Into the Impossible With Brian Keating - Nobel Prizewinner Reinhard Genzel: The Monster Black Hole at the Heart of our Galaxy! ​(#209)

Episode Date: January 25, 2022

Reinhard Genzel studied physics at Bonn Univ., and received his doctorate at the Max Planck Institute for Radioastronomy Bonn (1978), He was a Postdoctoral Fellow, Harvard-Smithsonian Center for Astrophysics (1978-1980), Cambridge, MA, was Associate Professor of Physics and Associate Research Astronomer, Space Sciences Laboratory, University of California, Berkeley (1981- 1985), Full Professor of Physics, University of California, Berkeley (1985-1986). He is Director and Scientific Member at the Max Planck Institute for Extraterrestrial Physics (since 1986), Honorary Professor Munich Univ. (since 1988), Full Professor of Physics University of California Berkeley (since 1999). Professor Reinhard was awarded the Nobel Prize for Physics 2020 together with Roger Penrose and Andrea Ghez "for the discovery of a supermassive compact object at the center of our galaxy." Since nothing, not even light, can escape black holes, they can only be observed by the radiation and the movement of nearby objects. Since the 1990s, Reinhard and Andrea Ghez, with their respective research teams, have developed and refined techniques for studying the movement of stars. Observations of stars in the area around Sagittarius A* in the middle of our galaxy, the Milky Way, revealed a supermassive black hole. https://www.mpe.mpg.de/ir/gravity https://www.eso.org/sci/facilities/paranal/instruments/gravity/overview.html Visit our Sponsor LinkedIn.com/impossible to post a job for FREE Search for The Jordan Harbinger Show on Apple Podcasts, Spotify, wherever you listen to podcasts, or go to jordanharbinger.com/subscribe 📺 Watch my most popular videos:📺 A New Contender is Here! https://www.youtube.com/watch?v=-6A6myur--c Frank Wilczek https://youtu.be/3z8RqKMQHe0?sub_confirmation=1 Weinstein and Wolfram https://www.youtube.com/watch?v=OI0AZ4Y4Ip4?sub_confirmation=1 Sheldon Glashow: https://youtu.be/a0_iaWgxQtA?sub_confirmation=1 Neil deGrasse Tyson https://youtu.be/1kxgK6J4S5Y Michio Kaku: https://youtu.be/3to9ymn-XKI Michael Saylor: https://youtu.be/CaN_CDKqXOg?sub_confirmation=1 Sir Roger Penrose: https://youtu.be/AMuqyAvX7Wo Jill Tarter https://youtu.be/O9K9OBd3vHk?sub_confirmation=1 Sara Seager Venus LIfe: https://youtu.be/QPsEDoOTU6k?sub_confirmation=1 Noam Chomsky: https://youtu.be/Iaz6JIxDh6Y?sub_confirmation=1 Sabine Hossenfelder: https://youtu.be/sh98cwRkzAA Sarah Rugheimer: https://youtu.be/w5DxU-lPYK4 Stephen Wolfram: https://youtu.be/nSAemRxzmXM Avi Loeb: https://youtu.be/N9lUceHsLRw Jim Simons: https://youtu.be/6fr8XOtbPqM Be my friend: 🏄‍♂️ Twitter: https://twitter.com/DrBrianKeating 🔔 Subscribe https://www.youtube.com/DrBrianKeating?sub_confirmation=1 📝 Join my mailing list; just click here http://briankeating.com/mailing_list.php ✍️ Detailed Blog posts here: https://briankeating.com/blog.php 🎙️ Listen on audio-only platforms: https://briankeating.com/podcast.php A production of http://imagination.ucsd.edu/ Support the podcast: https://www.patreon.com/drbriankeating Produced by Stuart Volkow (P.G.A) and Brian Keating Edited by Stuart Volkow Music: Yeti Tears Miguel Tully - www.facebook.com/yetitears/ Theo Ryan - http://the-omusic.com/ Additional Video and Images: European Southern Observatory ( www.ESO.org ) www.Nobel.org The GRAVITY collaboration, Max Planck Institute (https://www.mpe.mpg.de/ir/gravity ) University California, Berkeley Learn more about your ad choices. Visit megaphone.fm/adchoices

We will not be able to send one of us with a rocket into the center of a black hole and check out the singularity and then say, hey, it's actually not the plunkling. It's two times the plunkling or something like this because we cannot send out any information. So that's a real problem. The other problem is so-called information paradox. As far as the classical theory is concerned,

if you throw in rocks, refrigerators, and a few cars, and everything else into the black hole, the black hole will all forget that. Hello to the Into the Impossible Family. Another phenomenal episode awaits you with Dr. Reinhard Gensel, co-recipient of the 2020 Nobel Prize for the physical discoveries that he and his colleagues made at the center of the Milky Way galaxy revealing a compact object. The Nobel Committee didn't specify what kind of compact object that was, however, we all kind of suspect it's a massive, super massive black hole, perhaps with the massive millions and millions

times greater than our son. He's a very, very open, vulnerable, honest, and hilarious individual who was destined, perhaps, if he didn't get more into physics, to become a great athlete and even participate in the German Olympic team in the 1960s. So he would have won a golden medallion, perhaps no matter what he did in life, but today we're talking primarily about his work in astrophysics that garnered him, along with Andrea Ghez, my colleague up at UCLA, who I still hope to get on the Into the Impossible Podcast. Please, if you are listening out there, Andrea, I'd love to have you on. But we also get into the importance of mentorship of how he learned from really two men in his life, two father figures. One, his actual father, Ludwig, who is a great physicist himself.

You'll hear him touchingly and lovingly talk about his late father. And also his ideological Father, Charlie Towns, Nobel laureate from UC Berkeley, who really inspired this quest to look in the infrared to peer through the dust that conceals and constrains our vision of the inner workings of the Milky Way galaxy. He's going to hear about that. Where do we go from here? What can we do with this technology? And what he's most excited about. So now, sit back. Come along on a ride into the impossible with Professor Reinhardt Gensel and yours truly Brian Keating. Any sufficiently advanced technology is in distinguishable from magic.

Open the pod bay doors, Hal. Welcome everybody to another edition of the Into the Impossible podcast. I am your fearful host, Dr. Brian Keating. And we have had a segment on this podcast for a long time now called Nobel Mines, where we have featured to date nine Nobel laureates in physics. Still trying to get some other disciplines, Reinhart. But so far, they've all. been too busy, those economists, they get very busy. But Reinhart is a legendary experimental

and astrophysicist. He's the co-director of the Max Pike Institute for Extraterrestrial Physics Professor at LMU, Emeritus Professor at UC Berkeley, up from here, and he was awarded the 2020 Nobel Prize in Physics, along with Andrea Gess and Sir Roger Penrose. Andrea has yet to answer my emails to come on the show. I'm hoping she will. But Roger was on three or four times just last year. And you and I celebrated along with the world, Sir Roger's 90th birthday, not too long ago. And I thought it would be a great opportunity to introduce the world to the astrophysics that you do with your collaboration.

And then we could have a discussion about black holes and how mysterious and wonderful they are and where the future of this field is going to go. So first of all, Reinhart, thank you so much for joining us on the podcast. Not too. Not too. So I thought maybe you could show your slides that you showed at Sir Roger's 90th birthday party just a few weeks back in August 2021. Sir Roger is now 3 billion seconds old, like a day over 2,9,9 million. Yeah, I know. He's an amazing person.

He really is. He's been a great friend and indulge him. me and some of my questions about singularities, extremal black holes and other things I hope to get into with you. So, Ryan, you know, Ryan, of course, I mean, we might come to this later, but, you know, this, you know, the weirdness of black holes, of course, often leads to interesting questions from the audience.

And, you know, one of the more common ones, of course, has to do with wormholes. Yeah. And I never knew what really I could say about this because, I mean, it's a speculation, but, you know, why would you test it in reality? So I asked Roger, I said, Roger, you know, I'm being accosted by these questions. And, you know, you're an authority in this, you know, tell me, what do you think about hormones? And he says, oh, rubbish.

Yeah, that's not too far off. I'm hoping to get Kip Thorne on the podcast. He's offered to come on. We haven't been able to make it work. Ask him that question. I will. I know. With Indistella, you know.

I know. And I wanted to just remind, you know, me and myself, I remembered that we met each other in 2005 at the 90th birthday party for Charlie Towns, who was your advisor. And I later want to talk about recollections of. Charlie Chance. I know he was a titanic influence in your life and really the path to the Nobel Prize really goes in large part, you know, alongside him with your work. So, yeah, if you would take us on your 40-year journey, that will take us back to where this all began. So yeah, please Yeah, well, so I mean, basically, I mean, there's sort of like a Russian doll situation here.

in the innermost part there is the research which I'm associated with in my group and the Institute and of course in the US Andrea Gessen Kirkbrook and

that's the inner part of the Russian dialogue. The next layer of course is the more general question of whether these objects which general relativity predict to exist like holes whether they really are there.

And so then what we are doing is just one version of possible approaches, which in fact people have made, and surprisingly so, lately with great success, actually, to test whether this black hole paradigm, as we call, and whether that's correct. The next level of the doll

has to do with the universe as a more global entity and the fact, okay, if you had such things as black holes, what is their role? You know, who ordered them, so to speak, and are they just there?

And what's their role? And so that is an extremely surprising story in which also has been, you know, we have been making empirical progress in this. Then comes to the next layer of the doll, which has to do with general relativity. I mean, here's a theory which is to start with, associated with, you know, extremely famous theoreticians, although I'm inside to start with, then others, of course, as well.

Schwartzschilds, Kerr, Penrose, etc. And so the question then is, is this theory, you know, correct? And then most theorists, but maybe also some of the experimentalists, would say, likely not. And that is sort of surprising here is one of the theories, which is, I mean, at least on the largest scales we know, namely that of the universe, rules supreme. And it rules also apparently supreme on the smaller scales inside, the cause of black holes where there's supposedly is an infinitely dense thing called the similarity, which most of us, of course, feel, ah, oh, okay, something is missing in the theory,

which is the expansion, the extension to the spinal scales as a quantum theory, and that is obviously missing. So this is really amazing that, you know, on the one hand, that theory is now 105 years old. presented blinds, right, in Berlin, 105 years ago, and you're still working on it. Even in fact, the experimental studies are just getting going. I mean, you know, if I look into the future, it's very clear where I would put my eggs in gravitational waves. That's clearly the ultimate way, probably, of approaching these things.

so close as then perhaps see some deviations of general activity. So I think the interesting aspect of the black holes is how much they captivate the mind and the intellect of not only professional scientists like us, but the mysteries that they reveal and provoke in the general public. And we've had on many guests from Lenny Suskin, obviously Sir Roger, Delilah Gates. And the one thing that keeps coming back is that these objects are laboratories. And in some sense, I was a little bit surprised when the committee awarded you and Andrea, you know, the prize not, they didn't say black hole, right? They did. Yeah. So what is that, what was the reason for that choice of words?

I mean, that's, that's, I would say I fully agree with that. They had to, you know, because, and I think that the Nobel committee is, I would say generally very good about, I mean, remember the prize for Ricardo Jacomi was 2002 or one. He could have gotten it for the detection of Stella Blackbirds. And yet they didn't, in the citation, they wouldn't say it in this way. And the reason is that, of course, what we have not yet shown, really, none of the observations has shown is that the so-called kyrometric,

which is describing the, in theory, which is describing what we would call these objects without charge and which have two numbers associated in them according to the theory, a mass and a spin. And that is it. Yeah.

Okay, so that's a remarkable thing that these objects are, you know, extremely simple theoretically, there's only two numbers. So that means the theory says there are no hills, there are no valleys, there's no, you know. There's no hair. And therefore is no hair, that's right. And so this test of no hair,

namely in mathematical terms that all other properties of the object in terms of higher moments of mass distribution can be predicted by these two numbers that is missing from the existing work on the supermass black hole in the galactic center and it is missing

in fact also for the in spiral of stellar black holes with LIGO and so that's why you know, one has to be really careful and say well we have everything we've shown everything LIGO has shown there are objects which

you know look like black holes and probably are black holes, but we are still not there. It seems unprovable to say, you know, because how else, what other evidence could one gather? Not for the singularity, we'll get to that later, but for the properties that, you know, the Event Horizon Telescope has shown, that Ligo has shown, that you, Andrea and your group has shown, what else do we need before? Well, okay, if you'll, yep, that's a very good question, Brian. I think the answer most people would say is no hair theory.

indeed and and so for the gravitational waves what would have to be done is the following. If you think of a black hole as really sort of an entity and you bang at it

it starts to oscillate, okay? And so there is a characteristic what one calls a quasi-normal frequency about it, which is essentially the time light takes

to move around the black hole on the innermost stable orbit for the light that's called a photon orbit. And so if you, if you, suppose you know the mass of the black hole exceedingly well, and then you had a, you know, a piece of light going around

this innermost stable orbit and it would exactly follow that orbital time scale. Then you have, proven, and you knew, of course, the spin, I should say. You know the mass and the spin, and now you make that measurement of this orbital time scale of the photons, then you really have proven, I know, I had one version of it. And indeed, that's exactly what in principle the gravitational wave community would like to do. Why haven't they done it? Well, because

the objects which they have looked at so far, namely stellar black holes, have a very short time scale of a 100 milliseconds and less for this time. And there is not much time to build up signal noise ratios. It's just a practical thing. The objects are small, time scales are short, and in fact, because they are small, the signal are really weak, although they are actually, and the objects are not that far away. So the ultimate objects, everyone knows, is a massive black hole.

and a cellar black hole which in spirals into it. For that, you cannot do that on the ground because of the frequencies of the orbital in spiral is much too long, initially at least. But because it's long, you can make various exceedingly precise measurements. So the space mission we all hope to have in space in 15, 20 years, might do that. Okay, so then we could do it.

Another way of doing it is in the Galactic Center, is to measure the spin. We're trying to do this with stars, which are still further in than the ones which we had seen previously. If you'll lucky we will see such a star. And then if the radio astronomers could measure the size of the photon orbit, so to speak,

it's called the shadow, of the black hole. We know the mass exceedingly well, then we have a test of the of the endo hair theorem as well. So I think there's good hope that this will actually come about, but then as you say,

this does not solve the quantum problem of the whole thing. Quantum problem number one is you will not be able to send one of us into a with a rocket into the center of the black hole and check out the singularity and then say,

hey, it's actually not the planklings. It's two times the plankling or something like this because we cannot send out any information. That's a real problem. The other problem is the so-called information paradox, which is basically as far as the classical theory is concerned, if you throw in rocks or refrigerators and a few cars and everything else into the black hole,

the black hole will all forget that. And so if you come back later and check it out, so to speak, you wouldn't know any evidence. But the quantum theory would tell you, no, absolutely not. The quantum numbers are stored somewhere, and there's even some proposals

where they might be stored, and they're exactly on the environmentalized surface. And so then it might drift out like fumes, like quantum fumes. And so if you want to, and speculate that maybe sort of a thing of the future. And of course, it could be that, you know, this will change the properties nearly amenterized enough that it's measurable. It's peak pollination season, and my business is scaling fast. To keep the nectar flowing,

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I mean, this... Yeah, and the more that we learn, the more mysterious these objects become. I talk with Lenny Susskin, who does have this proposal of the stretched horizon, as you just said, the kind of one plank length above what we'd consider to be the event horizon. I actually don't think it's an important distinction that we say, oh, we can't observe these things in theory even because the event horizon shields it. What I have an issue with is that people will talk about the need for quantum gravity based on the existence of an unobservable singularity. either in a black hole or at the origin of the universe, which I study. So these are two, as Roger and Stephen Hawking showed, unobservable, even in principle regimes. And now that's not to say that they're right.

It could be that there was a collapsing epoch before the universe originated. As you probably know, your advisor, Charlie Towns, when he won his Nobel Prize, his students, Arno Penzius and Robert Wilson, were busy measuring the CMB. And when they measured the CMB in 1964 and then released in 1965, their interpretation, well, I should say the interpretation of Jim Peoples and Robert Dickie and others was that it was the after effect of a pre-collapsing phase to the universe that we had witnessed the cycle. They never mentioned the Big Bang once in that paper. And I think a lot of people had trouble with that, the notion of Fred Hoyle, and others.

And I wonder, what do you make of these controversies in physics? The late great Stephen Weinberg, he just passed away. He used to say that physics thrives on crises, but luckily there aren't so many crises. Well, I mean, I think, first of all, of course, this is the scientific principle, and that's what makes us indeed capable of telling truth from fake news, the famous fake news.

And that is that we have a theory in this case, which is already pretty well tested in some regimes, and we keep getting going at it, okay? I mean, but, you know, people are different. I think I've, you know, even very good astrophysical theorists would tell me, say, a few years ago, before our latest breakthrough in a way. Rynaud, why are you doing this?

I mean, everyone knows that general activity is correct. Okay, much more important is, so to speak, the cosmological evolution of the blackwood. That is important because that affects galaxies and how they grow or not grow. But why do you try to test general activity? Well, because my physics side tells me, you know, if you're doing,

can't verify all the predictions of the theory, then the theory is in danger, so to speak. It could be wrong. And we better check it out. And in this particular case, of course, by testing generativity in the galactic center, we are also testing this paradigm that galactic nuclei, in fact, of almost all galaxies you now think, have such a beast in their midst, and in fact it's a symbiotic relationship, right? So that they grew up together and grew up together and after a while,

the Black Hole became active typically and started actually, you know, damaging some of the galaxy embedded in. When I think about the future of your field, I definitely want you to show these wonderful images that you showed it, Rogers' birthday fest shrift, as you might say. But before you do, you know, the thought occurred to me that a lot of what we've learned in recent years, thanks to LIGO and other projects, was also what falls under what's known as multi-messinger astronomy, where you observe something in light, in electromagnetic waves and in gravitational waves. Is there hope with the tools that you and your colleagues are developing that there could be a multi-messinger signal, say if one of these gas clouds S2, whatever you guys called it, if one of those were to be gobbled up and you were to witness it with your A.O. technology, et cetera, and a massive telescope.

And is there any hope that LIGO or some perturbation to the Milky Way's black hole, that that could be a multi-messinger signal that would tell us something? That's a very interesting question. I mean, the answer at first would have to be, yes, but highly unlikely. Okay. Why unlikely? Well, the situation is for modedly small black holes, the stars, which they come too close, do get disrupted, so to speak, and then outside of the event horizon, and then they fall into, partly at least, into the black hole, part of it gets rejected. And actually, the galactic center there is some evidence we have that there is gas on an orbit, which is almost straight in, if you like, which went into the central region, and then came back out again on this orbit, but it's gas, not another star, or at least not only a star. And this gas cloud was extended.

And so it's very much possible that that is one of a case of one of a class of stars, which from time to time, you know, do in fact come so close to the center of a galaxy that they would get disrupted. And at that time, of course, you would see gravitational waves. The problem is that this, statistically speaking, happens once every 30,000 years or so. the chances of catching one of them, and that all in the galactic center is really very low. In the more general sense, absolutely not. I think in a general sense, we are now in a time, as you will know,

where people are looking for these transients, and they're finding them. And so if you then have a sensitive enough gravitation wave detector, you could look at these regions and then perhaps detect them. So chances are that this will be possible. Whether it's happening in the Galactic Center there, we really have to appeal to a lot of luck. This is sort of a very nice movie, which, in fact, Andrea made about 10 years ago

to just show the inner work here, if you like. So these are our test particles, our stars, which we've been looking at. It's remarkable. any theorists 20 years ago when we discovered these would have sworn

that these stars cannot exist. Why? Well, you know, we have a very good theory, of course, in principle how these clusters around the black hole or stars should look like.

And that is because the dominant thing is gravity, right? And so stars, if they're heavy, will over time move toward the center. That's correct. We can get close to the black hole. But the time it takes a billions of years,

these objects which we're seeing here in this movie all are less than, say, 50 million years old. So they couldn't have possibly over time by equilibrium processes, as we say, you know, moved into the center.

So the question is, therefore, how did they? And so they are a tremendous gift to us Because some of these stars In fact, not few, this year we had Another three stars coming in Just like this famous star is too Did in 2002 and then again in 2018 And came as close as about 15 light hours

So that's sort of the You know On the order of a hundred times The distance between the sun on the earth So that's sort of the world So that's solar system scales. Tremendous, okay, tremendous. That gives us this ultimate way of testing it

because it does go so deep into the central region. But who did that? Who made these stars to go in there? And so that's one of these things in science and say in astronomy certainly that the universe has all these surprises for us. And sometimes the surprises are wonderful. They really helped the field to go forward enormously, because before we had this orbit of this particular star,

we had sort of a statistical assessment of the situation. Not that it wouldn't be any different, but I mean, most physicists would have said, yeah, that sounds plausible that there is a mass in there, but black hole, why? Could it not be a cluster of neutron stars or something else? And that's exactly, despite the fact that we had this breakthrough, why the Nobel Committee is still a little cautious on this, because we could, you could think, although not really anymore, that it's not a single-blockhole, for instance,

but a double-blockhole. We think we have now actually excluded that also, at least to the extent that the second object is more massive than, say, thousands of more massive, or so. But I mean, there's all of these things you have to check in and that's, check, check out. And so that's where time is needed and that's where these journeys become pretty long live. But you're right. If you then get someone to help you like gravitational waves or very, very interesting for us would be this radio imaging,

then you could make progress in a much shorter time scale. Okay. Yeah. And when I think about the, you know, technology versus the theoretical technology, you know, the hardware versus the, you know, software, so to speak, I think about LIGO, obviously tremendous technology. And it's purely relativistic, in a sense, event horizon, you know, people quibble, are you really seeing the event horizon or just the light shadow? You already mentioned that. I think they're both fascinating. But still, you need numerical relativity. You need to treat it. purely relativistically. And interferometry has been around for, you know, what, 80, 90 years. It wasn't new technology in that sense. But I would say the technology that you employ, you know, adaptive optics, laser guiding, et cetera, et cetera, I think that might be interesting from my audience because typically they're hearing about, well, this is a test of pure general relativity. But if I'm, if I'm not mistaken, the fastest velocity of, say, S2 was about a few percent of the speed of light.

Yeah, about two and a half. So you wouldn't necessarily, I mean, you could do a lot with Kepler, just using Kepler and not Einstein. And so in a sense, the compact object or whatever as a test laboratory for general relativity, it's also a test for classical relativity, which makes it more interesting to me in a sense that the adaptive optics and the story of this 40-year journey, as you described it, where that begins. And how can we see through this? I mean, if you look up at the Milky Way, and I've been to the Southern Hemisphere, I've been, you know, I've seen the Magellanic Club. You can't see, you know, Saj A Star with your naked eye. That's right. That's right.

The Milky Way is rotten, filthy place with lots of dust, just like Los Angeles is. And I want to know, how can you see through the dust? I mean, how is this even possible that we could penetrate through this cloud that veils our vision and obscures it? everything. Right. So that brings us back to the 70s, actually, and in fact, Charles Towns and his work in Berkeley, which whom I then joined as a post-organishly and then as a faculty member in the early 80s. So the situation was that the so-called quasars had been discovered in the 1960s, by the radio astronomers looking just, you know, what does the radio sky look like? And he found compact radio sources pretty bright.

And then they asked their optical colleagues, why did you take a picture of those? And what do you see? And then they used palomar and they came back and said, well, it looked like stars. Not very interesting. But so luminous, how could that be? And then the trick was that once you look at their spectra in the optimal, you can see that they're actually highly redshifted in terms of the online image. And therefore, if you interpret that redshift as an effect of expanding universe, and you apply then the conversion from redshift into distance, and all of a sudden, the objects are billions of light years away.

And so what looks like a little star actually is enormously luminous. So that went on in the 1960s. And, okay, people in the starts to think, you know, who can create all of this energy. And it turns out if you would pack stars in that region, even if you work hard on it, it won't give you the kind of phenomena you would see. Because by that time, not only optical light had been seen

and radio light, but also x-rays and gamma rays, your multi-messinger, as you see. And so it was clear, these are unusual objects. They really have to. And so luminous, 1,000 to up to 100,000 times more luminous than the entire Milky Way. How can you have that? And that's where this crazy idea of black holes came in. Now, they weren't called black holes back then. They were called Schwartzschild's throats.

The strange word for nowadays, okay, Schwarzschildthroats. And so that is within a decade, people basically convinced themselves that the most efficient way to generate energy is to let material fall onto a big black hole. And before the material disappears behind the environmental rise, that energy, which is released, can be leading to this enormous amount of radiation.

So next question. How do you test that? Well, to test gravity, we know what we have to do. Think of the solar system, right? I mean, the solar system has our sun dominating the entire mass and we have planets. And so if you go back to Tisha Bra and Kepler, right, but the way to do this right is you basically observe the motions of the planets. And then you use Kepler's laws or Newton, And then you find that if there is a dominant central mass and the planets are in orbits around that mass,

well, then the innermost planets move faster than the outer ones by an absolutely predictable amount. And if you test that in the solar system, then you have, so to speak, you know, proof that the sun dominates the mass by far. Well, so the same idea you would want to use also in quasars, but they're too far away. That was really very clear. They're too far away. And so then it was a critical paper by two British very famous theorists, Donald Lindenbell and Martin Rees in 71, who basically speculated at the time, well, maybe these black holes, which have been talked about in these quasars.

are not only present in these rare quasons, but maybe they are everywhere. Perhaps every galaxy has, and it's just that only a few are creating material at such rates that they are bright in that call the quasars. And in fact, that's our picture nowadays, not at that time. So what's the closest galaxy there for? Well, our own by huge factor.

And so in the paper, in this 1971 paper, Lindenbell and Rees then actually made us a little recipe of what should be done. It's not exactly how it. They didn't mention stars. And molecules were not long at the time. So they proposed more H1 observations, et cetera, et cetera, and variability studies and so forth. But in the end, I mean, that's the idea.

So let's go ahead and observe the galactic center and observe all of this. And the answer, of course, is with the radio you can, but you can't get really close enough, at least not at that time. What about just looking at the stars and so forth? And that is impossible because of the dust in front of the galactic center, which attenuates optical light by so much, even nowadays, you cannot practically observe the electric center in what we would call the optical band. But if you go to slightly longer wavelengths by, say, a factor with a few,

the extinction is so strongly dependent on wavelength that you can peer through the dust screen at a few micrometers and certainly at 10 micrometer. And that's where Towns came in because Towns, you see, he got his Nobel Prize for the... of the laser and the laser was on the East Coast in many years and all of that. And at some point, he decided to move west to California and start a new profession as an astronomer. Okay.

But he knew, of course, things which astronomers didn't know, which was, you know, lasers, and he knew about the possibly very exciting. exciting possibilities with infrared light. And infrared is exactly what you need here. And so that he, he and his students then built a spectrometer and used that spectrometer to look at doppel shifts of ionized gas in an infrared line near the galactic center. And sure enough, they saw that the motions of those glass clouds were very large. When I then joined, we did ever more of that. And so by the mid-80s, we had a, we wrote a big nature payment saying the galactic center is a few solar, has a few solar, millions solar mass black hole.

So there it is, you know, mid-80s, so that's 40 years, 30 plus years ago. So it's clear that we thought we had the result in towns felt, okay, more than this, you know, we're done. but nobody else believed us, you see, and that's it. I was about about adaptive optics. I mean, I know the story I've had Claire Max in conversation before, and adaptive optics, I understand, was embargoed. It was the national security and, et cetera, and we were... Yeah, okay, so at this point in the 80s, 70s, 80s, we used infrared

and long wavelengths infrared, where adaptive optics actually doesn't really do much. 10 microns plus we didn't have 10 meter class telescopes so we would observe on on four three meter class telescopes

at 10 microns and there you know if you have good seeing on monocale you're doing okay and the technique at that time

as I said you measure that by spectroscopy the Doppler motions and so that is but the reason the reason people felt that they wouldn't believe it was exactly that. And then they said, well, clouds of gas are very tenuous things.

Plus it's ionized gas. Ionized gas, you know, you can push around with magnetic fields. You can push it around with stellar winds. How do you know that this is what you're measuring is gravity? How do you know that this is orbiting gas? Could it be that it's actually ejected gas and so forth? And there's some truth to that. although what we know now is does show that we have the right rotation,

but the question is, well, it's believable. So the big jump then came into the 90s. Step number one, exchange gas by stars, try to move the motions of the stars, and then make that measurement as precisely as you can. And precise, in this case, means you have to measure the central, of a stellar object to more than one over 100 of its diameter due to the seeing or the resolution of your telescope.

And that's where indeed it became clear you cannot do that with normal techniques. So that's where initially we used a sort of on speckle imaging, where you would take short exposures and, in any short exposure, in any short time, the atmosphere, so to speak, then still more or less stationary. But after about thousands of a second, then the image gets distorted. And then two things happened at the end of that phase,

which is number one. We all went to bigger telescopes, Andrea first in the mid-90s. We had the 2001 and then adaptive optics. Now you mentioned that already that the story of adaptive optics actually like the detectors were using. I mean, the imaging

detectors in the infrared also had the same, if you like, heritage like adaptive optics, namely that for a long time, not now anymore, but at that time there were all products of military developments in the United States because, of course, the military people wanted to look at

Russian weapons and some lights and that was their way of, you know, look at the infrared, of course, you can look at the hot exhaust of rockets as they get launched, and that's the way to predict, so to speak, okay, there's an attack coming or something like this. So that's how the imaging detectors and the infrared came about. And then the adaptive optics came about because the military wanted to check out the details of spacecraft up there. And so in the US, by getting that technology to come out of the military sector, the classified sector, was wonderful. And who did it? because towns actually was deeply involved in many of these connections between research and the government and at the end of the Cold War.

The Jasons, he was a... That's right, exactly. He was the one to suggest that Jason be founded. No, it's clear. I mean, I should say in Europe, there was a civilian-type. development, both of the adaptive optics but also infrared detectors. Initially, that couldn't be on par with the US just because, you know, the amount of money you have to have in order to develop a system like that initially is so high that the kind

of money astronomers had in either US or, you know, it wasn't enough. But nowadays, it's different actually, so that, you know, the, you know, the, you know, nowadays astronomers develop the top technologies, detectors and the force themselves. I'm mentioning this because Martin Howard

once wrote a very influential book where he basically his thesis is that without access to military technology astronomy never would have gotten where it is now.

And the other It's truth to that. Actually, truth to that, certainly in space. Yeah, there's always been a partnership from Galileo, the first telescopes that he invented or he used. He tried to sell to the Venetian Senate to use for military spying on ships in the lagoons of Venice. And that was one of the first things he realized he could make money off of astronomy. And so, yeah, there's always been some connection between the military. and now we see, you know, basically the Hubble Space Telescope is kind of on a par with some of the best military spy satellites, except it looks in the opposite direction.

And speaking of space, what would your project, you know, the gravity group, what would be the evolution and what could a spaceborne, you know, where you don't even need adaptive optics? Or, you know, are we going to be there with things like JWST or are we going to be able to observe? future follow-ups to not only the massive black hole in our galaxy, but maybe in others as well in the inferral? Yeah, that's a very good question. I would say at first, most of us thought that the sky was the limit, and indeed, you would go ahead and build ever bigger hotels and close to space. And you see, I've had the privilege to be associated with two major space projects.

projects as a PI Institute, as well as being chair of those committees on the European side, these are the European Space Agency. And so initially for very long wavelengths, infrared astronomy, far infrared astronomy, we all were thinking about a telescope of substantial size. In fact, the US thought they could launch a 30-meter telescope, 30, meters. Now, you have no rocket where this would fit in. Therefore, the idea was, you may recall these pictures of, you know, astronauts, you know, assembling such structures in near Earth and building this, as it was called, the large deployable reflector. Now, that fell apart for the following reasons. Reason number one, we astronomers learn.

that near Earth orbits is no good. Absolutely no good. And even if you had a telescope there, it would still be disturbed by the Earth because of its stellar influence, all the space chunk up there, et cetera, et cetera. So we want, certainly in the infrared, but also now, of course,

in the microwave background studies and so forth. You want to get away from Earth as much as possible. And, okay, so no astronauts, you know, with a screwdriver. So you would then think about, like in case of James Webb Telescope, structures which you can fold, and then when the launch is taking place, you basically unfold and so forth.

But that's very risky, very risky. And we'll see, I really dearly hope, when James Webb will be launched, and it will actually unfold as prescribed. And so in Europe, we felt that this was just not possible. Unfortunately, because we had then a similar mission, which in the end got launched as a three and a half meter telescope, but it started as a deployable eight-meter telescope,

and we had hoped it would be that size. And in the end, the engineers in ESA said, no, it's true. Whether that's the right decision or not, I don't know. Certainly, you know, historically, I would say, the more cautious Europeans, as a result of there being more cautious, they went faster, actually. I mean, the James Webb has been on the books since the 90s.

Okay, they still don't have it up there. And now let's go to Interpromont Street. And here the story is quite similar. In principle, you know, it's obvious what you have to do, right? I mean, you have to take launch, you know, for, say, two and a half-meda-class telescope or something like this into space, and then, you know, we do magic to align that should be possible. I mean, that's how Alisa also will want to operate. The problem, again, is stationkeeping, technology, and then the cost.

Certainly in Europe. we just had a review again of the of the space mission that Berlin dot the Kone and they looked at a space interferometer again

and in the end threw it out and even in the US I mean the idea of a space interferometer was around two one or two decades decades reviews ago right the TPF the

terrestrial planet finder my God I mean that's what everyone would like to do, but it wasn't realized too costly. And so there is, I'm afraid, there is a sort of a truth in Martin Howard's statement that there is sort of a limit. I call that sort of the region of death. It's like in the super collider. Yeah. If a project becomes larger than something and the James Webb is awfully close to that. Yeah. Then at least you have to be fearful. of that your project gets dragged out for, you know, sheer incredible amounts of time more than perhaps the, you know, the lifetime of a single scientist.

But if you go too far into this territory of death, it's just societies will not, or at least understandably will hesitate to spend that much money. So that's why I would say, I'm afraid, For now, it's gravity. And here I want to come back to Charlie Towns. When Towns wrote once a very nice piece for any reviews of astronomy and astrophysics, one of these chapters on, you know, himself. And he described what he had done in astronomy and amongst you will find the pharma tree.

Okay. Now, you said in the pharma tree is 90 years old. That's absolutely correct for the radio astronomy side. But you go to the infrared, where you are much shorter wavelength, the atmospheres is a shorter coherence time, and on top of it, typically you have larger bandwidth. All of it conspires to make the problem more difficult by the vital factor of 100,000 or so. And so what is a pretty obvious thing to do in the radio, and still pretty obvious in the millimeter, becomes absolutely, you know, extremely difficult in the optical.

Now, Thomas did it at use the trick at the time. He used 10 micons again, so a little longer. And he transformed the long wavelength, 10 micro radiation, into the radio through mixing. Okay, so mixing with lasers. And so that made it possible for him to do, in this wonderful little paper of this, he actually says,

what I really want to do in the end is to look at the black hole within the pharometry. So that's what we've now done. In fact, unfortunately, we succeeded only after his past away, but I knew what we were doing. But now, just to tell you,

I mean, the effort or the complexity in the end, the sensitivity, what we in the end had to realize was about, I would say, 100,000 times better than what Charlie had done there. So that's... You've got a plan to use the KEC, two telescopes of KEC to do interferometry, either in the optical or in the, you know, some micron. And to my knowledge, it didn't produce anything. It was a vast technical challenge, and maybe it will, maybe it won't someday. but yeah, it's exponentially harder to do it for the reasons that you mentioned.

And I want to take one other step maybe laterally and focus on these questions that you kind of are rare, Ryan Hart, because you have a commanding knowledge of the experimental side, of the practical side, but you also obviously understand the theoretical implications. A lot of my work as a teacher, as an experimental astrophysicist and communicator is to tell people, that there are other people, you know, Sir Rogers wonderful, you know, Stephen Hawking's wonderful, but these are theoreticians. And I almost feel like a good experimentalist should know the theory as well as a theorist, but maybe not create new theories. I mean, I think that's too much. But if you're just, you know, just applying, you know, the technology without understanding

the theory, I don't think that's a fulfillment of what an experimentalist should do. And so I guess what I'm asking you is what is your philosophy of a well-rounded scientist? Charlie was a paramount person like that in the tradition of Enrico Fermi, you know, one of the last people that could do theory, that could do experiment that understood the fundamental question. What is your philosophy, the students that you mentor, the postdocs, etc. What do you try to inculcate in them to have them fulfill their potential as a complete scientist? Right. I mean, I would not have the audacity to say that I understand the theoretical work at the depth which is needed in the end

to make reliable statements. So for instance, you know, if you want to investigate, you know, the star cluster in the center and make a proposal how these stars would come about, that's sufficiently complicated, I would say, that I certainly would be able to do that. And so here's rule number one is you have to have a team. And after all, that is what happens. It's not a single individual here. It's a substantial team, which in our case, of course, grew over time.

Was initially largely based at NPE, but is now European. Okay. I mean, the indifromatry is really involves at this point. about a hundred people. So that's clearly not done anymore, even at a pretty well-endowed Max Funk Institute. But it's a range of people in a team so that you can talk to people about various things.

And Towns knew that as well. Now, of course, his mantra I still know was, oh, yeah, well, okay, the people at NASA are doing this, and the other thing. No, I don't want to do that. I think the best science is done only with a student. Hans would insist on that philosophy. That's where I would not agree with him.

I mean, the fact, you know, we talked about the defraimatory, you can, in hindsight, you can, you know, see this is a different amount of pioneering of a field, but you could also call it a failure. Because, you know, that he wouldn't get, the Galactic Center type sensitivity was clear after a traditional period of time. And so this, you have to buy the bullet. Sometimes you have to realize, okay, if you want to get there with this type of technique

to get that kind of resolution, you will have to go into a different domain of work. And that then includes larger TUs and that includes collaborations, Towns wouldn't like to collaborate with other teams. It was always, you know, the fifth floor and verge. I mean, that's how we lived up there. Everyone, you know, up there was part of the gang. But I mean, I think I am very proud of over time I managed to bring to fruition and create what I call my Champions League team.

so we have people in Munich who are you know top people world-class people by themselves could be

could be you know top people anywhere and the fact that they in the end shows to stay rather than become

professor elsewhere may not happen too but it's I'm extremely glad for that because that's the thing now of course

another thing that thing which I would say is important in addition to the range of things. You have to write you have to write kind of hunting skill or smell. You have to sort of know

what is and what isn't possible and where you know the time is ripe to get in. I mean again I could go with the informatory and say of course I mean I grew up as a radio story in my thesis as a student I used

via B.LBRI to look at waterway premises in their motion. So I'm an informantist at heart. Still, it was clear until, you know, about 15 years ago that informanty in the infrared forget it. Yeah. Not at the kind of sensitive. But now that's very different.

What we are looking at here is sort of the central few arc seconds in the upper left of the galactic center. The upper left is the best you can do with a 10-meter-glass telescope in seeing limited conditions. So what do you see? You see some very bright, near dark stars. These objects are really very massive, actually. Some of them are under solar mass, Volfrey-Stars and other stars, and all-stars.

Very near the center. Now the center is right in the middle. Okay? And so if you had radio eyes, then you would see in this very center, this compact radios for Sages star, which was sort of the first X-marks-the-spot kind of situation. So the adaptive optics then improves this image from the top left to the top right by about a factor of 20 in resolution. So with a 10-meter telescope now in adaptive optics on under very good conditions, wow. Now you can see individual stars very clearly. Some of the brighter ones, of course, you can see the artifacts of the adaptive optics not being perfect.

You see this sort of ringing there. And then now in the center all of a sudden, there it is. That's J-Star. That's the black hole, which also there are radio. Okay. And just on the top part of it, there's a little spot of the upper part of the small square. That's that star S2. So this image actually is from this year.

So this star S2, which has been our key object to look at for this orbits, is already now, so it was gone outside of the center this year. Okay? it was very near, in fact, more or less on top of, on these scales of the central object. But now, the interferometry. So we are now from this upper right image to the lower right image. Okay. And again, that's the little square which you see is now what you see as a big square on the bottom.

Yeah. Okay. And whoops. What do you see? not only one object but heck one two three four five six or whatever yeah

and that in fact is what what the breakthrough is the breakthrough is the resolution and therefore the precision of measuring things very accurately but the other thing is also

of course we can actually now with this kind of in the problem finally go deep and so these these fainter stars which you see there are faint on then what you can see in adaptive optics on the uppers

image mainly because of confusion. It's not that, you know, a single adaptive optics assist the telescope can go very, very deep. But in a crowded field like this, that's not the limit. The limit is really how you can distinguish. And then you take several of these images

over three months and then you get the left the bottom left, okay? So red was in March, green is May and blue is July. And wow, I mean, you look at that. I mean, there's very obviously one star, which came extremely close, even closer than the S2. Another one is sort of moving the other way,

and there are a few more. So that's really the key thing. I would say the informantry is a very serious contender now in my view. For certain types of measurements one would like to do. One other application where it's been a breakthrough without how I actually expecting it, was an exoplanet spectrum. So you wouldn't think that. I mean, if you should think about these exoplanets,

the problem is you have a planet. And then you have the much, much, much, much, much brighter central star. And the way usually this is dealt with is you basically you master the bright star and then you look only at the planet. Well, with adaptive optics, that's fine because then the star becomes ratherly compact. You can't actually see the planet. But the adaptive optics is not perfect. And the star is, say, a billion times,

or certainly a million times brighter than the planet. And a little bit of this uncorrected light is then floating around near the planet and generates noise. So the noise is now not anymore instrumental in this. It's due to uncompensated. light from the scattering from the star right right and so the interferometry on the other hands doesn't do that because the same effect in the adaptive optic systems on the on the individual telescopes which we're using also make not not perfect correctors but they're not

correlated and so the the pharma that are completely so that's why all of a sudden they Currently, the spectrum which you're producing with gravity of exoplanets are the best in the world by Factor 10. Are there any applications of polarimetry? I know that in reflectometry, et cetera. How can that be used to enhance the scientific data? Well, I mean, the galactic center, what happens is you see, let's again look at the bottom left there. So this is what looks like a light blue object in the center. So if you take a time trace of that, then you would see varying on typically time scales of 30 minutes or so,

which, by the way, is the orbital time scale of gas on the innermost stable orbit. Okay, so that's our interpretation. That's what you're seeing here. It's very, very hot, about 10 billion, 100 billion degrees, sorry, 100 billion degrees, gas, which is doing superl radiation. So it's polarized, typically 10% and 30%. So in fact, by using waveplates,

we can analyze the polarization of the emission. And what we find is that the polarization is highly aligned. So with that technology, we can actually study magnetic fields. Yes. In the vicinity of the black world, extremely exciting.

Extremely exciting because one of the tenets in this field is that what you're seeing here, most people would say is gas, which has been decreed, although not like a quasar, but at very low level. So there's a small amount of stuff falling into the electric center. People would say, say an asteroid every two days or something like this, yeah, on this order. and that would explain the amount of radiation which we see. And then the magnetic field would be not in a disk, but in a sort of a donut of this hot gas. And if the gas is dense,

well then as you know, the magnetic field is tied to the gas and then it would be dragged along in this disk-like configuration and would have sort of a toroidal shape. When you look at what we're seeing from the variability, that's not the case. It's not toroid. It's polaroidal, so, you know, probably determined by the black hole. Similar thing is this been found by the EHT measurements in M87. So that really is a sort of a bit of a shock that the magnetic field structure is tied to the black hole itself

rather than to the creation zone. So that's the kind of stuff which you detect on the side, you know, when you... Right, yeah, yeah, it was an unintentional serendipitous discovery. I think about, you know, all the things that when I, you know, the founder of this field, obviously Einstein in some sense, I had a conversation with Barry Barish last year and actually inspired me to write a second book about the... called Think Like a Nobel Prize winner. Hopefully you'll be in volume two.

But Barry was the inspiration for volume one. And the reason was when he told me that he suffers from the imposter syndrome. And I said, oh, yeah, I'm sure you did when you were at Berkeley as a kid. And, you know, and you were around people like Lawrence and whatever. No, no, no. I feel the imposter syndrome now, even after winning the Nobel Prize. Because when I got my Nobel Prize, I don't know if this happened to you, Reinhart. You're a very curious person.

just like Barry is. But he looked through the logbook. I actually don't know if you've gotten the medal, whatever you've gotten, you've gotten. But he said when he accepted it in Sweden, he looked through the logbook to see who won it in the past. And he saw Feynman and Charlie and he saw Fermi. And he saw Einstein. He's like, oh, my God, I'm not worthy. I'm not worthy.

He's too good. And I'm not good enough. And I said, come on, you're, you know, Einstein was, he felt like he was an imposter compared to Isaac Newton. He actually wrote about Isaac Newton as being the creator of all of Western civilization. And then I pointed out that Isaac Newton felt inadequate compared to Jesus Christ. Yeah, well, I mean, look, Brian, it's very clear that amongst every group of people and Nobel laureates are just another group of people, there's a range of excellence, if you like. but then, you know, I think I'm a little more cautious with the, how shall we say, the ultimate Einsteinian adoration. Because, I mean, if you look, you know, Einstein did all of this, yeah, but it's not that he found the first solution, right?

I mean, it's structured and other things like the expanding universe who wouldn't believe. and he wasn't a wrong train there. And certainly the whole issue of philosophical discussion of the quantum theory and so forth, he was not always on the right side. So he had his failures to. Yeah, I know. I always joke that it's too bad that he had that blunder

because he could have had a good career. But actually what you're saying is exactly aligned with what I was going to ask you, which is that, you know, given that Einstein didn't really believe in black holes, He called La Maitre's idea atrocious. He thought the gravitational waves would never be detected. He thought that, you know, the quantum theory was unrealistic and should be based on reality and measurable principles.

What aspect of your career might you say, might people look back on, you know, 100 years from now and say, oh, well, Reinhart was, he was too timid. He really didn't realize how powerful things could get. Is there anything like that, or do you feel like you're very optimistic about the future of your subfield and physics in general, that we are going to break to some ultimate law, understanding of quantum gravity or of the true nature of the information loss or the nature of entropy in black holes, you know, as a whole? What do you make of this? Well, okay, I mean, certainly I would say I'm very much a pessimist. Most people feel that I'm either. No, there's pessimism and pessimism. My father would always characterize this. My father was a physicist too, by the way. So he said, okay, well, there's two extreme types of people. There's pessimism, there's optimism, and there's happy and they're sad.

The worst people are sad pessimists. But actually, happy optimists are not much better. Yeah. And so I always hope for that. I'm a positive pessimist. But I mean, I think it's clear that you discussed this already, that we are, we happen to be in an absolutely incredible phase. And this will not go on at this speed forever. Okay. That's one thing. The second thing is, it's a. depends on your taste. I use computers, of course I do, like you all do, but I'm not a hacker.

And for my taste, if I were a new student now, I don't think I would go into a song because I mean, I think it's just not my thing to you know, to only sit there and do MCMC and the rest of it.

Different people are differently. I mean, I use, I mean, if I want to test something, I would test things by basically looking at the project, a problem from different sides, and check out plausibility and so forth. And not only relying on, you know, 100,000 MCMC, if the noise is not Gaussian, which it never is. That's right. What do you do, right? So I think that's clearly what in astronomy what's coming next, say on the one hand,

huge, huge surveys where you can't really think about anything anymore but you have to dump it into some artificial intelligence thing. And then with artificial intelligence, I would say, okay, if you should program the thing to recognize rats and dogs, and all of a sudden there's an elephant in the image here. What does the artificial tell me these two? Okay, so sorry for inappropriate comment here. So that's one side, the other side, is that as absolutely fascinating

the exoplanet story is and will be in terms of, you know, getting at the chemical composition of exoplanes, seeing all these different types. I think that wouldn't excite me personally. This is a personal preference. So I would go do something else instead. So it's just, at least for me, I was lucky to be in the right place at the right time

and I think had the right mentors. That's, I think I find that extremely important. And I find a little sad that mentors. have gotten lately as a sort of a concept into a bit of a bad this reputation

because people feel okay well maybe people are of using the mentorship in some fashion and certainly

in a team if you have only people who say I want to be I, I, I, I and I then as you well know I mean that's

not possibly you have to give and take them. And it's different, different types of people there. When you mentioned, you know, in a past interview, you kind of are, you consider yourself the son of two fathers, obviously Charlie Towns we talked about. Talk about your father Ludwig. What would you like to tell him, you know, about what you've discovered and what you're excited about, even pessimistic as you are?

Yeah, no, my father was, you know, super ex-examination. I mean, I'm a dwarf compared to my father. He would really do things, everything by himself. Even when he was already pretty bad shape in health while, he couldn't really move around anymore. He would go ahead and build

little apparatus of all kinds, mostly electronic type apparatus and then have young people come and he would explain it to me. So he loved that enormously. And so this, my father was, as a physicist, was successful as a teacher like, like hell. I mean, he's a solid state physicist. And I would say, you know, his students and postdocs and so forth, he educated.

There must have been probably 50 professors of the general universe. I don't know. I think it's very, very successful. And everyone who heard his lectures was absolutely excited about that, including me, I of course inherited his superbly handwritten notes for lectures. And I used them here in Berkeley for quantum lectures and so forth, really wonderfully done. I mean, in a, you know, very clear, very well spelled out.

but understandable. Yeah, not hidden behind, you know, too much, you know, complexity and mathematics, but as, as obvious as you can make it. So that was very good. Now, I initially, when I was a boy,

I had two things that I was like, I want to become an archaeologist. And then I did a lot of sports. My father didn't like that. That was not good. Okay, clearly. Now, the archaeology, sort of evaporated

after a little while because I realized that I would have to go to I thought Greece and Egypt and so was all done and so where would I go? Well, you know, somewhere in the jungle and jungle has snakes etc.

No go, no go. You are a pessimist. And yeah, vacation in the coast of it. Yeah, but in the sports. I really, seriously. I try to you know Make every get-together chill

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What sport was that, runner? Truck and Field. Oh, yeah, yeah, no. When I was 16 years old, I was Germany's best javelin's boy. Wow. How did that? Wow. But as I said, javelin is a very true.

tricky discipline because the centrifugal force, if you throw the thing more than, say, 70 meters at the tendons here, okay? Stress. It's so high that if you're not perfect in technique, you basically rip out of little bits and pieces of your tendons, which happened to me. And it happens to almost every javelin throw. And then if you do immediately get that fixed. or not properly fixed

and then you're out of business. And I did also the Decker's long and Pendet's one of these kind of things. But of course once I studied physics, I knew I had to make the choice. So you did win a gold medal. Let's go.

Yeah, okay. Yes. Yeah. One question I had for you was your decision to, you know, to move more permanently to back to Germany, Was that more personal or I've actually had Lord Martin Rees on my podcast earlier this year. And he was saying, you know, one of the models that that's appealing is the Max Planck Institute model,

where you have more decoupled from teaching and the responsibilities that, you know, say, I have or you had when you were in Berkeley. You know, and yes, you don't get to do the one-on-one with a student, you know, or, you know, my friend and our friend Paul Richards, you know, with his students. and he's been a great mentor to me. But you lose that. But on the other hand, you have more kind of, I don't know, maybe there's more efficiency because you can only have postdocs and professor level people. So was that part of the reason you moved back to Germany?

Well, okay. I mean, I think the situation in that sense was complicated. I love Berkeley. I really do. I still do. That's why I'm here. and world was wonderful

family liked California in fact my older daughter is here probably in California so all of this was wonderful this weather was you know double a plus what else would you better than else it was clear

that I mean see the Galactic Center is not the only thing I'm doing I'm doing extra-galactic cosmology of galaxies and so forth, and star formation and all of that, and molecular spectroscopy, and all of that. And it was clear then that the kind of resource you would need for both building instruments, but also for doing things, would be definitely above the scale of a single NSF grant. And you see, Towns was in a totally different regime. If you go back to his great times when he did the Mazur at Columbia, the funding was very much like Max Plan.

There was a colonel from the Air Force coming every year, he said. there were at that time two with Nobel laureates is it a Robbie and Cush he was the assistant professor okay in fact Cush and Robbie tried to get towns off the laser and Mesa right Charlie you're a very good physicist but you know this is what you're doing there is not going to lead anywhere

you know we recommend you do some molecular beams okay don't don't do this this is kind of you know we You won't get tenure. I mean, anyhow, so the colonel came every year and visited the labs. That's what town saw, you know, and basically walked around, and they told them, you know, showed them equipment they had and so forth. At the end of the day, he then said, well, that looks wonderful what you guys are doing.

Well, I'll make sure the tech check is arriving next week. Yes, that was how things went at that time. And in fact, towns for quite a while got this kind of a deal from the Navy. They gave him money directly without, yeah. But of course, I, when I was trying to do my thing like you and everyone else, you know, how many proposals are you writing Korea and for ridiculous sums of money? Yeah. Okay, you'll be, you used two weeks to be excellent for $5,000.

all those. Come on. And now here in Berkeley, there was a thing called radio lab, radio astronomy lab. So they, in fact, had state funding. Not anymore, by the way, which is the reason why the radio lab has ceased to exist. But all the wonderful discoveries, the millimeter interferometry, Jack Welsh, and in fact, countless discoveries with Jack Welsh on detection of molecules, all were part of this sort of state funding thing

where they had enough money to have a few senior people, postdocs, etc. And it was clear to me that is that kind of funding was needed. But ever more impossible. And then came clearly the Reagan years were, you know,

there was not all that much interest in this kind of work. Okay, if you had connection to NASA, a different story, but we didn't. at the time. And then, on the other hand, I knew Max Punk, because I had done my thesis at a Max Punk.

My father was Max Punk director then. So I knew everything about the society, and I knew, well, okay, well, it was, Berkeley is great. You know, probably Max Plan

is a little better, absolutely it was. I mean, that was the, I mean, blue skies or not, that was the right basically, you know, this, what they call the long trust. So they basically, you know, the process is pretty difficult and takes a long time, but then once you hire, you know, okay, there are visiting communities coming, checking on you, but really, I mean, it's a wonderful system. You don't have to write the causes unless you want to do more than sort of the standard

funding or the max private group. If you want to do that, then it's very difficult. It's wonderful. I'm not sure here comes the pessimist that this system will really be able to sustain

the times because it's too much in a way centered on the directors. So we are the senior staff you have, as I said, Champions League team is not recognized by the MPG. And that's, I don't understand it.

And okay, now, of course, MPG and MPG is not the same thing. I mean, our institute, if you like, an extreme institute in terms of cost of experiments, space work and all of that. The typical institute, the typical Max Punk Director has a group of maybe 10, 15 people, at the heyday of Herschel are almost 60. So, I mean, there are differences between institutes, but clearly, we are not very well-tuned to the situation that you have very senior,

highly qualified senior scientists who have essentially no official recognition in society. Oh, okay. Who is this? Well, Reinhardt, I want to finish up if you have a couple more minutes left with some questions that I ask all my guests that are so gracious with me as you have been today. And throughout the time that I've observed your career and really been fascinated by the breadth and the depth that you engage in from radio astronomy and work with Alma and Apex, et cetera, and Atacama to obviously the work. that garnered you this Nobel Prize. So I want to first ask you a question that I asked, kind of in the spirit of Richard Feynman,

who said that the shortest sentence that summarizes the most information about the physical universe is what he called the atomic hypothesis, that everything's made of atoms spinning around. I want to ask you, what do you think is the most fascinating aspect of the physical universe that you've discovered in your life, that you'd most want to, say,

engrave on a time capsule for other civilizations, maybe billions of years from now when the people that live around Sajah star come to visit Earth. What would you tell them about what humanity has discovered as of 2021? Well, I would say for sure, the universe is beautiful. I mean, I think it's just, I always, my allegorical walk through the forest, but basically I say, you know, doing astronomy in many ways, it's going into a new forest which you've got up in and you look at all

these beautiful trees and and so forth and wow, and they're so big and there's this and there's this and there's flowers there. There are red flowers and blue flowers and all of that. So they explore the universe and its beauty. And now comes the physics part.

Then you discover however after a little while of studying and you be sure to study it well, that's what towns would have said, then you would find that blue flowers happen to be always on the left side of the road. Now that gives you a thought, you know, why is that? Okay, why would that be? And then you develop an idea why that might be.

Then you go ahead and test it, say, and you make more experiment with it. So that's my view. I mean, it's the, so there is the beauty part. awesome. And then the next thing is, of course, you then zoom into the few important physical questions and don't get, that's also important, of course, don't get completely fascinated only by the complexity. I mean, you know, then it becomes a hodgepodge of, you know, undigested ideas. You have to get to this point where you're picking out. the real gems of the wonderful universe.

That's delightful. Okay, so we went billions of years into the future with that question. Now we're going to go maybe 30, 40, 50 years back in the past. And it's the name of this podcast is Into the Impossible because Sir Arthur C. Clark, who is the namesake of the center that I co-direct at UC San Diego, he said the only way of determining the limits of the possible is to venture beyond them into the impossible. And I want to ask you, Reinhardt,

is there anything that seemed impossible to you as a 20-year-old, perhaps 30-year-old, that because of your courage, you found that it was possible by only going outside your comfort zone? Is there anything that gave you the courage or advice to your former self that you would give to a young Reinhard

to go into the impossible? Any advice to your former self? Yeah, well, okay, I mean, again, let me come back to the sports. I think that the sports for me was a uniquely preparatory. I didn't know that, but I mean, that's certainly, I would say, uniquely preparatory pre-exercise to do science because you really sometimes have to bite.

Yeah, you have to work extremely hard. You have to stay at it. You have to focus. and the focusing part is, I would say, something which I took from that, and that helped me to get sufficiently deep. You know, some problems are just of a type where you have to look at it first.

I mean, as I said, like the forest. I mean, it's people, some people, I see, going to the forest and then the exit again, okay? But you have to first study, you have to really work hard to apply. And then, of course, the other thing I said, you have to have a certain sense of smell

where the flu, the blue flowers might be found, and now you check that out. And I guess I was lucky, and I had the right people with me. that's that makes all the difference well Ryan Hard Gensel fellow colleague here in San Diego or in California rather at least for the time being we'd love to get you down here in San Diego if you can never break yourself away from the wintertime in Germany and don't want to visit your daughter maybe you come down here and visit me in San Diego I would love to see you in person again we haven't been in

person since that town symposium in 2005 and that's too long although we've been together virtually now a couple of times. RONRONR, thank you so much for spending so much of your time with me and going into the Impossible with my audience. Okay, thank you. Any sufficiently advanced technology is indistinguishable from magic. Kind of riding high at the Into the Impossible podcast. We recently broke into the top 10 in all of science in the Apple podcast rankings, and it just

delights me to no end that we are being so lovingly treated and rated and viewed and listened by all of you, both an Apple audio podcast, Spotify, Overcast, wherever you get your podcasts, and I do urge you to keep sending in those reviews. I read each and every one like this one that I just received recently. I'll read it here from someone called Beckinsby, who says, I love listening to Into the Impossible. Never disappoints. Brian seems to have such a good rapport with so many scientists of distinction. He gets to the heart of things in a way that even I, an artist can kind of grasp. Well, thank you, Beckinsby.

That really means the multiverse to me, as I always say. Thank you so much for all your encomia and an encouragement, because it's hard to do this without feeling like sometimes I'm screaming into the void. And I want you all to come along on this ride. We have many, many phenomenal minds coming up. Dame Jocelyn Bell Burnell is soon to be on the show. Marilyn Simons. and also in a conversation,

a very special conversation with Hakim Al-Oshayi. You won't want to miss any of those. And later on this year, this coming quarter, we have David Chalmers coming on, the person who coined the term, the hard problem of consciousness. And we also have a very special episode with Ed Young, writer and Pulitzer Prize winner for I Contained Multitudes.

He's coming on to discuss his fascinating new book as well later on in the year. So you don't want to miss it. subscribe, follow, rate and review this podcast, wherever you consume them. And don't forget to go on Apple iTunes if you're watching this and go on to YouTube if you're listening to this and subscribe, Dr. Brian Keating over there on YouTube. We just broke through the 50,000 followers mark and just over about a year and a half. It's unbelievable.

And as you know, I want to keep growing it because I want to promote the work of scientists, authors, thinkers, so that they can sell more books. They give me a taste of each book. No, I don't get it. but I love doing it. Books inspired me. Books furnish a life as Richard Dawkins said. Still trying to get him on the show. Stay tuned for that maybe. But they furnish a life. They are a form of magic. As Carl Sagan said, that translates time and translates space from an author's mind to your mind. So I want to encourage people to write and to read. And it's my way of giving back. And I get the side benefit of getting the education that I should have gotten perhaps as

a youth, but it did inspire me to become a scientist, I'm sure. So please do the favor of getting all the books and articles and so forth that you can find from all of my guests. Ambition comes in all shapes and sizes. At First Citizens Bank, we roll with your goals because we're built for what you're building. Fit for your ambition for Citizens Bank.