I thought, “Mm, OK, I don’t understand this. I certainly am not in favor of this war.” I thought it (the war) was a fraud to begin with. But I really didn't want to have to deal with the consequences of having to confront all the depth of that. So I had to go see the draft board. I was called up for military service. My number came up. And I went down for my physical exam, and I flunked the exam, as I expected I would, because I was extremely nearsighted. I knew that my eyeglass prescription was over the limit and they wouldn't take me. And I was glad of that, because I didn't really want to have to go through the real moral searching and depth of, well, if you don’t agree with this, then what do you do? That was a time when some people were going to Canada to avoid the problem.
Anyway, I didn't want to get involved in the protests, because I thought, “This is just crazy.” Protesting doesn't necessarily move the world in the direction you want to go. It was a time when Ronald Reagan was governor of California, and he got to improve his presidential prospects by acting tough. They sent a tank, an armored tank, to park at the foot of the University Boulevard, down by the Bay, and they sent helicopters to tear-gas the campus, which they did, including the hospital. OK. But news coverage was how tough is Ronald Reagan, and how great it is for us to be proud Americans. Oh, man. OK. So you can swindle all of the people some of the time. And so anyway, I had a lot to think about from that.
I'll ask a more specific question, and that is, one of the boutique protest movements that might have been relevant for your department was the influence of the Pentagon in physics research in general, which was a highly sensitive topic during the time of the Vietnam War. I'm curious if you ever thought about that specifically, as a member of the physics department.
Yeah. I was aware there was such a thing. I didn't know very much about it. I did know that my thesis advisor, Paul Richards, went to Washington quite often, and he did get money from the Navy, I think. So he had about seven different fund sources in Washington, and it was good that he did, because they all fluctuate. So if you don’t have a lot coming, there were times of scarcity. After that, the Mansfield Amendment was passed, right? Isn’t that the one that said, OK, the military cannot fund a lot of the research that they had been doing? So, well, this is trickier than it looks. I always felt everything about that was trickier than it looks. We still have issues about whether science is in service of the military as compared to in service of the public. Because how do we know—? Is there a distinction?
So eventually I had a sort of closer encounter with that in—I think it was 1970, I decided to apply for the Hertz Foundation Fellowship, which I did receive. But as part of the motivation they had, they wanted us to declare our support for the United States. Hertz was a real patriot, and he wanted scientists to help us save the country from challenge. So I thought, OK, of course I'm defending the United States, but some of the things that we have to defend against are within the United States, and the people that run away with their version of America. And the McCarthy era was not so much before that time. I was aware of Joseph McCarthy in 1953 or so, and the anti-communist scare that ran around. My mother was a school teacher. She was asked to declare loyalty to the United States, to be a school teacher of fourth graders and second graders. She was pretty upset about that. And anyway, so I thought, “This country has a lot of problems, and yes, I'm happy to defend the country, but some of the enemies are the people who claim they're our friends. So, watch out.” That was my sort of simple version of this. Nothing’s ever simple. I wasn’t thrilled that the University of California was involved in the nuclear weapons program. On the other hand, my interview for the Hertz Foundation was in Edward Teller’s kitchen. So I got to sit up there on a stool with him and think about these things all at once.
What was your reaction to meeting Teller?
Well, I kind of liked him. He was a very forceful character. I was going to be an astrophysicist, so I'm not necessarily going to be helping the Defense Department. Anyway, I do remember the question that he asked, which I couldn't answer. He wanted to know, why are the clouds arranged in rows? And then I couldn't answer, so he explained it, and it was very clear. And I thought, “Hey, that’s really interesting! This is a guy with a lot of interest in a lot of areas.” It was a long time ago.
I want to ask the last question before we move on to your time at Columbia. You described your dissertation as you were writing about a failed experiment, right? So I wonder, first of all, what’s the value in writing about a failed experiment? And what perhaps were some of the long-term lessons you took away from that experience in terms of forming your idea about how to do research, how not to do research, and how to forge ahead and not get stuck on failure?
Oh, wow. Goodness. A lot of things I drew from that. The immediate one was if you do not test it, it will not work. Very simple. And so that was a pretty good lesson to have in my heart as time went on and I got into a NASA project. Because when you are in trouble as a NASA project, people are going to say, “Well, do you really need that? Do you really need that? Do you really need that?” And, “Why don’t we take a chance? Why don’t we take a risk?” And so they're supposed to ask you that question, and you're supposed to say, “No! [laugh] Do not take a risk that’s stupid!” You're asking us to believe that we're smarter than we are, and nature hates us for that. So if there’s a way that you could have made a mistake, then you did make a mistake. You have to behave that way. And so not making a test is guaranteeing a failure. That’s the way I look at it. So that was number one. Number two, I said, “OK, as far as life is concerned, this is stuff that happens all the time.” Most things don’t work out the first time. So my thesis advisor said, “Well, we have resources. We'll fly it again.” And it did work the second time.
But what was your decision to sort of end your involvement at the point of, “Well, here’s what didn't work, and I'm going to write about it”? Why not sort of see it through to the point of writing about a success story?
Oh. Well, among other things, I already had a job offer to go to the Goddard Institute for Space Studies in New York. So there was a time limit on that. Besides, I also thought, yeah, I really liked that man. That was Pat Thaddeus. I don’t know if you've ever come across him.
After New York, he went up to run the Center for Astrophysics at Harvard. Anyway, he was a brilliant storyteller, a wonderful scientist, and I thought, “I really want to work with him.” So when he called up and made me a job offer—"I'll do that.”
How did he hear about you? What was the connection?
Well, I expect Paul Richards must have told him. But I met him in person in the summer of ’73. The California astronomers had a science meeting up at Tuolumne Meadows in Yosemite. Have you been there?
Anyway, it’s up at about 10,000 feet. It’s pretty chilly at the first of September. But it’s a beautiful place to see the sky. And so people gave their science talks, and at night, famous astronomers would show you the constellations. So Pat Thaddeus came all the way from New York to that meeting. I don’t know why he came, exactly, but he came. So I met him there. So it was only a month or two later when I got the phone call from him—“Would you like to be a postdoc at NASA with me?” “Oh, absolutely.” So I thought, “Well, I don’t know whether this cosmic background stuff is ever going to pay off. That was awfully hard. So why don’t I try something different? OK.” And when I went to New York, I was fully expecting to be a radio astronomer for the rest of my life.
Because Pat was great. Well, Pat was great. He was onto something wonderful. It was a growth area, and it still is. Anyway, that was then. Then stuff happened.
John, what was your sense of some of the big research questions that were being asked at Goddard during your time there?
Oh, Goddard in New York?
It was a pretty small place. I wasn’t that aware of what the other scientists were working on. Probably two thirds of the staff members there—there were about 100 people—were working on earth science. There was a small number of people doing astronomy. As it turns out, you can do radio astronomy from New York City with a telescope on the roof, which people don’t think about. But carbon monoxide emission at 2.6 millimeters or so comes through on dry days in New York City. So you can build your four-foot-diameter telescope, which they did. They had it up on the roof of the Pupin physics building at Columbia University, and they were doing radio astronomy, mapping the galaxy. I said, “OK, this is exciting.” And Pat Thaddeus was also a real chemist, so they made their own molecules in the laboratory and measured their spectra. So the game was discover something in the sky, determine what it is from understanding molecules. That was pretty exciting. So, OK, that was my future, I thought. So Pat had a project for me. We're going to go measure silicon monoxide masers. You know about silicon monoxide masers already?
I don’t. I don’t.
It’s a diatomic molecule, and in the atmospheres of outflowing gas from some red giant stars, they can have a population inversion. It’s pumped by the radiation field, leading to a cascade that inverts the population. So you can get pretty darn bright radio emission coming out at 43 gigahertz, 86 gigahertz, even higher. So, OK, let’s go build a little receiver and take it down to the telescope in Texas and put it on there and measure something. So that was my first project at Goddard in New York.
Now, this is the same place—Palestine, Texas? Or a different spot?
No, a different spot. That was the McDonald Observatory. They have a small millimeter dish there, which is big enough for the purpose. So anyway, that was really hard, too. Nothing about this world was easy. For instance, you discover that being a radio astronomer, there’s no night and day, so you're on 24 hours a day.
Oh, man. That’s hard! Also, if it’s your own apparatus you just built and you're a beginning engineer, then it doesn't work half the time. So OK, that’s also hard. Anyway, it was an interesting project to do.
What were you looking for?
Well, number one was, could you discover this 43-gigahertz radiation? It had never been detected. People had seen it already at 86 gigahertz, but not the first transition. So OK, let’s go measure. And OK, build a microwave receiver that’s at the right frequency and go see what’s there. So just very basic build something and measure something. You're not at that point trying to prove a theoretical prediction of any sort. It’s just, “Nothing is known. Let’s go measure.”
At this point, are computers becoming a part of your research?
Yes, in a way. Because I thought, “Well, you ought to be able to make a theoretical model of this silicon monoxide.” So there’s a radiative transfer problem. You've got some coefficients. You should be able to set up the theoretical prediction. So OK, let’s do it. So I made a calculation, put it into the Goddard supercomputer, which was the IBM 360/95, which took up a whole floor of the building. And these days, you’d sniff at its power, but we were very impressed because it had quite a few megabytes, like eight megabytes or something, of storage. So if you worked really hard, you could get your 200-order matrix inverted. So you could start to learn about this. So I thought, “OK, this is interesting.” I'm working on this. But I'm not really a good theorist at that point. I'm just a beginning theorist on that. So I didn't get very far. I don’t think much ever came of it. When I moved to Washington, I had many boxes of punch cards, and I used them to keep the garage from floating away. They were completely useless.
Anyway, I did attempt to do that, and I swore computers were never going to be my thing again. Because to get any progress at all, you had to stay up until 4:00 in the morning when you could get your job to run sooner on the computer. OK, I hate computers. I still hate computers.
Because they never do what I want them to do; they only do what I tell them to do. And there’s often a big difference. I'm not a good typist. Anyway, things are better now, but it was hard. So that’s what I was doing. Tried to get into that work. And that’s when the COBE satellite got started. So, I'm thinking it would be a good time to take a little break and walk around and stretch for a minute.
And come back. Give me about two or three minutes.
OK. No problem.
OK, I'm back. Let’s see. We were about to talk about the beginning of the COBE mission.
Exactly. My question there is, how did you first hear about this? Was it just such a big deal that everybody was aware of this?
Well, I'm just a kid, you know. I'm only 28 years old. So just a new postdoc, new in the laboratory in New York. But Pat Thaddeus heard about the announcement of opportunity that was issued in the summer of 1974 from NASA headquarters. So he asked everybody in the lab, did we have an idea? OK, well, I don’t know how many other people had an idea, but I had mine. And I was pretty aware that you couldn't do much better on the cosmic background spectrum experiment without going into space. That the atmospheric interference was an insurmountable obstacle. So the next step is clearly a spectrometer in space.
Now, we're talking about an unmanned mission.
Oh, yeah. I was never even slightly interested in the manned space program at that time. But this was 1974. It was only five years after we landed on the moon, right? And it was right about the time that the lunar program was ending. I don’t know if it had just ended or was about to end, but anyway, no more rockets to the moon. What is NASA going to do now? So apparently somebody up at headquarters said, “We better start some science.”
So somebody had a good idea. Probably Nancy Roman was part of this, since as you know, she just got a telescope named for her. By the way, she was a Swarthmore graduate back in about 1948. So she was already a hero by the time I got to college. At any rate, so NASA is looking for new science projects. And supposedly—well, I heard that they were not expecting very many proposals to come in. But they announced that they had an opportunity to use either a small rocket called a Scout, or a large rocket called a Delta, and they were accepting proposals. OK, so my boss is a NASA guy. He’s the head of astronomy at a NASA laboratory. So of course he hears about this. OK, so this is long before email. He must have gotten a letter or a package in the mail, or a phone call or something. So anyway, ask everybody in the lab, “Do we have an idea?” “OK, yes, I have an idea. Let’s get this spectrometer into space.”
And you're thinking specifically about your own dissertation research and thinking, like, had you not been doing this in Texas but it was already in space, that it would have gone a lot better?
Yeah. In fact, we had already talked in Berkeley when I was still there about what was the ideal. And so with the balloon payload, you could not provide a calibrator body. A calibrator would have been an object the same temperature of the sky that would cover the apparatus entrance and be exactly like the sky, and then you would be able to say, “Yes, it is the same.” You couldn't do that mechanically on a balloon payload. It was just impossible to think of a way. But we all knew that if you had been in outer space, it would have been easy, because nothing could prevent you from putting it in. The air would not condense onto the apparatus. Everything could be at 2.7 Kelvin. It would be a perfect differential thing, and we could do it. A totally ideal experiment was possible in space. OK. So I knew that. So I said, “Well, let’s pursue that.”
And was your sense that your idea was pretty unique? In other words, was it not sort of self-evident that an unmanned space mission was the best avenue to pursue this question?
To me, it seemed self-evident, but nobody else proposed it to NASA, as far as I know.
What were other proposals if not what you had proposed? What else was there to propose?
Well, there’s an awful lot. I think NASA got over 150 proposals. So they didn't expect nearly that many. But then they had to read 150-something proposals. And in the end, I think about a dozen were chosen for a flight. So I wasn’t involved in that part, but I think so. By the way, after I said to my boss, “Let’s try this,” he said, “Well, I know what to do. We'll call up our friends.” Friends included Rai Weiss at MIT, who had been working on a balloon payload, also, to measure the spectrum. We'll call up Mike Hauser who had just recently been hired at NASA Goddard in Greenbelt to do infrared astronomy. We called up David Wilkinson at Princeton, who was a world authority on measuring the microwave radiation, also. So then we brought in some colleagues from our various institutions, so we ended up with seven authors on the proposal. It wasn’t just the cosmic spectrum experiment we were after. We wanted to also make a map of the sky to see those hot and cold spots that might be there. And we wanted to make a shorter wavelength instrument that would pick up the light of the first galaxies.
Was this proposal—was there more or less equal contributions from the seven? Or was there sort of a lead investigator with the others concurring?
Well, there were a lot of contributions from everyone at the conceptual level. I was actually the main editor of the whole proposal, so I did really feel a sense of ownership of it. On the other hand, it was also clear to me that only one of these experiments was my idea. The others were other people’s ideas. And so in the end, there would be plenty for everyone to do if we were chosen. We had originally four instruments, not three, because there were two anisotropy measurements. One was going to use bolometers and cryogenic detectors, and one was going to use microwave receivers. So we decided after not too long that the cryogenic version was too hard and took it out. But that would have been Rai Weiss’s project. He’s pretty famous for something else now!
But he was chairman of the science team that we made for that project. So what happened then? Well, we sent in the proposal. NASA did not say yes, but they said, “That’s interesting.” So for a little while, they sent me a little bit of money at Goddard to work out whether it was possible to do the spectrum experiment as a small more or less cylindrical experiment that would be hidden above the secondary mirror of the IRAS, Infrared Astronomical Satellite, which was being developed in partnership with the Netherlands and with Britain. I had some pretty good ideas, but it’s probably a good thing that they did not say yes, because it would have been pretty marginal, and it would have been pretty hard, and I was not nearly well enough prepared to do it. So they were right to say no, in the end. But at any rate, a couple of years later, they said, “OK, maybe we'll do this.” So we had hopes of that, so that’s when I moved from New York to Goddard in Greenbelt. In early ’76, I moved here. In late ’76, NASA said, “OK, we will be interested enough that we will set up a study. We will send money to Goddard to do some engineering. We will actually create a new science team.” Not just members of our original team, but they chose—as it turned out, which I hadn’t really known at the time, there were two other competing missions that were both going to go after the hot and cold spots, the anisotropy. One was from Berkeley and one was from Jet Propulsion Lab. And so now we had three different ideas about how to do the anisotropy experiment. So this gets interesting.
So a new team of people that we didn't really know very well, we're all going to have to learn to work together. So in a good way, and a bad way, both. As you know, we ended up having to write a book about the trouble. [The Very First Light, by John Mather and John Boslough.] A long time ago, now. So where were we? We were getting to the summer of—submitting the proposal was summer—we were working on submitting the proposal in ’74. We had the first meeting of our group of seven in, I think, September of ’74. And the proposal would have probably gone in, in roughly December. I don’t know exactly. It was a pretty thin proposal. We didn't know much.
What exactly were you proposing in terms of the kinds of questions that you hoped the research would answer?
Basically, nothing was known about the cosmic background radiation at that point, except it probably was cosmic. It wasn’t 100% certain. There had been previous measurements of the spectrum, including the balloon payload that I worked on, when it worked, the second time and the fourth time, and got better data. But everybody was seeing that there was a little bit of excess radiation at short wavelengths. So that cast doubt on the whole story, because, well, something’s going on. So is the radiation really cosmic? Is it really coming from the Big Bang itself? That’s sort of your number one question. Is that spectrum ideal, or does it have a distortion? So at the beginning, people really hadn’t even thought too much about what would make any of that happen. In ’74, when we wrote our first proposal, there was no serious prediction for anything, no theory to be tested. Nobody had predicted what the anisotropy should be, either. There was at that time just the beginning of understanding the cosmic structure. There was a beautiful Princeton poster that showed the positions of 100,000 galaxies or a million galaxies or something, and they were clearly arranged in strings and clumps. So people were just beginning to grapple with the statistics of that, and what could make that happen. Nobody knew.
And how much work had been done on measuring anisotropy prior to this? How developed was that field?
There had been quite a few attempts, and they had gotten as far as determining that there was a dipole anisotropy due to the motion of the earth. So that’s about a part in a thousand, because that’s the speed of the earth is about a part in a thousand of the speed of light. So, pretty small. But we thought, well, if there’s anything that’s cosmic, it’s going to be a lot smaller than that. So we didn't have a theory to test. We didn't know how hard we had to work. So our alternate statement of how well we had to do was measure as well as the universe will allow us to measure. So we knew that we would have interference from the galaxy, and the electrons in the galaxy, and from the dust grains in the galaxy.
So OK, build your apparatus so it’s capable of measuring the difference between them. So dust and the electrons are all concentrated in the galactic plane, and you have evidence of them from both shorter wavelengths and longer wavelengths, so you should be able to understand this. So number one, you better have a very sensitive apparatus to detect these probably or possibly very faint things.
Number two, you better have more than one wavelength, because you're going to use the wavelength dependence of the foreground objects to model and subtract them. So we started off with four wavelengths. At a certain point, as we got into the project later on, money got tight, and time got longer. So OK, what are we going to do now? We said, “Well, we're going to improve the technology on the receivers at the short wavelength, and by cooling them down to a lower temperature, make it more sensitive.” And the second thing is, we're going to give up on the longest wavelength, because it wasn’t that great anyway, and besides, there’s a possibility of making a measurement with a balloon. And so some of our team members split off and built the balloon payload to do that.
John, I'm curious—among the collaborators on the proposal, it seems that you're pretty well covered in terms of instrumentation and measurement, but who has the experience in the space missions? Who’s the one who’s going to say that this is a feasible proposal? That this can be actually carried out in space.
Well, none of the proposers.
[laugh] Was this recognized as a problem at the time? Were you looking for outside help?
Well, actually, no. We were adopted by Goddard Space Flight Center. So they gave us the engineering team that it would take. A very experienced engineering team that were just finishing up the IUE observatory, which was built and operated at Goddard. That was a time that you could go down to the basement or the downstairs of Building 21 and sit in the control room and drive the telescope. So these were brilliant engineering team. They had just had a great success. So they got the assignment to take this new technical idea and turn it into something real.
Now by 1976, this is a real job with NASA? You're a staff scientist in the civil service?
Yeah. Before that, I was a postdoc. So ’76, in the summer, I arrived at Goddard, and in the fall, we got this whole thing rolling. And suddenly—and I'm this 30-year-old kid, has no idea what to do, but I've been adopted by professionals. So I go to all their meetings and I learn what they're doing and chip in here and there. And eventually, we build a concept.
What’s the next step. How do we get beyond concept?
NASA said, “Well, not only are we setting out this study, but you're going to have to write another better report.” So there was another phase of competition. I think they sponsored 12 projects at that time to be carried further along to see, well, how hard are they, and what does it take to do them. How much money is it? How much time? All that.
And this is a winner-take-all kind of competition? One proposal will emerge from this?
I don’t know how they did that. I have the impression that most of those missions were eventually flown, just not right all at once. In fact, this was quite an interesting challenge for NASA, because you start off thinking, well, you're going to have one or two, and by golly, you've got 12 wonderful things; you have to do them all. So how are you ever going to choke this down? This is the boa constrictor and the elephant, you know? Or maybe 12 small elephants. But at any rate, it’s a big deal for NASA to take on all these projects. And it did take us a long, long time to get them all done, whatever the total list ended up being.
Was your sense, John, that this was a golden time for NASA? That the response to this was, “These are all great proposals. Let’s do them all in due time”? Was it a time of real possibility, looking back?
I don’t know. I suppose so. I was not at a high enough level to see that. I just had my nose entirely pointed towards Cosmic Background Explorer. So I’m just—"I'm not going to worry about the rest of the world. I'm just going to do this. This is all I can see.”
So then what happens?
Yeah, so we survived that. We kept on not failing. So they said, “OK, keep on going.” At a certain point after that—I don’t remember exactly when it was—the budget looked like it was going to escape, that this project was getting harder and harder. Because among other things, we said we were going to build cryogenic instruments, things that operated at liquid helium temperature. NASA was at that time finishing up the IRAS satellite, and it was the first ever big helium cryostat in space, and it was one pain in the neck. It was really pushing the edge, and it was scary enough to NASA management that the deputy administrator of NASA was at the launch site and he was afraid to push the button to launch it, because he was afraid it would not work. His name was Hans Mark.
Anyway, so just to give you a sense of how much stress there was in the world about cryogenic missions. The military had tried lots of cryogenic things; they had all failed, for basic elementary reasons. So it was kind of scary for people. And here are these university people; they have never built a space thing before. Why should we believe them? And so as time goes along, it gets harder and harder and harder. And money is tight. We're actually trying to do this at the same time that we're building the Hubble Space Telescope, although that work was mostly being done at Marshall Space Flight Center. And nevertheless, Goddard had some parts of it. Anyway, this got to be a challenge.
So at a certain point, NASA Goddard management said, “This is interesting enough. We would like to adopt this project as an in-house project.” So most projects, you know, we receive the money from headquarters and we have a contract with some outside organization to build the thing. And it looked pretty clear that this was too hard for that. That we could never afford the budget that it would take to pay somebody to do this. And we didn't even know how to write the contract. If you said, by the way, “We need to do 1,000 times better than it has ever been done before,” we didn't think anybody could answer that. But the internal science team, we thought we knew how to do it. So OK, let’s work daily with the engineering teams at Goddard, and we'll figure this out. So that is what happened. Goddard adopted it, said, “We will contribute our in-house civil service manpower to this project.” And we did it that way.
What do you think was the deciding factor in terms of embracing something that was thought to be impossible, pursuing it with outside partners, that made it at least feasible, conceptually as an in-house endeavor?
I think personally the most important thing was people did understand that this was potentially revolutionary. That this is not just another project. This is something that could change our view of the world. So even from early days, some people had been saying, “Well, this could win a Nobel Prize.” And so I thought, “I'm not going to think about it. I'm just going to do my job. But yes, it could.” So we already knew—well, I'm not sure exactly when it happened—but the Nobel Prize was given, of course, for discovering this background radiation. And so, well, this is really, really, really important. People understand that. And so if we knew this—
When you say “really important,” what are the most fundamental questions that could be answered if everything goes according to plan, that made this so that NASA said, “This is a big deal, we're going to go full stop with this”?
Well, I think part of what you're asking is, what is the real technical question? And part is, what does the science world think about it already? So the technical question was, “Is the Big Bang the right story? Is the expanding universe the right story?” And there are a lot of sub-questions in that. If it is the right story, then how did the galaxies come? Where did they come from? Because it seemed quite mysterious. People were just beginning to realize that there was a structure that had been seen in the maps of where the galaxies are located, and that we had no clue what made that happen. So what is there to measure? Well, there’s not very many things to measure. You can measure the galaxies or you can look for this cosmic background radiation. And if you could measure it, it would tell you something that you never knew before.
So at the beginning, we didn't know how important it was going to turn out to be. We didn't know if you could see it. We didn't know what it would mean if you had it. Because there were no theories being tested. After a while, people did get on to the fact that there were theories you could make. That having measured the placement of the galaxies, the correlation of the galaxies, you should be able to calculate, how did they get there. And there were a lot of choices you could make about your story, but basically they all require that there had to be something built into the structure of the early universe, so, better go look for it. No serious prediction about what there is to see, but there must be something, so go look. So our story resonated.
It turned out there were committees of physicists that met and told NASA their opinion, and there was one from Snowmass where as I remember it, that they said, “Yeah, this is really, really important. You should do this.” Long before the decision was made to bring it in-house. So I guess I'm telling the technical part. The personal part was there were people at NASA headquarters and elsewhere who really understood that this was a potential scientific breakthrough of great importance. So those people somehow did the right thing to make it happen. So they included people who recognized that this wasn’t just astronomy; this was physics, for instance, and a very, very fundamental sort of thing. Some astronomers would say, “Well, why do we need this? We can’t point this telescope at anything. And we point telescopes at things. That’s what we do. We're astronomers. So there’s nothing in this for us.”
So I think that had to be defended. So there were individual people like Nancy Boggess and Nancy Roman and Frank Martin and NASA administrators who said, “Yeah, we see the promise of this, and it is worth going after. So maybe it’s really, really hard, but that means it’s really, really important.” Anyway, so individual people whose—I wasn’t there. I wasn’t part of these conversations. But people saw the importance of it, and they made it happen.
John, can you explain a little bit more about this divide between physics and astronomy? This question of why this was important simply on a physics basis and not just on an astronomy basis?
Yeah. Just a little. Most NASA astronomy missions are to help astronomers point a telescope at something. That’s what we do. We study stars. We study galaxies. We study planets. We study every little thing out there, because that’s our custom. You can do that from the ground. When you get to something that cannot be done from the ground, that becomes NASA’s territory. So we build telescopes to observe at wavelengths that you can’t get through from the ground. So the ultraviolet, the infrared, all kinds of wavelengths where the atmosphere just blocks you. X-rays, gamma rays, all those things you can’t do at all from the ground. You still end up—it’s a telescope. We point it at things. So when we say, “By the way, we want to point it everywhere, and by the way, there’s no chance to apply for observing time on this”—so most of our astronomy world survives by getting observing time on a telescope. And if it’s a NASA telescope, they get a little money to go with it, so they can publish what they got. So here’s this new idea, this COBE satellite, and there’s none of that for them. So it takes a little while for them to warm up to the idea. You could see why. There’s nothing in it for them. Not right away.
Now, in the end, of course, we got a huge wonderful surprise. We saw the hot and cold spots. And ever since then, thousands of astronomers have been working on them. And two more space missions were already flown, and another one is probable. They didn't know—nobody could know—that we would see the spots to just the level that had been predicted by some pretty good theories, by the time of launch, and that you would be able to make such amazing interpretations as we now can do. So I think most people did not anticipate that extraordinary explosion of information that you could get from the position of random hot and cold spots. It’s just nobody had thought about it that deeply.
Who else came on when the satellite project was really up and running? Who else joined the team?
Well, we had the original six that were chosen by NASA headquarters, and then gradually, over the course of quite a few years, we grew that team to about 19, including a guy from the Air Force lab, various young faculty members around the country, more people at Jet Propulsion Lab, more people at Goddard, a couple of really bright theorists—Eli Dwek at Goddard, who’s still one of the world experts on dust—Ned Wright at UCLA, who had been one of Rai Weiss’s people at MIT. Ned is very famous now for his projects that he has done, in particular the WISE mission, the Wide-field Infrared Survey Explorer. So they mapped the sky many times, and saw lots of wonderful things with their little satellite. So all these people brought unique perspectives and abilities to the mission. And just for the record, I should say Ned Wright is the first one that saw the hot and cold spots. So how did he do it? He had his own laptop, and he had his own personally written code. And he knew how to get his personally written code to run on his little laptop quicker than anybody could do with a big computer. He’s incredible. So he was the first one.
And what’s the significance of being able to see these hot and cold spots?
Well, number one, we think they're real. That was the first big question: are they real? So I’m jumping ahead a lot, but this is a very dramatic part of our story. So in summer of ’91, I think, the science team was meeting at Nancy Boggess’s house, and Ned came with his little 35-millimeter slides that he has taken pictures of his computer monitor to show us the hot and cold spots that he had found.
And oh man, this is what we had been hoping would be there. How do we know this is real? So this is a time when polywater and cold fusion were not old yet. So we knew that it was really possible for people to go off the deep end with bad science, so we better make sure that we do not embarrass ourselves and do not embarrass NASA by doing that. So we better check this, and check this, and check this, and check this, because our entire future reputation is on the line with this particular detection. Those hot and cold spots better be real if we say so.
I'm curious, John, are you relying on—are there outside consultants who are sort of serving in an advisory role to what you're doing, or is this entirely an in-house operation in terms of who you're communicating with?
This is entirely in-house. Our science team includes universities, quite a few. UCLA, by then, Ned Wright moved there. Santa Barbara, Berkeley, Jet Propulsion Lab, Princeton, MIT, and Goddard. So all of us—a lot of people involved. Anyway, so definitely we better check this, and check this, and check this. So we were very systematic about it. But from Ned’s perspective, it meant that his observation—he did not get to be the person to make that announcement.
Well, it was George Smoot, of course, as the principal investigator. But then he kind of jumped the gun, too, in a way that undermined the fact that it was a team project.
Now, you and Mike Hauser were also principal investigators. But he was the principal-principal investigator, essentially?
Well, I was the project scientist, which is a job that oversees the entire mission, as well as being the principal investigator for the spectrum experiment.
And what was Mike Hauser’s role?
He was PI for the DIRBE instrument, the Diffuse Infrared Background Experiment. He was also my supervisor within NASA, the man who hired me in to Goddard, and he was the best man at my wedding.
You've also called him your greatest hero, so I'm a little curious about his style and why you admired him so much.
Ah! OK. Well, he still is one of my greatest heroes. I have a few more to add now. Because Chuck Bennett is also a hero in my book. But anyway, Mike really had an extraordinary ability to see to the heart of things and to make sure that we were doing the right thing, whatever the right thing was. That we were ethical, and we would give credit where it should be, and that we would check our work, and just do it well. Just a person of true scientific integrity. And common sense. And something that annoyed me also was that he was really good at challenging things and—saying, “John Mather is really optimistic about this,” and Mike would say, “Well what about this and what about that?” I needed that. [laugh] It was also annoying. [laugh]
But that’s one of the ways you learn to love people who challenge you, because you know this person is on your side.
Given the stakes and your reputations collectively, when did you know it was the right time to submit the report?
Of the hot and cold spots? Well, we worked and worked and worked, and we had many things to do between Ned’s presentation and the announcements. So number one, we had to write the Astrophysical Journal articles and finish them, so we swore that everything in them was true. Number two, how did we have to do that? Number one, we had to make a darn long list of all the things that we might have done wrong, or in which nature could have fooled us, and you have to check every single one of those you could possibly check. We also had something other people wouldn't have known much about. We had our team that had built the apparatus to fly a balloon. So members of the science team had built this apparatus, and they had measured the spots with a balloon apparatus. It only measured a small piece of sky, but they could say, “Yes, sure enough, we see the same spots that you see.” So the plan was, OK, that gives us some confidence that we didn't just make one giant mistake. There are spots in the sky, and somebody else can see them, too.
Even though they're our very same team members and our colleagues, it gives us a whole lot more confidence that this is not some random number fluctuation that has happened to bite us. So the combination of really careful rehearsal and rework of all the calculations, multiple ways to check every number, and confirmation by a completely separate piece of equipment—that made us confident enough to try it, and go public.
How was the report received?
Well, it was front-page news around the world. The little picture of the sky was in many newspapers on the front page, in color. So well, gee, that’s like huge success as far as public outreach is concerned. I've never seen a picture of a spectrum on the front page of a newspaper, but I have seen maps, images like that. So that was pretty exciting.
What year was this?
That was April of ’92. So those pictures became the front page of Physics Today, of the cover of Physics Today. So the phone rang and rang and rang, and I talked to everybody for days and days.
And where do you build from here, with all of this interest, all of this momentum?
Well, we weren’t done yet. We had several more years of analyzing the rest of the data. So that was ’92; we actually ran the observatory for four years total, into ’94. So gradually, we were able to improve the quality of the maps, quite a lot. The random noise averages down as the square root of time, as it should. Systematic errors that you might have can go away faster, because you get better and better at detecting them. So the final maps are a lot better than the first maps. So that kept us quite busy for a long time.
How did this research fit in with the overall mission of NASA during these years, in terms of the way it conceptualized launches, expendable rockets? How did it fit in with the way that NASA saw its mission going forward?
Well, we were part of a huge change. Because when we first started studying the project at Goddard in ’76, we said, “Well, of course we're going to use a Delta rocket that goes right where we need to go.” By the time we submitted our next report—“Oh, no, you can’t go there. You’ve got to use the space shuttle, because we're not building any more Delta rockets anyway.” This is the bargain with the devil that NASA had to make to get the space shuttle—"Kill everything else. You have only one child now. Too bad for you that you like the other children.” Then the Challenger blew up, and it became very obvious that we were never going to get the launch that we needed from a shuttle. Because we were going to be the first and only space shuttle launch from California. We needed a polar orbit for this work, so OK, so now a huge change is required. You're going to have to find another way to space. So our project management started hunting around for another way. They found a European rocket or a Russian rocket or something, and OK, as soon as headquarters got wind of that, they—“Hmm, we're not going to let that happen!” So it was just barely possible to find enough pieces of the old Delta rockets lying around to be able to reassemble a whole new one. So that was done.
Was your sense that this was about a more constrained budgetary environment in general, or was this more about NASA was simply pursuing new endeavors in new ways?
This change was just driven by tragedy. It became totally obvious that the space shuttle was not going to be the thing people promised it to be. It was dangerous as hell to fly. It couldn't carry what people needed it to carry. It couldn't go where it needed to go. And it’s very infrequent. And it sure was dangerous. So eventually people said, “Well, golly gee, it was kind of obvious that Delta rockets weren’t dangerous like that. Nobody is going to die if something bad happens. So, stop doing that. It’s not a space truck. This is precious human cargo.” So this was long before SpaceX turned up with their cheaper way to go. But there are lots of stories behind that particular Delta rocket. We don’t really have time to tell them all, but—Mike Griffin was in the military side of the world at that time, and he was the person who helped us find the rocket pieces. Now, he’s back in the military world. So that was part of the story.
Another part was that the rocket just before ours blew up. So somebody had to find out why. This was another case where better is the enemy of good enough. So that rocket had one extra wire that was added into the wiring harness for some good reason, but it turned out that the wiring was insulated with Teflon. And Teflon isn’t very hard; it can flow like wax. So it was a case where this cable went around a sharp corner, and the insulation got cut. So then something happened and the rocket blew up. So the next one, they fixed that. As far as I know, they've all been fine ever since.
What was the fix? How’d you do it?
I don’t have details, but I think they said, “Well, let’s not use Teflon insulation anymore.” Well, we shouldn't have done that in the first place. We were just lucky before that event. Another story about the rocket—you probably have heard that some of the parts had been lying around where pigeon droppings fell on the outside, so there were holes that had eaten right through the aluminum tanks. So we patched them over with pieces of aluminum and welding. And that was fine, and then the rocket goes up just fine with that. So we had a rocket with welded patches on it. And the night before the launch, I think it was, they determined that the flight computer in the rocket itself wasn’t good anymore, so they had to change the flight computer in the rocket right on the launch pad. That’s a scary thing, when you've got—I don’t know if they had the fuel in it yet or not, but anyway, it’s a scary thing to be working on your gigantic explosive device, close up.
John, when did you have a sense from those early inklings about being recognized for the Nobel Prize, that this was something that was actually going to happen? Was this sort of an out of the blue kind of news event, or had things sort of been buzzing around for a little bit of time?
Well, about a year before the Nobel announcement, some report occurred that said that we were being considered. A few months before the Nobel announcement, somebody told me he thought it was my year. That’s all I knew. Because as you know, the Nobel discussions are entirely, completely secret, and the records are sealed for 50 years. I have to live a long time to find out what they said. Hardly anybody finds out what was said about themselves. Since then I did learn that one colleague of mine sent in a nomination. But I'm sure it’s more than one nomination required for something like this. When the anisotropy maps came out, it was pretty clear that they were attracting huge attention. By then, it was clear that they had to be followed up. So by the time of the Nobel, we had already launched the WMAP mission, which had confirmed those original maps, and we had seen how powerful that was. What you could learn from the WMAP pictures was far more than what we could learn directly from COBE. So at that point, yes, it was important, and they (we) got it right. So I think then it became plausible that a prize could come.
The politics are always so convoluted with these kinds of awards, so I wonder if you've ever thought, of all of the people that collaborated on this project, why you and George Smoot?
Yeah, I guess one argument is simple. We were the principal investigators of the two exciting experiments. If you wanted to extend to a third person, who would it be? And that’s a trickier question, because our team is big. And you could say, “Well, it should have been Ned Wright, because he saw the spots the first time.” Or it could have been Chuck Bennett, because he actually was the person who made the equipment work. He was deputy PI for George, and as far as I was concerned, he was a far better scientist and far better everything than George. So from that perspective, it should have been Chuck. You could also say, “Well, how about going back to the very beginning and it should have been somebody else, who told us to do this” or something of the sort. Maybe a theorist. Maybe it should have been Jim Peebles. But I think if you're the Nobel Committee, you have to think of something that’s simple and defensible. So I can see why they would do it the way that they did it.
The other thing that’s so interesting with the way that these things play out is that the research—there’s such a long gestation period between the decades of research and the particular year that it is recognized by the Nobel committee. So do you have any sense—maybe you're not the best person to ask for this, but do you have any sense, why 2006? What happened I guess in 2005 that made them pull the trigger for the following year? What was it about that particular point in time?
It’s hard for me to guess. That was a year where we also got another prize in cosmology from the Gruber Foundation. So I think people had recognized that not only did we do a good job, but it had been confirmed by WMAP. And so that makes it—so the word was beginning to sink in that WMAP had done a good job, too. Their mission lasted a long time, and it kept on getting better and better data. And so honest, this is a super spectacular thing, and so who do we honor now? They have to be thinking about that question. So you could imagine that they would have found a way to honor Chuck because of WMAP. But they didn't do that, but they could have. So I don’t know how they work these things.
Can you describe the call when you got the news?
Yeah. It was a quarter of six in the morning here. I was in this house. I was sort of aware because of previous prompts that maybe this would be our year, so I was aware of the day that they might call. I was also aware that my mother was old and ill, and there was a chance that I would be getting a phone call early in the morning from our caregiving person. Anyway, so the phone rings, and “We're very happy to let you know that you're winning the Nobel Prize this year.” So I said, “That’s lovely! That’s very nice” so my wife would know this is not a bad thing.
Because we were both rarely awake at a quarter of six in the morning. Anyway, the phone call goes on for a little while, and then—“Will you stay on the line for a discussion with our news media?” So, OK, we do that. And then, OK, well, hang up. So, now what’s next? So immediately the phone is ringing. So the house phone is ringing. The cell phone is ringing. I talked to a few people for a while, and I get to the point where I say, “If I don’t do something different, I'm never having a bite to eat. And I need to have a shower. And I've got to go see the doctor this morning for a different reason, so I'm just going to ignore this, have a shower, go to work, talk to my friends over there.” But it only took about an hour before the news media were at the front door with cameras, and my neighbors had put up balloons.
It was pretty intense, that day. As it happens, NASA was entirely, completely unprepared for this. Nobody had planned for the day when we might get a prize. I think universities always have in mind that their particular scientists could get chosen, because they nominate them, probably. So I'm sure they're always ready. But we were not ready. So it took us until late afternoon before we were ready to have a press conference. And that was that. So, pretty intense. [laugh]
In being recognized for—I don’t know what the right word is—confirming the Big Bang theory of the universe—is that the best word to use, is “confirm”? Is there a better word?
Actually, I like to say we measured the Big Bang. Because I was never—from my mind, the Big Bang story, which is the wrong name for it anyway, was never in doubt. I thought the evidence for it was extremely strong, and there was no way around it. That’s what I thought. I wasn’t interested in confirming—
What’s a better term?
I would call it the expanding universe. And the reason I choose that, by the way, is when people say the Big Bang, they picture a firecracker, which is exactly the opposite of what scientists have observed. Firecracker is finite. It happens at a place and a time in a universe that already exists. So the expanding universe involves a probably infinite universe all expanding into itself, all at the same time, more or less uniformly. And it’s not an explosion; it’s an expansion. So people picture that the universe was all compressed into a point, because it’s a Big Bang. Well, no, that’s false, also. The universe was not compressed to a point. So anyway, the nomenclature of Big Bang conveys completely the wrong picture to practically everyone, including scientists.
Does the phrase “expansion,” “the expanding universe”—is that also more accurate in so far as it doesn't presume a particular beginning point in time, before which there is no time?
Yes, it’s certainly more accurate about that origin of time, if there is an origin of time. I try to dodge the question, by the way, by saying—imagine running the expansion backwards, from what you've seen to going farther and farther back in time. You get hotter and hotter and denser and denser, and the stuff gets squeezed together, and the things you know about get ripped apart. And protons and electrons are ripped apart. Protons especially. Antimatter is created out of energy. Anyway, it gets to be pretty different. At some point, you get to where you think you couldn't even guess the right laws of nature. You say, “Well, at some point, the quantum gravity ought to turn up.” And so quantum gravity probably affects time and space. At this point, I think we declare we give up, and we call it the Big Bang, because we have no idea. So from my perspective, the Big Bang is where you run out of imagination.
Now, I wonder if you can sort of translate a little bit about what the Nobel Prize committee said about the work. Why is COBE the starting point for cosmology? What does that mean—it’s the starting point for cosmology?
I think they actually had another word in there, of precision cosmology. So we were the first people that measured something precise. We got the temperature of the background radiation to 2.725 plus or minus a small amount. We got the hot and cold spots, measured the spectrum of the hot and cold spots, how bright they are at different wavelengths, spatial wavelengths, quite well. So suddenly, we went from “We just have no idea how big is the universe” to here was a pretty precise picture, and we have the beginning conditions. We have a snapshot of what it was when it was young. And if you take that picture and what you think are the laws of nature, you should be able to predict where the galaxies have gone since. So it was the beginning of kind of closed loop analysis that you can now do. So you don’t just say, “I don’t know how the galaxies got here.” You say, “I've got a picture of how this should work. I've got a formula. I've got a computer simulation. I can tell you how I think it happened. And I can tell you how much dark matter I need, and how much ordinary matter I need, and how much dark energy I need. And I can get, based on the new measurements that we have from WMAP and Planck [the ESA mission], I can get these numbers down to a percent accuracy, more or less. We think. Of course, there’s still room for argument. But at any rate, it’s the beginning of getting from, gee, I don’t know, to percent. And so it really was that beginning.
As with all scientific discovery, there’s a highlight of what is discovered, what’s known, but then also by default, there’s also a highlight of what’s not known. So in what way did the COBE project highlight or isolate or make more clear what remains unknown, as a result of the research?
Well, COBE only started the measurements of the cosmic background fluctuations. After people saw there was something they had to measure better, then we have, as I say, thousands of people have been working on it ever since. So COBE showed us that there was something to measure and that we did not know nearly enough about it, and that we should get the spectrum of the cosmic fluctuations as well as we can. Then, we knew that we couldn't measure yet, but we should try to measure the fluctuations of the polarization. You probably read about that, too—that it means a lot to the possible presence of gravitational waves in the early universe and hence, to the equation of state of matter in early times. So we don’t know that answer yet, about the early universe, but this is pretty important.
So here’s a sort of intuitive picture. If you have ordinary air, you can have sound waves, and you only have pressure waves. If you have a solid, we have sound waves with lateral polarization as well as pressure waves. So you now have three modes of propagation of sound waves in solids. Electromagnetic waves, we think of as transverse. You have electric and magnetic fields perpendicular, traveling through space. And now your question is, “Well, what’s the early universe like?” Is it like a solid, a liquid, a gas? Does it have rigidity? And what other kinds of waves could be propagating? So if it’s got some rigidity, maybe it could have gravitational waves that are longitudinal. Maybe it could have gravitational waves that are lateral, as the prediction has been confirmed with LIGO. So what’s going on? What are the material properties of that early material? And so measuring the polarization of this radiation has a way to tell us that. So we don’t actually see the Big Bang, but we see the effects of—this is a sort of secondary thing—the polarization is produced in the microwave radiation at the moment of last scattering.
When the universe becomes transparent, the last electron that hits the radiation is bathed in a sea of cosmic microwave radiation, which may or may not be equally bright in all directions at that time. So there’s a tiny trace of polarization that comes from that last scattering. So that’s what we look for. So it is predicted that there’s a piece of this polarization field that could come only from the Big Bang. And so that’s why it’s so exciting. It’s the last piece that we could possibly think of measuring about the Big Bang.
I want to ask a question that inevitably has philosophical implications, and that is the extent to which you see your research contributing to perhaps the most existential question in physics, which is, could the universe have created itself? It obviously begs a binary kind of decision because it’s a very interesting answer if the question is, “No, the universe could not have created itself.”
So to the extent that that touches on philosophical or even spiritual questions, where do you see your research advancing that question, about whether the universe could have created itself?
I don’t really give it any thought. There’s nothing I can imagine measuring that would tell me the answer to that question. So I've never heard of anything that you could measure—I can’t think of anything you could measure. So for me, it’s almost like how many angels are there on this pin head? There’s just nothing you can do with it. Conversely, though, once in a while we get a mathematical theory that is so persuasive and beautiful that we say, “Well, maybe that’s really true.” So Dirac gave us antimatter with a very simple equation. So yeah, we worship that equation and say, “Oh, well, maybe we could do that some more. Maybe we’d get a picture of the expanding universe that includes something that came before it. Some origin story for it.” So I'm not against it. It’s just—it’s really hard to think of a thing that we would use that could tell the difference between one story and another.”
As a Venn diagram, you answer by saying, “I wouldn't know how to measure it.” Is that completely in the same shaded circle as “What’s unmeasurable is also unknowable”?
Not exactly, because there are things that you can be sure of because we're persuadable. It doesn't mean they're true but you can be sure anyway.
There’s a distinction between true and sure. So if we got a story about quantum gravity that seemed so beautiful and produced explanations for all of the measurable constants of nature, then we’d say, “Ah, this is so beautiful it must be right.” So what does it tell us about what came earlier? Then we’d have a story and we might believe it, and it might even be true. But you would never be able to prove that that was the only story. That’s the tricky thing about our stories—that it’s really hard to prove that they're the only one. If you could prove that it was really the only story, then you'd have another leg up. You could say, “I have evaluated all possible theoretical explanations of quantum gravity, and this is the only one that’s possible.” Then you might really have a good reason to believe it.
And that would be a little different from my opinion that there’s nothing to measure. Because if that theory produced an explanation for everything that we have measured, then it would be pretty persuasive. There’s a lot of constants of nature. And the speed of light, the fine structure constant, the constant of gravity, the various constants describing subatomic physics, the weak and strong nuclear forces—all those constants come from somewhere. If we had a story that said, “This is the one and only possible theory that gives those numbers,” then we would say we tested it by measurement. But it’s tricky, because you know the numbers in advance. So you can’t swear that—it’s really hard to prove there’s no other explanation.
Maybe a different way of asking the same question is, to what extent do you see your research contributing to a grand unified theory?
As far as I can tell, it’s way beyond my territory. We can show you what the universe has done. There is a hope that the grand unified theory will explain the cosmic spots, including the polarization. If it does, then I'll be thrilled. But I'm not currently working on that. That has gone to the next generation of measuring people, who are working on the polarization.
A sociological question—the Nobel Prize is so different from other awards you can receive as an astronomer, as a physicist, because it is orders of magnitude more prominent, global. I mean, you received the Heineman Prize; the news media didn't show up on your front lawn the next day, I assume.
That’s true. Yeah, they did not.
I'm curious if you ever thought about how that level of recognition might be useful as a platform or as an amplification device for other things that you care about that might not be directly related to the research for which you were recognized.
Ah, well, yes. I'm aware that it gives us a voice. All the Nobelists have voices. And it’s a voice the you have to use cautiously. You can’t just go around saying, “Peace is good. War is bad.” That doesn't do anything. You can sign petitions and statements occasionally. I did one recently about the NIH withdrawing its support for a research organization on viruses. And curiously enough, I got an email from a fellow who said, “By the way, this isn’t what you think it is.” He said, “Well, it’s more complicated.” So even some things that seem kind of obvious aren’t always obvious. So it was pretty clear that having that designation made it easy for me to go around and tell people how great the Webb Telescope is. I get invitations all the time to speak somewhere. Even now, they know I can’t travel, but they say, “Can you talk to my class by Zoom?” So all the time, answers like that. So yeah, one has a forum. But I've always thought, “Be very cautious about using it.”
In what ways has that level of recognition enhanced your capabilities as a scientist, perhaps in terms of the people that you talk to, the institutions that you liaise with? And then conversely, in what ways has it hampered your ability to just simply work as a scientist, because of all of this attention that you otherwise would not have received?
Good question. The number one thing that happens is you're always in demand to go somewhere and do something. So if you think that’s not science, then you're not doing science for a while. I got travel invitations, speaking invitations. I got asked to be part-time head scientist for the Science Mission Directorate at NASA headquarters. I did that for a year. Went to a lot of meetings. I thought, “Wow, that’s interesting,” but I didn't do anything that was very interesting for other people. I don’t think I really contributed to the progress of science by doing that. So anyway, at this point, I think, well, time is scarce. It’s precious. So don’t give it unless you're doing what you think you want to do. So that’s sort of a general lesson, is if you've got the Nobel Prize and you're still not happy, it’s your own fault.
Time is precious. Spend it where you want it. So it has certainly given me lots of opportunities to talk. And in one way, it has been curious—I've been able to step back a little bit from day-to-day activities on the Webb Telescope to create a little thinking time. So a couple of years ago, it occurred to me that an old, old idea could come back to life, which was can’t we fly a laser in space to focus telescopes onto for adaptive optics? This is an old idea. It’s kind of an obvious old idea. But I think it’s something that could be done now, at a much lower price than before.
So I started up thinking about it. I gave a talk—one of my many public talks—I gave a talk at Goddard. A young fellow came up and said, “I've got some time, if you've got anything to work on.” I said, “Yeah, you want to work on orbiting this and that?” Actually, at that time, I was working on an orbiting starshade to see exoplanets. That’s a lot harder, but it’s also something that’s an old idea that could come. OK, so because of having a little bit of time for that and also not going to a meeting to make the Webb Telescope happen, I was able to think of that other idea. So there’s a lot of things one way or another. Somebody explained to me once a long time ago, “If you're not already recruiting and training your replacement, you're chained to your own oar.”
So if you want to have any flexibility in life, you have to give your job away, as much as possible. So now my job as project scientist on the Webb Telescope, we've got about 14 people at Goddard that do that job. They work with the engineers. They make the project ready. And it will be ready.
Given that we're talking about work that takes us up to the current day, I thought for the last portion of our conversation, we can talk a little bit about the origins of the Webb Telescope. Obviously, this is an interest that predates your recognition by the Nobel committee. Can you explain, when did you get involved in the Webb Telescope, and what were the original objectives and goals for what you were hoping to accomplish?
A little background. Just before the Webb Telescope project was started up, I was thinking, “What are we going to do after this Spitzer Space Telescope?” So my friends that worked on it said, “It’s too small.” And so I thought, are we sure that you can’t make a deployable small telescope, maybe two or three times as big as Spitzer? So I started drawing sketches about this, and I gave a colloquium at Goddard about it, and people laughed at me and said, “Well, that’s too hard. We’d never do that.” But at any rate, I was already thinking about this. And some months later, I got a phone call from NASA headquarters that said, “We're studying the successor for the Hubble Telescope. Do you want to work on it?” And this was while we were just getting prepped for writing WMAP proposals. So OK, I'm committing a little bit to WMAP, but I'm not really critically important. I think this telescope would be really cool. I’d like to work on that. So the phone message said, “Call me up.” This was Ed Weiler calling from NASA headquarters. “And if you're interested, I need a proposal tomorrow, because we've got some money. We need to get a study started.” And call up John Campbell. He’s the head of the Hubble project. And we're starting this new study. So, OK. I called back. I said, “Yes, I want to do it.” And we got our one-page proposal sent in the next day, and so we started the official study of the Webb Telescope. So I didn't know it was needed. I was not paying attention. But there was a committee that included people at the Space Telescope Science Institute and various universities that were declaring at that moment what the new telescope should do. And they were writing a book.
Now, in conceptualizing this as the successor to Hubble, at that time, what was the reputation of Hubble? Was it already—I mean, we understand today that it has wildly exceeded expectations. Was that the tenor of the basic understanding of what Hubble was at that point, also?
Yeah, I think people had seen that it was a miracle. This was summer of ’95, that this committee was meeting. The Hubble had been repaired. They had taken their deep field picture, and they had seen galaxies everywhere. And they had seen, gosh, this telescope is great. No matter what you do to it, it’s not going to be good enough to answer all our questions. So, it had succeeded dramatically, and they could see that there were new questions. And so they wrote their little book; it’s called HST & Beyond. If you want to see an example of a beautifully written science report, Alan Dressler was the principal writer of it. The committee did a fantastic job. It was poetic. It’s inspiring. You read that book, and you say, “I want to do this project.” There’s no question in your mind. So I'm all in. I'm going to do this.
What were the objectives of the Webb Telescope that could not be achieved by Hubble?
Ah, well the little book has quite a lot of them. The one that was jumping out at people at the beginning was Hubble was going to see the first galaxies growing, and you can’t. They're too far away. They're too far back in time, which means they're redshifted outside the range that Hubble could even see. So no matter how long a time exposure you would take with Hubble, you’d never see them. So that’s what the deep field showed us. The little red specks are not primeval. So go get another bigger telescope, please, and make it do infrared. So that was number one. And there were plenty of other things that obviously also we should work on. Infrared lets you see inside dust clouds and do a lot of other things. At first, the objectives were not exactly the same as they are now, because we hadn’t really settled on what’s the engineering design. So the question was, well, what’s the wavelength range that we're going to cover? We had good detector technology that would go out to two and a half microns, and a similar one out to five microns. And then you had to jump to a whole new technology, which goes out to 28 microns. And then that big question had to be decided: Are we going to include that capability? Because it gives you a whole new set of things you can see, and new objectives you can choose. Anyway, so that was a long, long drawn-out discussion. It was a little unclear for many years about whether we were really going to do it. It turned out to be fantastically difficult and a pain in the neck. And I hope that it’s absolutely worth it, too.
Were you involved in the decision about naming it after James Webb? And why was Webb chosen to be honored in this tremendous way?
No, I wasn’t even slightly involved. I heard about it after the fact. That was entirely done at NASA headquarters. I think the initiative came from our NASA administrator. It was Sean O’Keefe at the time, and he knew James Webb. They had both been at Syracuse and taught management. Anyway, Webb was a great hero for O’Keefe, and he wanted to honor him. So there were a whole lot of steps they had to go through, that I found out about later. Number one, you have to find out if the family is OK with that idea. Number two, you have to make sure that nothing bad would be—nothing surprising, bad, would happen if you did this. There’s no skeletons in his closet. So you have to do a little bit about that. And in this case, they have to say why we should name it after a non-astronomer. Because NASA names all of its telescopes after astronomers, so what’s going on here? So headquarters had to get this all wound up and packaged before they could tell anyone. By the way, I met James Webb’s son, James Webb, who’s a ceramics artist in New Jersey. He came to one of my public talks there.
And I certainly hope we get to include him in our launch process.
What’s the status of the project, of the Webb Telescope project as of now?
Well, as of January, we were projecting a launch in March 31st or so of 2021. We knew that would be hard to do, but we were doing pretty well on our calendar. Now, since the virus turned up, we've been greatly slowed down. So we haven't completely stopped work. We're continuing at a slower pace, very carefully. And so we're not aware of anything that’s at great risk to us, so we think it’s just ordinary—let’s go carefully through the steps, and we should be able to launch. So we haven't, however, decided when it will be. We have the telescope now assembled in its final form, as far as I know. It’s folded up as it will be during launch. And we're about to run it through its final vibration test, to say, “Yeah, is it going to survive launch?” Of course it will, but you have to make sure that you know exactly. You're not taking any chances on this one. So that’s the next big step. Then you vibrate it. Then you have to say, “Will it really unfold?” So that’s the next big step after the vibration test. Then it presumably does that correctly, and then you fold it up one last time, button it up, shift the rocket to the launch facility, and then you go. So, a lot of uncertainties in how this is going to go, but so far, so good.
What are some of the top line lessons learned from the Hubble experience that may have proved useful in the concept and design of the Webb Telescope?
Oh, my goodness. Well, number one lesson that everybody talked about at the beginning was, make sure you get your design settled and your technology settled before you finish the design. On the Hubble, they reached way out into the future and they said they were going to have stuff that didn't exist when they needed it. You can’t just order up inventions when you need them. So the particular case in point that jumps out at me is the camera. We have CCDs everywhere now, right? Originally the Hubble was going to have vidicons, intensified vidicons, which is an ancient television technology and would have been terrible. So somewhere people realized, yeah, CCDs could do our job a whole lot better. Better make ‘em. But it was hard. And there’s lots of recipes and lots of ways to make mistakes. And so even after they got the ones they were going to fly, it was still unsure.
I think if I remember right, they changed the detectors out on the launch pad. So it was that close to not being good enough. So everybody said, “Well, don’t do that again. Make sure you get all your technologies firmed up and ready before you have to design the mission around them.” So we did that. We listed out our ten major technologies that we had to have. We got them all finished up before we designed the mission. Mostly. And then we still got bitten a couple of times, but anyway, most of it was OK.
John, I wonder if you can talk a little bit about designing the telescope with two things in mind—knowing what you want to discover and being prepared to learn things about the universe that you didn't even know to ask, because of the new things that the Webb Telescope hopefully will be able to do. So in terms of the concept and the design, how do you account for things that you'll be prepared to understand that you didn't even know to ask before the launch of the telescope?
OK, several things there. One is since you don’t know what you're going to be looking at ten, 20, 30 years from now, you should not make a thing which is tuned to a single science project. You don’t just say, “I know the oxygen line at 5007 is the only thing I care about, so I'm going to have a filter for that.” You're going to have to say, “We're making a generic instrument with lots of choices.” So that’s number one. Number two, be flexible about everything. You have to say, “Well, I don’t know what exactly the detector voltage should be, so I'm going to make that adjustable.” Things like that. Then you design a system which can be pointed anywhere at anything as long as it’s in a certain range of angles. So you don’t say, “I know where I'm going to look.” So then we get to, how do you decide where to look? And so we do it by proposal competition process. We allocated a certain fraction of the first year of observing time to the people who worked on designing and building the instruments. We allocated another set to people who proposed observations in a competitive process, and we got about 100 proposals and we chose 13. And now we're holding off at the moment. We will have another round of proposals where people say, “Well, now, I know where to look, and this is what I want to do.” Some of these things do change a lot over time. For instance, when we started, we didn't know much about exoplanets. We had a hint that there were a few. Now we know they're pretty nearly everywhere, and we have some hint about how to use the telescope to see them.
So, those will be managed by people using the very latest finding charts that we get from the TESS mission and the other missions that can say, “Well, I think there’s going to be something to see right now.” So we made a couple of tiny changes to the mission design to help with that. Actually, we didn't have to do much. The mission was already quite powerful and quite flexible. So we didn't have to do much to improve that. So yes, we can look for exoplanets, even though we didn't know there were any of them there when we started.
What are you most excited about in terms of what you hope the Webb Telescope will accomplish?
I am hopeful that there’s something out there that nobody knows about. Now, it’s a little less likely to be completely surprised now than it was 50 years ago, when people were first putting stuff up into space. But one area I would hunt for is suppose there’s a population of things that were formed in the early universe, and there are none of them left anymore, because they've all been swallowed up into something else or they've all burned out. So there’s a chance the Webb Telescope would see some of those. There’s a chance that there’s some population of nearby objects that are pretty faint that you could never see before, because you didn't have the right equipment. Somebody told me once, “You know, this telescope could see the heat and the reflected sunlight of a bumblebee at the distance of the moon.” All right. Better check that, but it’s true. So there are no bumblebees in space, I'm sure, but there could be little things that nobody has noticed. So think of the population of something out there, and say, “Well, how could those escape our notice? I don’t know.” Because we've been looking for a long time now. We've had the Hubble for a long time. But I imagine there’s still something there that will still be a great surprise. That’s what I'm hoping.
So there’s a wide open question I've worked on a little bit called the diffuse infrared background light. We got some hint of it from the COBE mission, from Mike Hauser’s experiment. It may probably have some spatial structure. So we've been working on that, some people at Goddard and others. So maybe we'll be able to see the things that made that. One possibility is some very early galaxies or something way out there. A big mystery right now is, how do the galaxies grow their black holes, or do the black holes come first? So we're kind of hoping to get some sense of that from the Webb that can see this happen much earlier. So those are some things.
Relatedly, do you think that the Webb Telescope will help resolve at least some of the mysteries relating to dark matter and dark energy?
I sure hope so. But we can’t see them either, but you can still see the effects that they have. So the dark energy searches, we'll certainly be doing what they've done with the Hubble, only better, with the infrared technology and the bigger telescope. We will certainly be able to map the effects of the dark matter and its gravitational deflection of light and its effect on the orbiting material out there. So people are going to be working on it. This was not especially designed for these purposes, because it’s a generic telescope. WFIRST is aimed much more at those two topics. The Nancy Grace Roman Space Telescope.
John, now that I think we're right up to the present day, I’d like to ask a few retrospective questions for the last portion of our talk and then maybe one or two sort of forward-looking questions. And so the first more is on the institutional side. Depending on how you measure the beginning of your affiliation, either from ’74 or ’76, in the next four to six years, you'll be with NASA for 50 years. I wonder if you could talk a little bit about how NASA has changed over the years, what its current role is in the broader endeavor of exploring our universe, and what you see as the most productive future for NASA, both as an American institution and as a science institution.
Oh, my golly. Well, nothing is ever a monolith, so I can’t really tell you about most of NASA. I can tell you about the piece that I see. I would say the tools that we have, have changed dramatically. When I arrived, most people couldn't use email, even if they had the equipment, because they couldn't type. The managers would say to their secretaries, “Would you print this out for me so I can read it?” And then they'd write something by hand—“Will you tell this person this?” So that’s how far back in time we were with computers. Nowadays, we design everything and see them rotate on the screen. In those days, a long time ago, you designed it with a sharp pencil and a piece of paper, you sent it to the shop, and they made it for you, and then it came back and it didn't fit. That was normal.
So a lot of things have changed about the technology that we have to do what we want to do. Now we can make a computer simulation of practically anything. And we couldn't then. So you should pretty much know whether your equipment is going to work before you build it now. You still have to see that you build it the way you meant to build it. So you still have to do tests. But a lot of that sort of process has changed. We are very much more formal about documenting things, because it’s pretty easy to put everything into a document archive, and you can be quite sure you're using the latest edition any day that you want. In the old days, it was pretty hard to be sure you had the latest document, and you would take your document, you'd cover it with red ink to make all the changes. As an example of my concern, when they launched the Hubble repair mission, I thought, “How did they know they were using the latest documents?” Oh, I don’t know, but anyway, they got it right, as you know. But I thought, “I’m not that careful.” How are we, as a society, careful enough to keep track of all this stuff? So we've gotten a lot better at formalizing our process and keeping track of the pieces. I think there’s still a lot of improvement to gain on that area.
I visited the SpaceX factory a long time ago now, and they showed me that they didn't use paper anymore. They had an iPad to keep track of the records on all the parts. Oh, I sure would like that. Why don’t we do that? Well, our system is different, for reasons. But anyway, they're doing the same thing over and over, so they might as well invest in the equipment to make it easy. So what else? You were asking me—
About the future. I'm asking specifically—you came of age during the golden age of space exploration, and you've spent your career coming on 50 years. So much of NASA in the middle part of the 20th century was it was a symbol of American leadership and greatness in the world. And historians and political scientists are increasingly thinking that in the 21st century, one of the big narratives is, this is the century of American decline, that we are ceding leadership in so many ways. To what extent do you think NASA has a role to play in sort of pushing back against that narrative? And should it have that role?
Yeah, OK, well, NASA is one of many organizations that certainly represent American leadership. I think, by the way, we're still in the golden age of astronomy and exploration. We are building things that are so much more powerful than we could do before. We can send robots anywhere that we want now. We've sent them to Pluto and beyond. We've sent them to Mars. We're going to bring back samples from Mars. We can bring samples from asteroids and comets. What do you want to know? We can find it out, if you give us a shot. So NASA is full of people who will say, “What do you want to know? Give us a shot.” And we do it not because we are NASA, but because we are the focal point for a nationwide, even worldwide, creative process, which we organize. We don’t say, “I know what to do.” We say, “Show me your idea. Send me a proposal. We'll work with you.”
So we compete to bring forward the best ideas and take advantage of the new opportunities that turn up all the time. So when SpaceX says, “We'll launch a rocket for you for a lot less money,” we say, “That’s great. We'll do that.” When somebody says, “We'll launch your CubeSat for a few thousand dollars,” we say, “Thanks, we'll try that.” So we do that, and it’s part of our nature by now. And we are definitely not a “do it all inside the lab” group. We are a “do it with the world” group.” So as long as there’s opportunity to pursue, I think we are a right organization to do it. We are certainly not the only ones. The Europeans do a very effective similar process. It’s organized differently but they do a very successful process. Our colleagues and competitors in Japan and China are doing brilliantly. The Indian Space Research Organisation has gone from practical things like supporting agriculture in India into pure research and sending a probe to Mars.
So we are no longer holding a kind of monopoly, but I think we can still lead as long as we are interested in doing so. So that means Congress has to like us. But I think they do. The manned program, human space flight program as we should now call it, is a different subject altogether, but I'm glad to see that we're trying some new things. I'm not close up familiar with any of the content there, but it was kind of embarrassing that we didn't have any humans going into space on our own rockets for such a long time. And we could have.
It sounds also like with regard to the rise of private enterprise in space exploration—Blue Origin, SpaceX, Virgin Galactic, things like this—it sounds like your approach is collaborative. That there are opportunities that present themselves, and the concern is not that they will make NASA irrelevant, but that each of these endeavors has their own contributions to make. Is that fair to say?
Yeah. Well, people think because of what they see on the TV that NASA is like the main thing in space. But if you look at the worldwide budget for space stuff, NASA is maybe 10%. So what’s the rest? Stuff people don’t see. The communications satellites, the weather satellites, the military satellites, the spy satellites, basically the GPS system. The budget that people spend on their pocket GPSs is probably much much bigger than the NASA budget. And of course that wasn’t a NASA project in particular, but it’s part of the space program. I don’t know. It’s probably even—the budget on space movies might be comparable to the NASA budget.
It’s at least in the same number of digits, I think. Anyway, people think that NASA has a much bigger budget than it actually has, because we do so well with what we do have. So I think there’s plenty of opportunity to continue in this domain, as long as people want what we're doing. And I think they do.
Now, a very current events kind of question—only very recently did the current administration name a sixth branch of the U.S. military, of course the Space Force. I'm curious generally, what do you see the Space Force and its impact on NASA? On balance, is this a good thing for NASA? Is it going to draw resources away from NASA? Do you have philosophical problems with weaponizing research that might have originated with NASA?
Honestly, I have no information at all about Space Force. I haven't been following it much in the news, and I don’t think they've announced much anyway. I think people are concerned that space is a battleground. And it is one, whether we like it or not. Because we're not the only players. Our space assets, peaceful ones and military ones, are all undefended and undefendable. There’s nothing much you can do if somebody wants to hurt you. So that’s a reason that there should be some thought given to a Space Force. What you're going to do with it, I have no idea. I said that assets are undefendable, and I think that’s true. You can threaten other people with destruction, but you can’t defend your own stuff. So the logic of how this works, I have no idea. It’s a little bit like mutual assured destruction in nuclear stuff, but I think the details are different. So one of the obvious hazards is if anybody blows up something that makes a lot of debris, not only our stuff but everybody’s stuff can die all at once.
So humanity’s global trade system and traffic system could quickly collapse in an hour. No, that wouldn't be so good. And it doesn't have to be a person you even know about. Somebody that just can get hold of a little rocket, then launch something into space and blow something up can make a heck of a big mess. So anyway, I would say that that means the dangers are not necessarily from the people you ever heard of. Somebody’s got to think about this, and it’s not me, but I'm glad somebody’s thinking about it.
John, for my last question, as I mentioned, I want to ask a forward-looking question, but it’s also sort of retrospective in the way that this question has been asked over and over again. Since the dawn of NASA in the Kennedy administration and all of the ideas and resources that have been poured into exploring space, there has always been the rejoinder, “Why spend money on this, when we can spend it on x?” And x could be anything right? Starvation, social security. Whatever it is, the rejoinder has always been, “There are better things to spend the money on, right here on planet Earth.” Looking forward beyond 2020 as the question inevitably will continue to be asked, what’s the most powerful response that will resonate in the years and decades ahead, to that constant question? Why spend the money on all of this stuff, given coronavirus or whatever else you want to cite as a better target of our resources?
Ah, good question. Nothing simple about that. Congress and all governments have choices about this, and so do private citizens. There are a few things where I think private citizens get to decide. If you want to be a space tourist and you've got a lot of money—well, all right. Fine with me. Be a space tourist. Should the government be supporting space tourism? Well, maybe; maybe not. It depends on whether there is a payoff for all of us in that. Maybe there is. Maybe there’s not. So how about fundamental science? Well, fundamental science becomes the property of all humanity, and it’s something that they can’t take away from you after you've got it. If you know how to build something or how to understand something, that’s a gift of today to tomorrow. If you want to see practical consequences, well, sometimes there are things that you would never have guessed.
An example turned up from the Webb Telescope—the person who figured out how to measure the shape of the mirrors as we were polishing them so we get them right went on shortly after to invent the equipment you see in your eye doctor’s office, that they use to focus their equipment on the back of your eye so they can see better inside your eye. And if you really want to get 20/10 vision because you're a football player, you can, because of him. So we didn't plan that, but it means that when the country and the world is supporting fundamental technology, there will be a lot of benefits. And you will not see the path for how they get there. So when this country was completely terrified of the Soviet Union in the 1960s—well, the ‘50s actually—the Sputnik went up in ’57. NASA was created in ’58. Around the same time, money started to flow throughout the country, not just to NASA, but for people like me to go to summer school and learn physics and math so we could defend the country. So the country was defended. Nothing really bad happened to us from the Soviet threat. And guess what happened as well? We became the world leader in everything technical. Every single thing. So the threat of total annihilation prompted us to do something that had obvious consequences that we now see everywhere.
Everything you can buy, everything you use to buy it with, that computer you type on—all of that came from the huge expenditure this country made into technology. And it was a lot of it not for NASA. Some of it was military. Some of it was secret; some now. If you want to see in your biology lab now, a lot of that equipment was made by physicists. And they can do that because of the investment the country made in things that seemed different at the time. So if you want to keep the golden eggs coming from the goose, you should at least keep feeding it. That’s my feeling about it. That’s a long-winded answer to what do you do; you could spend the money on something else. Of course you could spend the money on something else. But research into new things that you need will pay off forever.
Well, John, it has been an absolute delight speaking with you today, and I want to thank you so much for spending the time with me.
Thank you, David. It’s a pleasure. I carry on a little bit long. My voice is just worn out here!
[laugh] Perfect timing.