Interview with Francis Everitt

0:00 Here we go. Seems to be working okay. And I'll just briefly say that it's the 20th of July at 3 o'clock and I'm speaking with Francis Everett. So you were going to say that... Okay, let's back off and not talk about PPN for a minute. Probably a good idea. I think that the whole problem of the relationship of theory to experiment in physics is actually quite peculiar. And one of the reasons it's peculiar is that sometimes experimentalists can test things that theorists may or may not be tremendously interested in testing. Sometimes theorists may be interested in test things, but there's no conceivable way experimentalists can do. For example, I mean, we could always say how nice it would be able to do some measurements at the plank planks. Right. But we're not going to make any measurements at the plank planks in my lifetime as far as I can see and probably not in yours. One can always be a little bit careful about those statements because maybe somebody will have some fantastic idea, but it doesn't look very likely. Now, with regard to the PPN formulas, and the thing that I think that was very interesting about it, there were two things, one which was less interesting and one of which was more interesting and both interesting. First was it brought order into a lot of theories, you know. I mean, there were all these theories of gravitation floating around and nobody could see what the connection of A to B to C was. And then the PPN formalism put a framework in which you could say, oh, well, this theory is going to predict a certain PPN parameter. That seems to me to be the less interesting thing about PPN. The more interesting and very surprising thing was that it fit to the suggestion of quite a number of new experiments. experiments. Now these experiments that were suggested by PPN were all null experiments. I don't mean to say that other experiments like the Shapiro time delay were not things that could fit within the PPN. Of course they can.

2:30 But it wasn't, Shapiro didn't come and think of his time delay experiment out of PPN. What rather happened was this highly peculiar thing which Cliff Will expressed at one time maybe still does of saying that general relativity is a minimalist theory. theory. So you find theories, find situations where Newtonian gravitation predicts a null result, general relativity predicts a null result, and some alternative theory, like the scalar tensor theory and the Nord-Vett effect predict a non-null result. Now that It seems to me intellectually extremely interesting and curious. And it's what I would call the more profound aspect of EPN. Having said that, in what sense do I mean more profound? I only have to think at the moment I mean something that took most people by surprise. and whether you really argue that profundity depends on surprise or on some other factor I'm not quite sure that's how it strikes me is that comment of any value or not I don't know very interesting because well for starters so far as I'm interested in the PPM framework I'd be interested to get an alternative viewpoint from the theorists that I'm used to talking case. Well, here is my next few points. As you know, it was something like 40, 50, I don't know, alternative theories of gravitation which mostly got put within the PPN framework and one or two maybe don't fit within the PPN framework and so forth and some are riddled with inconsistencies and so forth. My own intuition is that when finally we disprove general relativity, I don't mean by we, we gravity probe B or anything, I mean we, the scientific community, the actual breakdown

5:00 down will be none of the above. You know, there's a very interesting precedent with electromagnetic theories in the 1880s. Probably you know this, but in 1884, J.J. Thompson wrote a survey article on comparing alternate electromagnetism. And I think there were either 9 or 11 alternate theories. And he tried to put them on a common basis by expressing them in Lagrangian form. And you know, Maxwell's equation has these terms in it's Lagrangian, some of Helmhoff's theory has those terms in it's Lagrangian and so on down the list. Theories by Betty and by Carl Neumann and by Lorenz, not Lorenz, but Lorenz and so on. At the end of his survey article, J.J. Thompson says, well, then, personally, the theory I think is best is Maxwell's, it's a pity we don't have enough it's valid or not. So immediately after that, four years later, a tremendous triumph of Maxwell's theory, electromagnetic waves. And then what was it? A further 12 years, and we find out that Maxwell's theory breaks down. How does it break down? It breaks down by quantization. So, which of those alternative 11 theories that have been proposed in the 1880s or the 1870s and 1860s contains the slightest glimmer or hint or anything of quantization? Absolutely none of them. So, however, whatever the breakdown or problems of GR will be, my sociological, because this is really not a scientific theory, my sociological feeling is that it will be none of the above.

7:30 Well, it's a very interesting parallel, actually. I can't really consider that. It's an active parallel. does your sociological theories develop from the feeling that just highly unlikely that a theorist is going to be able to anticipate the way that GR will break down? No, I think it's a bit more peculiar than that. I mean, I think what I'm about to say is so absurd that I'm dissatisfied with it, but I'm blurted out anyway. way. The fact of the matter is Maxwell was much smarter than any of these other people. He produced the theory on various grounds, some of which were highly intuitive, but which all sort of worked. In the same way, Einstein was much smarter than any of these other people, and he produced a theory. Now this seems to me a fairly rotten sort of argument that I'm producing, but I don't know quite how else to put it. There is a piece of sociology about gravitation, all theories that I find profoundly disturbing. That is theorists who catch what you might call the Einstein syndrome. You know, Einstein took ten years to think of general relativity. If I go off into my closet for ten years and start with some theory based on group theory or some other exotic mathematical thing, I will eventually produce the mega achievement

10:00 that Einstein did. It's the most peculiar vortex I can name, though I won't, at least the three theoreticians I know who seem to me to have caught this disease. What do you make of that as a sociologist? I think it's interesting because, in fact, the question I was actually going to ask fairly numerous alternative theories that are put forward serve a useful purpose in science even though it's unlikely you feel that anything will be indicated in relation to GR but is there some, and this is one of the ideas that I'm interested in particularly if one has a group of theories that maybe many people I think are not likely to prove to be a real theory, a true theory of gravity for instance Is there some purpose, sir, by having this store of theories at all? Are they ever useful to you in your role as an experiment? Well, why don't we take another example, hidden variable theories in quantum mechanics. First of all, I am by no means convinced that all the alleged disproves of hidden variables, going back to von Neumann and other people, you know, and this almost theological claim and that we have disproved hidden variable theories, I'm by no means convinced those arguments are as watertight as they're made out to be. You know, people will claim Bell's Theorem to me and will say that the experiments of Alain Aspect finally conclusively confirmed Bell's Theorem And so, you know, stop talking about hidden variables. On the other end, I've never seen anything of the slightest value come out of any hidden variables theory.

12:30 So that's a fairly schizophrenic point of view, isn't it? The people who prove to you you mustn't do it are the only people who convince me that it may be worth doing. So, possibly there is no great practical advantage which is derived from having various alternative theories, but on the other hand, in principle, there may be nothing against many of them. Well, I suppose we now go to string theories on which my real knowledge is extremely slender. I have no idea whether string theory is really going to meet anywhere with all the hype, but maybe it is. so I'm perhaps a little more persuaded than it might than I used to be. Now, it appears that you would much more likely expect a scalar tensor theory of gravitation out of string theories than you would a pure tensor theory. And then there's the various questions of what do you do to make the scalar term disappear, two alternative points of view on that subject, like male, the scalar term requires mass, or alternatively that is this attractor mechanism suggested by de Moore and Polyakov and Nordvet, which makes the sort of, as the universe expands, sort of approximates towards the scalar term more and more, but it doesn't ever quite go there. Is that a worthwhile enterprise? It seems to me that it's more of a worthwhile enterprise than most of these other things that were demolished or bounded by PPN. Why does one think that? I don't know. I certainly don't think it because there's a thousand theorists out there.

15:00 sort of following each other like sheep through a field of mathematical elegance. What were you working on with Kip, by the way? I worked on radiation reaction of orbits of small particles around a curve that was And also a little bit, well, primarily on that, using perturbation analysis to analyze the in-spiral due to gravitational radiation reaction. Especially with the view towards possible space-based gravitational reaction in general. Hopefully to understand better the in-spiral waveforms. When were you with him? From about 1991 to 1996. Did you do a Ph.D.? And then you promptly are doing another Ph.D., or you just made yourself into a sociologist without... ...benefit of... Simultaneously with the physics Ph.D. that I did, and that's what I went there to do, I, um, with, uh, the topic was a kid's suggestion, I did a history of science, I wrote a thesis in the history of science on, um, fairly broadly speaking, but not everything, but, uh, the history of the, the same gravitational radiation reaction problem, in particular, the quadruple form of controversy and work of Bondi and many others in the 50s and 60s, looked at earlier too. So I wrote a thesis. So you wrote two simultaneous theses? Yes. That's quite an achievement. It took a while, but it was very enjoyable and it worked very well I felt that doing both often helped each other. Certainly, I got a better notion of some of the older literature in my own field than I would have known. Who is your sociology of Pareto? Diana Barkin. She's a historian of science there.

17:30 She's one of more or less the two that they have along with Dan Kevles. I know Kevles. Yes. And subsequently, I would like to work with this chap Collins in the car. Or by good fortune, there's also a relativity group which is working in a similar area to where I had been working, so I still also maintain a little interest in physics, too. Well, I was interested then also in asking about, maybe if it doesn't take up too much time, just to ask a little bit about some of the early background to Gravity Pro-V and the genesis of the experiment. and if it leads into that I'm also interested in for you is the goal of the experiment for instance is it to disprove Einstein's theory simply to provide a test of it or is it simply to discover the effect whatever it would be I'm sorry to sound so old fashioned it's to find out objective scientific truth is on a particular measurement. So, I guess the only question I would have in response to that, which sounds like a fair enough answer, is why is this particular measurement important as opposed to, say, I'm not quite sure that I understand the nature of the question. Well, I mean, yeah. I think you can justify an experiment on a whole variety of ranges, you know, grounds. One of the grounds on which I would justify gravity probe B is it's a physics experiment,

20:00 whereas none of the other tests except gravity probe A, I would count as physics experiments. Let's say if you take the radar time delay experiment and its various forms, that's an astrophysical observation. This is a physics experiment. Actually, if you want me to soon talk sociologically for a minute, I find a very curious thing here. Radar time delays now to part in 10 to the third, maybe better than that, confirms general relativity, right? Why do I believe that? that the radar time delays to confirm it to that happen. I suppose in my case it would be because that's the report or the version of the report that I've heard about such experiments more or less at second hand. I certainly don't believe it because I know that it's true. Neither do I believe it because it's possible for me to find out whether it's true. Let's say there's a computer model which has a 2,000 parameter fit. that for me to in fact penetrate that computer model would probably be five years worth of work. Nevertheless, I believe the result. Why do I believe it? Because based on your understanding of other results, and your understanding of the way they support G.R., you find it happily that those results disagree with G.R.? I believe it on the basis of a character judgment.

22:30 I happen to know Irwin Shapiro. I happen to know that Irwin Shapiro is a quite outstandingly honest and careful human being, and because he tells me that they've looked at all of this, that and the other, I believe that they have looked at all of this, that and the other, and therefore I believe the result. I find this extremely peculiar if I think about it, and I even find it disturbing for the following reason. I am under the impression that I am a reasonably honest person. I even think that I am a reasonably careful person. However, if you were to really probe some of the things, the calculations I have made over the years on Gravity Probe B, and the horrible mistakes that I have made, mistakes which were missed by all of the review committees which I only found out afterwards by myself or by somebody else in our group. Just makes me wonder, could it be that really Irwin has actually missed something and could Would it be that the fact that it comes out and agrees with general relativity is because of course once you've found out a result that confirms general relativity, you stop looking for the possible troubles. I don't think so. I mean, I think in this instance I'm a believer, but when I look at some of the other claims that have been made about various experiments and I also make character judgments on those people, and I'm not wanting to make odious comparisons, I don't emerge as a believer. What do you make of the sociology of this? Well, I find it very interesting, as a matter of fact, the paper that I'm just more or less trying to address some of the issues, because, as you say, from an outsider's point of view,

25:00 than probably most or many theoretical results, one actually has to apply somewhat external characteristics in deciding whether to believe the result. After all, you haven't done the calculation or the experimenter yourself. So as you say, you must estimate the reliability of the experimenter and no doubt your influence a little bit by, or maybe a lot, depending on the case, by whether the result is expected or not in regards to your prejudices. And there, as you say, there's always the worry that that may have influenced the experiment, too, because, as you say, if you get to an expected result, one may be more tempted to stop searching for possible errors. Well, we certainly know an example with the Einstein-DeHaas experiment where they got the expected result And if they had only been more honest and careful experimenters, they could have stumbled on a great discovery. Sure. So we know that can easily happen. and I suppose and so I our columns, the chapter I'm working with has also looked at this in the experimental case he's trying looking at the Joe Webber controversies and one of the ideas that I tried to follow also in this recent paper that I wrote is to look at a case where there's a controversy that develops over a result because in that case people talk more about their reasons for believing the result and they often several people will try to work on the same problem from different perspectives and often they'll disagree and then you see people struggling with which one they believe and what criteria they apply and it certainly seems to be the case that a reasonably potentially long period of time, like several years or maybe even several decades in the case of this gravitational radiation reaction problem, where you've had long periods of controversy, you can find that scientists are actually obliged to rely on criteria like

27:30 their personal estimate of the reliability of them, and so on, when judging which results are right or wrong. I've encountered this conference that was held in Dusseldorf about four years ago by Marx principle by Ian Barlow, is that his name? Yes, and somebody else. Yes, I have. That is one of the most extraordinary sociological things I have encountered, because they had votes of confidence in Marx's principle of the beginning and middle and end of the meeting or something like that. Do you remember that? Yes. Did they change during the meeting? Oh, they changed. There was a slight move from being 52-48 against Marx principle in some form or other to being 57-43 in favor of it. I don't know. Totally weird. Yeah, well, that's impossible. I do come across a similar, more tongue-in-cheek instance of democratic science in the case of the gravitational waves, where allegedly at a meeting at one point in the 50s, people were wondering whether if they had a ball in either hand and they dropped one and held the other. which would generate gravitational waves, which one was accelerating, the one accelerating in the local frame or the one being prevented from falling in the GDC. And according to Ted Riemann, I think it was told me, John Wheeler asked everybody to vote to see who thought which bomb was. And apparently they were 50-50 too. So I suppose there seems to be a strong sociological underpinning to scientific discourse. That's not too surprising to me because it's conducted by people.

30:00 And I suppose it would be interesting, but I don't know if anyone has looked at it yet, And to look at what happens in the longer term, after all, the scientific results of previous eras, where the people involved are by and large passed on, now form the basis of our work today. and I wonder if primarily we believe and mostly it's not people don't spend much time reproving those old results except from a pedagogic point of view so I wonder if it's somehow the way that those results fit in with our own current understanding our own current work that gives us such confidence in the whole framework that it seems to fit together Because clearly in the final house, there's some reason why we believe in many scientific results that we obviously haven't had the time to decide ourselves. And as you say, there's the curious fact that it's the ones that we have actually looked into most closely ourselves that we know most about the possible sources of error. There's a quote. I think it's from Einstein. Anyway, that when an experimentalist produces a result, everyone else in the world believes in it, except the experimenter, so. Yeah, at a certain point I find myself going on the opposite side and sort of saying you really can find things out in science, but I am actually disturbed about the radar time Not that I'm disturbed about it, but it disturbed me when I realized that that was the only ground that I believed in it. It especially disturbed me when I found out that we had been told there were really two

32:30 two completely independent groups verifying it. The MIT Shapiro group, because it was originally at MIT, because he's not there anymore, and the JPL group. So now you've got two groups doing it. That beautiful statement, though true, isn't by no means the whole truth. Because the fact of the matter is I'm not sure I would want you to publicize this because I'm gossiping knowledge. The JPL people couldn't get their programs to work properly until the MIT people went there and helped them go. So the alleged independence was not as real as it was made out to be in the public relations exercise. Is this a life work of yours or are you going to move on to something else? I think I'll move on to something else. However, certainly, what I'm working on right now seems to be going to take, I don't know, it seems like it's going to involve several years of work. And how does the work at Cardiff fit in with the work of that Edinburgh group? Is it totally different? I think it's quite different. It seems to be quite separate. In fact, to date, I haven't met, I've not personally met several of the people at Edinburgh. I've never visited there. But on the other hand, it's broadly sympathetic to the Commons comes from, very broadly speaking at any rate, a similar perspective to a number of people in there and is identified with a sort of strong program. We had a visit at Stanford about nine months ago from Andrew Pickering, who's no longer

35:00 in Edinburgh, I think. And I found it quite interesting that he seemed to have moved a long way away from it. He was talking about the history of chemical industry in Germany and the latter part of the 19th century and there was very little Edinburgh sociology in it, it was more like straight history. Well, my impression, of course I wasn't really around for the previous era of the strong program, but as regards issues like the debate between realism and relativism, I know that Harry Collins says now, for instance, that he doesn't think that the type of research which he does is going to decide somehow between realist and relativist positions. I don't know if he ever thought that, but I think he hoped that it would have an interesting light to shed on it, and my bad it does. But that he is mostly interested in showing, just as I was discussing a minute ago, that in the medium term there are strong sociological considerations which inform the way scientists go about their interaction with each other, especially in the reception of each other's results and in the way that I suppose that they do their work in response to one. So I suppose one could argue that the sociologists of science, like many other fields, have settled into a reasonably pragmatic position where on the one hand, they might like to feel that in some philosophical sense that all or most of life is explainable by sociological forces, but in practice they're satisfied with explaining those aspects of it that they can reach. In a similar way that physicists would say, well, all or most of life is explainable by physics, but there are certain parts of it that we can really examine with our techniques. That's my impression from what it's worth.

37:30 Do you have other things you would like to talk about? I don't want to take up your whole afternoon. I guess I had to go back to something I mentioned earlier. I was interested, just briefly, if it's a story that can be told briefly, So hearing about just the origins of the gravity probe, the experiment, and when the idea of doing a space germ-spathic probe experiment to test the frame dragging, I mean, first of all, I'm interested in particularly the causes, you know, of why it was decided that such an experiment can be done now, especially what can be done at a certain time. First of all, I wrote up a historical article about this, which was as accurate as I knew how to make it, in the volume Near Zero, New Frontiers of Physics, in honor of William Fairbank. Have you encountered that volume? I can show you a copy. It was published by W.H. Freeman and was edited by four people, one of whom was myself. It's a fairly complicated story, and one of my difficulties is I got three different different stories from the three people who preceded me, different and incompatible stories from Fairbank and Schiff and from Cannon. My story from Schiff is not really personally directly from Schiff but more from his notes, his contemporary notes which I had copies My disposition is to believe the Schiff story, but of course what I'm really telling you at that point is the Francis Everett interpretation of the Schiff notes as compared with the Fairbink

40:00 account and the Canon account. But what happened was Schiff, in my story which is given more detail in this article, Schiff began thinking about testing general relativity, actually in a quite negative way when he wrote an article for the American Journal of Physics about sort of September of 1959 in which he concluded there are no real tests of general relativity, there never will be any real tests of general relativity, and the reason that he was making that argument was the redshift experiment tests nothing, the perigilion of mercury tests something, but he had a very ingenious argument which he was not quite original in creating, but in reality the starlight deflection tests much less than you at first think. And the only thing you could do would be a second order redshift, to do a second order redshift experiment you would need a clock that was a part in ten to the eighteenths. In 1959, that was ridiculous, and in 1999, it's still reasonably ridiculous. So a very pessimistic article. After he had sent this into the American Journal of Physics, in November of 1959, he saw a completely bogus ad in Physics Today from JPL JPL was developing a fantastic new gyroscope, much more accurate than any previous gyroscopes and so he began thinking about what you might do with gyroscopes. And we have 55 pages of notes from Schiff on this subject which have a little note at the top saying December the 22nd, 1959, 2009, work began five weeks earlier or something like that. And when you read through these notes, basically you get the impression that the stimulus of reading that ad for JPL for

42:30 a cryogenically magnetically suspended gyro which led absolutely nowhere sort of got Schiff's various fairly torturous paths, he came up with an idea of the gyroscope experiment. So that's my deduction from Schiff's notes, and there's some quite interesting places where you can see him in the notes, suddenly realizing something and crossing out what he'd done on the previous page, and going forward from there. I need to come back in a few minutes to talk about George Pugh, but let's leave George Pugh on one side for the moment. Fairbank's version of events is I, Bill Fairbank, was thinking about what I could do with a perfect superconducting gyroscope. I went and talked to Leonard Schiff and said to him, tell me Leonard, what could you do if I were to give you a perfect gyroscope? And Leonard Schiff, like a good little boy, ran away and did some calculations and came back with the answer. Canon, who subsequently became chair of the aero-astro department and had various other careers, including a career at Caltech at one point as you don't call it dean of engineering but whatever you called it of engineering at Caltech. Cannon's version was Schiff and Fairbank were talking about doing some sort of ground based gyroscope experiment. Cannon had been thinking about how to do orbital gyroscopes and wonderful things you could do with orbital gyroscopes. So he explained to Schiff and Fairbank that you would do much better to do an orbital experiment than a ground based experiment. and they saw the light, and so that was how GPB was conceived. As you might tell from my mildly sarcastic tone, I don't believe Cannon and I don't believe Fairbank. And I do believe Schiff. Now why did Schiff do a calculation for an orbital thing rather than from a ground-based thing?

45:00 He knew how to solve the equations in free fall and did not know how to solve the equations for a constrained system, though eventually he figured out how to solve the equations for a constrained system. And so it was much easier to work it out for an orbital experiment. That's interesting. Now, here you come to this remarkable business of simultaneous discovery, and perhaps you do and perhaps you don't know about this, George Pugh, who was, had just completed his PhD at MIT, went to work for the Defense Department, and in January of 1959 he went to the American Physical Society meeting that was in New York, the annual, the old-fashioned annual big New New York meeting which used to have about 10,000 people each year at it in those days. And he heard Hussain Yilmaz describe his alternative theory of relativity, of gravitation. In the course of this paper, which was a ten minute paper in that APS meeting, Gilma is argued, or maybe it was a few guests from the argument, I'm not quite sure about that, And that it might give different predictions from general relativity, and Pew started thinking about doing this with an orbiting gyroscope. In fact, Pew's paper was published, was never published, except as Weapons System Evaluation Group Memorandum No. 5 from the Department of Defense, the WSEG, to which he belonged,

47:30 which was something deep in the Pentagon. And I didn't see a copy of it for years, though Schifford had a copy. It's actually a very brilliant piece of work, because in that paper He suggested the idea of the drag-free satellite and has absolute priority over everybody else as the true originator of the concept of a drag-free satellite. He had the idea of a gyroscope that was about this big, acting as a massive spinning object inside a satellite which was going to be drag-free to protect it which had some kind of telescope buried in the gyroscope to perform a gyro readout, an optical readout. But when I finally read it, which I probably didn't until about 1974, I felt that we at Stanford really treated Pugh not very well because it was a very, very clever paper. and he was the originator of the Drag-Free Satellite, which is of course one of the foundation things for Gravity Probe P. And this had been somewhat suppressed. When Dan Debray came to his 60th birthday, we had a celebration about Drag-Free Satellites and invited George Pugh out to participate in it, and it was all a very pleasant occasion and some regressing was done, but here you find a quite curious thing that Schiff and Pugh came up with this idea within a month and a half of each other and really from completely different starting points. Yeah. I don't know what sociology or simultaneous discovery you believe in. Yes, an interesting topic, but hard to know exactly what would explain this, how it happens so often. Yeah, unless you have some sort of Jungian theory of the collective unconscious. Yes, sort of archetypes. Maybe there's an archetypal gyroscope. Interesting. Now, the way I got into it was Fairbanks came and gave a talk at the University of Pennsylvania

50:00 where I was, having begun working on low-temperature physics there, though my background in Britain was different, and I had done this experiment on third sound, which is a surface wave in liquid helium. Fairbank came and was very sort of enthusiastic about my experiment in a way Fairbank could be very enthusiastic. And I didn't really feel that there was much of a future for more work in liquid helium, at least as far as I was concerned. So Fairbank and I had talked about various things and he said there was this wild idea of doing a gyroscope experiment and sort of one thing led to another and I came here as a postdoc not realizing in the least what I was getting into and in fact at that time not even realizing that we were going to be doing it collaboratively with the aero-estro department which was our the experiment. It's a collaboration between physics and the astral people. I tell a good deal more about this in these articles if you want, if you're curious to look at them. I am, I'd be very interested to look at them. Let me show you the book. Sit, sit. Okay. Here's the book. and there are a few things there are a few things not irrelevant in my article about Fairbank but the main thing I was drawing your attention to

52:30 you see by the way an article by Kip Thorne history and overview of the gyroscope experiment and various sort of things have gone from there. Do you want to take the necessary reference material? I'm going to go and get a cup of tea. I can continue talking for a little while with you if you wish. Okay, thank you. Thank you. Thank you. So, how are we doing? I mean, one can sort of talk about these things endlessly, aren't one? Well, I find it very interesting and I think very useful from my point of view. There are a couple of other questions that I wrote down earlier, which maybe I'll ask in the video piece. One is, and I'm, well, one is basically, when, to return comparison of theories. Are there any theories that you have in mind that once you are at the stage of writing

55:00 a paper with results from the experiment, that you'd actually give predictions of a theory and compare with the results, or does that not really form any part of how you see the presentation of results from the experiment? want to present the results, the results of the experiment. And it's not that I mean I'm not interested in theory, I'm very interested in theory, but the results of an experiment are the results of an experiment. I'm interested in that particularly because one of the things, at the risk of going on too long, but one of the things that got me interested in what I take to be the topic of what I'm looking at right now is looking at the presentation of the results of the Taylor et al. observations of the Banger call star, which showed the existence of orbit decay, and that seemed to me an interesting case where you have a very interesting result, which could be presented just as a result. But in fact, a great part of the papers in which they present the results are given Yes, and also they do a lot of comparison with different theories, including theories that one might argue were not very serious in any rate. So I was curious as to, you know, is it a general phenomenon that one feels obliged to sort of discuss this, or from your perspective it's more a question, this is an experimental result which stands by itself? Well, I mean, it's the personalities of the people involved, not that Joe Taylor I think would tend to do it that way, but when he collaborates with Thibault Demois, who's preeminently a very good, I may say, theorist, Thibault always wants to sort of press the limits, well what are we finding out, and you know these various alleged strong tests of general relativity that kind of had a come out of it, or strong tests of, which is fine.

57:30 And finally, from talking to Cliff Will, who was giving me a brief description of experiences that he'd had on, I guess, what were basically NASA oversight committees looking at gravity and so on, and he was discussing the arguments that were put back and forth about the experiment and its nature. I was curious, and he described arguments that were made against the experiment and for the experiment and so on. So I was curious to get your view of what were the arguments put forward by people who the idea of a gyroscopic experiment and what were the kind of arguments that could be made in response or were made in response to it. I'm not completely sure they want to record the answer to this one. Sure. Well, I could just turn it off if you are happy enough to talk without it. Amen.