Hello, and welcome to the Physics World weekly podcast.

I'm Hamish Johnston.

It's book week here at Physics World.

And over the course of three days, we're presenting conversations with the authors of three fascinating and fun books about physics.

Today, my guest is the physicist Daniel Whiteson, who along with the artist Andy Warner has created the delightful book, Do Aliens Speak Physics?

This episode is supported by the APS Global Physics Summit, which takes place on March 2026 in Denver, Colorado and online.

At the largest physics meeting in the world, you can join thousands of physicists, students, and policy leaders for a week of connection and collaboration.

Immerse yourself in the cutting edge science that's shaping our shared future, and be part of the global physics community driving innovation forward.

Explore the meeting at summit.aps.org.

Is physics universal, or is it shaped by human perspective?

This will be an important question if and when we are visited by an advanced alien civilization.

Would we recognize our visitors alien science?

Or indeed, could a technologically advanced civilization have no science at all?

These questions and much more are addressed in do aliens speak physics?

And here to talk about his book is Daniel Whiteson.

He's a particle physicist at the University of California, Irvine from where he joins me.

Hi, Daniel.

Welcome to the podcast.

Hi.

Thanks very much for having me.

I'm so excited to talk about aliens with you.

Yeah.

Well well well, so am I.

I really I really enjoyed, reading your book.

It was it was a lot of fun.

And and and I have to say, you know, there's a lot of really fascinating and, you know, dare I say, profound ideas in there about, I mean, maybe not so much about aliens, but more about how we perceive science, today, and, you know, what science was like in the past, and and what it could be in the future.

So, yeah.

Dear reader, if you think this is only about aliens, it's not.

There's lots of, of of really interesting stuff about science and the philosophy of science.

Well, you really put your finger on it actually because the book I originally wanted to write was, do we think about physics in a way that's universal or has our humanity somehow injected itself into our science in a way that's imperceptible to us?

And I actually pitched that idea to my 14 year old, who's my Gage.

And he was like, boring.

And so instead I said, all right, what if it's a book about when aliens arrive, could we talk to them about science?

And he was like, oh, that sounds like fun.

And I thought, cool.

It's actually the same book, but, you know, just in this sort of more concrete context where you're, like, faced with the task of communicating with your interstellar colleagues.

But, yeah, in the end, I really just wanted to think and write about the nature of science and what we've learned and how much humanity is in it.

Yeah.

That I mean, that's definitely what I what I got out of it.

And, yeah, I I I really did enjoy that sort of aspect of it.

But let let let's go for the first, you know, the first sentence of the book.

I think you begin the book, imagine the day the aliens arrive.

And I'm just I'm just curious.

Do you I mean, do you think that one day we will be visited by representatives of an alien civilization?

Because, you know, you know, that's the whole premise of the book.

Mhmm.

But is that is that purely rhetorical?

Or, you know, do you do you have an inkling or or a wish for that to happen?

I certainly do have a wish.

I mean, I've literally fantasized about that because it feels to me like we are slowly chipping away in the minds of truth trying to understand how the universe works.

And we've been going at it for thousands of years, and we've made some progress, but we also have these hints that there's so much left to understand, you know, dark matter, dark energy, the expansion of the universe, cosmological questions.

So it's frustrating to imagine that there could be aliens out there that have spent a billion years working on these projects.

They could just have the answers.

And the day they show up, if we are working on the same questions and if we can communicate, then they could leap us forward into our scientific future and just tell us these truths.

Wow.

What an amazing day that would be.

I mean, it's like seeing the face of God, you know, or, you know, revealing the source code.

Wow.

That would be amazing.

So I definitely wish that would happen and fantasize about it.

Whether I think it's likely to happen, you know, that's nonscientific speculation, but, you know, there are many, many planets out there and around many, many stars, and the universe is quite old, so there's a lot of chances for it.

On the other hand, you know, we haven't seen anybody yet.

And, of course, there's the famous Fermi paradox about why that might be.

And my suspicion is that, aliens will arrive in the future.

It's just a question of time.

You know, it's an issue of overlapping for long enough for somebody to develop the technology to explore the galaxy.

And so I think it's important to sort of mentally prepare ourselves.

What would it really be like when they arrive?

Are we ready for it?

What work do we need to do before they get here to make sure we have a chance to leap forward into our scientific future?

And it is, you know, it is interesting that over the last thirty years, you know, we went from knowing about zero exoplanets, that's planets that orbit stars other other than the sun.

Now we know that there's thousands out there.

Yeah.

So, you know, in a sense, you know, maybe if you had asked me that question thirty years ago, I would have said no, maybe not.

But now that I know about all these exoplanets and the fact that we're discovering more and more every day, it it it it sort of hits home, doesn't it?

Quite literally that, that that it is a possibility.

And I suppose that makes the Fermi paradox, you know, the idea that, if there are aliens out there, why why don't we know about them?

Even more positive, isn't it?

Yeah.

It does.

And I think you're right.

We're living in a very exciting time to be thinking about these questions because for hundreds or thousands of years, we've known about, you know, fewer than 10 planets in the universe.

Now we know 5,000.

We're looking on 10,000 soon.

And I think in the next few decades, we're very likely to see, you know, undisputable hints of or or indisputable evidence of life around, other planets on around other stars.

You know, not direct imaging or visitation yet, but, you know, biosignatures in atmospheres, we have the technology very soon to be able to do that.

I think it's likely that will happen.

And so we're living in a moment when our understanding of who else might be out there is really changing so rapidly.

And so it's very difficult to predict what we're gonna know in a hundred years.

But, you know, the situation I'm imagining requires much more than knowing there are aliens around another star because the difficulties of communicating with distant aliens are really enormous.

I mean, I spoke to linguists and philosophers who think it might be literally impossible to decode an alien message without some sort of common context, you know, without them arriving here and us being able to, like, point at an apple and say apple and point at two apples and say two apples and build up a dictionary.

I think at a distance, it would be very, very difficult, maybe impossible, to actually figure out what they are saying.

You know, this symbolic language is very frustrating and cultural.

So that's why I imagined aliens arriving on Earth, because then we can maybe make some progress and figure out, you know, do we have mathematics in common?

Can we begin and from that and build up into an actual linguistic communication?

I wanted to ask you about, the extended Drake equation, which is something that's central to your book.

You know, it's I suppose it provides a scaffolding for Yeah.

For you to hang a lot of of your ideas and analysis on.

Now this extended Drake equation, is that something that you came up with, or you and Andy came up with?

Because you you didn't come up with the Drake equation.

That's that's existed for a while now.

So is, I mean, may maybe I could ask you to very quickly explain what the Drake equation is, and then maybe the extended Drake equation.

Yeah.

Well, you already touched on the ideas quite quite well, I thought.

You know, a lot of these questions, are there aliens out there that we communicate with?

They have a lot of parts to them.

And in order for it to work, in order for us to meet aliens or hear from aliens, you need a lot of things to all fall in place simultaneously.

You need enough stars.

You need enough planets.

You need enough of those planets to have life.

You need enough of those to become civilized.

You need that all to happen at the same time.

And the Drake equation does two things wonderfully.

I think it breaks this big question into pieces that you can think about individually, like, what do we know about how many stars have planets, etc?

And because it's multiplicative, it takes all of these factors and multiplies them by each other, it emphasizes that you need all of them.

I mean, it doesn't matter how many stars there are and how many planets there are If the probability for life around a planet is one over 10, right, then the number is tiny.

Or if we are if it's one over, you know, the number of planets in the universe because we're alone.

Right?

Any individual factor can kill you.

So I was thinking about that when I was tackling this bigger question of not just are there aliens out there, but are there aliens out there that do science the way we do and decided to break it down in pieces?

So the first piece we added to the Drake equation, because we're looking for something more specific than just aliens communicating, it's aliens who we can talk to about physics.

The first piece was number one, do they even do science, right?

Could there be aliens out there who are just, you know, slime on planets or even aliens out there who are technological but not scientific, who develop, you know, techniques to manipulate the universe without wondering why, without having that same human curiosity about how it works?

And then the second piece was, can we communicate with them?

Can we establish, like, a mental bridge so we know we're talking about the same stuff, and, you know, we could even get their answers, you know, even if they have some, like, deep understanding of quantum gravity, could they communicate it to us?

And the next piece we thought about was what about their questions?

Would they ask the same questions about the universe?

Are our questions human?

Would they be curious about different things?

And then the last piece are the answers.

In order to fulfill my fantasy where we sit down and learn about what's inside black holes and where the universe came from from these super advanced aliens, we also be have to be able to appreciate their answers.

You know, I found when reading about the philosophy of science and how science has evolved, that there's a lot of subjectivity in the answers that we accept, what we find intuitive, you know, and then there's also the question of like, would we even be smart enough to answer to hear their answers and understand them?

Wouldn't that be so frustrating to have aliens show up, have them be friendly, have them, you know, possess the knowledge of how the universe works that we've been desperately working towards and for us to just go, I don't get it.

Right?

I mean, what a sad trombone that would be the end of that story.

But the so to answer your question about the extended Drake equation, this is a way to break up this very amorphous question into pieces and and tackle them one by one.

And also to emphasize that for this fantasy to come true, we really need all those things to happen.

They need to do science.

We need to be able to communicate with them.

We have to have questions and answers in common with them.

I see.

And I I wanted to start with the first one, which is science.

And, so I think there in in the book, you're you're sort of making a a distinction between science and technology.

And I think right to begin with, I suppose me with my physics background, that gets me scratching my head because I think, well, you know, how can you have science how can you have techno technology without science?

How can you have science without technology?

But then I thought because I was talking to somebody a few days ago about thermodynamics, and how, you know, thermodynamics came about in the nineteenth century, basically by people who wanted to make better steam engines and pumps and things like that.

And so I thought, well, okay.

Yeah.

I can sort of understand in that situation that the technology led, and maybe the science came later.

But are are you saying that it it could be that there are civilizations out there where there's only technology and no science?

I'm, you know, I'm struggling with that, but I suppose your point is that that could exist and that could make it very difficult for us to to to understand, such a civilization.

Yeah.

You put your finger on it again.

I mean, the whole exercise of the book is let's investigate our assumptions.

It's very natural for us to think, well, science is the engine for discovering the way the world works, which technology requires.

Right?

But that's the way we've done it.

That's the way our civilization works.

That doesn't mean it's the only possible way, and the book is basically an exercise in, like, let's think about if we can imagine another way.

That doesn't mean that we're arguing it's the best way or it's the only way, but, like, let's explore the edges of the sandbox and question our assumptions.

And we can't do that, of course, by visiting aliens yet.

But what we can do is look back at the history of our development and think about whether things could have been different.

And right away, when you look back into our history, as you say, we've been technological a lot longer than we've been scientific.

You know, people have been making incredible swords, improving on the technology to be sharp and hard without understanding what's going on at the microscopic level and the solid state physics.

You know, and there's lots of things that universe today, technology that we have that we don't fully understand.

You know?

Nobody knows how Tylenol works.

Right?

Like, it's amazing.

But we can develop technologies without understanding them.

The crucial thing, of course, is we want to understand them.

We have this innate curiosity.

To us, it's satisfying to know why.

And, of course, understanding it, building a mental model of how it works lets you accelerate that development.

But, you know, as I said, for a long time, we were technological before we were scientific.

And so I thought about, you know, is it possible to have a species that is just technological?

And one thing we did in the book, which I had a lot of fun with, was come up with these hypothetical case studies rather than just thinking about it abstractly.

Is it possible?

I sat down to write these little fictional narratives, you know, a couple of pages to imagine a scenario which bends our assumptions.

And so in this case, I thought about how a civilization might actually develop an understanding of general relativity and the way space works is an intuitive way, in a way that they just use it and become familiar with it, and eventually use it to travel the galaxy so that they could even show up here with effectively wormhole or warp drive technology.

And we ask them, hey, how does that work?

And they're like, well, I can show you how to do it.

What do you mean?

How does it work?

You know?

They might be technological without being curious.

It might be enough for them to be like, well, here's how you do it.

You surf the curvature of space time.

I'm not saying that's more likely, and of course I'm not saying that we don't need science to develop technology, but, you know, if you have a lot of time and incredible variety in the universe, you might get all sorts of weird aliens, and we should be prepared for aliens who show up and don't understand why we want to ask why about the universe, why it's not enough for us to just do it and to use it, you know, to wonder how those swords work and why yeast ferments and how Tylenol works and all these things.

So a lot of this book is about asking how much we have in common with aliens.

And this part, this curiosity, this desire to understand, boy, that's, you know, subjective.

It feels very cultural.

And, you know, also, if you if you look back at just the history of science, people have this conception that science came together as empiricism on top of, you know, just platonic thinking.

A few hundred years ago when Galileo and Bacon, you know, were inspired to do experiments and to actually, you know, confront ideas, with with data.

But the truth is a little bit more subtle than that.

You know, science is a process that's been evolving for a long time.

The Greeks did some experiments and, you know, the Arab scholars did experiments, and the Chinese did experiments.

And so it's not just like a eureka moment where we develop science itself, and now we have this process which is fixed.

It's growing and evolving.

It's it's, hard to imagine that in a thousand years, our own conception of the process of science would be exactly the same.

Probably it's going to keep changing.

And so when aliens show up, if they've been doing this for a billion years, they may either have no idea what science is and not care about it, or they could have some super far in the future developed version of science as a process.

And they look back on our science, they're like, y'all are kind of primitive.

Like, how come you didn't consider this other way to develop knowledge about the universe?

And so the first chapter is just to, like, get you warmed up to think about how aliens could really approach a lot of these questions of science and technology very differently than we might.

And, so moving on to communication, I mean, I suppose there again, you, you know, you've got, I suppose different ways.

I've you know, I think in the book you point out very nicely that humans have used, you know, sort of a wide range of of, well, languages and and ways of writing that, you know, even, I suppose the classic example that you give are the Egyptian hieroglyphics where, you know, for a very long time, I think thousands of years, scholars were trying to interpret them in the wrong way.

You know, sort of weirdly sort of thinking that the Egyptians didn't communicate like we did.

Obviously, it was something completely different and and and completely missing the point until the, I suppose, the Rosetta Stone turned up and, and set people straight.

So, I mean, one sort of idea that I think you introduce is the question of whether physics or maybe mathematics or maybe computer science could form the basis of, I don't know, a universal language or a universal translator that Mhmm.

Could we could go from our way of communicating into, let's say, physics and then out to, the alien way of communicating.

Is that can can you talk a bit about that?

Because I found that really fascinating.

And it sort of made sense to me when when I I sort of gave up some of your ideas about how maybe physics is very different.

And, but yeah, I thought it was a very interesting concept.

Can you talk about that a bit?

Yeah, I think a lot of people imagine that, you know, when aliens arrive, obviously they won't speak English.

That'd be ridiculous.

And they might use some weird sort of, language or communicate with their senses, with their sense or with colors or whatever.

But that at the foundation, we have math and physics in common.

And, you know, Carl Sagan has a famous quotation about this, and he designed the pioneer plaque, which describes some basics of, you know, hydrogen and our representation of the solar system.

And it's all, you know, pictograms.

It's obviously not using words.

And I think, you know, the inspiration is, is, is right there.

It's a way of saying, like, let's try to describe some core basic concepts that maybe we have in common.

But, you know, in the end, all of these things are symbols.

All of our attempts to transmit an idea from one brain to the other have to pass through this symbolic representation where we scratch images onto a surface and pass them to somebody or encode them in data and pass them pass them on.

And that encoding, that translation into symbols is totally arbitrary.

You could pick any symbols you want.

And so to imagine that aliens are gonna, like, look at the pioneer flag and go, oh, yeah.

I can tell you met hydrogen atom.

And, oh, yeah.

I see what you mean.

This must be a pulsar.

It's hopeful, but a little bit naive maybe.

And so I was thinking, you know, what could we rely on?

What way could we use to try to establish connections with aliens?

And so I actually called up Noam Chomsky because he famously answers his emails and asked him.

I thought, you know, who else better to ask about communicating, with aliens and the foundations of language?

That's the the famous linguist, Noam Chomsky.

Yeah.

And, you know, he said we should begin with arithmetic.

He said arithmetic is very likely to be something we have in common.

And he had a reasonable argument for that.

You know, he imagined, that aliens probably count themselves.

You know, they are individuals.

And so there's one alien, two aliens, they learn, you know, counting.

And from that you build arithmetic and, he and Marvin Minsky together have this argument about how from arithmetic, you can build up essentially all of language that from arithmetic, you get all of math because we've learned the last few hundred years that all of math rests on arithmetic, which is based on these PNO axioms, which are the foundation of all of mathematics.

And so basically once you have arithmetic, you can build up all of math.

So imagine a scenario where aliens show up and we establish one and two and one plus one equals two etc etc and from there we can build, most of mathematics and from there we can communicate perhaps in the language of computers writing programs essentially as Turing machines.

Turing machines are the simplest possible computer that you could build.

Not that you have to build them in this silly way with tapes and and and and rulers etcetera, but just as an argument for what computers can do.

That from arithmetic, you can get to mathematics, and then you can get to algorithms, and then you can use algorithms as the foundation of a way to communicate with an alien species.

You know, essentially moving information around, writing a program to do something as a way to communicate this is what we want or this is how we do this calculation.

And that's very attractive, but still at the foundation of it are some assumptions.

You know, how do we know that aliens have individuals that they count?

What about aliens that are like beings in the atmosphere of a star and they're made of plasma and the edges of their bodies are not so crisp?

If you dig into it, it's not even easy to understand where is the edge of me.

I mean, you have this concept of yourself as an individual and you and I are different people.

But, you know, if we're in the same room, where exactly would we draw the line and say, this is Daniel, this is not Daniel.

Is it at the edge of my skin?

Is it the little hairs that perturb?

Is it my personal space?

Very quickly, you find the philosophy there is somewhat cultural and arbitrary.

And if we had a different kind of body, ones that were more flowy and less less crisp, we might never come up with the concept of integers.

You know, it might all be, real numbers.

And so start trying to start with one and, and one and two might get us off in on the wrong foot.

So everywhere you go, there are these philosophical assumptions we're making, these cultural assumptions we're making about how to communicate and what's really at the foundation.

But it's a lot of fun to dig into these things and to wonder about various scenarios where aliens might arrive and and the difficulties we might face with communicating with them.

Yeah.

Because one one thing that, you know, I I thought, you know, from the point of view of physics is I I I think you allude to this in the book somewhere about, an alien civilization seeing, you know, the Earth as a as a system in the same way that we would see, I don't know, the electrons in a semiconductor Mhmm.

As a system.

And so, you know, humans would be, well, I suppose from our point of view would be sort of an an emergent phenomenon within that system.

And, you know, would they necessarily see us or perceive us as individuals, or would, you know, would they be you know, would would we be sort of like quasi particles to them?

You know, things that that that sort of exist, but really are are completely dependent on the environment, which I suppose we are, you know, to a certain extent.

We are quasi particles within Earth because we we couldn't exist, you know, in the same way that, I don't know, phonon doesn't exist in, in a vacuum.

We wouldn't exist in space for very long.

It you know, I I I suppose those were the the sort of thoughts that I was having when I read the book.

And, you know, I I, you know, it was real it was I suppose it just made me think in a in a very different way, about what it means to be human.

Yeah.

That was something that I didn't expect to get from the book, I suppose.

Yeah.

Well, this is a really fun topic and and one that's so fascinating and mysterious.

This question of, you know, why things emerge.

You know, as you say, we are emergent phenomena.

We're not fundamental to the universe.

There was a time before there were humans.

There may be a time after there were humans.

We're not necessary.

We're like this special combination of particles that do this thing when they're all together.

It's like ice cream or kittens.

Right?

It's not, fundamental fields or strings or whatever, and that's obvious.

But the thing that's fascinating is that you can sort of zoom out from the microscopic details of the universe and think about people and build from that an understanding of society and psychology and economics, the way you can, like, zoom out from particle physics and do chemistry and think about atoms.

Even though atoms are not the fundamental building block of the universe, it's possible to tell fairly simple, fairly understandable stories about chemistry or to zoom out to biology and think about ecosystems.

And it's amazing to me that the universe is understandable at all these different levels of zoom.

It's not obvious to me why that even is, you know, why can you make chicken soup or understand humans without knowing quantum gravity?

You know, I can imagine a universe where that's not possible at all, where everything is just chaotic from the fundamental level and nothing simple emerges.

And because we don't know why simplicity emerges and why at these levels, then we can't be sure that it is emerging, that it's a property of the universe.

It's not some bias that we have where we're seeing it in some way because that's what's important to us.

You know, the famous experiment where you watch a video of a basketball game and they tell you to count the number of passes and you don't notice that there's like an ape walking through the background.

And Right.

Yeah.

What you perceive and what you see and what you ask questions about in the universe depends very much on what you're interested in and what's important to you.

And so it may be that our, you know, the fact that we grew up on a planet, for example, makes us preordained to think about planets and to think planets are really important in the universe.

And maybe that's not.

Maybe planets are trivial and not interesting and other aliens could think about the universe in terms of different foundations.

So if you look at the way we represent the solar system, for example, planets are, like, always out of scale.

We, like, zoom them out way out of scale, And we don't even have, like, a good definition for what is a planet, right?

We have this very awkward sort of, you know, the retcon definition to make planets an interesting and special thing because we grew up on one.

But, you know, aliens who again grew up in interstellar space or the atmosphere of a star or inside a star or on a moon or, or something might have a very different sense of what's foundational, what's important.

And they could see different, I don't know, layers of Zoom, see different things emerge and and use that as the basis of their questions and of their science.

And so, yeah, they might not even recognize that humans are what we consider to be the foundational element of our society.

They could think of groups of humans or, you know, parts of us.

And and again, not to say this is the most likely, but it's just an exercise in questioning our assumptions and wondering where our humanity is biasing our perspective.

So so if we assume that we can we can have some sort of communication with an alien civilization, we we sort of move on to the, I suppose, the questions.

Yeah.

You know, human human scientists scientists ask certain questions of nature, and you know, I suppose you've pointed out that those questions are probably very biased Mhmm.

In terms of our environment.

What, I mean, what are the possibilities for the sort of questions that, an alien civilization could ask?

And, you know, would the answers to those questions even be meaningful to us?

Yeah.

Well, one way to start to think about that is to think about You know, what universe are they perceiving?

Right?

We have a certain set of senses about how the universe, it says that our senses that give us a window to the universe, They may have a different set of senses or it could be very similar.

You know, we know for example, that most of the universe is invisible to us, neutrinos and dark matter and dark energy.

None of this is something we can register directly.

We, of course, can build technology, which senses it and translates it into something we can sense scribbles on the computer screen, but we can't immediately understand it.

And I think this definitely shapes the kinds of questions we ask about the universe, you know, what's out there.

And what's interesting to study.

We spend most of our time thinking about the 5% of the universe that we can directly interact with, but also it changes the way we get those answers and the answers that we find intuitive.

You know, think about how we ask and answer questions about quantum mechanics.

We tend to talk about these quantum objects in analogy to things we find intuitive, to things we can sense.

So we talk about the photon and we describe we compare it to waves in the in water.

We compare it to tiny bits of rock, you know, essentially mini particles.

And we know that neither of those are correct.

The photon is neither a particle nor a wave.

And, you know, there's lots of confusing popular science about how it's both and sometimes or whatever.

But the reality is it's neither.

It's something new and weird that can only be partially described by our intuition.

And so in that sense, we're fundamentally limited from deeply understanding what is a photon because we're coming at it from these intuitive concepts that are based on the way we perceive the universe.

And so imagine aliens that are like really microscopic.

So for them, quantum phenomena are not a bizarre recent discovery, but something they find intuitive.

Maybe they can interact with quantum objects without collapsing them.

And so they can like per perceive superposition to them.

The quantum objects are intuitive and so, you know, the kind of questions they would ask could be different, but most importantly the kind of answers they find intuitive and and the answers they accept could be very, very different, because to them these things are intuitive.

In the end, we're always translating our explanations for the universe back into the concepts we find intuitive, which are shaped by our senses, which affect the way that we think.

And so, you know, what is it like to be an alien that can taste electrons and experience photons and and to think about the quantum universe in that way?

It's it's hard for me to even put myself in that in the mind of that kind of creature.

But I think it's important to recognize that they could be inspired to ask different questions about the universe.

Maybe they're not so interested in drilling down and to understand the fundamental nature of the universe.

Maybe they figured out that there is no fundamental nature.

Maybe it's all just layers of emergence.

And the answers that they find acceptable, you know, we struggle with photons, but they might be like, yeah, okay, it's just like that, and move on, you know?

And and do you think, you know, let's say, for example, we were able to communicate with, let's say, this micro microscopic, civilization that exists in a quantum world.

I mean, do you, you know, there's the the the possibility that we could learn a lot from them about quantum mechanics.

And they might be oblivious to a lot of things in the in the classical world.

Mhmm.

I mean, do you do you think that there could be a meaningful exchange of knowledge between two such civilizations, or will they always exist in solitude just because, you know, the the the the meaning of things is so different in each, you know, it's almost like two different universes.

Yeah.

No.

I think there's a lot that we could learn and a lot of information we could exchange.

And I really hope that when the aliens arrive, even if they're super advanced, that we do have some nuggets that we worked out that they find fascinating and useful.

But I think that regardless, we'll learn something.

I mean, imagine aliens arrive, microscopic or not, they might just have a very different set of answers to how the universe works.

You know, we have a theory of the universe, and it's very, very effective.

It's so precise and accurate that it makes people feel like, Wow, this is like the source code of the universe.

It must be true.

But we really have no guarantee that it's true, and specifically in the sense that there could be a second theory.

You know, philosophers of science debate this endlessly, whether there could be multiple independent, conceptually different, but both simultaneously effective theories of the universe.

And when I first read about this, I thought, no, that's impossible.

If you have two theories that are making the same predictions, they must be fundamentally equivalent at some level, and this is sort of an open question in philosophy of science, but it might be that aliens show up and, you know, we have a theory of quantum fields and they have a theory of schwontum fields or something, you know, some categorically different story about what's happening in the universe because in the end our theories of the universe are theories about the invisible.

They are talking about what's going on behind the scenes to explain what we do see.

You know, for example, nobody's ever seen a field.

We only see fields when they affect things we can see.

Like, we talk about electric fields, but really it's an intermediate calculation in our minds to explain what happens to an electron.

Right?

The field is never observed directly.

So is that a real thing, or is that a fiction in our minds?

So when aliens show up, if they have a completely unique description for how the universe works totally different conceptually from ours, we will still learn something.

Even if they don't improve our knowledge, we can look at theirs and compare and say, Oh, this is interesting.

These parts are similar, but this is very different.

So no matter what happens, we'll learn something about how human, how arbitrary our theories are.

And if they show up and they are doing quantum field theory and string theory, that'll also tell us a lot like, wow, maybe this is true.

Maybe this is fundamental.

Maybe this is this is universal beyond just the human scope.

So I think we're guaranteed to learn something either way.

I see.

Well, that's great.

I mean, that I suppose that brings us to the end of the extended Drake equation.

I I wanted to ask you about, your collaborator, Andy Warner, who's who's done some fantastic cartoons that, I think there's there's at least one on every page, isn't there?

Yeah.

At least in the in the PDF version that I have.

And we were chatting before this interview, and you said that Andy doesn't have a physics background.

Is that right?

That's right.

He's an artist, but he also knows a lot about the history of science.

I've, been following his cartoons online for years.

He does fantastic, nonfiction cartoons.

He's written really fun books, you know, like the history of ordinary objects, everyday objects.

And I really enjoyed his style and his humor.

And so one day I just cold emailed him and said, hey, do you wanna collaborate on a book about aliens?

And we started chatting and explained to him the idea.

And then I realized not only could he add a lot of really fantastic visuals because I think it's really helpful to, you know, see what these aliens might look like, but he also knew a lot about the history of science and was into the philosophy.

So, yeah, he doesn't just illustrate the book.

He also took all of my writing and made it under more understandable and added lots of details to it and history.

We had a great time working together on this book.

It was it was a pleasure working with Andy.

Oh, that's great.

And I suppose another another thing I'd I'd like to ask you about I know I know this is a bit of a downer, but, you know, there there is a school of thought that, an alien encounter could be a complete disaster.

You know, it's a sort of colonial, idea.

It's you know, go ask, the indigenous people of The Americas how great it was when the Europeans turned up, that that sort of thing.

Are you, does that worry you?

I mean, I suppose in a sense there's nothing you can do about it.

But, do you see different degrees of encounter?

Mhmm.

Some being very positive and others, well, maybe being a disaster.

I mean, I think there is a a cartoon right at the beginning, isn't there?

Where you address that.

You and Andy address that in the book.

Yeah.

We we have no idea what aliens would do if they show up.

Up.

You know, are they gonna nuke us from space?

Are they gonna enslave us or eat us or drop wisdom bombs on us?

We really have no idea, what they might do.

I'm a big reader of science fiction, and obviously this is all just speculation.

But to me, it seems strange to imagine aliens would come and, like, try to take over the Earth or whatever.

It's not like the Earth has special resources.

You know, you want water?

There's, like, planets filled with water in the outer solar system.

Help yourself.

You know, you want heavy metals?

The asteroid belt is filled with platinum and gold and whatever.

The only thing that's really interesting about the Earth is the life here and the intelligence here.

And so, like, yeah, come talk to us.

It's hard to imagine, but, you know, I just written a whole book about how we shouldn't base our assumptions.

We shouldn't make assumptions about what aliens might do or think or want.

So there obviously is the potential for great danger there.

Civilization is at stake.

But, you know, I am so curious about what aliens might be thinking about the universe and if we could learn from them that personally, I would take the risk.

Like, if there's an alien ship zipping by the solar system, we have the option of whether to let them know we're here.

I'm saying yes.

Let's hit that red button and let's gamble it because we would learn so much about life and the universe and ourselves by talking to alien scientists.

I I wouldn't wanna pass up the opportunity.

And and what about, you know, this idea of trying to communicate, with aliens, you know, in the sense of, sending out messages, you mentioned the sort of Carl Sagan and and is it Frank Drake Frank Drake, messages that were sent out on, is it Pioneer and and Voyager?

Is that, I mean, is that something that we should be doing?

Is it, you know, could it work or is it futile?

The distances are so great.

I think it's worth doing, but obviously I shouldn't speak for humanity and it's a complicated question.

I know the folks at SETI have spent a lot of time thinking carefully about this.

I spoke to Jill Tartar about this and building a consensus on the Earth from all different cultures and backgrounds about whether or not this is the right thing to do is a challenge, and that's the right way to do it.

You know, like one flipping physicist who's curious about the universe should not be determining the fate of the planet.

We should be careful and thoughtful about that.

And I know people send messages into space without necessarily, you know, coming to a consensus.

But personally, I think it's unlikely that we are going to receive a message that we understand.

For that to happen, you know, we have to anticipate the technology they use, the encoding they use, reverse engineer it when we have no idea what the message is supposed to look like?

That's very, very difficult.

Mhmm.

As we were talking about earlier in the podcast, like, even breaking down human languages is challenging and almost impossible, and we weren't able to do it for hieroglyphics without the Rosetta Stone.

And even still, it took twenty years, and there are existing human languages we have not been able to decode.

So the idea that we could get, like, a a snippet of alien language and somehow be able to figure out what it says seems very unlikely to me, which is why in the book, again, I focused on aliens arriving because then we have, like, a physical context from which to build up potentially some kind of communication.

But so personally, I say yes.

Let's broadcast to the universe because I wanna start the first inter stellar science conference.

But I acknowledge there are risks there, and everybody's read the Dark Forest trilogy knows all about them, and my voice definitely shouldn't be the loudest.

But for me, the curiosity about the universe is paramount.

Well, that's great.

That's, that's a good place to leave it, Daniel.

So that's, that's your book, Do Aliens Speak Physics, and, that's cowritten with, Andy Warner.

And I'll put a link, to the book in the notes for this podcast.

Thanks very much for the conversation.

Always wonderful to talk about aliens with interested folks.

Great.

Thanks for coming on the podcast, Daniel.

That was Daniel Whiteson of the University of California, Irvine.

He's cowritten, Do Aliens Speak Physics?

With the California based artist, Andy Warner.

Their book is published by w w Norton and Company, and I'll put a link to it in the podcast notes.

Thanks to Daniel for joining me today and to our producer, Fred Isles.

Thank you for listening to this podcast, which is supported by the APS Global Physics Summit.

To continue advancing physics beyond this podcast, participate in the APS Global Physics Summit on March 2026 in Denver, Colorado and online.

Experience high impact scientific sessions, networking opportunities, workshops, and community building events designed for every career stage.

Learn how you can attend and shape the future of physics at summit.aps.org.