Preet Bharara:

From CAFE and the Vox Media Podcast Network. Welcome to Stay Tuned. I’m Preet Bharara.

Sean Carroll:

Every possible measurement outcome happens, but in a separate copy of the universe. The equations that were invented decades before to understand how atoms behave and how electrons move around, these equations clearly predict that. It just took 30 years for physicists to admit that maybe we should listen to what the equations are trying to tell us.

Preet Bharara:

That’s Sean Carroll. He’s a theoretical physicist and a Homewood Professor of Natural Philosophy at Johns Hopkins University. Carroll has long sought to present the complicated world of physics in an approachable manner. He does just that in his popular books, including his latest, The Biggest Ideas in the Universe, Space, Time, and Motion. Carroll also talks with other physicists, philosophers, and thought leaders on his Mindscape podcast. Carroll joins me to talk about the relationship between science and philosophy, how to comprehend quantum mechanics, and whether there are billions of similar universes operating alongside our own. That’s coming up. Stay tuned.

Q&A

Now, let’s get to your questions. This question comes in an email from Kat who asks, “What did you make of David Weiss’s testimony in front of the House Judiciary Committee this week?” Well, to remind everyone, David Weiss is the sitting US attorney from the District of Delaware, who is a holdover from the Trump administration and has been the chief prosecutor responsible for overseeing the investigation and prosecution of the sitting president’s son, Hunter Biden. And there’s been some twists and turns along the way. But you’ll also recall that not too long ago, David Weiss was elevated from not only being US attorney to being the special counsel, overseeing the investigation of Hunter Biden.

Republican supporters of Donald Trump have raised questions about his independence and about whether or not he was blocked from doing the kinds of things that he wanted to do. David Weiss made clear during his testimony, according to reports, that he was the ultimate decision maker in the Biden case, and was at no time blocked from doing what he wanted. He also commented on the extraordinary nature of his giving testimony at this time. He said, “To my knowledge, I’m the first special counsel to testify before the submission of the special counsel report. I have done so out of respect for the committee’s oversight responsibilities and to respond to questions raised about the scope of my authority.”

So it’s sort of an astounding thing, given all these questions and speculation about his independence and about his role and about what other people may have said and done, that he pretty much I think has set the record straight. Here’s my observation about the whole scenario. The critics here are not arguing about process, it seems to me. They’re not arguing about fairness. What they’re seeking is a particular outcome, and nothing short of a series of capital level offenses leveled against Hunter Biden would satisfy them.

But it’s not clear what they want in terms of process. In fact, I’m hard pressed to understand what could have been a fairer process or process more divorce from politics than how the Hunter Biden investigation has unfolded. First, it’s already mentioned, David Weiss is a Trump appointee, not a Biden appointee. Number two, he has made clear repeatedly, and most recently in the testimony he gave this week, that he was the ultimate decision maker with respect to all matters relating to Hunter Biden. Merrick Garland has confirmed his independence on multiple occasions as well. And then took the extraordinary step of further removing David Weiss and making him more independent by elevating him to the status of special counsel. And then the Department of Justice let David Weiss testify in the extraordinary manner that I just mentioned and that he suggested as well.

So I’m not sure what else the Biden administration could have done that would satisfy the critics here. It seems to me that the only way to satisfy them would’ve been if Biden appointed Roger Stone or some strong Trump ally to oversee the prosecution and investigation of Hunter Biden. So at the end of the day, reasonable people in good faith can agree or disagree with charging decisions and with the fiasco of what happened at the initial plea proceeding with Hunter Biden, and they can say that the charges that are ultimately brought are too strong, are too soft, are too numerous, are not numerous enough. But it is not based on the process, it’s not based on politics. I think that David Weiss’s testimony made that clear and that the criticism here is largely political.

This question comes in an email from Rachel who writes, “I saw you tweeted an article from the Washington Post about Trump and some others plotting revenge on anyone who has criticized him if he wins the 2024 election. How bad is this? Can you discuss?” As I said in an uncharacteristic tweet about the article, this is scary next level shit. The article and the reporting, if true, doesn’t even need to be commented on very much. Just listen to the title of the article. Trump and Allies Plot Revenge, Justice Department Control in the Second Term.

Let me read you just a couple of passages from the Washington Post article. “In private, Trump has told advisors and friends in recent months that he wants the Justice Department to investigate one-time officials and allies who have become critical of his time in office. This is quite a list including his former chief of staff, John F. Kelly and former Attorney General William P. Barr, as well as his ex-attorney Ty Cobb, and former Joint Chiefs of Staff Chairman General Mark A. Milley, according to people who have talked to him, who like others, spoke on the condition of anonymity to describe private conversations. Trump has also talked to prosecuting officials at the FBI and Justice Department, a person familiar with the matter said.”

Here’s another passage from the article. “To facilitate Trump’s ability to direct Justice Department actions, his associates have been drafting plans to dispense with 50 years of policy and practice intended to shield criminal prosecutions from political considerations. Critics have called such ideas dangerous and unconstitutional.” There’s even a name apparently for this enterprise. It’s called Project 2025. Also from the article, “Much of the planning for a second term has been unofficially outsourced to a partnership of right wing think tanks in Washington. Dubbed Project 2025, the group is developing a plan to include draft executive orders that would deploy the military domestically under the Insurrection Act according to a person involved in those conversations and internal communications reviewed by the Washington Post.”

I don’t know what else I have to say. The fact that Donald Trump is fairly openly plotting revenge, that some of the people who are helping to plot revenge are folks at the center of the big lie. Also, according to the article, Jeffrey Clark is leading the work on the Insurrection Act under Project 2025. If even a fraction of the plans described here are true and are able to come to fruition, I think it is not an overstatement to say it will change America deeply and profoundly, and for the worse.

The only thing sort of surprising to me about this article is that it’s not getting more attention, it’s not getting more play, and it’s not being emphasized enough. One could also note the deep irony of this article coming out at the same time that Donald Trump keeps saying in braying fashion in the case against him, brought by Letitia James in New York State Court, that the case is a sham, the trial is a sham, and it’s evidence of a banana republic. No, that’s evidence of the rule of law and equal status before the law. What Donald Trump is plotting, per this Washington Post article, that would cause us to descend into a banana republic. And often when that phrase is used, it’s hyperbole, it’s exaggeration. In this case it wouldn’t be.

Now people will say there are still judges, cases still have to be decided by juries. There are appeals courts, there are good people, there are still opponents in the Senate and in the House. That all may be true, but I’m really, really worried about what happens to our system of justice, to our democracy, not just based on this article, but based on everything else we’re seeing if Donald Trump becomes the vengeance president in 2025.

THE INTERVIEW

Preet Bharara:

I’ll be right back with my conversation with Sean Carroll. Sean Carroll tries to make the tangled world of physics make sense to people like you and me. Let’s see if he has any success. Professor Sean Carroll, welcome to the show.

Sean Carroll:

Thanks very much for having me.

Preet Bharara:

So it’s an auspicious occasion. I’ll start out with that and tell folks who are listening that you and I are having this conversation on Tuesday, October 31st in the afternoon, a date which is also known as Halloween. Does physics have anything to say about Halloween?

Sean Carroll:

Nothing especially great. I’m a sucker for Halloween. I love Halloween. And after having moved to Baltimore a year ago and purchased a house, I get to actually hand out Halloween candy tonight for the first time since I was in high school myself. So I’m extremely excited, and physics has nothing to do with it.

Preet Bharara:

I was going to say, if I dressed up as a witch and you looked at me and I was a witch, if you looked away, could I actually be scarecrow or something else?

Sean Carroll:

No, no. Physics is very much about the real world. There’s crazy possibilities out there, but at the end of the day, we’re about the real world.

Preet Bharara:

So I will tell you that I undertake this interview with a good bit of humility. This is not my wheelhouse, the kinds of issues that you write and speak about and teach, but I’m going to give it a shot. But can we start with what drew you to astronomy, physics, science in the first place? Because I think you’ve said in things you’ve written that it was sort of an unlikely course for you.

Sean Carroll:

Sure. I will first mention that I have my own podcast, Mindscape. And I know exactly the feeling that you’re going through because when I talk to economists or biologists, I feel very, very much out of my depth. But I started when I was very young in physics. I just got into it when I was maybe 10 years old. And I honestly can’t tell you why. It’s just that I started reading books about planets and stars and even more particles and gravity and general relativity and the big bang, and I glommed onto the idea that I wanted to do this for a living without at the time having any idea what it meant to do that for a living. And I’ve never been surrounded by people who could really give me good advice about these things. So I kind of stumbled my way into actually-

Preet Bharara:

You discovered it on your own.

Sean Carroll:

Yeah. And honestly, it’s only in this last year that I have a job doing exactly what it is I wanted to do. So it’s taken me quite a while.

Preet Bharara:

Wait, what do you mean by only in the last year? Haven’t you been doing what you wanted to do before, including writing books?

Sean Carroll:

I’ve been doing many things that are a lot of fun. And the things I’ve been doing are very much things I wanted to do, but the specific thing that I kind of took years to figure out that I want to do is just think about, well try to better understand the fundamental nature of reality from a perspective that is somewhere in between physics and philosophy. Thinking about the natural world, right? Thinking about it on the basis of data and theories and matching them, but thinking about it in the kind of super specially careful way that philosophers do. And that’s just not a job that exists. So I’ve been employed as a physicist for a long time, but both my popular writing and my philosophical inclinations have been more tolerated than encouraged until now, when they’re actually part of my portfolio.

Preet Bharara:

You said something interesting about yourself, I think, and it was something like, as you were growing up and becoming intellectually curious, you were always drawn to the big questions. You never cared to figure out how a phone works. I was struck by that. What did you mean by that?

Sean Carroll:

Well, I think that there’s a million different routes to get into science broadly, or just academia broadly, or even just being curious broadly. Some people like to take things apart, figure out how they work. I’ll put it this way. Because I was roughly scientifically inclined, a natural present to get on birthdays and Christmas was a chemistry set. And I don’t think I ever once did the experiments that were outlined in the instruction booklet that would come with the chemistry set. I would take the alcohol and light it on fire. I would randomly mix things together and see what colors were created and so forth. But experiment and building things with my hands was, I liked it, it was fun, but it was never my thing. But thinking about the fundamental nature of stuff, that was what kept me up at night.

Preet Bharara:

So you mentioned philosophy, and your title at Johns Hopkins University is Homewood Professor of Natural Philosophy. Now, ordinary laypeople, myself included, tend to think of philosophy and physics as two distinct disciplines. I guess the question is, what is the relationship between those two? Are they overlapping? Do they intersect? Do they proceed in parallel? Are they the same set of questions? How do you explain that?

Sean Carroll:

Yeah, your everyday person point of view here is also the same as the everyday physicist point of view here. That philosophy is a very different kind of thing. The title that I have, Homewood Professor of Natural Philosophy, I love the fact that I got to choose it. The Homewood professors don’t really belong to specific departments. So I could have just called myself professor of physics and philosophy, but I was hearkening back to the days of Isaac Newton and Galileo when science, what we now call science, was a subset of philosophy as far as they considered it. So Isaac Newton’s masterwork was the mathematical principles of natural philosophy, for example. And it was only in the 19th century that you really had a distinct notion of science apart from philosophy.

And what that’s meant, because academia is academia, is that once you splinter into different departments, you stop talking to each other. In fact, you erect barriers to prevent people from talking to each other. And one now is left with the impression that these are two very different things. But there are deep questions about the nature of the world that are clearly both addressed by physics and by philosophy. What happened at the origin of the universe? Why is there something rather than nothing? Even very basic physics questions like what does quantum mechanics really tell us? These are questions that philosophy cares about just as much as physics does. And so I’m sitting at the point where it’s a very natural place to be intellectually where I think about questions that are both philosophical and scientific, but there’s not a noticeable academic home for those kinds of things. So actually my colleagues and I at Johns Hopkins are trying to create one. We’re trying to make natural philosophy happen once again.

Preet Bharara:

Is there a trend in the sciences, and even in the humanities, towards overspecialization and focusing on the study of narrow questions as opposed to taking big steps back? And if so, is that bad?

Sean Carroll:

Yeah, that’s a complicated one. I’m glad that we have five hours here to discuss this, to really get into all the details. Short answer is yes. There absolutely is a trend toward hyper-specialization. I mean, it’s completely, you can’t dispute it, right? There are more departments, more specialties, more background knowledge that anyone has to have in some very narrow area in order to get a PhD and become a researcher.

On the second hand, it’s actually been helpful in many ways. There’s only so much capacity anyone individual human being can have. So you can’t know everything. Maybe you could have known everything that was all the cutting edge research in all the different disciplines a couple hundred years ago, but that’s absolutely impractical today. So progress is made by narrowing your focus a little bit. On the third hand though, something is lost in that process.

Preet Bharara:

Wait a minute. How many hands do we have?

Sean Carroll:

We have as many hands as we need to make the point. So at this point, it’s just going to be three hands. Don’t worry.

Preet Bharara:

So this is not the physics part of you. This is the philosopher part.

Sean Carroll:

Yeah, this is the thought experiment part here. Yeah. Even though it’s been very, very productive within academia, within science to specialize, you do lose that sort of synthetic generalist connection making point of view. So the way that I try to advocate for it is most scientists should be pretty narrow. They should specialize. They should be the world’s experts in their fields. But we also need some people who are generalists, some people who are able to see connections between different fields where you might not notice them if you were just a specialist. And academia completely fails at its task of nurturing and rewarding those people.

Preet Bharara:

Are you a humanist thinker? And if so, what does that mean?

Sean Carroll:

In some very general sense, yes. There’s a historical notion of humanism, which was, it is actually hard to pin down. It’s not the same as something like atheism. It was more or less from the Renaissance onward putting human beings at the center of study of philosophy and so forth. Trying to figure out what human beings are, even if the answer was organisms made in God’s image, right? Today humanism is more associated with free thinking, with naturalism, with atheism, with a move away from religion, organized or disorganized. But I don’t think it has a once and for all fixed definitions. But happily under almost any of the reasonable definitions, I would count as one. Yes.

Preet Bharara:

So that raises the question that you have addressed on a number of occasions about what you say is the incompatibility between science and religion. That they are not compatible with each other. So lots of people would disagree with you. I imagine that there are people who are both accomplished physicists or other kinds of scientists who are religious and believe in religion. Could you explain why you have the view you do?

Sean Carroll:

Yeah, 100%. I want to be very clear about the compatibility question between science and religion. I would argue that in principle, science and religion are perfectly compatible because they’re trying to do different things. Religion, sadly, is hard to define. So even if I offered a definition, there’s going to be some people who disagree with it. But let’s imagine that we know what it is. Science is trying to understand how the world works. So there’s no necessary reason why the practice of religion and the practice of science have to come into conflict.

But there is a conflict because, as it turns out, the world that is revealed to us by science is different than the world that is generally envisioned by religion. Not always, because again, religion covers a lot of bases, and there are naturalistic religions, religions that are ways of thinking about what it means to be a person without making any claims about the fundamental nature of reality.

But most religions, especially in the Western world, are saying something about reality. They’re saying that there’s a supernatural realm, that God created the world, that there have to be principles underlying why the world is here rather than not here. And none of that is backed up by our scientific investigations of the world. So yes, there absolutely are colleagues of mine, very close friends of mine, students of mine for that matter, who are deeply religious, and we have no trouble talking and having useful conversations. I think that they’re making a mistake. They think that I’m making a mistake too. So that’s how it goes.

Preet Bharara:

Are you talking about sort of the purpose of religion and how many religions, as you said a second ago, identify some supernatural power? Or are you talking about the stories that some religions tell? So for example, the idea that the Earth is only 6,000 years old? Or both of those things?

Sean Carroll:

Well, I would say it goes way beyond the Earth being 6,000 years old. As I keep saying over and over again, sorry to be redundant about this, but there’s a variety of kinds of religious belief. Even within Christianity, some people believe the world is 6,000 years old. Some people think it began with the big bang. Georges Lemaitre, the first real theoretical pioneer of the big bang was a Belgian priest who consulted with the Pope. So there’s no, again, necessary incompatibility there.

But all of them, all the Christians that I know, think that God had something to do with the creation of the world. So it’s that kind of story that is told by religion that I think that science does not back up. And I actually would go further than that. I think that ever since Friedrich Nietzsche, we have known more or less that there is this way of understanding the world provided to us by religion that hasn’t really worked out, and that gives us incredible challenges. We have to replace a lot of what was getting us through the day. Science is about what the world does, but religion is about much more than that. It’s about how we live and how we live in community with each other, and what it means to be a good person. And we’ve dramatically updated our picture of what the world does and is without doing the deep thinking about those other questions.

Preet Bharara:

This may be apocryphal or I may have this wrong. I thought I read once that Albert Einstein once said something like, or maybe it was a different scientist, that the more he learned about physics, the more religious he became. Are you familiar with that or do you understand that phenomenon at all?

Sean Carroll:

He did say things like that. Albert Einstein, who was absolutely one of the best physicists around, and someone who I admire greatly, one of his many, many talents was being super duper quotable. He could coin a phrase, even if a phrase that he coined at one point was completely contradictory to a phrase that he coined at some other point. So he liked saying these poetic things. He liked kind of being provocative. He also was very, very clear that he did not believe in the traditional Judeo-Christian notion of a deity. He even said some pretty insulting things about people who do. He was culturally very Jewish, and his Jewish identity was very important to him, and so there could be a sense of being religious, once again, which is maybe different than the sense where you have a feeling that supernatural entities play an important explanatory role in our best theory of the universe.

Preet Bharara:

I don’t mean to take a shot at trying to characterize what he was trying to capture with that quotable quote, but it seems to me part of the point is that people who believe in religion or believe in God or believe in some deity are in part also just in wonder and engaging in wonderment at how the universe exists, and the plentiful of life on this planet, possibility of lives on other planets, and just the unbelievable difficulty in appreciating and understanding nature. Which is a little bit, I think, what Einstein and others maybe have been trying to get at when they say that the more they studied nature and how the world works and how the universe works, the more they had a sense of wonderment. Does that make any sense?

Sean Carroll:

It does because it is kind of amazing to we human beings, both that the world kind of is intelligible, that we can make sense of it. This is to me the great lesson of the history of science that as many mysteries as there are, the thing to be impressed about is not our shortcomings at understanding the world, but the enormous progress that we have made in understanding the bits of the world that we have. And then secondly, the specific way that the world behaves is kind of orderly and law abiding, but very different from our sort of simple, intuitive notion of how it should be. So I get the wonder aspect. I’m 100% on board with that. I just don’t think it leads us to the supernatural.

Preet Bharara:

What does science have to say about free will?

Sean Carroll:

Oh my goodness. That’s tricky.

Preet Bharara:

We have another five hours.

Sean Carroll:

Yeah, I know. The five hours is not going to be enough.

Preet Bharara:

This is the problem. If you were a guy who was more focused on how a phone works, we could do that in 20 minutes.

Sean Carroll:

Exactly. I know. I could really get through it. It’s funny, I’m literally talking about this question of free will in the classes that I’m teaching right now. Science doesn’t have that much to say. Or rather, what science has to say about free will is pretty simple, and it’s more the 20 minute discussion than the five hour discussion. Because as we study the brain and the mind and how they work, science is hunky-dory. Science is making progress. There’s plenty we don’t understand, but we’re just understanding more and more. We’re pushing back the frontiers of our knowledge. There’s no roadblock we see to having a perfect understanding someday, many, many years in the future of how the brain and the mind work.

On the other hand, there’s a question of does it count as free will, right? If I have behavior that is a manifestation of the collective behavior of 85 billion neurons in my brain hooked up in some enormously complicated network of connections, at what point do those mechanistic doings of the chemistry and electricity in my brain become labelable as a person with thoughts and feelings and morals and values? And that’s a whole wicket of very difficult questions that philosophers have fun with.

The most popular answer among philosophers is also the one that I subscribe to called compatible, which is basically the idea that, yeah, we’re made of stuff. We obey the laws of physics. There’s a way of talking about human beings, which is just as collection of atoms obeying the laws of physics. In that way of talking, there’s no notion of free will playing any role. But there’s another way of talking about human beings as people, as entities, with agency, with volition, with the ability to think and make decisions. That’s a perfectly valid way of talking about human beings also. And at that level, free will’s an indispensable concept.

Preet Bharara:

I’m going to ask you another one of these big questions. What is time?

Sean Carroll:

Well, the good thing about time is there’s more than one thing that it is. There’s sort of more than one definition. And this very often happens when you have a word like time. Time by the way, is the most used noun in the English language.

Preet Bharara:

It is?

Sean Carroll:

It is. And it turns out to be true in almost all languages that whatever the noun meaning time is, that word is used more than any other noun in those languages.

Preet Bharara:

I have never heard that. I’m going to have to look that up and make sure that you’re correct.

Sean Carroll:

Happily for you, I’ve written a book called From Eternity to Here, which is exactly about this question of what time is and how it works, and that’s where I found all these fun factoids in doing research for the book. So when we have a word like that that is useful to us in our everyday lives, then we try to define it scientifically. We realize that there are different notions scientifically that more or less line up in our everyday experience, but are actually different.

So Isaac Newton would’ve said, time is just one thing. There’s an absolute time throughout the universe. We use it, for example, to locate ourselves in the universe. When you and I say, we’ll do a podcast interview at 3:00 PM, we know what that means, right? We were able to process that and put it to work. It’s a label on events in the universe. But then there’s also the personal time that we experience, the time that ticks off on our wristwatches. And that is the great insight of Albert Einstein, one of the many of them, when he invented the special theory of relativity, that that personal time that you feel along your wristwatch, the duration you experience, need not be the same as this universal time that we use to label the universe.

That’s why someone who zooms out at the speed of light or goes to a black hole and hangs out for a while and then comes back, those people will have experienced less time personally than someone who just stayed behind. And then there’s a whole nother question about the flow of time. Why time seems to have a direction, why it moves from past to future. That would require a while. I’m happy to go into that for the rest of the podcast, but that’s really a very rich question.

Preet Bharara:

I want to do a little bit of it because it’s my understanding that maybe you or others have said there’s no known law of physics or in science that rules out the possibility of time running backwards, and yet we’ve never experienced that. Is that correct?

Sean Carroll:

It’s a little tricky. I would not put it that way, but I think I know what you are getting at.

Preet Bharara:

How would you put it?

Sean Carroll:

There’s a couple of things to get on the table. One is if you were Aristotle, okay, so if you were a very, very smart, but pre-modern science thinker, time would just be a thing that kind of propelled you forward, right? There’s the universe, and the universe keeps changing, and time is that process of change in some sense. And the fact that the past and the future are different from each other, right? We have memories of the past. We have records, we have photographs, or drawings or footprints, whereas we have predictions about the future. There’s a big imbalance between how we treat them. That was never an issue. That was never a question. Of course, they’re different. They’re just different. That was just a fact of the world.

And once we started to understand physics, we realized that our best ideas of the fundamental laws of physics actually do not have that directionality built into them, whether it’s from Isaac Newton or Albert Einstein or anybody else. So suddenly in the 1800s we have a new challenge. Why does time seem to have a direction even though the laws of physics don’t have such a direction built into them? And that’s the subject of the arrow of time, and it involves the increase of entropy, the disorderliness, the messiness, the randomness of the universe. Now, what you’re asking about I think, is whether or not it’s possible to travel back to our past, to do basically a time machine kind of thing.

Preet Bharara:

Backward. And you say it’s not.

Sean Carroll:

I say that it’s probably not.

Preet Bharara:

Oh, you’re hedging. Now you’re-

Sean Carroll:

We can’t prove it.

Preet Bharara:

… look, this is a good philosopher.

Sean Carroll:

Yeah, we don’t know. This is a true and interesting thing. I’ve written papers about it and others have also. Once Einstein invents his new and improved theory of relativity, the first theory of relativity, the special theory came in 1905. In 1915, 10 years later, he gives us the general theory of relativity where space and time are curved. And so you can imagine space time curving in on itself so dramatically that I could hop out in a rocket ship ,and rather than ending up four light years away, I can end up four years in the past because time is literally curving back on itself. Now, as far as we know right now, this is only an exercise of imagination. Things like this do not happen in the actual world. We are safe from being invaded by people from the future.

Preet Bharara:

As part of the issue that I think you’ve suggested in one of your books that travel into the past produces crazy paradoxes, and we’ve seen them in movies and in science fiction stories, and paradoxes don’t really happen.

Sean Carroll:

Yeah, sorry. I think there’s two issues which kind of nicely dovetail with each other. One is it would be very weird if travel to the past were possible.

Preet Bharara:

Wait a minute, wait a minute. The standard of it would be very weird is met in all sorts of other areas of quantum mechanics and physics, which we’ll get to in a moment. So I don’t know how that has preclusive effect.

Sean Carroll:

That’s why I’m saying that these two aspects are dovetailing nicely because this is a case where it would be weird. It wouldn’t necessarily be illogical. I’m working on a co-authored piece with my wife, Jennifer Ouellette right now, where we take 20 movies dealing with time travel, and we rate them both on how good they are as a movie and how realistic the time travel is. And as you might expect-

Preet Bharara:

[inaudible 00:33:00].

Sean Carroll:

… all possibilities are being covered in this set. Because you can easily imagine going back to the past and if you’re there, you mess it up, you change something. You kill baby Hitler or you prevent JFK from being assassinated, or whatever it is. So that would be weird if it happens. And physicists and philosophers argue about could there be a rule that says you can go back but you can’t change it somehow? Or do you create a new universe when you go back? But the other fact to keep in mind as I indicated, is that we don’t know how to actually do that. We can speculate about it, but it seems that the universe just doesn’t let us. So this kind of weirdness is one that the universe is saving us from confronting.

Preet Bharara:

As an aside, are you a fan of or did you read Douglas Adams’ Hitchhiker’s Guide to the Galaxy, or any of the books in that series?

Sean Carroll:

I did way back when. Yeah.

Preet Bharara:

Way back when. My one takeaway from the book, or the series of books, was that you don’t want time travel because it makes the problem of tense usage very difficult.

Sean Carroll:

It’s already difficult enough.

Preet Bharara:

It’s already difficult enough. But there is, and maybe you were alluding to this, there is a form of time travel in the other direction that does exist, and that is experienced in a modest way. So if you and I got into a rocket ship, and we traveled very, very fast approaching the speed of light or at the speed of light for a few minutes and then came back to where we were, what would time be on Earth?

Sean Carroll:

The people on Earth would’ve experienced more time than we would have.

Preet Bharara:

So it’s effectively, you can go forward in time as you experience time simply by traveling fast. And that’s done, and that’s a known physical fact, right?

Sean Carroll:

Absolutely, 100%.

Preet Bharara:

But not the other way.

Sean Carroll:

Of course, we can all go forward in time. Since we started this conversation, I have personally gone forward in time by about half an hour, and it just took me half an hour to do it. What Einstein lets you do is basically go to the future faster. What he doesn’t seem to let you do is to ever go backward into the past.

Preet Bharara:

I’ll be right back with Sean Carroll after this. I know one of the things you do, and it just occurred to me when we’re talking about travel backwards and forwards in time, is you consult as a scientist on movies.

Sean Carroll:

That’s right.

Preet Bharara:

And I was just thinking when I saw, I think it’s the original Superman, and Lois Lane dies, or she’s dying, or I think she dies. And Superman, Clark Kent as Superman, is very, very much grieving and upset, and do you remember what he does?

Sean Carroll:

I do. I remember it very well.

Preet Bharara:

He flies so fast around the world that he reverses the rotation of the Earth. And he reverses the rotation of the Earth going back like one or more days, and then goes back and rescues and saves his love Lois Lane. On a scale of one to 10, assuming hypothetically that you could reverse the rotation of the Earth, would that take us back in time, sir?

Sean Carroll:

So that movie is not going to do well on our ranking of scientifically respectable time travel movies.

Preet Bharara:

Is it on the list?

Sean Carroll:

Yeah. Well, I think it’s on the list. I haven’t done my part of the writing yet, so I don’t want to speak out of turn, but I’m hoping it is. No, that is completely nonsensical, both for science reasons, moving very quickly around the Earth does not send time backward, but also for logic storytelling reasons. Once you figure out you can do that, and you use it to save your girlfriend, and you never use it again to save any other terrible calamity from happening, that seems a little selfish to me.

Preet Bharara:

Well also just, and this is outside of maybe your sphere and mine, as a matter of tectonic plates and other things, what happens to the Earth if it suddenly stops rotating in one direction and rotates backward in the other direction?

Sean Carroll:

My whole thing being a science consultant for movies is tell a good story. Usually these movies are not going to try to stick close to the laws of physics as we know them. Back to the Future is a great story. It’s a great time travel movie. It makes absolutely no sense as time travel, I’m sorry to report. One of my very few but very proud contributions to popular culture is that I was a consultant on Avengers: Endgame, the Marvel movie where they use time travel. And there’s a scene where they’re talking about how realistic it is. And Paul Rudd playing Ant-Man goes, “So you’re telling me that Back to the Future is just bullshit?” Yeah. That line came from me in talking to the writers of the movie when I was trying to explain to them why Back to the Future is not a good paradigm-

Preet Bharara:

That’s awesome.

Sean Carroll:

… for how to think about time travel.

Preet Bharara:

I want to get into some other questions about, I guess, what people call the multiverse or the many worlds theory. But I think before we do that, can I ask another big definitional question? And the question is what is quantum mechanics? And before you answer the question, I will say that I feel much better about myself after reading something that you wrote because I’ve never understood quantum mechanics. It’s been explained to me many times, both in school and then in readings that I’ve done. And you write, “I think I can safely say that nobody really understands quantum mechanics.” And then you also say what’s surprising is that physicists seem to be okay with their not understanding the most important theory they have. So what hope does a layperson like me have of understanding this if the physicists don’t really understand it either?

Sean Carroll:

Well, there’s understanding and there’s understanding. Physicists are really good at using quantum mechanics. That is to say they can set up a physical situation, they can solve some equations, make a prediction, and they can test those predictions against experimental outcomes, and it’s incredibly extraordinarily successful at that. Where they get into trouble is if you say, okay, explain to me exactly what is happening in the process of that calculation you just did? What is the physical reality you are describing? That’s where quantum mechanics gets into trouble.

So it’s best explained by comparing it with its predecessor, classical mechanics, that came from Isaac Newton. You have objects that have mass and they have velocity, and all the stuff you did in high school or college physics, balls rolling down incline planes. But one of the features of that picture was there is no issue with looking at the system. You have a ball rolling down an incline plane or the Earth orbiting the sun. You just have it. There it is. I can measure it to whatever precision I would like.

Quantum mechanics comes along, and says that the way that we describe a physical system when we are not looking at it is very different from what we see when we do look at it. If you take an electron, a little subatomic particle, the way that we describe it when we’re not looking at it is as a wave, as something we literally call the wave function, which is an incredibly boring name for a very profound idea. But it’s spread out. It has no point, like location in the space. It has a profile that has different values at different points in space. But when you look at it, when you say, I’m going to measure the position, it doesn’t have a position before you measure it. But nevertheless, you can measure its position and you can get an answer. And that’s-

Preet Bharara:

Well, that’s why you lose me.

Sean Carroll:

Yes, exactly.

Preet Bharara:

Because that makes no sense.

Sean Carroll:

And if you ask physicists what’s going on, they’ll kind of hem and haw.

Preet Bharara:

So let me, I guess, ask this more foundational question. Why is it important to understand it?

Sean Carroll:

I think two reasons. One is because of course it’s important to understand it. That’s what we do. That’s our job. The kind of science I do, the kind of philosophy I do, et cetera, it doesn’t have an immediate useful role in the world. I don’t cure diseases, I don’t solve poverty or anything like that. All that I do is help us as the human race better understand our universe. That’s the entire point of what I do. So I think that understanding quantum mechanics is part of that, one of the biggest parts.

But the other thing is we do have questions in physics that are considered very important, very pressing questions. Why do the masses of certain particles act the way they do? Why is space time doing certain things? And we’re stuck. We don’t know the answer to these questions, even though we think that fundamentally quantum mechanics is at the heart of the matter. So I strongly think that it’s at least possible that maybe the reason we don’t answer these questions effectively is because we don’t understand quantum mechanics better. So I think it’s important both in principle and to help us do other questions in physics.

Preet Bharara:

What does the science of quantum mechanics tell us or suggest about the existence of other universes parallel to ours and how many there might be?

Sean Carroll:

People disagree about that. The straightforward answer from my perspective is quantum mechanics seem to suggest that there are many, many, many universes, much like ours, but not exactly the same. They differ because the outcomes of different quantum measurements were different in these universes. So when I say that an electron has a wave-like character and is all spread out, and when you look at it, there are many different answers you could get, but in practice you only get one.

The most straightforward interpretation of the equations of quantum mechanics, which was put forward by Hugh Everett back in the 1950s, says the reason why you only see one outcome is because actually every possible measurement outcome happens, but in a separate copy of the universe. And the thing to emphasize here is he didn’t just invent that. He didn’t just think it sounded cool and was kind of mystified by it. The equations that were invented decades before to understand how atoms behave and how electrons move around, these equations clearly predict that. It just took 30 years for physicists to admit that maybe we should listen to what the equations are trying to tell us.

Preet Bharara:

Does that mean, just as a very mundane example, that there’s an argument there’s another universe that exists in which you and I are having this exact same conversation with one word different, another one where we’re having this exact same conversation with two words different, and so on and so forth?

Sean Carroll:

The basic answer is yes. The only amendment I would have is those people are not us. They bear a very similar relationship to you and I that an identical twin would bear to you. There was a moment in time when we were the same person, but now we’ve gone our separate ways.

Preet Bharara:

But infinitely at every moment, that goes forward?

Sean Carroll:

That’s another one like the time travel question where physics doesn’t quite know the answer. The number of other universes, if this whole picture is true, which we’re not completely sure of, is certainly very, very, very, very large. Whether it is literally infinite, or just really big is something that modern science hasn’t quite yet pinned down.

Preet Bharara:

Is the universe that we experience right now, with all the galaxies and systems and black holes and everything else, is that infinite, or just very, very large, or do we not know?

Sean Carroll:

We don’t know that one either. In fact, there the limitations are quite severe. Because when we look at the universe, we look at it using light typically. And whether it’s X-rays or visible light or radio waves, it all travels at the speed of light, which is fast, but still finite. So when you look at distant objects, you’re looking at them some time ago. If it’s a four light light year away object, you’re looking at what it looked like four years ago. So because there was a big bang about 14 billion years ago, there’s a limit to how far we can see out in the universe, and everything looks perfectly normal up to that point. We can tell you that on the basis of what we see. But how far, if at all, it stretches beyond that, we don’t know.

Preet Bharara:

So what are the implications for philosophy and for our understanding of reality and our understanding of meaning if it is true that there are infinite variations of you and me and everyone else?

Sean Carroll:

The good news is there are almost no philosophical implications of that.

Preet Bharara:

There aren’t?

Sean Carroll:

Well in a down to Earth sense, what is the alternative? Quantum mechanics works. So we’re not comparing the many worlds version of quantum mechanics, which we’ve just been discussing to some classical physics version. Classical physics is out the window. So the alternative is that when you look at that electron and you measure it, there is some irreducible random element in what happens, right? You can’t predict exactly what the outcome will be, but you can predict the probability that it’s going to have different things.

So if you’re interested in things like what is the best action for me to take? You’re interested in moral or ethical questions. One picture says, well, there’s a certain probability something’s going to happen. There’s a certain probability something else is going to happen. The other picture says, both things will happen with certainty in different universes, but the universes are not counted equally. One counts more than the other for strict mathematical reasons. And at the end of the day, what you end up with is all of your rules about how to behave and how to be and how to care and value the universe end up to being the same in both pictures.

Preet Bharara:

I wonder if, we have come a long way since Copernicus came on the scene and corrected the view that the Earth revolves around the sun as opposed to the sun and everyone else revolving around us. And it seems to me that that’s good. But I wonder if there remains a lingering tendency of people to imbue themselves with more importance in the universe than they actually have.

Sean Carroll:

Well, you’re setting me up. You’re giving me a softball here. This one I like, this question. Because to me, one of the reasons why people resist this many worlds version of quantum mechanics is that they literally are annoyed by the prospect of all these universes they can’t see.

Preet Bharara:

You know, I found myself being a little annoyed myself.

Sean Carroll:

And as a human being, I respect and validate your annoyance there. But as a scientist and philosopher, if that’s what the equations say, the equations of our best theory that is invented to fit the data that we do see, then my principled advice is to suck it up and accept that until you come up with a better theory.

Preet Bharara:

Your blog is called what?

Sean Carroll:

The blog is just called Preposterous Universe, preposterousuniverse.com/blog. But I’m not a very good blogger these days. Now that I have the podcast, it’s taken over my time.

Preet Bharara:

The podcast. Well, I was going to ask. That was a roundabout way of trying to ask you why preposterous?

Sean Carroll:

Well, that’s a very good question. It comes back to the amazing discovery in 1998 that I was not part of, but I had a front row seat for it, which is that our universe is accelerating. What I mean by that is if you look at distant galaxies in our universe, they’re all moving away from us. And you can actually use the laws of physics to predict what the velocities should be as a function of how far away they are. And that rate of expansion of the universe changes over time. What you would naturally expect is, as gravity pulls everything together, galaxies move apart, but they move apart more and more slowly. They’re being slowed down by their mutual gravitational attraction.

When we actually went out there to measure it, we found the opposite. Something is pushing galaxies apart. The good news is that we already knew the right theory to explain this because, guess who invented it? Albert Einstein back in 1917. He noted that if empty space itself had energy, the activity, the consequence of that energy would be to push space apart in exactly this way. So we suddenly have a theory that was very surprising and beautiful, but it fit the data great.

The only problem is it seems wildly unnatural to us. We can talk about what we now call dark energy, the amount of energy in empty space. We can measure it, we can talk about its properties, we can verify predictions. It all holds up very, very nicely. But the fact that it has just the amount it does is a complete surprise to us. So I started talking about the preposterous universe that we live in, but it’s a joke. Because of course, the universe is not preposterous. It’s only preposterous relative to our expectations. So it’s a reminder that it’s the universe that is the final arbiter here, not our expectations.

Preet Bharara:

Now, I must ask you about this other concept that is controversial that some people talk about from time to time, and that is the possibility, this is even more preposterous to a layperson’s ears than what you were just talking about, what is the possibility, speaking as a scientist, that we are in a simulation, whatever that means?

Sean Carroll:

It’s a possibility. I’m not going to stop you from believing it, if that’s what you want to believe.

Preet Bharara:

Like 1%, like 5%?

Sean Carroll:

Look, it’s very hard to put a probability on it. I think I should put a probability on it, and I think it’d be very small. It’d be less than 1% in my mind. And the reason why is the following. If you want to contemplate different theories of the fundamental nature of reality, then you should sit back and ask yourself, if that theory were true, what would I expect the universe to look like? Is there any consequence? Is there any prediction? Even if it’s kind of just a vague tendency. And the truth is that our universe shows no evidence whatsoever of being anybody’s simulation. It acts precisely like a universe that is just perfectly natural. And then the top level existence, the top level reality that is out there.

Preet Bharara:

But why can’t that just be the genius of the simulation?

Sean Carroll:

It could be, but that’s not our job. You’re not asking me is it possible? Because you did ask me if it was possible and I said yes. But now you want to know if it’s probable. And there I have to say, well, is there any reason? Is there any explanatory value that I get from giving that a high probability? Is there any feature of the universe that I can’t otherwise account for? And I think it’s the opposite. I mean, not only do I not especially account for features of the universe by imagining it’s a simulation, if I did imagine it was a simulation, didn’t know what the universe looked like, I wouldn’t imagine that it would look like this. So until someone gives me some reason to think about it this way, I’m going to go along thinking that I am at the top level of reality.

Preet Bharara:

This is another controversial one, which is going to annoy some people if you answer it the way I expect. Is there any possibility of life after death?

Sean Carroll:

Any possibility?

Preet Bharara:

I keep doing it. I keep doing the same thing.

Sean Carroll:

You’re a lawyer.

Preet Bharara:

What is the likelihood of life after death?

Sean Carroll:

Very, very, very tiny.

Preet Bharara:

Why in your mind is it basically impossible?

Sean Carroll:

Yeah, it is possible because many things are possible. I always tell my podcast listeners, if any physics question ever begins with is it possible that-

Preet Bharara:

The answer is yes.

Sean Carroll:

… the answer is always yes. But that’s not what we care about. Is it worth taking seriously? I don’t think that the possibility of life after death is worth taking seriously. Because again, the progress of scientific understanding of what a person is, of what it means to think and feel, et cetera, has situated ourselves in this physical universe where we have a pretty good understanding of the fundamental laws that govern atoms and particles, the molecules of which you and I are made.

When you have a memory, that memory is a certain feature of the neurons in your brain, the way that they’re wired together and the way that they fire. There’s no place for that to go when you die in terms of the currently known laws of physics. And there’s no evidence that there’s anything other than the currently known laws of physics at work when you die. So the choices are either there is no life after death, which is, I think we can talk about that too, but I think philosophically that’s fine actually. We should face up to it. And as a society, we are bad at facing up to it, and that’s a problem.

But then the other possibility is you have to dramatically violate the laws of physics in some way for which we have no evidence. And you have to do it in such a way that your actual physical existence here on Earth is kind of a useless afterthought. If all of my thoughts and feelings don’t depend on my body and my brain, then what am I doing? Why am I exercising to feel better, and then drinking-

Preet Bharara:

Well, the one possibility-

Sean Carroll:

… coffee in the morning? Yeah.

Preet Bharara:

Well, I want to come back to that point in a moment, but the one possibility is, for life after death, if we are in a simulation.

Sean Carroll:

Sure, there you go. Take both-

Preet Bharara:

That’s low likelihood, too.

Sean Carroll:

… incredibly improbable ideas and glue them together.

Preet Bharara:

So as a philosopher and someone who thinks about, I think you think about meaning, given what you just said, how are we supposed to think about our life on Earth? By the way, these are also questions that bear on religion or that religion tries to address. And that’s why various religions talk about souls and life after death. And some religions talk about reincarnation and different modes of continuing to exist in some form after death because the idea of it being otherwise causes people to kind of throw up their hands. How do you think about that?

Sean Carroll:

I was just at a workshop at the Santa Fe Institute where I have a part-time position. The Santa Fe Institute is the world’s leading research institute devoted to the study of complex systems. That goes from all the way to hurricanes up to human societies. And the workshop was devoted to the question of immortality, what it would mean to be immortal. And some clever person actually took a poll of the people in the room who note we’re all there for a workshop on immortality. And the question was, would you like to have a lifespan greater than 10,000 years? And most people in the room said, no. I said, yes. I’m like, I could keep myself amused for 10,000 years. I still haven’t even learned to play the piano. It might take me 10,000 years to do that.

So I think that people, when it comes to this desire to live a long time, or to live even after your death, haven’t really thought it through. I don’t think that they’re putting enough emphasis, giving enough credit to the reality of the experiences we have during our lifetimes. In one of my books, I point out that the average human lifespan lasts three billion heartbeats. It’s just an average. You don’t get more lifespan by not exercising or anything like that. But three billion is an interesting number because it’s big, but it’s not crazy big. You can hear them ticking off. Once per second, a heartbeat goes away. To me, that’s where the meaningfulness comes from. The idea that we don’t have 100 years here on Earth and then infinity extra years after. That would seem to incredibly cheapen our time here on Earth. If the time we have here on Earth is precious, is finite, and is all we get, that’s where meaningfulness comes from because it is what we do here on Earth that is the only thing that can possibly matter.

Preet Bharara:

Well, I like that answer. On the question of whether or not I would want to live to be 10,000, I would need to know the answer to the question of what level of back pain would I be experiencing?

Sean Carroll:

We’ll give you health. We’re thought experimenting here. We’ll give you perfect-

Preet Bharara:

So give you health.

Sean Carroll:

Whatever was peak Preet. Whenever in your life you were at your peak physical form.

Preet Bharara:

Both as a scientist and as a philosopher, what’s your take on AI and whether or not it’s an existential threat?

Sean Carroll:

I don’t know whether it’s an existential threat or not. I am very, very, very skeptical that it is, but again, there’s a possibility of it. My take is that there’s a whole bunch of really obvious threats that are not existential, but that are very near term and very looming from AI. There’s also huge benefits. It’s a very typical mixed thing, just like fire has advantages and disadvantages. So does AI, right?

Preet Bharara:

And water.

Sean Carroll:

Yeah, exactly.

Preet Bharara:

Lots of things, right?

Sean Carroll:

And I think that if we actually put an effort into thinking carefully through and guarding against the obvious near term worries that we have about AI, that will have a downstream effect of helping us prevent the bigger existential threats. Whereas if we spend a lot of time talking about the existential threats, these near term threats are going to knock us down before we ever get around to it.

Preet Bharara:

What I like about your work is that it’s accessible to laypeople and you write for laypeople, you do a blog as you have mentioned, but you’re also pretty open about a professional experience you had some years ago where you were denied tenure, I think it was at the University of Chicago. And you place some of the blame for that on fellow academics’ responses to the fact that you were writing a popular blog? Can you explain that and what you think happened?

Sean Carroll:

Actually, to clarify that one, I do not think it was the blog. I did have a blog at the time. In fact, I literally wrote a blog post afterward with the title It’s Not the Blog.

Preet Bharara:

Okay. My bad.

Sean Carroll:

I don’t think it helped. I think it hurt a little bit, but it wasn’t a major thing. I’ll tell you what hurt more is that I wrote a textbook on general relativity for graduate students. And that is why… I mean, they explicitly told me that that-

Preet Bharara:

Why would that hurt?

Sean Carroll:

Here’s my understanding, such as it is. I didn’t get a vote. I wasn’t there. So it’s all kind of secondhand, right? But when you hire a faculty member at an elite research institution, you do so as a department. You hire with hope, right? You’re like, this person could be great, so let’s give them a chance. But when it comes to keeping them six or seven years later, you fire on the basis of fear. You are really, really frozen with fear at the prospect that you will give this person tenure, and then they’ll be your colleague for the next 40 years and they will stop doing work. That’s what you’re really desperately afraid of.

And as a result, the single thing that is in people’s minds is we don’t want to give tenure to people who indicate that they are interested in doing things other than research. And that includes writing textbooks. It also includes writing blogs. But I don’t even think that most of my colleagues knew that I had a blog at the time. But the fact that I would take almost a year of my life to write a textbook when I could have been doing research was a gigantic strike against me.

Preet Bharara:

Well, I find that quite terrible. Because what happened to the principle of paying it forward and seeding the ground and cultivating future minds who might be researchers themselves in their own right coming up the ranks? Who’s supposed to do the teaching then?

Sean Carroll:

Yeah. I mean, it’s hilariously incoherent. Because many of my colleagues, including ones who voted against me, had written textbooks themselves. They just were smart enough to do it after they got tenure. So even if you’re going to write a textbook, you can’t let people know that you’re the kind of person who would write a textbook.

But look, I am completely in favor of departments and universities having the right to not give people tenure if they don’t want them around, if they think they can do better with somebody else. My complaint there with that particular arrangement was just that they never gave me any hint that anything was going to happen. Everyone who talked to me said, “Oh yeah, you’ll get tenure. No problem.” And that was a life-changing kind of blow when it did happen.

Preet Bharara:

Yeah. Well, that’s where you began to learn a little bit more about probabilities too.

Sean Carroll:

There you go.

Preet Bharara:

And anything’s possible. I’m going to ask you for some free advice. One of the reasons I’m very excited to have you on, and generally we have people who are lawyers or policymakers of a certain stripe on the show, is that my youngest son is thinking about and choosing between, he’s a freshman in college, majoring in engineering or physics, or some other discipline that’s related to those things. Do you have a view? You’ve written about the fact that you got both your undergraduate degree and your graduate degree in astronomy versus some other related discipline like physics, which we’ve been talking about a lot. Does it matter?

Sean Carroll:

It does matter. As I indicated at the beginning of our conversation, I have made things harder than they needed to be for myself at every step along the way. And you can become a physicist getting an astronomy degree, or vice versa. For that matter, I have friends who are professors of philosophy who got a degree in physics and not in philosophy. Many things are possible in this issue also.

But it’s very hard to pursue a career in academia and get a job. The number of people who want to get these jobs… I tell my students in the graduate program, the ones who are going to get a PhD, the rule of thumb is maybe 25% of you will actually get a faculty job as your long-term employment. So you are absolutely playing a game of probability here. And by being quirky, by writing books, by majoring in the wrong thing, et cetera, et cetera, you don’t make it impossible for yourself, but you’re not making it easier on yourself either.

So one final thing I did want to get across is that I love encouraging people to become professional physicists, philosophers, whatever, but it’s not my primary thing. I want everyone to love this stuff. My most recent book is trying to explain physics to a broad audience, but with all the math. So I teach you the math, and then I try to get you excited about looking at equations for the first time anew. And I don’t know whether it’s working or not, but that’s really what I’m about. I want all human beings to have passionate opinions about contentious issues in modern physics.

Preet Bharara:

As opposed to learning how their phone works.

Sean Carroll:

That would be great too. I should learn how my phone works. You’ve really made me feel guilty now, that I don’t know how my phone works.

Preet Bharara:

No, no, no. It’s totally fine. I don’t know how anything works. Professor Sean Carroll, latest book, The Biggest Ideas in the Universe, Space, Time, and Motion. Thanks so much for your time.

Sean Carroll:

Thanks very much for having me. This is great.

Preet Bharara:

My conversation with Sean Carroll continues for members of the CAFE Insider Community. In the bonus for insiders, Carroll and I talk more about depictions of time travel in Hollywood films.

Sean Carroll:

Keeping all those laws fitting into your fictional world helps the story have some verisimilitude, even if it’s on a planet in a galaxy a long, long time ago and far, far away.

Preet Bharara:

To try out the membership for just $1 for a month, head to cafe.com/insider. Again, that’s cafe.com/insider.

BUTTON

I want to end the show this week by celebrating one of the Big Apple’s most enduring and exhilarating yearly rituals, the New York City Marathon. Last Sunday, November 5th, some 51,400 runners completed the 26.2 mile course, which starts near the foot of the Verrazzano Bridge in Staten Island and finishes after winding through Brooklyn, Queens, the Bronx, and Upper Manhattan in Central Park. It’s hard. Frankly, I get tired if I drive 26.2 miles.

The New York City Marathon has been around since 1970, and is put on by a local running group, the New York Road Runners. Literally millions of New Yorkers line up to watch the runners go by. Many of the participants also raise money for a variety of worthy causes. Behind each of these finishers is a unique story. Running a marathon, even for the most fit athletes in the world, is a true undertaking. New Yorkers are awed each year by the grit and resilience of these marathoners. This year is no different, and I thought I’d highlight some.

The New York Times covered the oldest entrant, Garth Barfoot. The 87-year-old Barfoot lives in a retirement community in the outskirts of Auckland, New Zealand. He’s run dozens of marathons, but he had never taken on New York City until this year. The self-effacing Barfoot, who has had three hip replacements in recent years, told the times, “I’m getting decrepit by the hour, so I’ve got to sort of hurry up and do this race before it’s too late.”

Another runner was Ukrainian veteran Roman Kashpur, who lost his leg after stepping on a landmine while serving in the Ukrainian army in 2019. He was fitted with a prosthesis and has since trained soldiers and helped to defend his nation against Russia. A week before the New York Marathon, Kashpur also completed the Marine Corps Marathon in Washington DC. Now that is commitment.

And there was Rahsaan Thomas. He was sentenced to 55 years to life in prison for second degree murder as a young man. Thomas became an acclaimed writer and podcast host while serving at San Quentin, even receiving a Pulitzer Prize nomination for his Ear Hustle podcast, which chronicled daily life behind bars. Thomas also began running the San Quentin Marathon, a yearly 105 lap loop of the prison yard. He also made a pact with a journalism teacher at the prison named Claire Gelbart that the two would run a marathon together if he ever left prison. California Governor Gavin Newsom commuted Thomas’ sentence in 2022, following almost 23 years behind bars. True to their promise, Thomas and Gelbart ran the New York marathon together on Sunday.

There are also stories of profound resilience, even among the most seasoned of marathoners. The women’s winner on Sunday, Kenyan Hellen Obiri, was on a road to redemption. She was disappointed by her sixth place finish in last year’s New York Marathon, her first, and saw this year as a golden opportunity. Sure enough, she delivered a staggering four minute 51 second last mile to pull away from the competition in just the final 400 meters.

We at CAFE also have a personal link to the marathon this year. Our very own editorial producer, Noa Azulai, ran the race too. Noah fundraised for the New York based nonprofit Sanctuary for Families, which supports victims of domestic violence, sex trafficking, and related gender violence. From all of us at CAFE, congratulations to Noa.

The world is scary in so many ways right now, and a long run through a big city might seem a little bit silly. But the marathon can also serve as a reminder that people of all backgrounds, skill levels and ideologies can still come together to honor their mutual achievements and passions. And I think that’s something to really value. Have a great week.

Well, that’s it for this episode of Stay Tuned. Thanks again to my guest, Sean Carroll. If you like what we do, rate and review the show on Apple Podcasts or wherever you listen. Every positive review helps new listeners find the show. Send me your questions about news, politics, and justice. Tweet them to me @PreetBharara with the hashtag #AskPreet. You can also now reach me on Threads, or you can call and leave me a message at 669-247-7338. That’s 669-24-PREET. Or you can send an email to letters@cafe.com.

Stay Tuned is presented by CAFE and the Vox Media Podcast Network. The executive producer is Tamara Sepper. The editorial producers are David Kurlander and Noa Azulai. The technical director is David Tatasciore. The audio producer is Nat Weiner. And the CAFE team is Matthew Billy, Jake Kaplan, Namita Shah, and Claudia Hernández. I’m your host, Preet Bharara. Stay tuned.