Raman Sundrum: Physics and the Universe – #44

Steve and Corey talk with theoretical physicist Raman Sundrum. They discuss the last 30 years in fundamental physics, and look toward the next. Raman argues that Physics is a marketplace of ideas. While many theories did not stand the test of time, they represented avenues that needed to be explored. Corey expresses skepticism about the possibility of answering questions such as why the laws of physics have the form they do. Raman and Steve argue that attempts to answer such questions have led to great advances. Topics: models and experiments, Naturalness, the anthropic principle, dark matter and energy, and imagination.

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Transcript

Steve: Corey, our guest today is Raman Sundrum. He was educated at the University of Sydney in Australia, and received his PhD from Yale University. He held post-doctoral positions at Berkeley, Harvard, Boston University, and briefly at Stanford. He was previously on the faculty of Johns Hopkins University.

Steve: He’s now at the University of Maryland, where he is a distinguished university professor. He is perhaps best known for his work on a model for extra dimensional space, which we’ll get into I think later in the podcast. What I’d like to do in our discussion today, is start by just having Raman talk a little bit about his biography, his career trajectory.

Steve: Then we’ll get into the modern state of particle physics, and where he thinks the field is going to go say in the next 30 years. We’ll first look back about 30 years, and then we’ll look forward about 30 years. Raman, we’ve known each other since the late ’80s.

Raman: That’s right.

Steve: At that time, I was a grad student at Berkeley and you were a postdoc.

Raman: Yeah.

Steve: I just read out your sort of career timeline, and so you had a number of postdocs. It was quite a journey before you became a faculty member, even though everybody in the field knew that you were quite talented.

Steve: I just wanted you to reflect on what the job situation was like at the time and has it gotten better? Do you think it impacts our ability to attract people into physics?

Raman: I feel like it was definitely a very different time. It felt like the field was going in a very predictable way, when I was a postdoc in the 90s. It just felt like I was out of sorts. I was questioning myself, as I was not getting jobs and so on and so on. I knew that I was somewhat outside the mainstream, in terms of how I thought about physics and did physics.

Raman: I think I didn’t really think of it as, the job situation as being dire. I just took it as whatever was normal. Looking back, I kind of count sort of the same number of high quality jobs now as then.

Raman: I’m not seeing… in terms of job numbers, that there has been a big change. The type of hiring… who gets hired? Has changed a lot. The way the field views itself has changed a lot. What it looks forward to has changed a lot, yeah.

Steve: Yeah, so maybe you could comment on those last few things, because I’m a bit out of it right now, being in an administrative job. How is the field different than say the in ’90s or early 2000s?

Raman: Right

Steve: How is it different for young people?

Raman: Yeah, so one thing in the ’90s, we were… in the beginning of the ’90s, there was still the possibility that America was going to have the grandest particle collider of all time. The Superconducting Super Collider in Texas. Then beyond that, with slightly complimentary abilities, was going to come the Large Hadron Collider at CERN in Switzerland.

Raman: We had this idea that a lot of particle physics… a lot of fundamental physics, is going to be done in the lab, so to speak. Now these were labs on a gargantuan scale, but we were looking forward to a lot of our ideas about theoretical physics playing out in these labs. It was all ahead of us.

Raman: A lot of the work that the top theorists who are getting hired were doing, were writing down theoretical models of what might be seen at these mega labs that were coming, these particle colliders. Of course, for various… I don’t know, political reasons, the Superconducting Super Collider or the SSC was canceled in the “90s.

Raman: That ended up delaying the future confrontation with experiment into the 2000s. When I was a postdoc in the ’90s, a lot of the top [inaudible] and a lot of the thinking was going into theoretical modeling.

Raman: A lot of the people that rose to the top in hiring, were people who had the imagination to put the intersection of quantum mechanics and relativity, quantum field theory as it’s known, into imagining what the physics just beyond our current understanding would look like. Then be tested at the Large Hadron Collider.

Raman: Of course, a huge sea change operating the Large Hadron for the last seven, eight, [inaudible] about eight years in earnest, nine years in earnest. There has been one spectacular discovery, which was the discovery of the Higgs boson, that many of your listeners would have heard of.

Raman: We have not gone beyond the standard model and what we’ve seen at the Large Hadron Collider directly. One big change has been that a lot of the thinking now, has splintered from this one oracle that was going to tell us what was going on, called the Large Hadron Collider to a myriad of other experiments.

Raman: That could give us information that might take us beyond the standard model of particle physics. There’s for example, dark matter, the evidence from astrophysics and cosmology tells us there is something huge that is beyond the standard model of particle physics, that we have very little idea about.

Raman: A lot of the thinking in the field has gone to, how do we mine dark matter in our experiments? How do we build better dark matter experiments than we used to do in the ’90s? These have flourished into sort of many different aspects.

Raman: Even theorists have been some of the most imaginative people, in designing and imagining what kinds of dark matter of physics and experiments to probe in the future. The cosmology has gone from great advances in the ’90s, to even greater advances now and with even greater prospects for the future.

Raman: A lot of the theoretical thinking has also followed that and said, “What can cosmological observations teach us?” People have also gone into thinking about particle colliders, well beyond the capacity of the Large Hadron Collider, Hence what we might hope to learn on that front.

Raman: In a sense, while I had a lot of sense as a particle physicist in the ’90s, of having all my eggs in the LHC basket, experimentally speaking, now we see our eggs are distributed among a huge variety of experiments. With almost equal probabilities for where Nobel Prizes might be sitting.

Raman: I think that’s a big thing and it reflects itself in a lot of the variety. There’s perhaps greater diversity of thinking, but it’s become more focused. A lot of the even theorizing, has become more focused on being a little bit agnostic about some big worldview of particle physics, and more opportunistic about experimental opportunities.

Raman: Whereas my sense in the ’90s was, there was a lot more theorizing along like, what is the particular paradigm that I find attractive? Is it supersymmetry? Is that Technicolor? Trying to start from high principles and going close to experiments.

Raman: Now it’s like, “What are the experimental opportunities? We’ll worry about the theory later.” That’s the biggest change in some sense that I’ve seen.

Steve: Getting back to the ’90s, how should we feel about a decade or two of work, where very imaginative models were built, but they all turned out to be wrong?

Steve: Should there be any look back, scorekeeping on whether the field was doing the right things in the ’70s, ’80s and ’90s? Or should we just say, “It is what it is. Unfortunately, all these wonderful, beautiful Baroque models, didn’t turn out to describe TeV scale physics.”

Raman: My feeling about the theorizing that took place in the ’90s and even the ’80s and the ’70s is, it’s sometimes a little bit like when we’re hiring a new faculty member or something. Or thinking about writing letters of recommendation, where you look at somebody and you see that, yeah, they did a lot of dumb things and they’ve done a lot of great things.

Raman: How do I usually rank people or think about their value to the field? I value them on their best work, because all the junk that people do, the sheer inefficiency of human beings, but you think of science, it cuts through that. It filters all of that out. Their best ideas stand the test of time and are highly valuable.

Raman: Indeed, when I look back on the theorizing that I would have done, or many of my colleagues in the ’90s and certainly before my time and so to speak in the ’80s, I would say… so I’m about to justify to you why some of it was absolutely top notch intellectual detective work.

Raman: And Absolutely necessary. Mixed up in that was lots of stuff that could easily be thrown away. We can only say that sort of with hindsight, which was which. There is an innate efficiency to science, where we have to have a free market of ideas.

Raman: We have to have a kind of adversarial system that eventually eliminates some of the bad ideas and keeps some of the good. First of all, I don’t want to justify the entire body of theory or entire body of detective work, even on the experimental part.

Raman: I do want to say that the best of it… and that’s a lot. That the best of it was the credibly valuable, and in a certain sense that I will explain, is going to stand the test of time. It’s simple enough, if you are a detective, if we just put ourselves in the position of a detective and he’s got a whodunit, the task to be resolved, what is the job of the detective?

Raman: One is, please put out possible hypotheses as to, “I think it’s the butler, at least the butler had the opportunity.” Then you have to say, “Well, what are the tests? If the Butler did it, shouldn’t his fingerprints be on the gun?” We need ways of experimentally checking our hypothesis. This is a cycle that we have to play over and over again.

Raman: We’re not talking about your average whodunit, which are tough enough. We’re talking about some of the greatest whodunits in the history of the universe. The level of pain and sweat and sorrow, should be expected to be incredibly high. We have to ask, on that stage… which is, I want to say [inaudible] kind of intellectually heroic, how do we judge what was done?

Raman: I want to say that the best work that was done in the ’80s and ’90s, some things that some people might look back and say, “Well, I’ve failed,” are some of the great hypotheses for who might have done it.

Raman: They were not just random like, “I don’t like to look at the butler. I think he did it.” No, the evidence brought there and the theorizing was exquisite, in terms of why you might think it was this person, or why it might be this plot playing out in nature.

Raman: The experimentalists have been part of that team, in terms of, “Okay, so let’s check for the thumbprints here in the cosmic microwave background. Let’s check for the thumbprints of these experiments in the Large Hadron Collider.” To me, I look back at that era and I say, “That’s the necessary process of science.”

Raman: The process of elimination of what is false, is the pursuit of the truth. To say that, “Oh, I discovered that some possibilities that were eminently plausible, turned out to be false. That is a failure of science, is to completely misunderstand the process of science.”

Raman: I guess in summary I would say, that I look back at those decades and I look at some of the theorizing that was done, and I am still agog in admiration. Even knowing that some of the specifics have now being falsified, they were worth being falsified.

Raman: Most things that come out of people’s mouths might at first sight say, “Look, it’s not even worth my checking, whether what you’re saying is right.” These were worth checking. It’s part of the process that I think will ultimately lead humanity to great discoveries.

Steve: My own view on this is that in many of these areas like supersymmetry or Technicolor, there were beautiful ideas that got the ball rolling.

Steve: Maybe the first hundred, or maybe even the first thousand or top hundred or top thousand papers, written in each category is very worthwhile. Future physicists will look back at these models, but then you have 10,000 papers that are… maybe should never have been written.

Raman: I would agree with that in hindsight. Although I would at least even ask you… it’s kind of a sociological problem of how to only keep those pearls of wisdom.

Steve: Yes.

Raman: Not the other ones, in a free market of ideas.

Steve: Yeah.

Raman: I would do more than that in some other way, so that only pearls were ever produced?

Steve: Right, so we can get into that. It’s interesting to ask like, would a different way of selecting talent or a different way of filling positions, have created a different set of papers written during those decades?

Steve: Before we get into that, I want to say, there is a big organizing principle that everybody at that time believed in called naturalness or the hierarchy problem.

Raman: Yes.

Steve: Which really motivated all of these models.

Raman: Yes.

Steve: Would you say, even today we don’t know, is a jury still out on whether we should believe in naturalness in fundamental physics? It’s almost equivalent to asking whether the murder actually was committed.

Raman: Right.

Steve: You’re going to find the butler, but someone might come along and say, “No, the guy escaped. He’s living in Bermuda. There was never any murder. This whole crime was a fake.”

Raman: Right, yeah.

Steve: How do you feel about that?

Raman: I have been wrestling with that for a long time. One of the things that every scientist has to wrestle with is, we’re trying to know the truth, but sometimes some of us are hoping that our pet view of the world turns out to be the truth. It distorts our coldblooded judgment. Usually your coldblooded judgment is far more accurate than your wishful thinking.

Raman: I have tried to set myself sternly by the hand and tried to say, “Think this one out as carefully as you can.” I’ll summarize it by saying that I still come out on the side of saying, “I take the ideas of naturalness very seriously.” Now on the face of it, experiments have taken the ideas of naturalness.

Raman: Naturalness is kind of a gambling tool. It’s a gambler’s tool. It’s just an extrapolation of how you would gamble if you went to Las Vegas. It seems like what would it been the best gambles, have not turned out to be correct, so something is up. You can say, “Who loaded the dice?” Something else is going on.

Raman: A number of ideas have come up, which I think are very interesting by their deceptive simplicity, like the anthropic principle, for how the dice could get loaded. At the moment, my view is, I think I still put a lot of stock in naturalness.

Raman: Not in some unloaded dice sense of the way of gambling, but the dice are loaded by something, by some other consideration. The dice are loaded, but you cannot give up gambling tools in terms of gambling on what are the best bets for what experiments might see. I have been pushing in many talks, the idea of frustrated naturalness.

Raman: That there is a natural sort of way of gambling, we know nothing. But clearly, experiment has spoken already, and it says that something in the way we’ve been gambling is just wrong.

Raman: You have to look and say, “What are the most…?” Given quantum field theory, maybe not all your listeners will know that the grammar of quantum mechanics and relativity is incredibly tight. It’s like the rules of chess. The set of games of chess is infinite. I think it’s infinite, but it’s incredibly a large number and it’s got great diversity.

Raman: Yet there is a kind of [inaudible]. The game of chess is still highly constrained by its ground. Relativity and quantum mechanics, the laws of nature are highly constrained by their grammar. Taking that into account, you have to ask how best to gamble on what’s going on.

Raman: I try to take that view as rationally as I can in every research project I do, in every talk I give in terms of where I tell people to place their bets. I believe that naturalness is still playing in my view, a huge role, but not exclusive role in how I gamble.

Raman: In my view, the naturalness principle is alive and well, scientifically. Sociologically, I recognize that many people feel like, “Oh, I tried using that gambling rule once and I got burned, and so I give up on it.” I’m not one of them, but [crosstalk].

Corey: Yeah, I think before we go a bit too far, can we for the lay audience, give an explanation of the naturalness principle? The sense in which… I think some examples of perhaps of how the laws of physics are constrained in their form.

Corey: Give us an idea of what is now thought to be the limit to set the possibilities, or structures of laws of physics. What’s out on the… kind of how to balance these days. Start with the naturalness principle. Most people who are not physicists, aren’t going to know what that is.

Raman: One thing that we see in the laws of nature, are simply that there are some very characteristic length scales. What do I mean by that? For example, if you are two meters high or two yards high, or you just have a meter stick in your hand, that is sort of characteristic length scale for human activities and for human beings.

Raman: We’re all in the ballpark of this thing. Yeah, I know some of us are this thing, but you’re all in the ballpark of about this thing. There is something about the human length scale that pervades a lot of our activities. Our cars are roughly human length scale, et cetera, et cetera.

Raman: Now, if you look at the laws of physics, fundamental physics, you find that there are a variety of length scales. For example, the smallest conceivable black hole, before you would have called it a black hole. The smallest than a black hole can be, is about 10 to the minus 33 centimeters. It’s the length scale called the Planck length.

Raman: That’s an incredibly 10 to the minus 33 centimeters or 10 to the minus 33 inches. That is an incredibly small length scale, but it’s one that characterizes quantum gravity. The range of the force, the weak nuclear force that for example, is responsible for radioactivity.

Raman: The range of that force, is in fact about 15 orders of magnitude bigger than the size of this characteristic, smallest black hole. If we look through nature, the size of an atom is many orders of magnitude bigger than the range of the weak nuclear force. We find that there are some absolutely characteristic, big picture length scales in nature.

Raman: Like the size of the universe is another one, that seem to be spread out by orders and orders of magnitude. In many ways, when we try to look from a theorist perspective, you’re a theorist and you’re making the laws of the universe, you’re playing God a little bit.

Raman: You find that in the presence of quantum mechanics and relativity, you find that when you try to write down the laws of nature, that the typical ones, if throw darts at the parameter space of the laws of nature, that this very hierarchical structure that we actually see in experiments is very atypical.

Raman: It’s a tiny corner of parameter space, in which something like that would happen. If you were throwing darts as God, throwing darts at the parameter space of the eerie that we currently believe, you would not get that hierarchical structure.

Raman: The question is, what’s going on? Throwing darts at the parameter space is like gambling. Where is the dart going to land? Well, it’ll lands in the typical spot on the dartboard. We don’t seem to be living in the typical place on the dartboard, or the parameter space of the standard model theory.

Raman: We seem to be in one, which is a carefully chosen place in parameter space, which allows these huge hierarchies in nature to exist. That is the puzzle of the hierarchy problem. What’s going on?

Steve: One of the things I’ve been thinking about since they discovered the Higgs boson and nothing else, and therefore we didn’t find a solution to this so-called naturalness problem, is that maybe the probability measure over this parameter space that Raman was talking about, isn’t as straight forward as it looks to us.

Steve: Maybe it’s determined by some very short distance or high energy physics, that will only become apparent to us when we say, fully understand the theory of quantum gravity. Maybe the resolution of this… maybe there is a resolution of this naturalness problem, that maybe only becomes apparent when you really fully understand short distance physics.

Raman: Indeed, I think one of the nice developments in the last 10 years and 20 years and so on, has been that people are rethinking naturalness. Sociologically speaking, some people have just said, “Look, I have no clue. I abandoned it completely. I’ve become kind of the handmade into experimentalists and that’s great.”

Raman: That’s a reasonable attitude. “I’m too dumb to know what’s going on.” That’s okay. Other people have been revising… have been playing with naturalness, and trying to see in what sense it might still be not an idea that is completely wrong, but merely more nuanced than we originally thought.

Raman: The anthropic principle is definitely one of those ideas. It was originally brought up as a kind of… I mean, originally in its modern phase since about 2000, has been brought up as a kind of replacement for naturalness. In my own thinking, which pervades all my work I would say, it is not a replacement. It is a refinement of naturalness.

Raman: That is, I think both considerations become important. One of the ways of thinking about it is, what we’re doing is we’re gambling on the laws of nature, because we want to know what experiment to do next, that will discover something interesting, something new.

Raman: That means, we’re necessarily gambling on the laws of nature. We’ve seen some of the laws of nature, but we know for sure we haven’t seen all of the laws of nature. In fact, in some sense, maybe we’ve only seen a small fraction of the laws of nature by some way of counting. It’s exciting. There is something to look for. How should we gamble on where to look?

Raman: When you’re thinking about gambling on the laws of nature, one consideration which seems like common sense after the fact, is whatever the laws of nature are, they have to be some way that allows intelligent life to exist in the universe. Otherwise, we wouldn’t be sitting in the asking ourselves what the laws of nature are.

Raman: This sort of almost circular logic is true of course, that if we’re gambling on which universe and which set of laws we got stuck with in our universe, we should say, “What does quantum mechanics and relativity allow in theory to be the laws of nature?”

Raman: Oh, there are many choices. Many chess games are allowed. Well, which are the chess games that get played most often or the easiest to play? We’re probably in one of those, not one of those exceptional chess games that hardly ever happens.

Raman: This way of thinking about the laws of nature, as to which are the easiest for quantum mechanics and relativity to put together, has to be qualified by whatever the laws of nature are. They have to be the kind that allow life to exist, life like us to exist. It is a kind of qualification of whatever you’re going to gamble.

Raman: Maybe if you are a theoretical physicist and you say, “What are the most likely laws of nature that quantum mechanics and relativity allow?” Then you say, “This is the most likely one.” Probably that’s where you should gamble. You find that the universe that that set of laws would create is a dead universe.

Raman: It’s one in which life could not even evolve. In that case, even though it’s the most likely kind of universe to exist, you shouldn’t expect to find yourself there, because you are alive. This is the kind of qualifier that the anthropic principle puts in it. It filters some of the gambling odds.

Raman: It’s like saying, “I’m going to throw the dice. What number is going to come out?” One, two, three, four, five, six. Let’s say that every time you get a six, you hide the result. You throw that dice away. Obviously it’s going to change how you gamble on the other five numbers. The probabilities change.

Raman: This is the nature of the anthropic principle recently, in a lot of the reflections on naturalness. It’s a way of saying, “The dice are loaded.” Another one that has come up recently, is the idea that in the measure, as you were saying, what are the odds? How are the dice loaded? Is the other way of saying, what is the measure of the probabilities?

Raman: It is considering cosmological evolution. A lot of the gambling about the laws of nature, have often taken the place of a kind of static consideration. Here are the laws of nature, fully evolved. We know that from the early universe to now, in some sense there’s been some evolution in the laws of nature.

Raman: There was a time when electromagnetism and the weak nuclear force, were fused together into one mother force. At some time, there was a so-called phase transition in the early universe, where the two forces split off.

Raman: In a sense, the universe has been splitting and evolving these forces. That in our gambling, we should take into account this dynamical process in how it changes the odds for what we’re expecting to see in future experiments, is also being revised.

Raman: Ideas like the relaxion, have tried to play with this idea that cosmological evolution, changes the probabilities that we would normally have thought about differently in the ’90s say.

Steve: I wanted to say, getting back to the first issue, first use of anthropic reasoning, which is just maybe how it influences the hierarchy between the weak energy scale and the Planck energy scale that you mentioned.

Steve: Is there a sensitivity…? The last time I looked at this, which was probably over a decade ago, there didn’t seem to me that much sensitivity in terms of favorability to complex life on the weak scale. Has the thinking changed on that? Are there some mechanisms by which the strength of the weak interaction actually plays a role in the ability of life to evolve?

Raman: Within the kind of standard model of particle theory thinking, I don’t know that much has changed in that 10 years that elapsed. In my own thinking, this idea of contemplating other possible laws of nature and whether they allow life, is a tricky game.

Raman: You then have to say, “Did it have to be literally our kind of life or could it be some other kind of intelligent life?” It’s a kind of uncertainty to which we are subject. Physicists love to think we’re different from the biologists and everybody else.

Raman: Our subject is so sharply defined and a clean game of chess. It’s too bad, it ain’t. At the highest levels of ambition, every consideration comes back with full force and full uncertainty. We are expected to not just be chess machines, too bad.

Raman: However, I have always maintained and still believe that if we try to imagine and calculate probabilities for life and other types of life too, too carefully, that we are liable to be making mistakes and compounding speculation on speculation. I would not trust the conclusions.

Raman: I’m totally with where you were 10 years ago, and even where the state of the art was 10 years ago, thinking about, what are the ingredients of life and so on? I would even push back on it. Let me give you a different example, because I find it so both scientifically interesting and hitting this nerve of the anthropic principle and naturalness.

Raman: One of the great scientific questions is, we know that the laws of nature favor matter, and anti-matter, hardly at all. In other words, anti-matter is kind of our evil twin. In the laws of nature, you could hardly tell the difference between matter and anti-matter. They both look like they’re sort of equivalent in some way.

Raman: Amazingly, if you look at the universe, you find that it is full of almost exclusively matter, with very small traced amounts of anti-matter. One of the greatest scientific mysteries that’s still going is, why is there so much more matter than anti-matter?

Raman: It’s a fantastic thing that the grammar of relativity and quantum mechanics, allows us to write detailed models of the answer to that question. It uses every trick in the chest playbook of relativity and quantum mechanics. Yet we have possible answers to this question, why there’s more matter than anti-matter?

Raman: Now, one of the examples of that… in fact, I consider one of the simplest examples of a theory of that sort, was one I wrote down with my colleague Yanou Cui, in 2013 or something. It was built on the shoulders of supersymmetric theory, as an example. She’s written some followup papers on this since.

Raman: Now, here’s the thing. Supersymmetry was originally popularized… and it wasn’t invented for this purpose, but became very popular as a solution to the hierarchy problem. To understand why hierarchies of length scales could exist in nature naturally, robustly. We built a supersymmetric theory, which also explained why there’s more matter than anti-matter.

Raman: There is an amazing thing that happens in the parameter space. If you throw darts at the parameter space, you find that you end up with the most natural theory of the sort we wrote down, which naturally explains why the hierarchies of nature of length scales exist.

Raman: It turns out that in most of the parameter space, when you throw darts, you find that the amount of matter and anti-matter is equal. In the beginning of the universe, all the matter and anti-matter annihilate with each other and leaves nothing there, no matter leftover.

Raman: This is a world in which all the length scales of nature are very natural. The naturalness problem is solved, but there’s no bloody matter leftover. I don’t have to talk about the architecture of intelligent life in great detail. There’s nothing to make it out of, in that universe.

Raman: The leaf is falling in the forest, but there’s nobody to see it. Now, it turns out that in one of Yanou’s models, where this is the case, that there is a slightly unnatural part of parameter space. That is, it’s not the generic part of parameter space.

Raman: It’s not too small, but there is a small-ish region of parameter space, where if you happen to live there, our mechanism works and there is enough matter to exceed the amount of anti-matter, so that we see why there’s matter in our universe. Now you see, there is a tension.

Raman: If the laws of nature took the form that is in that paper, and you lived in the generic part of parameter space as gamblers would say, there wouldn’t be any matter in the universe. If you live in the special corner, it looks less natural, but there is a chance that life could evolve and look around and say, “Why is the world the way it is?”

Raman: This is the nuanced view of naturalness that I am promoting, but it’s not based on very fine details of why carbon plays such an important role in our kind of life, et cetera, et cetera. It’s based on very crude considerations of the anthropic principle.

Corey: Raman, can I hop in. Raman, I want to ask you about this again, because you probably didn’t answer my question whether it’s mostly that there were detailed conceptions of life, or kind of a broad sense that, look, that you can’t have life if there’s no matter. You can’t have life if everything is 100,000 degrees kelvin all the time.

Corey: When we think of the anthropic principle in most people’s hands, is it any more constrained than simply these kinds of basic boundary conditions? You can’t have life if everything is gaseous basically. Does it go beyond that generally? Or is that the general way which has presented very, very basic constraints, and simply complex objects existing in some kind?

Raman: My own sense was that it was varied. People’s views were varied. The famous Nobel Prize Winner, Steven Weinberg, who again, made the anthropic principle from cookie to mainstream, used a criterion for life, as just being galaxies form. Like, we at least got to have galaxies. You can’t just have matter just screwing around as dust everywhere.

Raman: That seemed like a mild use of it. This idea that there has to be some matter in order to even have life, to me, seems like a very mild use of it. It varied from person to person in a lot of the research.

Raman: That’s why I call it a marketplace of ideas, because different people can bet, “No, I really think you’ve got to have the carbon atom.” It’s like, “I don’t even care if I go to some other planet on the other side of the galaxy. It’s going to involve carbon.”

Raman: You might have different hunches. Each of us sort of has to ask whether we are willing to gamble all, which in my view is, where to look for future experiments to pan out. We’re all hunting for gold and I want to know where things are going pan out.

Raman: How much are we willing to gamble that this conception of what it takes to create life, is going to constrain where I look for new experiments to corroborate me? I think it varies from person to person.

Raman: There were situations where I would not be willing to gamble, because I thought that some of the considerations were too specific and we may be at risk of our imagination of what life is, being too constrained by what we’ve seen already. The answer to your question is sort of all of the… it was all of the above.

Raman: I did not find it so fruitful in its most specific extremes, of what it required of life. The fact that anthropic considerations come into the universe we happen to find ourselves in, to me, this seems extremely likely.

Raman: Whether we are able to figure out the rules of that by pure human thought, is not obvious. The fact that the anthropic principle is playing some role, I find it incredibly plausible as does a large fraction of the community.

Corey: Let me now express this skeptical question and maybe give an analogy. As far as I understand what you guys are trying to do… there’s some I question ask about what the laws of physics are. It seems like you’re trying to ask a deeper question, as to why they are the way they are.

Corey: Let me ask a skeptical question about that, possibly answering that question. You roll a bunch of dice, and we find ourselves in a particular world where we see dice turned up on certain sides around us. Now you might say, “Okay, I want to know what probably has led to this distribution.”

Corey: It seems like you guys want to ask more radical question, which is, why perhaps were the probability set the way they are? Not really, what they are in our particular universe. Some might say, “There’s no way you can do that. You live in one world. You guys are trying to make inferences about what the distribution of possible worlds are.

Corey: How can you do that from this one single universe you live in? Maybe you could travel outside of your own universe. You could do that, but how are you guys going to possibly solve this question given that we have this set of…?” Maybe there’s some other solution over time.

Corey: Maybe there was some evidence that the probabilities have changed. We can see history of that. It seems like you’re trying to ask about possibilities, that you just simply don’t have access to enough example distributions to infer.

Raman: I very much sympathize with that viewpoint and say, it may well be, we don’t come with guarantees. That’s absolutely for sure. This way of thinking, is only one way of us trying to gamble on what experiments to do and where to find new discoveries. It’s one way. It does not come with guarantees.

Raman: There is certainly a way of thinking, when you only get to look once. You only get to look once, but you do many experiments, but you only get to pick one random one and look at what it is. There is a way of gambling as best as you can in that situation. Let’s choose anything.

Raman: If you throw the dice and you get us, “Here is a dice in which, if you get a six, I give you a car, but we’re only throwing it once. Here is another dice. If you get between three, four, five or six, I give you a car, but we’re only doing this once. I want to give you a choice, which game you want to play, but you only get to do it once.”

Raman: Yeah, the whole notion of probability is all about, well, you do it many times and probabilities become certain. That’s the axioms of profitability there. Well, we’re only going to do this once, but I know which one you’re going to choose. I know which game you’re willing to play.

Raman: You’re going to go and say, “Well, the probabilities are, I’ll play the game where I get three, four, five and six and he gives me a new car.” We are gambling, whether we… like, is there guarantee that you’re going to get the car? No.

Steve: I think what Corey is saying though is like, suppose you know you got the car, what can you conclude about which game you were playing? Were you playing a game where only six-?

Raman: Exactly, yeah.

Steve: Yeah, and he’s… yeah.

Raman: Even there, you know that… yeah, you’d say, “Well, it was probably that.” If this game was only about, “Oh, I think your car came from the three, four, five, six game. I think it probably didn’t come from the one where you had to get a six, to get the car.”

Raman: Then you’d say, “Well, who cares? Who cares? I mean, I have no way of knowing, I can’t play the game again. What am I going to do?” Unless there’s something correlated with that decision, which you can go and test. If it’s the three, four, five or six game, then when you open the glove box, you’ll also have a diamond ring inside.

Raman: Then you might sort of decide, “Well, that’s a pretty good bet. I’m probably thinking it’s the three, four or five or six one and I know what to do next.” We are looking for the next law of nature. We’re trying to figure out for example, what is the identity of dark matter? Or how did the Higgs mechanism truly work?

Raman: We have something to gain in the future and we’re trying to see whether our gambling tells us, what are the best places to look? Or what should we give up on? If the LHC did not see something beyond the standard model to date, it may tomorrow, maybe we should stop running the LHC. That’s a question we could ask.

Raman: Is it a good gamble to stop running the LHC? That’s a once in a lifetime decision. You don’t get to do that 1,000 times. You have to use probabilistic thinking, as we do in everyday life, to make that judgment call. Is it worth doing that? This thinking comes up even when you don’t repeat it many times, to make probabilities and to certainties.

Raman: I would argue that we use that kind of thinking in ordinary life. This is not some strange, weird philosophy by some desperate political theorists. This is an extension of ordinary thinking about ordinary once in a lifetime decisions, or twice in a lifetime decisions.

Steve: Corey, I’d like to make the comment that the vast majority of physicists are experimentalists. They’re working on gathering data, pinning down the laws of nature, et cetera, et cetera. You have the smaller community that are thinking very complicated thoughts about, “Oh, what’s next? Why are the laws the way they are? Is there any inkling of why that might be?”

Steve: In a way, this isn’t the primary necessarily activity, at least in terms of head count of what… or dollars expended, of what physicists are doing. It is important, because sometimes some insight will come from that small theoretical community.

Steve: That will actually inform the next billion, $10 billion machine or dark matter experiment that people do. Maybe you’ll get to the answer faster, because of some of the insights from the small community.

Steve: If you think of it as, this small community is the whole thing, then I can forgive you for thinking like, “These guys are like philosophers arguing about how many angels can dance on the head of a pin.” It can seem that way, but in the past it has paid off to have a community like this reasoning this way.

Raman: I would actually greatly agree with what Steve just said, because in some sense, this way of gambling on the laws of nature… well, we have gambled in the past in various different ways. We’ve gambled with some aesthetic sense, on what the laws of nature are and people have made their gambles.

Raman: Of course, the best of those have actually survived and have become the laws of nature in the modern era. This idea of having to speculate a little bit theoretically, and then checking and looking experimentally is a time-honored tradition. There could be bad versions of it, or good versions of it or lucky versions of it, but it is a time-honored way of doing science.

Raman: That’s what I think even I said, this is one of the ways we are gambling on which experiments to do. One thing that Steve is hinting at also, which is definitely true, is that this way of thinking of gambling on it, like thinking about, what’s the typical universe, the typical laws of nature and so on?

Raman: The ideas it’s brought up, in terms of which experiments to pursue again and again, even when you erase all the philosophy and you say… just as an experimentalist, “Is that a good experiment to do?”

Raman: Again and again, you are struck by the fact, “Wow, I did not independently think to do that experiment, but now that I look at it, what a stunning way of probing nature,” so orthogonal to everything that’s gone before.

Raman: For example, thinking about supersymmetry, invoked often as a solution to naturalness and the anthropic principle, in some set of considerations led to an idea called split supersymmetry. In which a certain kind of new particle could emerge, that could be producible at a collider and it would have a very distinct behavior.

Raman: It would leave a very distinct kind of track and hints in the detector, than the kind of things that people were looking for prior to that. Remember nobody tells the experimentalists, they have to listen to any of this philosophy.

Raman: They can do whatever they want with their experiments, but they hadn’t conceived of looking for this kind of particle, this highly stable, charged particle. All of a sudden, they were like, “Wait, I don’t even follow your philosophy, but that’s a damn good idea for an experiment.”

Raman: Whatever you consider, this kind of… as Steve pointed out, so the angel dancing on the head of a pin aspect of the subject, it produces the goods in the sense that it produces places to look experimentally, which often direct agnostic thinking about where to look, does not bring up.

Raman: Then when somebody tells you, “Hey, have you ever thought to look in this direction? I may be completely certifiably insane, but I think you should look in this direction.” Then you think, “Yeah, you are insane, but that’s a good idea.” You go, “Look…” I feel like again, and again, the subject has had that feel to it.

Steve: I want to take a step back from the slightly philosophical bend here and ask some concrete questions like, so you mentioned dark matter.

Steve: We haven’t discussed dark energy at all, but I’m curious, how surprised will you be if say 30 years from now…? Let’s say we have about 30 years of life left in us. Maybe not high functioning life, but we have about 30 years of life left.

Raman: Mine is a high functioning life. Steve, I’ve not become an administrator yet.

Steve: Okay, good. I meant like as you get older, you get dumber and you can’t walk and things like that.

Raman: Speak for yourself.

Steve: Okay, so let’s say you got 30 years-ish. Maybe for you, it’s 50 left. What are the odds that at the end we’re not going to have found the actual particle nature of the… or whatever the nature is of the dark matter and similar question for dark energy?

Corey: Before you just hop in, can you define each of them and distinguish them?

Raman: Yeah, dark energy is basically the statement that we’re observing. The observational basis is, we are observing that our universe… which everybody knows that we live in an expanding universe. For the last 20 odd years, we have seen evidence that our universe is not only expanding, the rate of expansion is increasing.

Raman: In other words, we’re living in an accelerating universe. Now, why that stands out, is that in Einstein’s theory of general relativity, which governs gravity and in particular governs the gravitational effects.

Raman: That dominate the universe on the largest scales, there was a connection between the expansion rate of the universe, how the universe expands and what the contents of the universe are. The contents of the universe dictate how space time stretches and expands.

Raman: Now, it turns out that most of the contents that we can imagine the universe is made of, like you and me are forms of matter. There’s radiation, like the light flooding in to the window. Most of the stuff the universe is made of, matter and radiation does not allow… it allows the universe to expand.

Raman: It’s consistent with the expansion of the universe, but it’s not consistent with the universe accelerating. It would normally only be consistent with the universe decelerating. There’s something singular that has to be in the universe, to allow it to be accelerating as we see it to be.

Corey: Okay.

Raman: In cosmic history, the way that Steve and I are trained to think about it, the universe has only been accelerating relatively recently, in some way of thinking about cosmic time. The question is, what is this magical substance that’s in the universe, that makes the universe accelerate in its expansion rather than decelerate in its expansion?

Raman: The name given to it… if you’re a complete agnostic, it’s just the name for whatever this hypothetical X is, is dark energy. The most obvious theory for it, is Einstein’s famous cosmological constant term in his Einstein equations of general relativity.

Raman: Maybe it’s something more subtle, than what Einstein had originally conceived as the cosmological constant. We don’t know for sure experimentally, we just call it dark energy. That’s what that is. It’s pointing to something that’s accelerating the expansion of the universe, and it’s not regular stuff like matter and radiation.

Raman: On the other hand, we also have evidence that the galaxies that we see with our eyes in terms of stars made of atoms, are really… they have a dancing partner which we cannot see, and is far more massive in the form of dark matter. For example, the usual spiral galaxy that we imagine a galaxy to look like, secretly has a bowl of dark matter surrounding it.

Raman: How do we know that? Well, we know it from a variety of ways. One is, the way the stars are moving… the stars that we can see, the way they’re moving, does not follow from the usual Newtonian laws of gravity or even Einstein’s refinement of the laws of gravity. They don’t work according to the laws of gravity that we have tested.

Raman: Unless there is secretly some invisible matter, which is adding to the gravitational force that these stars feel. This sort of invisible person pulling on us, this invisible stuff that’s pulling on the ordinary stars, is given a name in honor of its mystery, dark matter. We see the dark matter… dark matter is like ghosts.

Raman: If you ever see a ghost in a movie, they sometimes… you can’t see the ghost. When the ghost walks by, the background ripples a little bit, just in honor of trying to show that there is a ghost walking by. We literally see that kind of distortion of the background, from the presence of a ghost.

Raman: When we look at very distant collections of galaxies, which are made of ordinary atoms that we can see, we sometimes see a distortion of the picture where the galaxies sort of get distorted into these art-like distortions, as if there is a ghost in front, between our eyes and those distant galaxies. There is a ghost in front, it’s dark matter.

Raman: It’s bending light, just like ghosts do in the movies. It’s distorting the light rays coming to us. We have a number of different ways from cosmology and astrophysics, of seeing that we’re not alone. When I say we, everything that’s made of the laws that we understand, atoms, electrons, quarks, gluons, all of that. We’re not alone.

Raman: In fact, we’re outweighed five to one, by whatever this mysterious dark matter is. That’s dark matter. The distinction between dark matter and dark energy is, dark matter by itself would still… it’s magical stuff, but it would still not allow the universe to accelerate in its expansion.

Raman: On top of dark matter, there has to be some other X, which is dark energy that allows the universe to not only expand, but accelerate. That’s the distinction I’m making between those two, or the world makes between those two.

Steve: Then back to the original question, what are our odds of discovering the true nature of the dark matter and also the dark energy, say in the next 30 to 50 years?

Raman: I guess my answer would be slightly different for both of them. My hunch is that we are… so first, let me make the relative statement. We’re much more likely to discover the nature of dark matter. We know something about it, it’s there.

Raman: We feel its gravitational effects, but to know what it’s really made of, are the little creatures living inside dark matter made out of dark matter particles? All of that kind of thing. I think it’s much more likely that we find out the answer to that exciting question in the next 30 years, than it is that we find out what underlies dark energy.

Raman: Nevertheless, it’s possible in an optimistic tape, that we find out something very significant about both of them. I would put more money on the nature of dark matter, than I’d do on our ability to discover the nature of dark energy.

Raman: In terms of absolute probabilities, what do I think the odds are that we would even make great progress on dark matter? 10%. You may say… or an ordinary person might say, “You’re not very hopeful.” I would say, “No, I’m a fundamental physicist. I’m even wildly optimistic and that’s why I’m calling it 10%.”

Raman: We are talking about mysteries, which are not like, “Will the yen go up tomorrow or not?” No, we’re talking about some of the deepest, deepest mysteries that humans have no right to know the answer to. To say you have a 10% crack at that, is enormous.

Steve: Now, wouldn’t you agree that your 10% though is low, compared to say the community of astroparticle physicists? They seem much more confident that 30 years to them would seem like their entire career. Maybe that they feel pretty confident they’re going to find something. Is that fair?

Raman: I think that when you wake up in the morning and decide to go for it, there is always two halves of you. I don’t know that I’m that different from everybody else, but there’re two halves of you. Only one of those answered your question. The two halves are sort of the… like, you’re trying your best to keep a level of indifference.

Raman: I don’t care whether they find it, I don’t care if they don’t. I’m just answering your question neutrally. At some point… every day you pull your socks off and then you say, “I’m going to go and battle the world. I’m going to make that discovery happen.”

Raman: Of course, the truth there is, if it is humanly possible, I’m going to do my damnedest as a theorist or an experimentalist to make sure that we see it. There are some things that are beyond the human control or ingenuity. We can imagine the kinds of situations where in 30 years, we will still not be able to pull this off.

Raman: When I put all of that together and I speak very neutrally and not emotionally, this is not as unemotional as I get. When I do that, I say, “Yeah, it’s 10%.” To me, 10% at getting that kind of mystery resolved is huge. The set of experiments we’ll do, it’s what one of my colleagues in the community has called a high quality note.

Raman: Even if you don’t get the answer, but you do this enormous array of experiments, each of which is trying to do the impossible, bring this ghost to life. If you have a 10% shot at that, it’s super exciting.

Raman: Even if you don’t succeed, but you do these incredible experiments, that’s what they were calling a high quality note. You have ruled out something brilliantly well, and that leaves other possibilities open to pursue for the next 30 years.

Steve: I feel like one of the things that’s not appreciated so much in other areas of science, is the idea of setting limits.

Steve: Even if you don’t find… you have say a direct detection experiment for dark matter, you don’t find the signal that you were hoping to find. You’re at least putting a limit on the properties of the dark matter. Otherwise, you would have seen the signal.

Raman: Yeah.

Steve: In physics, we value that. Not maybe as much as the discovery, but we certainly value it in a very non-trivial way. You could make a whole career by setting really beautiful, strong limits on things.

Raman: Yeah.

Steve: I find in other fields, I’m always shocked to meet another scientist… say a neuroscientist, and he said, “Well, what’s the upper bound on the rate of neurogenesis in adult? How many neurons can I expect to grow next week?” They have no idea. They don’t even think that way. That I find very different in the way that physicists think versus other scientists.

Raman: Indeed, if you just put yourself in the position of a murder detective or something. To be able to say with super high confidence, “The butler did not do it.”

Steve: Exactly, yeah.

Raman: “I can rule that person off. I’ve been at this for 40 years. This is a cold case. I’ve been at it for 40 years, and I now have discovered something super important. I’m so excited. The butler did not do it.” That’s incredible, for this detective that’s been going 40 years to know for sure.

Raman: Now, that doesn’t tell him who did do it, could be somebody else, this, that, the other. There’s work to be done. This is a high quality, I can… like, if you never were quite sure, then you’d always be circling back to the butler. “Maybe it was the butler.”

Raman: If you think you’ve done this absolutely top notch job of ruling out the butler, you’ve done every experiment on the butler possible, even that is a great act of science. That’s why I don’t want that to be called a failure.

Raman: I do have faith, even though I have no scientific reason to say it, that over the long haul, which goes beyond my life, I think that… yeah, I do think that humans, if we survive, I think that humans will find out, what is the nature of dark matter? There, I’ve said something even hopelessly optimistic, but I believe it to be true.

Steve: Yeah.

Raman: I believe it to be true, because I’m constantly amazed by what the human is capable of doing.

Corey: Steve, I think this is also just a difference in physics. To some extent, you guys are very lucky, because you’ve fairly simple systems and then probably the distributions are pretty well understood on the… You know how much systems are going to vary.

Corey: I think it’s a very important question for neuroscience… just others to ask, I really wonder how precise your confidence intervals would be, given that you actually don’t know much about how organisms vary when you get to such a complex level.

Steve: I’m totally okay with people saying, “We don’t have the experimental tools to get a decent bound. I thought really hard about it. The uncertainty is enormous.” I like that answer. That’s a good answer. The answer I don’t like is like, “Upper bound, why do you care about that?”

Corey: Yeah, of course. I think that’s a deficit. Yeah, absolutely.

Raman: Yeah.

Corey: Maybe a deficit is born of just a lack of experience with things, where you got comprehensible answers and people stop. The question just never became part of the culture as result.

Steve: Right, exactly. What’s funny is that, as they get better and better tools and technologies, what was absent for good reasons is now abstinent, even though there is actually money to be made by you trying to address those questions. If you see what I’m saying.

Corey: Yeah.

Steve: What wasn’t possible for a long time, can suddenly become possible, but they’re not used to thinking that way.

Raman: Yeah, indeed. I do think that there is some sort of a… like the proper take on our field, requires understanding the level of its ambitions, the range of experiments and probes that we are doing, the richness. Even as an outsider, I think that can be understood. Like what we are daring to ask. Like, why is there matter? What a question.

Raman: It sounds like it’s the kind of question only a lunatic would ask, but the fact that we can write detailed theories that then require experimental checks for answers to that, I think once you appreciate that level of ambition, I think you become more forgiving.

Raman: Not forgiving about crappy second rate papers, but forgiving of the highest level of work, which sometimes temporarily at least, ends in failure. “Oh, the butler did not do it,” but it’s secretly the stepping stones to ultimate success. The grandeur of these questions, is worthy of more than one generation. That’s my take.

Raman: I think once we accept it and proclaim it to ordinary people, I think they will accept that some part of the portfolio of human activities, somewhere on the fringe, there should be these guys pursuing this level of extreme activity. I think it can be explained and it can be understood by ordinary people.

Corey: It should.

Steve: I think for the man in the street or even the professor out on the quad, what you just said is entirely reasonable. They would say, “Oh yeah, absolutely. Civilization should have a group of people pursuing these questions.” The problem is when you get into the level of the bureaucrats that are allocating national budgets.

Steve: Someone says, “Oh, I’m going to have a cure for cancer for you. I’m going to have a cure, a vaccine for COVID-19.” That can suck all the energy, all the money away from some field that says, “Well, we’re doing really hard stuff. It’s going to take us 50 years to make progress on this, but keep funding us.”

Steve: That’s the battle which I feel at least in my career as a physicist, we’ve been kind of losing. If you look at our share of natural research R&D budget, it has not been going up and we didn’t get our Super Collider for example, that was a big tragedy of our young lives in some sense.

Corey: Right.

Steve: Yeah, and so we’re kind of slowly losing a battle here. I don’t like that. The other comment I wanted to make is that, I feel that… just speaking personally, I was rather spoiled, because I came into the field when this sort of quantum field theory revolution had happened, engaged theories and all kinds of huge progress had been made.

Steve: You get spoiled by that. You think, “Oh, this is the normal pace of discovery. Oh, in another five years they’ll finish the SSC and we’ll have the Higgs boson, and maybe a bunch of techno peons or something.”

Corey: Right.

Steve: Then you don’t get that. For me, the issue was that I could see other areas of science where the technology was at a propitious place too.

Corey: Yeah.

Steve: We experienced that feeling of riding on a motorcycle at 200 miles an hour, that maybe some older physicists got to experience, but we, I would say didn’t get to experience.

Steve: Now in some other fields like genomics or AI or internet related stuff, there is that kind of excitement and pace of change. However, the questions they’re addressing are not quite as fundamental in my mind, is what say, you’re working on.

Raman: I think I agree with all the sentiments, which are sort of partly just… this is the emotional take that anybody who lived through what we’ve lived through would feel. In a sense, often when we’re trying to sort of understand the situation we’re in, where we’re looking for some precedent for how to think about it, how to label it.

Raman: In some ways, what’s happened is rather unprecedented. The discovery of quantum mechanics and relativity under very… finding them under very humble rocks, like a little bit of radioactivity, a little bit of a static electricity and magnetism.

Steve: [crosstalk].

Raman: Yeah, exactly. Suddenly it’s like the fire hydrant of fundamental physics is pouring out of the beginning of the 20th century, and it’s like it’s both super fundamental, rocks your entire worldview, all your philosophies have to change and it’s cheap. It’s just pouring out at a high rate.

Raman: That very abundance has pushed us to where we are on our understanding now, which is incredibly high compared to 150 years ago. We are victims of our success, because we have climbed incredible mountains as a species. We know that we are still only at the foothills of our understanding and we say, “Why not go higher? We’re humans.”

Raman: What is technically feasible, has not kept pace at quite that rate. We know the grand, grand questions await us. Yet we find ourselves as us, compared to where we want to be in terms of our strength and we don’t know what to do. We don’t have a situation which has a precedent like that.

Raman: In the past, it was just like we were one idea away from immense power to do a whole new range of things. Truly, we may be again. We may again, be victims of thinking, “Oh look, I have a simple way of checking quick orders of magnitude estimates, to tell me why life is really hard as a fundamental physicist.”

Raman: Then may be in 30 years, we’re laughing at that. I’m playing this podcast or whatever and we’re like, “Gosh, they were so hopelessly blind, because they never saw this thing coming from left field.” I feel like, yeah, I get the sentiment. The real question is, with all of these other things going, one, COVID-19.

Raman: Okay, cancer research, pandemics, all of these things. Then other things which are on their ground floors still, like machine learning or something like that. Why do we have to go back to this ancient business of fundamental physics? Why do we have to keep putting money in? I would say, “Look, it’s an unprecedented situation.”

Raman: If you’re looking for some good old history lesson to tell you why you should do it, you’re out of luck. We’re going to have to use our own judgment. I would say, in the portfolio of human activities, this occupies a relatively tiny fraction of our efforts. The people who do it, the best of them, have been incredibly creative.

Raman: Even if… and the spinoffs from it, have been a little bit like what I said about experimental spinoffs, from thinking about the naturalness problem. The spinoffs have been all sorts of practical things. In order to do their experiments, they push materials research like crazy.

Raman: They push atomic physics like crazy, quantum physics like crazy, machine learning like crazy. Just to do whatever it is these crazy fundamental physicists do, pushes the art of everything else in a way that may not get pushed by itself. These guys are really smart. They’re really imaginative.

Raman: They may be crazy, but then imagine it. Is it good to have that sort of gesture in the court? Yeah, it’s good. How much should we have of them? Tough call, subject for another podcast. Should we? Yes. We should not only have them, we should not just tolerate them. We should celebrate them, I think.

Raman: Look at the questions they’re going for. Yes, while we’re worried about COVID-19, I’m still worried, where did all the matter come from? That’s the beauty of humans. I would celebrate it, rather than for some political short game, try to set things at odds with each other. In that sense, we’re utterly vulnerable.

Raman: Anybody can attack us and some pretty plausible, doing it. I think they’re wrong. If you hold them still long enough to debate it, they will be seen to be wrong. The other point that I’ve made in meetings with serious people, is that you never know with fundamental physics. You never know. I am dabbling with wormholes in my research.

Raman: You never know what crazy thing is going to happen. As one physicist said, “I don’t know how likely any of these things are.” If anything like all the things you’re watching on Star Trek are ever going to happen… and maybe it’s long odds that they are. If they are going to happen, it’s going to happen by this kind of research. That’s how I answer that.

Steve: Without setting out to do it, I feel like you’ve given a good response to our earlier podcast with Sabine. Maybe we should stop there, because we’ve had you now for almost 90 minutes and we should probably let you go, but that’s a great place to cap it off.

Raman: Very good. It’s a pleasure to be here.

Steve: Yes. Well, we’ll have to have you back.

Raman: Sure, that’d be fun.

Steve: Take care.

Steve: Hey, before I let you go. How’s the family, your daughter, how old are your…? You have two daughters [crosstalk]?

Raman: I have two daughters, yeah.

Steve: Two daughters.

Raman: I forget whether the other one was there when you had visited, but she probably was, yeah.

Steve: Yeah.

Raman: Yeah, anyway I have two daughters.

Steve: Yeah.

Raman: One is about to finish high school. She’s going to do engineering at Carnegie Mellon. The other is in seventh grade.

Steve: Oh, wow. She’s pretty young, yeah. Well-

Raman: She’s really-

Steve: Our kids are in just… they’re in ninth grade. We have a boy and a girl, twins.

Raman: Twins. Okay, great.

Steve: Yeah, so-

Raman: That’s the beginning of high school, so-

Steve: Yeah.

Raman: Was that an adjustment or they were just fine?

Steve: Oh, it was a huge adjustment actually.

Raman: Yes.

Steve: I’m a super high investment parent. This last few weeks with the lockdown have been hugely stressful. Not because of like… even though we have all this crisis management stuff we’re doing at the university, but maybe stressful, because I got stuck doing homeschooling with my kids. Their school didn’t really pick up right away. Now, they’re going to start next week.

Raman: Yeah.

Steve: We weren’t sure what their school was going to do. We were just on our own for three or four weeks-

Raman: Right.

Steve: … teaching them. That takes a lot of time. After I finish something like one of these video meetings, I have to run over there and see what my kid is doing with his calculus or something, so yeah.

Raman: Right, so I had exactly the same experience as you. I’m in exactly the same position, with one difference. My kids fired me, so-

Steve: I didn’t let them fire me.

Raman: Yeah, but I-

Steve: I refused to-

Raman: I’m a weakling, and so I don’t know how to reinstate myself into like, “I have this whole program of like, look, I’ll teach you stuff. It’s even better than doing your classwork.”

Steve: That’s what-

Raman: Yeah, and they show absolutely zero interest in anything I’m saying. I’ve been fired. Hence, I have time to talk to you.

Steve: Oh, that’s great. Yeah, all right. Take care.

Raman: Okay, then see you-

Steve: I hope to see you in person soon.

Raman: Yeah, absolutely. Okay, see you then.

Steve: Okay, all right. Bye-bye.