# Jim Gates updates his theorist’s bucket list and surveys the damage being done to US science and society

An episode of [Physics World Weekly Podcast](https://invisiblenetwork.ai/podcast/1400686733), 20 Feb 2025, 47 min.

Audio: https://media.blubrry.com/physicsworldweeklypodcast/content.blubrry.com/physicsworldweeklypodcast/20Feb2025JimGatesBucketListV2.mp3

The theoretical physicist and media personality is our podcast guest

## Transcript

[0:00] Hello
[0:06] and welcome to the Physics World Weekly podcast.
[0:10] I'm Hamish Johnston.
[0:11] This episode features an interview
[0:14] with the American theoretical physicist Jim Gates.
[0:18] In it, he updates his theorists bucket list,
[0:22] which he first shared with Physics World back in 2014.
[0:27] Gates also reflects on how the current political upheaval
[0:32] in the United States is affecting science and society,
[0:37] and what scientists can do to ensure
[0:40] that the public has faith in science.
[0:44] The interview was done in London by my Physics World colleague
[0:48] Margaret Harris, who joins me for a quick introduction
[0:53] and preview to the interview.
[0:55] Hi, Margaret, welcome to the podcast.
[0:58] Hi, Hamish.
[0:59] So, Margaret, can you tell us a bit more about Jim Gates
[1:04] as well as being a famous and esteemed researcher?
[1:08] He also has a very public persona in the US.
[1:12] So who is gates?
[1:14] So Jim Gates is a theoretical physicist at the University of Maryland,
[1:18] and he has a list of honors as long as my arm.
[1:21] His many awards include the US National Medal of Science,
[1:24] which was given by President Obama.
[1:26] And he's a fellow of the American Physical Society
[1:29] and the American Association for the Advancement of Science,
[1:31] as well as the Institute of Physics here in the UK.
[1:33] He's also a past president of the US National Society of Black Physicists.
[1:38] And as you mentioned, he's appeared in several science documentaries
[1:41] aimed at the general public.
[1:42] He's been kind of a friend of the magazine since, well,
[1:45] I think about 2012 or thereabouts, when he wrote for us
[1:49] the first time about, a topic that he was very close to his heart,
[1:53] which was a dangerous which I'll get on to a little bit later.
[1:55] Okay. And and he was in London.
[1:58] That's where you you met up with him?
[2:00] Why was he over on this side of the Atlantic?
[2:03] Well, he came to wanted to give a series of talks, including, departmental
[2:07] colloquium at Imperial College London in a public talk at the Royal Institution.
[2:11] But I kind of up with him at a talk he gave at the Royal College of Art.
[2:15] And one of the interesting things about Jim's work
[2:17] as a theoretical physicist is that a lot of it is highly visual.
[2:20] He invented this mathematical object that referred to called an Adinkra,
[2:25] and it's a geometric representation of equations in an area of physics
[2:29] called supersymmetry theory.
[2:30] And these geometric representations look like a set of colored lines and modes.
[2:35] And the more complex ones are visually beautiful, as well as being
[2:38] sort of quote unquote beautiful in the physics sense.
[2:41] And he wrote a feature for Physics World about these objects called the cross.
[2:45] You can find it on our website.
[2:46] And you first spoke with Jim Gates about his
[2:50] theorists bucket list back in 2014.
[2:54] I mean, what is this bucket list?
[2:57] I'm guessing it's, it's things that a theoretical physicist
[3:00] would like to do or like to see happen before they kick the bucket.
[3:05] Is that the the general idea?
[3:07] Yeah, that's the idea.
[3:08] These are things that that,
[3:10] Jim, as a theorist would like to see experimental evidence for.
[3:13] And his bucket list in 2014 had four items on it.
[3:18] The first was the Higgs boson,
[3:19] which had actually already been observed at that point back in 2012.
[3:22] And the second was gravitational waves.
[3:25] The third was evidence for supersymmetry, and the fourth was evidence
[3:29] for superstring theory. Now natural next question
[3:31] what is supersymmetry and what is superstring theory?
[3:35] I think we've probably talked a lot about Higgs bosons
[3:37] and gravitational waves, but the other two might be
[3:39] a little less familiar to listeners of this podcast.
[3:41] So supersymmetry is a theory that each the fundamental particles
[3:45] we know about in the Standard Model of particle physics has at least one
[3:50] very similar twin that differs from it only in its mass and its quantum spin.
[3:55] For example, the known force carrying bosons, which are the photon
[4:00] and gluons and the W and Z particles, they all have quantum spins equal to one.
[4:05] So there are super partner particles or particles as they're known for short
[4:10] must be fermions, which have spins equal to one half.
[4:13] Similarly, the matter particles, you know, electrons,
[4:16] neutrinos, quarks, so on are all spin one half fermions.
[4:21] So they're twins.
[4:22] They're particles.
[4:23] Must be bosons with spin equal to zero.
[4:26] So that's supersymmetry theory.
[4:28] Now superstring theory
[4:30] takes us one level deeper and says that all these particles,
[4:33] super super particles or otherwise, are in fact tiny vibrating strings.
[4:38] And the different vibrational modes of these strings
[4:40] is what gives rise to the very various particles with the properties we observe.
[4:44] There's no observational evidence for this theory,
[4:47] but it does provide a solution, or maybe a possible path to a solution
[4:51] for some of the problems or inconsistencies in the standard Model,
[4:55] like the fact
[4:55] that gravity seems to behave differently from the other forces we know about,
[4:59] which are the electromagnetic force and the strong and weak nuclear forces.
[5:02] So that's a brief introduction, a very brief introduction to
[5:06] supersymmetry and superstring theory.
[5:08] Well that's great. Thanks, Margaret. Thanks.
[5:10] Thanks for the introduction to Jim Gates and also to the those two rather esoteric,
[5:16] bits of physics and, I suppose without further delay,
[5:21] here is that conversation between Jim Gates and Physics World's Margaret Harris.
[5:27] I'm here.
[5:34] So a decade ago, Jim, we
[5:37] spoke about the things on your theorist bucket list. Yes.
[5:41] You have a list of the things you'd like to see discovered
[5:44] or proven or explored or understood before you.
[5:48] As you said, that's the bucket. Yeah. Well, exactly.
[5:50] The first thing on your list you mentioned was the discovery,
[5:54] the Higgs boson that has happened.
[5:55] Yes. That's been ticked off.
[5:58] The next thing on your list, again ten years ago was gravitational waves.
[6:01] Yes. So that's also, I think, being successful.
[6:05] The initial success in the detection of gravity waves
[6:08] was a spectacular day for, a lot of us.
[6:12] In fact, I was with Washington, D.C., at a conference
[6:14] giving a talk, and, the, National Science
[6:18] Foundation had organized a press event around the announcement.
[6:22] And so I was, I was asked by some people,
[6:28] if I would, make a contribution to BBC America
[6:31] talking about, the discovery of, gravitational waves.
[6:36] And I must admit, some friends watching the interview said, Jim,
[6:40] you know, you were giddy, and I said, yes, I was.
[6:43] Why were you so get it?
[6:44] Well, first of all, because I had been following
[6:48] the development of that detector almost from its birth.
[6:52] So the first time I heard about detecting gravity waves was around 1985.
[6:58] I was a new, maybe 85, 87.
[7:00] I was a new, associate professor at University of Maryland
[7:04] and, of a gentleman by the name of Rick Isaacson,
[7:08] who was a program officer at the National Science Foundation.
[7:12] One day he called me in of our office to say, Jim, I want to show you something.
[7:15] It was the proposal from, the Caltech and MIT collaboration
[7:22] to be funded to begin to build the detector.
[7:26] And I read it and I said, this will never work.
[7:29] Fortunately, Rick, Rick Isaacson, to those of of the community
[7:34] who know the story, is, in fact, the superhero that made this happen
[7:37] because for decades he was the person
[7:40] in the National Science Foundation with a faith that this could happen.
[7:45] And when it happened, it was just an amazing day.
[7:48] So those works knew the whole story were giddy.
[7:51] Why is it that the discovery of these gravitational waves,
[7:54] why is it so exciting?
[7:55] So there are a couple of reasons that, I know personally, I'm excited.
[8:00] And I think, most, theoretical physicists would agree with this assessment.
[8:04] The first thing is that this was probably Einstein's
[8:09] final big prediction that there would be
[8:12] observable waves of gravity, gravitational waves in the universe.
[8:16] It's very funny.
[8:17] If you go back into the literature, he first says, yes,
[8:22] this is possible, but at some point he changes
[8:25] his mind, says it's not possible that maybe these things don't exist.
[8:29] And so there's another round of discussions
[8:31] where some error was found that he reverses that. Yes.
[8:35] It's possible.
[8:36] So first of all, it's very interesting if you know the whole story, to think
[8:40] about how human this is, the bounce back and forth
[8:44] and this idea about whether, his intuition was correct
[8:48] and then to have Mother Nature said, look, you got it right the first time, kid.
[8:52] I mean, it's just so lovely story.
[8:53] So that's
[8:54] the one thing, is the confirmation of the theory of general relativity.
[8:58] The a sharp current, a confirmation that is unlike anything that I
[9:03] unlike anything I could imagine happening in my lifetime, quite frankly,
[9:06] even though it was on my bucket list.
[9:08] The other thing is because is because
[9:11] our species knows about the heavens.
[9:16] Mostly because
[9:20] there have been entities in physics that are like mercury.
[9:24] You know, Mercury was a guy,
[9:26] carried
[9:27] messages from Mount Olympus to humans
[9:30] in our version of the story,
[9:34] the character of Mercury is replaced by photons,
[9:38] its light that has been telling us for hundreds of thousands of years,
[9:43] maybe a million years, that there's something out there.
[9:46] And we look up in the night sky and those are photons
[9:50] bringing the message of whatever it is.
[9:52] It's out there.
[9:52] Now, of course, this drove
[9:56] the development of science for several hundred years,
[9:58] and certainly is part of the I would call it the science
[10:03] Big bang that happened in Europe around Newton and Galileo.
[10:07] So with the detection of gravitational waves, a new kids on the block
[10:13] to do the messaging, the new kid on the block is the graviton.
[10:18] That is, just as light
[10:21] has an aspect as a particle, we call it a photon.
[10:24] If you're a science fiction fan for Star Trek, you'll probably remember
[10:28] these things called gravitas.
[10:30] And so once we have detected gravitational waves,
[10:34] the next big thing is to be able to detect gravitons.
[10:39] Now there are a couple of steps in that.
[10:42] And, LIGO is starting to take one of them, I believe,
[10:47] now, because one of the things about
[10:52] photons is what we call polarization.
[10:56] They basically, if,
[10:59] a photon is coming straight at you, you could spin
[11:03] and they could spin either, in what we physicists call a right hand sense,
[11:06] that's like closing your right hand and looking at your thumb.
[11:08] Or it could spend in a left hand sense, in which case it's
[11:12] the spin vectors pointing away from you.
[11:14] Those are the only things that are allowed for light.
[11:16] For the graviton.
[11:18] It's also true.
[11:19] And so the next thing you want to do is measure
[11:22] polarization to confirm that prediction of the mathematics.
[11:26] Like gravitons come in left handed polarized states.
[11:29] And right here the polarized states.
[11:30] Then the next really big step is you want to actually see gravitons.
[11:36] Now for photons.
[11:39] That was the work, that Einstein, gave, in 1905.
[11:45] There were four just beautiful papers written that year.
[11:48] One of them was on the photoelectric effect.
[11:51] And the result of that observation is that the energy
[11:57] in light comes in packets.
[11:59] It's quantized.
[12:00] And the particles that carry that quantized energy are photons.
[12:05] So we want to verify that for gravitational waves
[12:10] and see the graviton as a quantum mechanical particle.
[12:14] It's not clear, how that technology is going to work out.
[12:19] Once we get all that knowledge, then we're going to be able to do
[12:23] something that we've never been able to do as a species in this universe.
[12:29] So everybody
[12:30] knows what the Big Bang, what came after the Big Bang.
[12:33] Well, the first big thing that happens is what we call inflation.
[12:38] When the universe went from being something smaller than the atom to
[12:41] this huge structure that we inhabit now,
[12:44] there was also a period of darkness.
[12:47] It's the first night, and that first night
[12:51] lasted approximately 380,000 years.
[12:55] Now, what was going on in that period?
[12:58] Well, in some sense, the average temperature
[13:02] of the universe was so great and the
[13:06] particles were in such chaotic motion that light could not travel through it.
[13:11] Light was frozen in this universe, for the from the time of the big Bang,
[13:16] up until 380,000 years,
[13:21] and at 380,000 years, the universe had grown so much,
[13:25] the average temperature
[13:27] and density of particles had dropped so much that finally light could travel.
[13:31] Now, what's really interesting is if you look at the universe with photons,
[13:37] the only thing that you can see is the first time light is able to travel
[13:42] through the universe. Sometimes this is called the first dog.
[13:44] And so we have been seeing this first dog since the 60s.
[13:49] It's called the cosmic Microwave background.
[13:52] And so if you want to peer behind that, think of it as a curtain.
[13:58] You can't use light, but with gravitational waves
[14:02] you can image the universe before the house with microwave background.
[14:07] This up there.
[14:08] So we will be able, as a species eventually to look
[14:12] maybe all the way back to the Big Bang.
[14:15] And that's remarkable.
[14:17] And then there's one other thing.
[14:19] And that's the Star Trek League,
[14:21] which has been the science fiction of Star Trek.
[14:24] They use graviton.
[14:25] And so maybe just as we have been
[14:28] using photons
[14:31] for our high technology coming out of the revolution
[14:35] that really started here in England with Faraday and Maxwell, maybe
[14:41] at some point in the future those steps will be repeated for gravitons.
[14:46] And so maybe there's some gravitational base technology
[14:50] out there that who knows what we'll do with at the time.
[14:53] Hopefully it won't be just creating graviton balls or beams
[14:57] like they do in Star Trek.
[14:59] What's the of the path to see the graviton experimentally.
[15:03] So so LIGO and its sisters, you know, Lord Ligo's,
[15:08] at the time of detection, it was three different detectors, two
[15:11] in the United States and one on the border of France and Italy, called Virgo.
[15:16] There is an a new LIGO site coming online in India now.
[15:21] And so what's going to happen is that
[15:25] if the world remains dedicated to doing science,
[15:28] which is a good question that we could talk about,
[15:30] but if there's a global consensus on, you know, continuing
[15:33] to do the science, more sites like this are going to come online.
[15:36] And so we're going to have higher fidelity pictures.
[15:41] And then when I say pictures now,
[15:42] I mean the images that are brought to us by the graviton is not by photon.
[15:46] So it would be able to developed well there.
[15:48] So this way
[15:49] it's going to be the difference between going from black and white TV to color TV,
[15:53] because there will be more information coming out of the gravitons.
[15:55] And so we'll be able to see more things of the universe.
[15:58] Now, the pathway to detecting gravitons.
[16:01] Like I said, there are two steps.
[16:02] First of all, you probably want to measure the polarization.
[16:06] And these fabri Perot parameter interferometers,
[16:10] which is what the Ligo's sites are based on, have that capacity.
[16:14] And one can imagine doing that measure.
[16:16] In fact, ligo's, the way to think about ligo's is two pipes at right
[16:20] angles to each other and light goes is the this is those pipes.
[16:24] So the pipes are evacuated, the circular.
[16:27] And so there's this, computer animation that I found
[16:31] which is beautiful, which shows
[16:33] what would happen to the shape of that pipe
[16:35] if there's a gravity wave coming from the back of the pipe
[16:37] towards your eye, the pipe deforms in a very particular way.
[16:41] And, if it's a polarized, like graviton wave,
[16:47] the bending has a certain signature, whether it's left or right handed.
[16:50] And I've actually used this video many times as I've been talking
[16:54] for the last decade about this.
[16:55] So if we are lucky enough we can actually see polarization.
[17:00] I would guess within the next ten years,
[17:03] I guess gravitons were number two on a bucket list.
[17:06] So that's like two A we've now covered two A let's get a two week two,
[17:09] because a quantization quantization is going to be a challenge.
[17:13] And back in the 60s,
[17:17] physicist at the University of Maryland, Joseph Weber, developed it.
[17:21] But now Weber bars are big metal bars.
[17:24] And the idea was
[17:26] you will call them down.
[17:28] And then if a graviton impinges on these bars,
[17:32] it would induce, lattice vibrations in the metal and you would detect those.
[17:36] And so that's the principle behind so-called Weber bars.
[17:39] So people and Weber bars,
[17:43] Joe, actually, claim to have detected gravitons in the 60s.
[17:48] But this is a claim that has never been verified independently.
[17:51] So, one of the things I tell people about science
[17:55] is that science can it probably doesn't have the capacity to see miracles,
[17:59] because if it's something that happens one time, how do you verify it?
[18:02] Right.
[18:03] So there's going to be a big push,
[18:06] I suspect, in going back and upgrading that technology.
[18:09] But one of the most exciting things about that is, I mean, they might be
[18:14] quantum Weber bars, not classical Weber
[18:17] bars, where you take not these huge.
[18:20] I mean, if you see pictures of Weber bars, they're big.
[18:23] But you can imagine a tabletop quantum experiment
[18:27] where the same principle
[18:30] that Joe Weber was talking about, which is that a graviton, impinges on a
[18:34] solid state system which causes it to which it takes photons.
[18:39] And then you detect the phonons.
[18:40] You can imagine now doing this with using quantum mechanical, Weber bars.
[18:46] And so that's the road that I could see
[18:48] to actually nailing down the existence of the graviton.
[18:52] So that's gravitational waves and gravitons today.
[18:56] And to be
[18:57] number three on your bucket list ten years ago was super partners. Yes.
[19:02] Supersymmetry. Yes.
[19:03] How have the prospects for supersymmetry developed in the past ten years when,
[19:10] there was a
[19:11] Second World War on our planet and it lasted
[19:16] longer in the Pacific version than the European version.
[19:19] And when
[19:22] the Emperor spoke to
[19:24] the Japanese people, the phrase was repeated.
[19:28] The situation has not developed to our advantage.
[19:33] And so we could apply that to supersymmetry.
[19:36] I believe, very accurately,
[19:38] that the situation has not developed to our advantage.
[19:42] Now, not all of us,
[19:45] were at the same place in terms of expectations.
[19:49] In 2006.
[19:51] I actually published a paper in this in physics today.
[19:55] And I said explicitly, I did not expect
[19:58] the LHC to detect supersymmetry.
[20:02] Why not?
[20:03] Well, it was back of the envelope calculation.
[20:06] I was looking at the issue of,
[20:10] anomalous magnetic moments
[20:11] because the numbers,
[20:12] magnetic moments, if you look at the math and the how it works, it they can't
[20:18] the magnetic models can be sensitive to particles you can't actually detect.
[20:21] And so by looking at the anomalous magnetic moment
[20:25] and then comparing the measured value to what is predicted by all the particles
[20:30] that, you know, you can put lower bounds on the particles that you don't know.
[20:34] And that's what I did to come up with this number that it looked to me like
[20:38] the lightest super partner was probably going to be in the range of 30 TeV, okay.
[20:43] Which is well beyond what the LHC, the LHC initial operation of seven.
[20:47] It's currently at 14, so I'm feeling comfortable about this issue.
[20:53] I'm not like the the people who said, oh my God, we got it wrong.
[20:57] Well, no, I didn't get it wrong.
[20:58] I think I got it right.
[21:00] But like Cassandra in Greek mythology,
[21:04] the seer, people don't listen to a seer.
[21:07] Awful.
[21:07] So now remember our theory.
[21:09] So it might be 66 years.
[21:11] It was 30, but to me, it's someplace that would seem reasonable.
[21:15] If it's not found by 100 TeV, which I'm going to.
[21:19] I'm going to kick the bucket by me.
[21:20] By the time we get that technology,
[21:22] if it's not found by then, I would get very worried.
[21:25] It would, but I am confident that it's out there.
[21:28] So that's one thing, is that
[21:31] there has been a pushback on the hysteria around supersymmetry,
[21:35] because that's what it was for me,
[21:36] was a hyperbolic hysteria that many people bought into
[21:40] one of the physics I most admire, Michael Peskin.
[21:43] He's at slack, and Mike Michael wrote a
[21:46] very highly regarded book with one of his students, Peskin.
[21:50] Schroeder is a textbook
[21:51] on, quantum field theory in elementary particle physics.
[21:55] And Michael was totally committed to the idea that supersymmetry was at hand.
[22:00] So he and I have had some discussions over the last year or so about,
[22:06] you know, why he was so convinced and, this, this thing called naturalness,
[22:12] which it's a it's a pretty argument, but I never found it convincing,
[22:16] which is part of it.
[22:17] Partly why I did not get on the
[22:19] supersymmetry is going to be found that the LHC bandwagon.
[22:21] So that's one thing.
[22:23] On the other hand, in this article,
[22:26] in the article that I did with you folks, in physics world
[22:32] before the second scientific run at the LHC,
[22:37] I pointed out that particle physics and observations
[22:40] of particle physics, typically high precision,
[22:46] observations, magnetic moments,
[22:48] branching ratios, decay rates, all sorts of things
[22:52] were not the only way to think about finding supersymmetry in particular.
[22:57] One could imagine that, particularly
[23:02] with string theory, that there might be cosmological implications.
[23:06] Now, for most people, that was limited to the question of dark matter.
[23:11] You know, in, in astrophysics and cosmology,
[23:16] as far as we can tell, our technology has only allowed us to measure
[23:20] something like 5% of the matter that's in the universe.
[23:23] So there's a crisis there.
[23:25] And one of the solutions was to imagine
[23:29] that the other 95%
[23:32] is made up of one component of dark energy and dark matter,
[23:36] and with the greater, proportion going to dark energy.
[23:41] But the
[23:41] dark matter contribution, if you look at the mathematics of supersymmetry,
[23:46] you can easily find that there are particles that we haven't observed,
[23:49] and they might be the lightest supersymmetric particle
[23:53] has characteristics that would be consistent
[23:57] with what I think of as observable dark matter.
[24:00] A very dark matter.
[24:01] There are two kinds of dark matter, actually,
[24:03] and I'm not sure how widely this is recognized.
[24:07] There is dark matter
[24:11] that still possesses either quantum chromodynamics
[24:17] or quantum flavor, dynamic or electromagnetic interactions.
[24:21] In addition to being dark.
[24:23] On the other hand, there's another kind of dark matter,
[24:27] which some people call profoundly dark matter, which would only interact
[24:31] gravitationally and in fact, if you look at string theory,
[24:35] it suggests that a profoundly dark matter
[24:37] is probably a huge component to the structure of the universe.
[24:40] But again, I I'm not a phenomenal largest,
[24:43] and I don't really know any serious studies of this issue.
[24:47] But as someone who believes a string theory basically is right,
[24:51] I wish someone would begin to answer that question.
[24:54] Now, why do why did I come back to this?
[24:56] Well,
[24:57] maybe a decade or so ago, Nima Arcanae, Hammett,
[25:02] and Juan Maldacena at the Institute for Advanced Studies,
[25:06] the place that was isat home when it came to us,
[25:09] wrote me a very interesting paper in which they argued that
[25:14] the heights of string theory predicts particles of spin greater than two.
[25:20] And so they
[25:21] looked at the issue of high spin particles,
[25:25] therefore very massive, having glancing collisions
[25:30] and, you know, not head on, but just grazing collisions.
[25:33] And what might the signatures that be on the cosmic microwave background?
[25:38] And so when they wrote that papers, I said, well, the next thing
[25:42] they're obviously going to do is look at what happens if you add supersymmetry.
[25:47] But they never wrote that paper.
[25:48] So the first year I was at Brown University,
[25:52] I had an opportunity to work with a young, astrophysicist there
[25:56] by the name of, Stefan Alexander and some graduate students
[26:01] and my postdoc, Konstantinos Lucas.
[26:04] And we looked at the issue of what kind of signature
[26:07] you would get for high spin, supersymmetric dark matter.
[26:11] And so it has a it has a characteristic signature,
[26:14] whether it's detect was a different question,
[26:17] but the form of the signal you can calculate.
[26:20] And that's what we did in this paper,
[26:21] which is one of the few times I've ever left mathematics to do some something.
[26:26] It looks like real physics.
[26:28] So, those are the challenges that I see
[26:31] for dark matters when we look up and begin to see signatures.
[26:36] And the final thing on your bucket list,
[26:39] which we've already touched on, was superstring theory.
[26:41] And you said at the time you did not expect to see
[26:43] either this or some of this
[26:44] unless I, unless I'm, blessed with a life as long as Methuselah in the Bible.
[26:49] I don't expect to see that.
[26:51] But, for me,
[26:55] for superstring to when
[26:59] observational acceptance, it will likely come about
[27:03] not from a single experiment, but from a confluence of observations.
[27:07] So a confluence of the observations of the cosmology astrophysics types
[27:12] I describe.
[27:13] And, maybe, perhaps the lightest supersymmetric particle is found.
[27:18] By the way, I don't expect extra dimensions ever to be found,
[27:21] but that's puts me.
[27:23] I'd like to say I'm a high dimensional refusenik, and probably so.
[27:27] So those are the kinds of things that I if I lived several hundred years,
[27:33] those would be the kinds of likely expectations I would have.
[27:36] And have you added anything new to your bucket list over the past ten years?
[27:40] You know, you're not sort of fixed to to stick with just one bucket list.
[27:43] That's true, yes, but I don't quite know how to verbalize.
[27:47] It has to do with a confluence of things around quantum mechanics and information,
[27:51] because in my own research, one of the striking things
[27:57] about these graphs that we developed to, we call them a decrease
[28:01] to understand the representation theory of supersymmetry
[28:06] is that error
[28:07] correcting codes are part of these construction.
[28:11] In fact, let me say that for me, this is the proudest
[28:15] piece of research I've ever accomplished to discover
[28:19] a kind of physics law,
[28:22] at least the possibility of physics law
[28:25] that includes error correcting codes.
[28:27] I know of no previous example in history where law physics
[28:31] includes error correcting codes, but we can clearly see it
[28:35] in the mathematics around these graphs.
[28:39] So that, first of all,
[28:42] had a profound impact on the way I think about information theory.
[28:46] So John Wheeler, in the 60s or so came up with this
[28:52] very interesting way to think about quantum mechanics.
[28:59] And one of the shorthand phrases of it
[29:03] is it from bit, namely, that the information
[29:06] that we see in the universe is somehow connected to bits.
[29:11] And
[29:12] I remember as a young person thinking, that's the craziest thing I've ever heard.
[29:15] But when I, in my own research,
[29:20] saw that it is possible for the
[29:22] the laws of physics to contain bits in the form of error correcting codes,
[29:28] I had to then rethink my rejection of what I thought was a wild idea.
[29:33] In fact, now that I've.
[29:34] Oh, I've concluded that
[29:35] if you do theoretical physics long enough, you too can become crazy.
[29:38] Because that's what sort of happened to me.
[29:41] So the fact that there at least
[29:46] in the
[29:47] mathematics of supersymmetry, there is no way to avoid
[29:50] the presence of error corrected codes and therefore bits.
[29:54] And because of that, my new sort of item
[29:59] for the bucket list is
[30:02] an actual observational demonstration
[30:07] that the laws of quantum mechanics
[30:10] entail the use of information in bits.
[30:13] That's the new idea.
[30:15] Well, any predictions for when we might find that out?
[30:18] Long after I've gone, though, that's all I could feel that.
[30:22] Would you know if I had another hundred and 50 years of life?
[30:24] That's where intellectually I would be going right now, because
[30:29] the hints are so stark that it suggests something's going on.
[30:33] And in some sense, often Richard Feynman is identified
[30:37] as the father of quantum computing.
[30:39] But if you actually go back and read, because I've read the actual writings
[30:43] area,
[30:44] it's not so much in my mind, not so much
[30:47] that he's the father of quantum computing.
[30:49] He basically says
[30:51] that there's a whole lot of computation somehow going on in nature.
[30:56] And that's a really exciting idea
[30:59] because I've seen a national year of quantum.
[31:01] We are asking a lot of people, we speak to this sort of quite nebulous and
[31:06] philosophical question, what does quantum mean to you as a scientist?
[31:10] I think it was, Feynman said.
[31:12] Nobody really understands part of a context, maybe of some,
[31:15] but some mainstream physics and this kind of right.
[31:18] Except I think there may be a hold in the formulation.
[31:21] So let me give you, as a physicist, a model to think about quantum mechanics
[31:26] that I've been sort of I haven't written anything but I've been thinking about it.
[31:28] Let's start with the bare okay,
[31:33] bubble, bubble, toil and trouble.
[31:35] Right.
[31:36] The three which is around the the cauldron.
[31:39] So let's imagine that those three witches were actually physicists.
[31:44] They might decide not to start the fire
[31:49] just to observe what happens to the liquid in the cauldron.
[31:52] It would calm down, and maybe one of them would put a
[31:57] small twig or something on this calm surface,
[32:01] give it a twitch,
[32:04] and the twig would begin to move along the surface.
[32:07] And if there were no friction, it would continue
[32:11] to move in a straight line without any loss of speed.
[32:15] That's what Newton teaches us.
[32:17] Now let's start the fire in the cauldron.
[32:22] The liquid heats up,
[32:25] the surface of the liquid begins to bubble.
[32:28] And then let's imagine doing the same thing with the twig.
[32:32] What happens now?
[32:33] It no longer moves in a straight line
[32:38] because of the the bubbles coming up out of the liquid.
[32:42] And so
[32:44] since they're witches, they can live forever.
[32:46] They can move form an infinite number of experiments like this.
[32:50] And in particular, you might want to perform one experiment
[32:55] where you say, even though the twig is not moving a straight line.
[32:59] Suppose sometimes it gets to the place where it would have been
[33:04] if it moved a straight line.
[33:05] It probably happens an infinite number of times.
[33:10] So you could watch those
[33:12] experiments, but there might be some times
[33:16] when it just gets a little a push, a little bit off of the straight line.
[33:20] But then as it nears the other side, it gets a push back in the straight line
[33:23] by these bubbles probably happens less than the actual straight line.
[33:30] And the point is that if you go to this thought experiment,
[33:33] you can begin to see why a fluctuating
[33:40] substructure
[33:42] moves away from Newton's laws.
[33:47] And we know in relativity quantum field theory,
[33:51] we know the masses that the vacuum is a fluctuating substructure.
[33:56] And so all one thing I began to wonder about is,
[34:01] is it just the quantum vacuum
[34:03] that actually makes us depart from Newton's second law?
[34:07] I posed this as an interesting thought experiment for anyone to go through.
[34:12] So these are
[34:14] the kinds of things that, as you said, year of the quantum.
[34:18] I would like to see this kind of a question
[34:22] address in a fully
[34:25] rigorous way to ask,
[34:28] are there classical models that demonstrate quantum behavior?
[34:32] And that's what my cauldron in which is, is all about.
[34:34] So we've talked a little bit about how science has changed
[34:38] over the past ten years.
[34:39] Of course, science is not
[34:41] unconnected with the rest of the world, and there have been some changes in
[34:45] other things that impinge on science, especially recently developing the US
[34:49] with threats to science funding generally
[34:52] and to support for diversity initiatives in science, specifically.
[34:56] What's your take on that?
[34:58] Where is that going to go?
[35:00] So unfortunately, it's been very predictable.
[35:04] I think it was two years ago.
[35:07] I wrote an essay called Pushed Off the Mountaintop.
[35:09] And in that essay, I was talking about the fact that people like me, I'm
[35:13] a man of color, an African-American scientist,
[35:17] that it looked to me like the United States was moving in a direction
[35:21] where it would be less likely that people like me
[35:24] would continue to have access
[35:26] to the kind of educational training that it takes to do this.
[35:30] And I took that title from a statement
[35:33] by Martin Luther King, or he says, I've reached the mountaintop,
[35:36] and the pushing off is closing down the opportunities for people of color.
[35:41] And, I'm still of the opinion that that decision
[35:47] that my country's Supreme Court made doesn't make sense.
[35:51] And it doesn't make sense in a very peculiar way.
[35:53] This is a decision about affirmative action. Yes.
[35:56] It doesn't make sense, because if you want to your stockbroker
[36:00] and you said, I don't believe in diversity, you would run out of the door.
[36:04] And that's kind of what this decision is like, saying is that
[36:09] that diversity has no role in providing and driving innovation.
[36:14] And there's lots of there's lots of evidence that's not right.
[36:17] The simplest evidence I can present to someone is to say, well, how do you think
[36:21] cities came into existence?
[36:22] They're places where innovation occurs.
[36:25] And why do they occur in cities?
[36:27] Because you have diverse people coming to cities, as you know.
[36:30] That's so that's the one to me, one of the saddest things of
[36:34] what my country is likely to go through for at least 50 years.
[36:38] It's not many people think it's a short term development.
[36:41] I don't think so at all.
[36:43] I think it's at least a 50 year development.
[36:45] I'm also some of an amateur historian
[36:48] because I, I like history, I have my entire adult life.
[36:52] And last time that these kind of conditions
[36:55] arose in the country there, it's very funny.
[36:57] In my country, there are two precursors to the current, conditions.
[37:00] One was the period where the Civil War,
[37:04] from 1865 to 1876,
[37:08] and the other precursor that sort of like this
[37:13] was what was called the, Red scare in the 1950s in the United States.
[37:18] And so if you look at my country's history, that sort of
[37:22] makes some predictions about politically where the country is going to be,
[37:25] not for a short while, but for a considerable while.
[37:28] You add to that the
[37:31] presence of a new medium,
[37:36] the internet
[37:38] and the fact that
[37:42] with this new medium.
[37:47] Anyone can reach many millions of people.
[37:49] Why is this a little bit frightening?
[37:54] Well, fake news, misinformation.
[37:59] I ran into,
[38:03] a philosopher, about a year ago.
[38:06] Less last summer, I guess it was.
[38:09] I had the joyful occasion of getting my 10th honorary
[38:13] degree from Harvard University.
[38:14] And I was in a conversation with this philosopher,
[38:17] and he made a statement to me which I found very profound.
[38:21] I've been turning it over in my mind.
[38:23] So I would this and trying to think, well, he said,
[38:27] if you stop and think of the, printing press,
[38:32] it allowed books to disseminate
[38:34] to Western European society in a way that had never happened before.
[38:40] And therefore it drove literacy, which is obviously true.
[38:45] And he said, so think about the comparison to what the internet is.
[38:49] So if we go back to the early example, how long does it take
[38:53] for literacy levels to increase 50 to 100 years?
[38:59] So then he says, now let's think about the internet.
[39:01] What's different about it?
[39:03] And the difference is that anyone can say anything and reach millions of people.
[39:10] And so the challenge is
[39:13] how long it will take for our species to learn to write the internet.
[39:19] That is right.
[39:20] And what he meant is write it without misinformation, a fake news.
[39:23] And if he's right, that's a 150 year long period.
[39:27] And so that's part of the challenge that, the US is facing.
[39:32] But, I mean, it's not just a challenge for my country,
[39:36] but somehow it seems to be particularly critical in the country.
[39:39] So what does this do about science?
[39:41] Well, in 2005, the outside world, your science,
[39:50] I was invited to deliver a plenary address
[39:54] to the American Association for the Advancement of Science large annual meeting.
[40:00] And in that address,
[40:03] which was entitled Einstein's Lessons with the Third Millennium,
[40:08] I made statements about science being turned off
[40:14] because it was clear to me, even back then in my country,
[40:18] that there were elements in our society
[40:21] that would be perfectly happy to
[40:25] deny evidence as brought forth by scientists.
[40:29] And it was also clear to me that these elements were becoming more strong.
[40:34] They're not weakening.
[40:37] So you put this all together, and it's going to be an extraordinarily
[40:41] important and importantly, challenging time for the continuation of science,
[40:45] because certainly at the level of fundamental science, this is something
[40:50] that the public generally has to say, yes, we want to invest in this.
[40:54] And if you have agencies and agents in the society
[40:58] denying vaccines, for example, or denying
[41:04] the scientific evidence throughout evolution,
[41:06] or denying the scientific evidence about climate change,
[41:11] if this is going to be
[41:13] something that the public buys into, then science is so
[41:18] potentially can be turned off.
[41:20] And that's the thing I was warning about in 2 or 5.
[41:22] What are some practical things that members of scientific community
[41:26] who don't want that to happen, can do to help prevent it from happening?
[41:30] First of all, to come down from the ivory tower.
[41:34] I've been parts of
[41:37] some activities in the United States,
[41:40] and they normally are, under the rubric of
[41:45] restoring trust, the public's trust in science.
[41:48] And I think that's the wrong framing me, quite frankly,
[41:52] it's the public faith in science as a under attack.
[41:54] And so from my perspective, I
[41:58] that's what I'd much rather have people really thinking about.
[42:01] What is it that is the issue I don't think is just a matter of trust.
[42:04] What would you say the differences between having trust the science
[42:08] and having faith in science?
[42:11] So what's the difference between faith and trust?
[42:14] Well, in my mind, if I
[42:18] trust some guy, I will listen.
[42:23] If I have faith in something, I will listen and I will act.
[42:28] And to me, this is a this is a sharp distinction.
[42:31] Personally, even though I expect
[42:35] that it's going to be really hard going for I am hopeful
[42:39] and I would urge young people never to lose that.
[42:43] We've got it.
[42:44] It's funny if you lose hope, there is no hope.
[42:47] It's just that simple.
[42:50] And so I am hopeful.
[42:52] Even though people may take my comments as, oh, he's just depressed.
[42:57] No, no, I'm not I because I'm a scientist and, it's the only thing
[43:03] I've ever wanted to be in life as a scientist starting at four years old.
[43:06] But because I'm a scientist, I believe that one must,
[43:10] in a clear eyed,
[43:12] hard hearted manner, look at the evidence that's in front of
[43:16] us and not sentimentally try to dodge what you see.
[43:21] And that's who I am. So I am hopeful,
[43:25] in spite of all the things that I've just said to you,
[43:28] I tell people, I've often said,
[43:31] Albert Einstein is my hero, Max of us in science, and he is.
[43:34] And one of the things, if you read enough about Uncle Albert,
[43:40] as I refer to him often, if you read about his
[43:43] life, you come to understand a couple of things.
[43:46] He was very religious up until age 12.
[43:49] What changed?
[43:52] Geometry.
[43:53] He says it exposes near the end of his life, however,
[43:58] you can find him talking about an illimitable spirit.
[44:02] What does that mean?
[44:04] He doesn't explain it.
[44:06] He just uses the phrase but admits something to him.
[44:09] And so
[44:12] the way I interpret what he had to say
[44:16] through the prism of my own life
[44:20] is that there's something very mysterious about this universe
[44:24] and that this great mystery, whatever it is, is something that
[44:29] comes as close to a miracle as anything I've ever seen.
[44:32] And that's what for.
[44:35] What gives you hope?
[44:35] Yes.
[44:36] Then I'll probably leave it there.
[44:39] Jim Gates, thank you very much for speaking to us.
[44:42] Thank you.
[44:42] Margaret, it's great to have the opportunity again
[44:46] here.
[44:46] If you want to time
[44:54] travel back to 2014 and listen to Margaret and Jim's first conversation,
[45:00] you can find that interview on the Physics World website.
[45:03] Just look for the headline, Terrorists Bucket List.
[45:08] That interview was a very early episode
[45:11] of the Physics World Stories podcast, which we produce every month.
[45:16] The February 2025 edition
[45:20] looks at the delicate, glassy formations
[45:23] known as Pele's hair and Pele's tears.
[45:27] These are volcanic materials that are named after
[45:31] the Hawaiian goddess of volcanoes and fire.
[45:35] As the volcanologists Ken Rubin and Tamsin Mather
[45:40] explain in to host Andrew Gloster
[45:43] that episode is called Threads of Fire,
[45:48] uncovering volcanic secrets with Pele's hair and tears, and you can find it
[45:54] on the Physics World website or at your favorite podcast provider.
[46:00] I'm afraid that's all the time we have for this week's podcast.
[46:05] Thanks to Jim Gates and Margaret Harris for a fascinating conversation,
[46:10] and a special thanks to our producer, Fred Isles.
[46:14] We'll be back again next week.

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