Michael Tinkham

Zimmerman:

How did you get to choose physics, how did you become a physicist?

Tinkham:

Oh my word! Seems we've had a conversation like this before, but I think it was earlier.

Zimmerman:

Yes we did, but I would like to have it recorded.

Tinkham:

Well, it happened that we had several sort of old group members and associates at social events during this weekend sort of, and they grilled me to find out everything about why I chose physics or whatever, and I never thought that was a question really worth thinking about, it was obvious. [Laughs]

Zimmerman:

Essentially when you were in grade school, high school…

Tinkham:

Right, okay, you want something from back then. Okay, let me just tell you the story of my youth, what the hell.

Zimmerman:

That would be great.

Tinkham:

Well, first of all, I was brought up on a farm in Wisconsin. It was run by my parents and so on. In addition to my parents I had a couple of uncles, both of whom happened to be chemistry professors at Marietta College, which is a small college in Ohio. But they all had gone to Ripon College, which is a small college in Wisconsin, and Ripon is the nearest town to the farm where I was brought up and so forth, and since so many parents and stuff had gone to Ripon in their generation, it was an obvious place to think of for me to go there. I know that doesn't explain why it is physics, but if you do chemistry, physics is not very far away. So these uncles, they'd show up at the farm in the summertime to do work there, and bring up students. This was during The Depression, so it was nice to have a summer job, even if it was working on a farm. And so my early youth then, the first two grades of education, I was often in the presence of chemistry students from Marietta College, chemistry professors from Marietta College, and so forth. So that looked pretty good. But then I got interested in ham radio, so I got my ham ticket, and that of course involved more electronics and less chemistry, and I worked my way up until I had my Class A ticket and was able to do all the things that were at that time possible. And then my future was affected by Uncle Sam getting in the war with the Japanese, so with my knowledge of electronics I was able to get into the radar program and get more experience. It was actually a pretty good training program for radio high-frequency stuff and so on. So I did a lot of that, so by the time I got out and ready to enter college, I was pretty much locked on the idea of radio or electrical engineering or something like that, which seemed to me to be the going thing. So I then went to Ripon. The program they had there was one that combined a couple of years of MIT with a couple of years of Ripon, so you had a combination of a big-time school and a small school.

Zimmerman:

They had a cooperative agreement?

Tinkham:

Yes. You signed up for five years at the beginning with MIT for the second half and Ripon for the first half. So I showed up at MIT basically at the end of my sophomore year with not very advanced preparation because Ripon being in the Midwest and so forth and not being intellectually a leading place, more of a family place sort of, it was rather nice when I arrived at MIT in the middle of this time, I was making a big jump from Ripon's business where you do well to know how to do simple calculus or something, which I think I did get that far at Ripon, but then it was MIT. I stayed on for my doctorate because I established contact with a professor. Woody Strandberg was my advisor there. He was mainly electronics and radio kind of a guy in physics. And so I did my thesis there.

Zimmerman:

I noticed that your thesis was in the properties of oxygen.

Tinkham:

Oh absolutely. I use that just to confuse ... [chuckles] No, that's right. See, oxygen is after all a magnetic system, and so the microwave magnetic resonance spectrum of it involves all\ most degrees of freedom. You have spin and you have rotational states and so forth. So I wrote a thesis that was quite fat and full of math because I was determined to produce a sort of unified point of view that includes all of these degrees of freedom in their own boxes sort of, but all coupled together. So the title of my thesis was I think "Magnetic Resonance Spectrum of Oxygen with ..." something, oh I can't remember. I don't have a copy of it here anymore; it's at home. Anyway, so that's where I started with combining my microwave, which I sort of got from ham radio and the Navy, and then the molecular properties, which we studied books about how the different degrees of freedom are coupled together and so on, so I have vibration, I have rotation, all that stuff.

Zimmerman:

Was it an experimental or a theoretical (thesis)?

Tinkham:

Well it was both because the data was all obviously experimental, and yet I had to do quite a bit of theory to just go through the motions to get them all coupled together right so you could get sort of a unified theory, which included both things which you measured in the microwaves and things which you just got from books about the vibrational spectrum, things like that. So when I was finishing my PhD I was worrying about what to do next, and what I managed luckily to do was to get an NSF fellowship, which enabled me to go to anyplace that would take me in sort of, and I chose to go with Bevus Bleanei, now deceased unfortunately, who was a leader in microwave magnetic resonance in England. So that gave me my first exposure to international living. I had only been to places like the near part of Canada before, so that it was quite an exciting adventure to meet England and Europe and all those nice people over there. And of course Bleaney is a very smart guy and very insightful. It was a very nice year to spend with him. He even offered me sort of a job, but I decided that having seen a year of England in the post-war period that probably Wisconsin or the United States at least was a more promising venue to look for a job in than England.

Zimmerman:

I was wondering about Europe at that time. That was about ten years after the War, right?

Tinkham:

Oh, it was much less than that I think. Well, now I don't remember.

Zimmerman:

I think according to this, you got your PhD in '52, '53, or thereabouts.

Tinkham:

I think '54, actually.

Zimmerman:

I came over from Europe in 1950, and at that time much of Europe's big cities were in ruins.

Tinkham:

Yes. Well, England was not as badly ruined as the continent obviously, but the things that impressed me about it, or depressed me or whatever, is that the food was not very good.

Zimmerman:

There were still shortages, probably.

Tinkham:

Oh yes, things were still rationed, I don't remember the details. What impressed me because I'm sort of a guy who likes to eat is the fact that food was sort of hard to come by, or have better quality. There was one restaurant in Oxford that was sort of known for where Americans go, so that had proper food, but most of the others were less grand. I remember that we had... well, I can't get this right, but I ate in the same sort of upstairs joints that the graduate students did, who I talked to more than anyone else. And I was considered rather luxurious because I was willing to pay the extra tuppence to have a kind of dessert with the meal, which would be some little dish of pudding of some sort or something like that, and all the indigenous people thought I was being pretty swank to do something like that, but we got along fine, they didn't hold it against me, but it was just a thing that distinguished our two standards of expectation.

Zimmerman:

I remember they asked that. I was in Holland, and at the cafeteria the main event was on Wednesday they had pea soup — it was a delicacy.

Tinkham:

Ah-ha. Yeah, there are people who like pea soup; it's not a lie [laughs].

Zimmerman:

What did you work on with Bleaney?

Tinkham:

I worked on just classic magnetic resonance lines in electric crystals with isolated ions. Zink fluoride was the basic crystal in which you put-Well, to tell a little bit more of the details of the human relations. The crystal that I worked on for that year was sent to Bleaney by another physicist I think in Scotland. Why I don't know what was the relative equipage situation or whatever. Anyway, so Bleaney got it and he then passed it on to me, he said this is your project — to figure out this complex spectrum of this crystal which has five different kinds of impurities and so forth. So that gave me an excuse.

Zimmerman:

Impurities make things interesting!

Tinkham:

Yes. So that gave me an excuse to learn a lot of quasi theory. Spin resonance, spin Hamiltonian stuff and so on. So that gave me another kick after the oxygen thesis that I had done towards always being interested in trying to do as much of the theory as I could just so I really understood things more than just description but something where it had a little deeper level on it. So that was basically the subject of my post-doctoral year. At Oxford I squeezed out of it a short paper in Proceedings of the Physical Society, two papers in the Proceedings of the Royal Society, all with Bleaney as the co-author. I think the mean publication output was that. In terms of experimental things per se, I found that I was somewhat limited in signal to noise because these are dilute impurities, so what I had to do was to increase the sensitivity of the rig, and what I did to do that was to take account of the noise to say that if it could work at a higher frequency we would have less noise. So I scrounged together a dozen little lead acid batteries and used that and managed to improve the signal to noise by the ratio of the 100 kilocycles that I was using just to modulate the field compared to the 60 hertz or something that people tend to do at the first cut at doing these things. So that made me able to see things that were smaller than had been before, and that was really nice. So I published a paper in Proc Phys Soc and the Roy Soc and so forth. And I'm sure that Bleaney's hand was important in this, but my name was on it anyway, [laughs] so I have to be thankful for that. So while this was all going on, I was of course saying well this is a one-year fellowship, what am I going to do now? And I had the good fortune to be able to have some choices because I had an offer from Bell Labs for whatever they call their regular staff people; an assistant professorship at the University of Pittsburg, which at that time had a fairly nice small magnetic resonance program at which Al Portis, for example, was working at that time, and I met him again at Berkeley when he was of course there where he had started with Art Kipp. In addition to those two offers, the important one turned out to be that I had an offer from Berkeley of a post-doc. So I had three offers: one as a staff member at Bell Labs, an assistantship, or a post-doc. And of course I chose the post-doc because it paid the least and had the lowest rank, but it did have Kipp and Kittel, who were capable of being very helpful in learning things and knowing what to do. So I came to Berkeley and was there for a long time, ran up the academic ladder, and then at some point I moved to Harvard.

Zimmerman:

What made you move to Harvard as opposed to Berkeley?

Tinkham:

That's a good question. Because I liked Berkeley from day one, so I certainly did not feel I had some motivation to leave Berkeley. What I had was a motivation to sort of consolidate family because my wife's parents lived in New York, so it was more of a struggle to get back and forth for holidays and so forth.

Zimmerman:

Did you get married as a graduate student?

Tinkham:

Oh no, it was probably during my actual assistant professor stage at Berkeley. I really don't remember — I didn't have that on the same page. [Laughter] But the thing that really clinched the argument was when we had our first child, Mary's mother, who was a doctor, although she was retired at this point, came out to Berkeley and spent a week or two there keeping the ship afloat while we got used to having a baby on board and things like that, and it seemed to us that really we shouldn't make that so hard, so if we moved to Harvard we were within a much shorter distance and could count more surely on having the support of the mother-in-law. Anyway, that's the official story, and as far as I know it's the genuine story. We agonized, you know, we made lists of the arguments that made the Harvard offer look better, which make the Berkeley staying offer look better. It was amazing how with some human brain skill that we had no knowledge of we were able to make these two lists exactly the same number of items, so there would be 37 reasons to go to the East Coast and 37 reasons to stay on the West Coast, or something like that. So that's why we had to rely on the mother argument being something that was okay. Anyway, do you want more physics of the current epoch?

Zimmerman:

If you would like to, certainly. One other thing, when you were at MIT, were there any classmates who were outstanding whom you collaborated with or made friends with or something?

Tinkham:

Well, I would say that the simple answer is no, but that's not very accurate, because after all, you work in a research group and you get to know all of these people pretty well, and mostly they're fun and okay and so on. But my project — I mean Woody Strandberg is an interesting character (I think he's still alive). But he encourages people to be independent and do their own thing sort of, and so no one else was working on oxygen or anything like that, and so I was just doing that, and I got into that because Woody had picked up a couple of papers that left some questions to be dealt with in this oxygen business, and he had earlier when he was even younger written or co-authored at least a paper on oxygen, but not magnetic resonance in oxygen, but the molecular oxygen, the O₂ resonance as opposed to a single atom and things like that.

Zimmerman:

By the way, does that relate to our current microwave ovens? Is that the resonance that we use?

Tinkham:

I don't know. It's 5 millimeter waves roughly is the frequency, but I never pursued it in industry or anything like that.

Zimmerman:

When you were at Berkeley and also when you came to Harvard, you had a lot of graduate students, you had a lot of publications; you had a lot of very significant achievements.

Tinkham:

These are statements, not questions.

Zimmerman:

Those are my statements.

Tinkham:

Okay, because I'm a little nervous about... anyway. Let's come to a question, though.

Zimmerman:

The question is could you describe some of the things that stand out?

Tinkham:

Well, one thing that stands out is the number of students that I trained, and I have all of their theses, the original copies, presently in my home, lined up on a shelf, and there are some number of them, like 65 or something like that, so it's a large number, and this was managed by having typically half a dozen at any time working on different projects, so the rate of production output is greater with a bigger number of channels working.

Zimmerman:

Did Harvard give you the resources to do it?

Tinkham:

Oh Harvard didn't give me a dime. You know, that's the usual things, grants from Uncle Sam. And that was in the good days when the government was still supporting science, not necessarily to make some political point or something that, but because it was probably left over from the war, the radar and the bomb convinced a lot of the people in Washington that science was a good thing to have strong, and so it wasn't so incredibly hard to get a grant. I had Navy support throughout, and NFS support throughout, and these were basically renewed every three years or five years or something like that, and it was not a big problem. I still had a role model, I had Charlie Kittel. He had had a bigger group, and he had been doing this well for a long time and was undoubtedly a leading contributor, and so he would sort of look at my proposals and give me suggestions on how I might be able to make it more punchy or something like that. But I thought for me personally, the size of the group of something like five or six, a pretty narrow range like that, was the best for me in the sense that if I had more I could spend less time with each one, so they didn't move as fast, so they didn't really gain very much from the risks of getting involved with supporting and leading more people, and so I kept it what I consider a reasonably small group. Some people seem to be able to run groups of 10 to 100 — well, maybe not 100, but...

Zimmerman:

Well high energy, they're 100s. I went into low-temperature physics in order to have my own apparatus.

Tinkham:

Yes. Well, I did the same. This is interesting but a somewhat difficult thing to think back over all these things and fear you're making some mistake in your remembrance of someone. But I think most everything I've told you is pretty factually demonstrable. Now I started out in magnetic resonance, as I've said, but I'd gotten interested in superconductivity, and I'm having a little trouble remembering exactly how this went. Because superconductivity is a fascinating thing, and as a graduate student I'd been well aware of the existence of this phenomenon and the fact that it wasn't understood, and so I'd always had a sort of a hankering to understand and explain in a better way that was available at that time. So when Charlie (Kittel)set up this group seminar to look into superconductivity, which his group had not worked in previously really, he appointed me to the topic and the list of the subjects of the seminar-the high frequency properties or something bland like that, which lead rather naturally to the energy gap and things like that. So I had this transparency that said "The role of C. Kittel," and it simply recited what I just said, that he gave me the assignment of looking up high frequency properties and building on that, and that was very important. But it wasn't that he did it. He never wrote a paper involving superconductivity as far as I know. That may be wrong, but if I am trying to fend off as the assumption that somehow if you work for Charlie Kittel you do what he says and you don't have any thinking to do at all, and I didn't believe that. I thought that I was allowed to think and do things and Charlie was very supportive and so forth. So it was a very ideal set up: someone who will give you the money to build the equipment and give you useful commentary, but not just take it away from you and go on to the bank. So I've had luck, good luck. Now, what other things might I throw in here, because that seems like a very short story.

Zimmerman:

What do you think… I saw that you are still active, and you just have your name on that paper with Millie Dresselhaus on the carbon nanotubes or something like that.

Tinkham:

Oh that's right! That was the last thing —

Zimmerman:

This was published in '08, so you are still active. You have really contributed a lot to the understanding of superconductivity, starting with the energy gap, and then you did I guess the single, well when I was there with (Chriss) Lobb (on an sabbatical), and a little bit after where you could observe this single electron change, by Joseph injunctions, in an island.

Tinkham:

That one is one that I don't remember as well. I don't know why. Maybe I wasn't as personally involved.

Zimmerman:

Let's see, what was the Coulomb blockade, things like that.

Tinkham:

Oh yeah, we certainly did Coulomb blockade stuff.

Zimmerman:

Then when the high-temperature superconductivity was discovered, you wrote a set of papers trying to explain it by looking at the nature of Joseph injunctions. That still is, in my opinion, a viable model.

Tinkham:

Well yes, it's a pretty good model. But the stuff that people were interested in mostly in that was how high is TC and things like that. You know, a model is only useful to people who want to find uses if it leads to a usable result, and something that can do something better than could have been done before. I never got into that. That is to say, I basically ignored high TC, which was a little bit bizarre, but I did anyway.

Zimmerman:

I started modeling the Joseph injunctions when I was there, (on a sabbatical in 1989), and now I have some students still working on it, and we have a very nice interactive thing where we can put on the magnetic field, we can put on a current and things like that.

Tinkham:

Yes. Well, I just got to be retirement age [laughs].

Zimmerman:

Who do you think your most outstanding students were?

Tinkham:

Oh my, I had a lot of them. I would have said over quite a range of time that my standard of excellence was my first two students, Ginsberg and Paul Richards, who were involved in the first gap stuff and a lot of other stuff. They were just tremendous guys. But then as the numbers came along, there were of course plenty of others but I can't remember names quick enough to recite them. So the fact that Richards and Ginsberg always come to mind is mostly because they were the first and second students. The third student was much less gifted and was not interested in superconductivity particularly, so he went off in a different field and disappeared into Westinghouse or something like that. So after that, there were so many, 60 names to appraise. I try to keep in touch fairly much. I mean we have maintained a Christmas card exchange tradition with a fair number of students; not all, of course, because they weren't all equally personally involved and so on. I have post-docs galore that have been wonderful. But with my brain having been banged, I don't have much memory.

Zimmerman:

What happened?

Tinkham:

It was an accident. As far as I can figure out what happened is one night when I was in bed asleep or whatever, I got up out of bed to go to the john or something like that, and in the process of navigating around the bed I fell into a dizzy mode and fell very hard against the comer of a bookcase that was right next to the bed. It seemed to be something that was recovering. I mean next day I wasn't aware of anything too serious. But within a few days it was clear that there was more damage than I had realized, and so I spent some days in hospitals and rehabs and surgeries and so on, and they found a ... oh, I can't remember the fancy medical name for it. Anyway, we now think that the surgeons were a little too optimistic and thought it would cure itself, it would drain and blah, blah, blah, and so they put off doing the surgical drainage, or whatever you call that when they take fluids out of a place where it shouldn't be. And so ever since then I have been trying to regain my memory, and not very well. I obviously have enough memory so I can fake it. One of my criteria is how well I can play the piano. I used to rattle off things, not big music but fun music, and that became pretty sparse. It's coming back. I can rattle off the Stars and Stripes Forever or something like that.

Zimmerman:

When did you learn how to play the piano?

Tinkham:

Oh, when I was five or something. It was parents send you to a piano teacher. If you live on a farm, they piano teacher is in town and it's a little harder to get there, but it's not that far. If you want a musical biography, I also play the bassoon, the tuba, the piano of course, and occasionally the organ, but that I didn't ever have any real access to. That seems to be about all. Music is something I enjoy very much. I played in the band at Ripon High School, played in the band at Ripon College, played in the band at MIT, and so on.

Zimmerman:

They have a very good orchestra at MIT.

Tinkham:

Oh yes. I was there during the 30 years or whatever it was that John Corley was conductor there, and he was a great guy. Not a stuffy Boston musician but a regular guy. So he played the Russian Sailor's Dance and all von Wagner where the tuba gets a chance to brum-baba-ba-bom-bom-bom. You know. [Laughs]

Zimmerman:

We recently heard the Bartok, The Miraculous Mandarin with the Boston Symphony, and the tuba got quite a workout!

Tinkham:

I haven't done that so I'm not personally familiar with it. I like the Schwanda der Dudelsackpfeifer type music. Are you familiar with that? The name of it is I believe Schwanda, proper name, The Dudelsackpfifer, which I think means a bagpipe player. That has in it a part where the pipe organ I think takes over the theme for a few bars and so forth. It's a loud, masculine type piece of music [laughter], which we all sort of like to hear, "Oh! We're going to do that this year!" [Laughs] Anyway. It's been an interesting life and career. Luckily neither is completely over, but the career is pretty over I think.

Zimmerman:

Well, at our age it is. And it's more relaxing because you don't really have to achieve anything.

Tinkham:

Yes, I'm not raising grants anymore.

Zimmerman:

You got off your knees, right, essentially begging for money?

Tinkham:

Yes, yes.

Zimmerman:

Anything else you would like to say, or shall we stop?

Tinkham:

I would like to say thank you for giving me that disk, which I look forward to seeing. It's a video, DVD?

Zimmerman:

DVD, yes.

Tinkham:

I can't even keep up with the names of the technologies now.

Zimmerman:

I don't know what DVD stands for.

Tinkham:

Well 'D' is probably 'disk'.

Zimmerman:

And 'video' would be the 'V'.

Tinkham:

I don't know. I basically try to sashay out of such discussions because I know my ignorance of technical methods will be revealed quite quickly. [Laughs] I guess the best thing for me to say is we probably should stop, but I have not pressing duties, so if there is anything else you want to touch on, I'm not looking at the clock.

Zimmerman:

What do you think of the ultimate explanation of high TC is going to be? Do you have any ideas?

Tinkham:

Oh! I avoided high TC, and partly because I didn't want to try to answer that question. I never could quite believe that you could get enough interaction out of phonons, although there are always some people who think you can, and I don't know that they're wrong or right.

Zimmerman:

People are thinking of other mechanisms other than phonons.

Tinkham:

Oh yes, I'm sure. They've been doing magnetic spins for decades.

Zimmerman:

I guess in March I saw Phil Anderson, and he's still sticking to his theory.

Tinkham:

Ah yes. Okay. You don't want any of my papers, do you? These things are all full of papers, and I haven't figured out how to get rid of them. The plan had been that Ike Silvera was going to put up a notice to the Department saying that these papers and books and stuff were basically available to Department members, but he then didn't get to actually doing it, and so they are. still sitting there as they were left by me.

Zimmerman:

Papers, publications?

Tinkham:

Yes.

Zimmerman:

By the way, when you were at Berkeley, Gene Dresselhaus wrote, I don't know if it was at the same time or it was another one, it was the Dresselhaus-Kipp-Kittel paper that he wrote. Did you ever meet Gene?

Tinkham:

Oh yeah, sure, he was a well-known person around there.

Zimmerman:

Was he older or about the same age as you are?

Tinkham:

I would say about the same age. I mean I don't know any better than that because I had known him for quite a few years, so he must have not been too different in age and so on. Of course Millie has become a hallmark of excellence.

Zimmerman:

Millie has been overshadowing him.

Tinkham:

Oh yes, for some time. In fact, one of the Dresselhaus remarks-not about him I could supply, but this is not for attribution-was that Charlie Kittel and Art Kipp, who had a joint contract for many years and were very supportive of Art doing experiments, cyclotron resonance and all that stuff, and Charlie doing theory. But they did not get along particularly well or communicate particularly well because Charlie was sort of a smart theorist and Art a plodding experimenter, just measuring good things and so forth. So the statement was made by somebody, and I'm not sure if it was Charlie himself, was that the only way that Charlie and Art could communicate was through Dresselhaus. This is particularly I guess in the days of cyclotron resonance when there was a question interpreting all the different features of the cyclotron resonance spectrum. That was a thing where Gene particularly did important theoretical work as I remember, although I wasn't involved in it. As far as I know, Charlie is still alive. I don't know that for a fact. Art I know is not. All too many people I know well...

Zimmerman:

Charlie Kittel I think is not alive anymore. His son is becoming famous.

Tinkham:

Ah-ha! His son is the guy that I was teaching calculus to when he was in high school or something when I was just first arrived and trying to live as a family member very informally. Charlie would invite me over for Sunday dinner or something like that, and I'd eat there and we'd talk about whatever we talked about. Oh those were golden days. Another person who I knew well who is no longer with us of course is De Gennes, who is deceased a few years ago, as I remember.

Zimmerman:

Yes, he died a few years ago. He got the Nobel Prize for doing work on babbles.

Tinkham:

That may be. He did so many things.

Zimmerman:

Where was DeGennes at the time?

Tinkham:

He was always in Paris. He was not at the Ecole Normale Superieure. (Actually he was at Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris, DeGennes and Tinkham met at Berkeley) That was where one of the other guys was always. He was at Orsailles when I worked with him, then he moved into the city and to the very prestigious one where you have very few lectures but each one is supposed to be of all. International level, or something like that. I know that perfectly well but I can't dredge it up now. Of course he was the one who surprised us all by having two lives and two families at the same time for much of his adult life. That was something that became manifest when he got the Nobel Prize because the newspapers reported that he had a certain number of children, and his children said, "That's not the right number. Who are all these other...?" [Laughs]

Zimmerman:

I remember when I was in Germany it was the custom that a man would have two families.

Tinkham:

I thought that was only a French specialty.

Zimmerman:

No, no, Germany too. Right after the War there was a shortage of males. A lot of people got killed.

Tinkham:

That's right. I hope that that will not repeat, but given all the proclivities of people that make war on each other and so on, it's hard to be optimistic about that.

Zimmerman:

It's hard to be optimistic about the world, but people get by and work gets done, and there is some good being done and some bad being done.

Tinkham:

The things that the bio science people have managed to do are pretty imposing. What they're doing about memory, which is something I'm particularly interested in, but they haven't done anything very miraculous for me. What they've learned about it is how the brain works, and a lot has been learned. Not enough to (sink your teeth into), but it's sort of a thing that makes it worth reading more.

Zimmerman:

Just the fact that one of these things (takes out a flash memory) can hold one gigabit of bites.

Tinkham:

That's sort of for people that keep up with computing and stuff. I don't have one of those things.

Zimmerman:

I think it was us who laid the groundwork.

Tinkham:

Oh yeah, sure. But (then what) I think when involved in discussions of learning and so forth, I tend to find some way to sneak in the fact that when I was in probably junior high school or something like that, I always used the slide rule, and no one else in this class or maybe even the school knew what a slide rule really was. But log rhythms and stuff are pretty simple, and so you can figure out how a slide rule works. But I haven't managed to similarly beat down those little boxes like you showed me. [Chuckles] I don't know how that works, so I'm like having the kids show me the slide rule of today and I not knowing how to use it. Anyway, I very much enjoyed the conversation.

Zimmerman:

Well, thank you.