Speaker 1: Welcome to Stuff to Blow Your Mind, production of iHeartRadio.
Speaker 2: Hello, and welcome to Stuff to Blow Your Mind. My
Speaker 2: name is Joe McCormick. Today on the podcast, we're going
Speaker 2: to be featuring an interview in which I talked to
Speaker 2: returning show guest physicist Daniel Whitson about his upcoming book,
Speaker 2: Do Aliens Speak Physics. Daniel shared in advance copy of
Speaker 2: this book with me and I think it's great. It
Speaker 2: is a fascinating book length thought experiment that is full
Speaker 2: of insights about what could be universal and what could
Speaker 2: be unique in surprising ways about human intelligence, science, language, mathematics,
Speaker 2: and culture. A bit of bio about Daniel. Daniel Whitson
Speaker 2: is a particle physicist and physics professor. He's the co
Speaker 2: host of the podcast Daniel and Kelly's Extraordinary Universe and
Speaker 2: co author of We Have No Idea, also co creator
Speaker 2: of the PBS kids show Eleanor Wonders Why. His book,
Speaker 2: Do Aliens Speak Physics? Is co written and illustrated by
Speaker 2: Andy Warner. And now onto my conversation with Daniel. Daniel Whitson,
Speaker 2: Welcome back to the show.
Speaker 3: Thanks so much for having me on. Excited to talk
Speaker 3: to you. Again.
Speaker 2: So the book is do aliens speak physics? And I
Speaker 2: have really really been enjoying this book. I planned to
Speaker 2: finish it with a full read for today, but my
Speaker 2: last night, my toddler was having some sleep disturbances. That
Speaker 2: was an all night thing, so I was rushing to
Speaker 2: get through the last couple chapters. Maybe you can fill
Speaker 2: me in with the greater detail that I missed in
Speaker 2: the skimming of the last two or three.
Speaker 3: Maybe you should have read the book to you toddler
Speaker 3: to help put them to sleep.
Speaker 2: Maybe I think she would really like the illustrations actually,
Speaker 2: but the problem is I had digital version, so that
Speaker 2: would involve showing it to her on a screen, which
Speaker 2: is a whole other thing. You know, that just turns
Speaker 2: into want to see other things on the screen. So
Speaker 2: can't wait for my print copy. That'll be slighting. But
Speaker 2: I guess we should start with the elevator pitch. What
Speaker 2: is the central question you're exploring in this book.
Speaker 3: Yeah, the question the book asks is whether aliens do science,
Speaker 3: and specifically physics, the same way we do. You know,
Speaker 3: when aliens arrive, can they just tell us the secrets
Speaker 3: of the universe? Can they leap us forward a thousand,
Speaker 3: a million, a billion years into the scientific future. Is
Speaker 3: science really just one track that way, one line and
Speaker 3: we could just sort of like skip forward, you know,
Speaker 3: with the benefits of all their time and energy. Or
Speaker 3: is science more complicated? Is it multiple paths? Are there
Speaker 3: multiple solutions? Do aliens even do science? So this book
Speaker 3: is an exploration essentially of like how universal is our
Speaker 3: theory of physics? Is what we're learning something about the
Speaker 3: universe or is it something about the way we think?
Speaker 3: Or both? And can we try to figure that out
Speaker 3: before the aliens arrive.
Speaker 2: One of the metaphors or kind of shorthand that you
Speaker 2: use in the book is the idea of an interplanetary
Speaker 2: physics conference. You're asking the question, if we ever make
Speaker 2: you undeniable contact with an alien species, can we get
Speaker 2: our heads together and communicate meaningfully about the laws of physics?
Speaker 2: And so to illustrate those kinds of meetings. One thing
Speaker 2: I really liked about your book is that each chapter
Speaker 2: comes with what you call a contact hypothetical, where you
Speaker 2: kind of tell a little story. There's some fiction writing
Speaker 2: in this book. It's mostly you know, nonfiction scientific writing
Speaker 2: and philosophical writing. But I like these little fictional scenarios,
Speaker 2: and I think we might want to get into a
Speaker 2: couple of these as we go along. But before we
Speaker 2: do that, to sort of frame how you explore the
Speaker 2: question of do aliens speak physics? And could we communicate
Speaker 2: about physics with them? You extend the classic Drake equation,
Speaker 2: So could you explain that? Maybe first explain what the
Speaker 2: original Drake equation is and how it works, and then
Speaker 2: also explain the way you extend it and the terms
Speaker 2: you added to it to get at this alien physics
Speaker 2: conference question.
Speaker 3: Yes, so the Alien Physics Conference is in there because
Speaker 3: it's a literal fantasy of mine, you know. I mean
Speaker 3: I got into physics to understand the universe and I
Speaker 3: want to figure it out. But sometimes I feel like, gosh,
Speaker 3: progress is frustratingly slow, and you know what if there
Speaker 3: are aliens out there that just have the answers, It's
Speaker 3: so tantalizing and frustrating to think that, like somebody out
Speaker 3: there has figured out what is quantum gravity? How do
Speaker 3: you build wormholes? How did the universe begin? Like somebody
Speaker 3: maybe knows these answers and they could just tell us,
Speaker 3: beam them to us, email us your textbooks, you know, imagine,
Speaker 3: you know, Newton getting to read Einstein's a relativity theory,
Speaker 3: or you know, Aristotle getting to read modern physics, like
Speaker 3: that could be us. Wow, so that's in there because
Speaker 3: that's my literal, like I can taste it, but you know,
Speaker 3: I also wonder if it's really true, and so I
Speaker 3: sort of The book is a meditation on like, all right, Daniel,
Speaker 3: calm down, Maybe those answers aren't actually out there. And
Speaker 3: we wrote those little fictional interludes to try to give
Speaker 3: like more concrete examples rather than just thinking theoretically about
Speaker 3: the nature of physics and the structure of and the
Speaker 3: philosophical underpinnings, like let's walk through what it might be
Speaker 3: like to give people a concrete example. And also we
Speaker 3: didn't want to tackle the whole question at once, like
Speaker 3: it's a lot of pieces, and so we were inspired
Speaker 3: by the way Drake took apart the question of are
Speaker 3: there aliens out there? And why haven't we heard from them?
Speaker 3: He broke that into pieces, and he starts by calculating
Speaker 3: how many stars are in the universe, what fraction of
Speaker 3: those stars might have life, what fraction of stars with
Speaker 3: life develop civilization? How long do those civilizations. Last, it's
Speaker 3: a classic approach in science. You have a problem that's
Speaker 3: too big to solve, so you break it into a
Speaker 3: bunch of pieces, none of which you maybe can solve,
Speaker 3: but some of which you can make a little bit
Speaker 3: of progress on. So you're not completely steymied by your
Speaker 3: inability to make progress in one area because you can
Speaker 3: move in another area. And for example, we now know
Speaker 3: that there are lots and lots of stars in the universe.
Speaker 3: Every galaxy that's out there has like hundreds of billions
Speaker 3: of stars, and there's hundreds of billions of galaxies, so
Speaker 3: the number of stars out there just in the observable
Speaker 3: universe is very, very vast, and shockingly, we've made progress
Speaker 3: on other aspects like how many planets does an average
Speaker 3: star have? And the answer again is surprisingly big. You know,
Speaker 3: there's a lot of uncertainty there and depends on how
Speaker 3: you define earth like planet, but like something like twenty
Speaker 3: five percent of stars out there have rocky planets that
Speaker 3: are you know, earth like according to some definition, So
Speaker 3: we're talking a huge number of earth like planets in
Speaker 3: the universe. But you know, the Drake equation is multiplicative
Speaker 3: the number of aliens that contact us is the number
Speaker 3: of stars times the fraction that have life, times the
Speaker 3: fraction that are technological, et cetera. So if any of
Speaker 3: those numbers are zero, were screwed, and we don't know
Speaker 3: what fraction of those planets have life, and what fraction
Speaker 3: of that life becomes technological, and how long that life lasts.
Speaker 3: So that's the structure of the Drake equation, and we
Speaker 3: thought it was a natural thing to do to extend
Speaker 3: that to answer the question how many alien civilizations are
Speaker 3: there out there that we can talk science with? And
Speaker 3: so to do that we broke it into several questions.
Speaker 3: We said, well, what fraction them do science? You know,
Speaker 3: is that even a thing aside of Earth is science
Speaker 3: like a human endeavor? Maybe everybody else is bored by
Speaker 3: the question, or you know, maybe they're technological but not scientific.
Speaker 3: And then we asked, well, can we communicate with them,
Speaker 3: you know, can we figure out a way to have
Speaker 3: a mental mind meld about these things? Do they ask
Speaker 3: the same kind of questions that we ask? Are are
Speaker 3: we curious about the same things? Do they find and
Speaker 3: accept intuitively the same kind of answers? Would they even
Speaker 3: take the same path as we would So rather than
Speaker 3: tackling this whole big question at once, and the whole
Speaker 3: question and even its parts are essentially unanswerable, but to
Speaker 3: even make some progress, we thought it was useful to
Speaker 3: break it into some pieces.
Speaker 2: So let's look at a few of these pieces one
Speaker 2: by one. One of the earliest questions you look at
Speaker 2: in the book is the question do aliens wonder? Why
Speaker 2: do they even have the motivation to pursue scientific questions.
Speaker 2: It's hard for me to imagine that aliens would ever
Speaker 2: develop the ability to travel or communicate between stars without
Speaker 2: having something like science. Obviously, you can imagine us traveling
Speaker 2: out and going to other star systems and finding bacteria
Speaker 2: and other things that we wouldn't think of as technological
Speaker 2: intelligences but are live on other planets. But assuming that
Speaker 2: they are a to somehow get in contact with us,
Speaker 2: a desire to understand and model the principles of how
Speaker 2: reality works just seems like it would almost be a
Speaker 2: must have. But you came up with a hypothetical contact
Speaker 2: scenario to imagine this. Could you briefly describe kind of
Speaker 2: sketch the contact scenario and then talk about some reasons
Speaker 2: for thinking a species maybe could actually communicate between stars
Speaker 2: or travel between stars without science.
Speaker 3: Yeah, this is really counterintuitive. And when I first started
Speaker 3: digging into this, I also thought like, of course, you know,
Speaker 3: everybody out there is going to be doing science because
Speaker 3: they're gonna be curious about the universe and science is
Speaker 3: the way to figure it out. But the more I
Speaker 3: talk to historians and philosophers, the more I unders you know,
Speaker 3: science has a lot of humanity in it, the structure,
Speaker 3: the institutions, the process, and it's fairly recent. It's something
Speaker 3: we've been doing, you know, in the way we call
Speaker 3: science for only a few centuries, which is a blip
Speaker 3: of time, and so it could be like an intermed
Speaker 3: it stepped towards something greater, a better way to learn
Speaker 3: about the universe. And so, you know, it's not that
Speaker 3: I don't think that aliens are doing science. It's just
Speaker 3: that I wanted to make the strongest argument I could
Speaker 3: that maybe they aren't because you know, deeply, because deep down,
Speaker 3: I feel like we're biased towards thinking aliens are going
Speaker 3: to be like us, the sort of star trek fallacy,
Speaker 3: like they're us with wrinkles on their forehead or with
Speaker 3: pointy ears. Right, But fundamentally they're human, and I think
Speaker 3: that that's narrow minded. So I'm trying to break out
Speaker 3: of it. And you know, the book is an exercise
Speaker 3: essentially convincing myself that aliens might be more alien than
Speaker 3: we imagine. And so your question is, like, is it
Speaker 3: possible to explore the stars, to come visit Earth and
Speaker 3: not be scientific, to be deeply technological? And you only
Speaker 3: have to look back at a history on Earth to
Speaker 3: see that, Like, we have technology, well before we have science.
Speaker 3: You know, people have been like fermenting yeast into bread
Speaker 3: and beer, which is you know, fairly technological without understanding
Speaker 3: anything about what was going on in it. Or people
Speaker 3: have been making swords, you know, which requires if you
Speaker 3: want to understand it, like pretty deep level knowledge of
Speaker 3: like solid state physics and metallurgy. But there were masters
Speaker 3: making incredible devices well before they understood why, and even
Speaker 3: people exploring the earth. Right if you say science began
Speaker 3: a few hundred years ago, well, humanity has been like
Speaker 3: venturing from shore to shore for thousands of years. And
Speaker 3: so I took that as an inspiration and try to
Speaker 3: come up with an example of how aliens might get
Speaker 3: here without being scientific. And I was thinking about a
Speaker 3: planet where you have some critters and they're floating through
Speaker 3: their oceans, and on their planet, the atmosphere is thicker
Speaker 3: than it is on ours, and so the boundary between
Speaker 3: the ocean and the atmosphere is a little fuzzier, and
Speaker 3: so it's not so crazy to imagine that they might
Speaker 3: stumble across some way to not just navigate their oceans,
Speaker 3: but also navigate their atmospheres, you know, just like we did.
Speaker 3: And in this case, these folks are like little bladders
Speaker 3: that can absorb, can emit air into order to go up,
Speaker 3: or accept ballast to go down. They're like little submarines essentially,
Speaker 3: but they learn to navigate their atmosphere, and then it's
Speaker 3: not too big a leap to imagine that maybe they
Speaker 3: also figure out how to coat themselves in something so
Speaker 3: they can navigate above the atmosphere through their solar system.
Speaker 3: And in their solar system, they don't just have a star.
Speaker 3: They have a binary star system, one of which is
Speaker 3: a black hole, and so they spend millions of years
Speaker 3: like whizzing around this black hole, and they develop an
Speaker 3: intuitive understanding of space and curvature, so they don't have
Speaker 3: an Einstein who's given them an equation. They just have
Speaker 3: a feeling for curvature, you know, the way that curvature
Speaker 3: is very counterintuitive to us. It's like, weird to think
Speaker 3: about space being bent between here and there and distances
Speaker 3: are oscillating, and what It's very hard for people to
Speaker 3: really grock general relativity because we grew up in a
Speaker 3: place where we imagine space is always flat. It's always
Speaker 3: our experience. But what if you didn't, and what if
Speaker 3: you spent millions of years whizzing around a black hole
Speaker 3: and really experiencing curvature and somehow intuited your way into
Speaker 3: manipulating spatial curvature and traveling the stars. And so that
Speaker 3: was like hypothetical scenario to try to make a concrete
Speaker 3: to give an example of how aliens could arrive here
Speaker 3: with warped technology effectively and not be able to explain
Speaker 3: it to us because they're like, what do you mean? Like,
Speaker 3: here's how you do it? What do you mean why?
Speaker 3: How Like.
Speaker 2: That kind of thing does seem hard to imagine, But
Speaker 2: I like the way you really like put the work
Speaker 2: in to sketch it out and compare it to I mean,
Speaker 2: as you're saying it seems like it would depend on
Speaker 2: a lot of trial and error, so it might be
Speaker 2: a much slower process than the progress of human science
Speaker 2: human technology. But a sort of branching question off of
Speaker 2: that is, do you think the desire to understand why
Speaker 2: to ask the question why is a core feature of
Speaker 2: intelli or could that be a specific feature of just
Speaker 2: human minds? You know, I was trying to think about this,
Speaker 2: and I had a suspicion that I don't know. I
Speaker 2: suspect that the question why has got to be pretty
Speaker 2: fundamental to intelligence, because we define intelligence largely by the
Speaker 2: ability to solve problems or learn, which is almost always
Speaker 2: going to be accelerated by understanding underlying principles.
Speaker 1: But I don't know.
Speaker 2: I could definitely be missing things there. There are contingencies
Speaker 2: I'm not seeing.
Speaker 3: I think you put your finger on the deepest part
Speaker 3: of this question, and that's really what we're going to
Speaker 3: get an answer to when the aliens come, is how
Speaker 3: much overlap do we have with them? If they do
Speaker 3: wonder why the same way we do, then we're going
Speaker 3: to have a lot in common and we're gonna be
Speaker 3: able to learn a lot from them. But if they don't,
Speaker 3: then it's going to tell us something. It's going to
Speaker 3: tell us that we are unusual in some way. And
Speaker 3: that's really my fantasy. I mean, I got into this thinking, Wow,
Speaker 3: it would be wonderful if aliens show up and they're
Speaker 3: basically just like us, but further ahead, because then we
Speaker 3: can zoom forward in science. But actually, I think that
Speaker 3: might be the most boring outcome. It might be the
Speaker 3: most amazing. We might learn the most, not necessarily about
Speaker 3: quantum field theory, but about the nature of humanity and
Speaker 3: intelligence and the experience of being alive in this universe.
Speaker 3: If they're so fundamentally weird and different that they're like,
Speaker 3: don't that these questions don't make sense to them, or
Speaker 3: they don't even ask these questions, that they have another
Speaker 3: way of having a relationship with the universe. Because I
Speaker 3: agree with you, it feels like it's essential. It's part
Speaker 3: of being intelligent, building a model in your mind and
Speaker 3: probing that model and using it to solve your problem,
Speaker 3: even if that problem is like, hey, how do we
Speaker 3: take down this mammoth for dinner? Or you know, how
Speaker 3: do I solve this social problem with my neighbor? You know,
Speaker 3: which I think humans have been doing for hundreds of
Speaker 3: thousands of years. But it could be not you know,
Speaker 3: it could be that that's as fundamental as like eating
Speaker 3: sweat things for breakfast. You know, the first time I
Speaker 3: went traveling and I was like, hmm, wow, people have
Speaker 3: like weird spicy fish soup for breakfast. I didn't even
Speaker 3: imagine that you could have other kinds of things for breakfast.
Speaker 3: Or the first time I saw like a toilet in
Speaker 3: a country where like you don't just sit, you know,
Speaker 3: I was like, oh, whoa mind blowing. There's so many
Speaker 3: areas where we can't imagine beyond our experience, and I'm
Speaker 3: hopeful when the aliens come that they're going to blow
Speaker 3: our minds with their different way of having a relationship
Speaker 3: with the universe. One of my favorite hypotheticals is maybe
Speaker 3: they used to do science. Maybe science is some sort
Speaker 3: of primitive way of understanding the universe, and what they
Speaker 3: have is like you know, science plus the way we
Speaker 3: think about natural philosophy, Like we look at Aristotle and
Speaker 3: we're like, cool, bro, you made a lot of progress
Speaker 3: just thinking about stuff. Why didn't you think about doing experiments?
Speaker 3: You know, empiricism is obvious, like come on, just go
Speaker 3: outside and try it for ten minutes. Why argue for
Speaker 3: hours and hours and hours. It seems obvious to us.
Speaker 3: And in that way, maybe the Aliens have upgraded their science, like, yeah,
Speaker 3: we used to do it that way, but then we
Speaker 3: came up with this other trick that's so much better.
Speaker 3: I can't believe you guys are still doing experiments or whatever.
Speaker 3: And so it could be that they don't do science
Speaker 3: because they've left it behind for something even more powerful.
Speaker 2: So another one of the questions you look at is
Speaker 2: assuming that aliens do ask the question why they do
Speaker 2: have some kind of scientific understanding, would we be able
Speaker 2: to communicate with them about it? And you asked this
Speaker 2: in a number of different ways. I definitely want to
Speaker 2: get into the question of math in just a second.
Speaker 2: But before we look at math, I want to look
Speaker 2: at difficulties in basic just language communication. And you draw
Speaker 2: the analogy with differentficulties in deciphering lost human languages. Could
Speaker 2: you talk a bit about that and how illuminating that
Speaker 2: those kind of troubles we've faced in the past are.
Speaker 3: Yeah, this is fun because you know, we haven't met aliens.
Speaker 3: If we don't know what Amilien language is like so
Speaker 3: you can speculate endlessly, but I wanted to try to
Speaker 3: dig into something more concrete. And the best example we
Speaker 3: have of intelligent civilizations who are a little alien to
Speaker 3: us are ancient human civilizations. So I thought, let's dig
Speaker 3: into what was it like to try to translate the
Speaker 3: writings of ancient intelligent human civilizations who are not around
Speaker 3: to explain it to us, because I thought that would
Speaker 3: be helpful to teach us, like what's important. How challenging
Speaker 3: is this? When do we succeed? When do we fail?
Speaker 3: And I'm kind of shocked to learn the answer, which
Speaker 3: was that this is a lot harder than I thought.
Speaker 3: I mean, these are humans, right, they have the same
Speaker 3: brain as we do, they live in the same world
Speaker 3: as we do, they have the same senses, that's the
Speaker 3: same environment, and they have lots and they left us
Speaker 3: lots of examples. But in some cases we still have
Speaker 3: not decoded their writing. Like, yes, we decoded ancient Egyptian hieroglyphics,
Speaker 3: there's an important caveat in that story, but we have not,
Speaker 3: for example, decoded Etruscan writing. And the Etruscan's like lived
Speaker 3: just a couple thousand years ago next to the Romans,
Speaker 3: and the Romans talk all about them, and we have
Speaker 3: lots of examples, and yet it still remains, you know, undecipherable.
Speaker 3: It's incredible to me. It tells me that like the
Speaker 3: barrier to accessing another intelligence, even one hosted on the
Speaker 3: same substrate, is very, very challenging. And it hints that
Speaker 3: in order to make these mental connections you need one
Speaker 3: essential thing, which is common context. You need to be
Speaker 3: able to like point at something and say, this is
Speaker 3: an apple, right, let's agree on the word apple, or
Speaker 3: you know, this is one, this is two. And you know,
Speaker 3: I read a really interesting set of articles by the
Speaker 3: folks at SETI, or actually anthropologists analyzing SETI, and you know,
Speaker 3: their conclusion essentially was that it's hopeless if the aliens
Speaker 3: communicate with us, if they send us a message SETI like,
Speaker 3: but they don't show up, so we can't like point
Speaker 3: to things and say, here's an apple, here's a doughnut.
Speaker 3: That it's essentially impossible to decode just written language from
Speaker 3: an alien species because we have no idea what it's
Speaker 3: supposed to look like. How do you know when you've
Speaker 3: decoded it correctly? You have no clues, no handles, and
Speaker 3: the best example of that, I think is Egyptian hieroglyphics.
Speaker 3: You know, there's this famous story the Rosetta Stone. They
Speaker 3: had hieroglyphics, nobody could decode them. Then we found this
Speaker 3: cheat sheet, right, it's got Greek on it, and it's
Speaker 3: got the same stuff in hieroglyphics. Since you're like, oh,
Speaker 3: I know how to translate these words from one to
Speaker 3: the other, I can go from there, do dot dot,
Speaker 3: I've cracked hieroglyphics. But that's not the way it happened.
Speaker 3: The way it happened is they found the Rosetta Stone,
Speaker 3: and it still took them twenty years. Twenty years when
Speaker 3: they had examples of decoded text in both languages. Why
Speaker 3: did it take so long Because they were making a
Speaker 3: fundamentally mistaken assumption about the structure of hieroglyphics. They looked
Speaker 3: at hieroglyphics and they were like, oh, these are pictograms.
Speaker 3: The ones that look like birds are mean birds, someway.
Speaker 3: The ones that looked like water mean water some way,
Speaker 3: but they're not. Egyptian hieroglyphics turn out to be phonetic
Speaker 3: in the same way that our language is, and so
Speaker 3: like a hieroglyphic means a sound, not an idea. They
Speaker 3: only realized this when they were doing a deep comparison
Speaker 3: with the Greek and they found some phrases in Greek
Speaker 3: that translated to sounds, and they noticed that these sounds
Speaker 3: were common across these across the translation. And so it
Speaker 3: was only because not only did they have examples of
Speaker 3: the translated Greek, but they understood how this Greek was spoken,
Speaker 3: that they could crack this code. So the key was
Speaker 3: cultural context, was having something in common to sort of
Speaker 3: nail languages to get other And the same is true
Speaker 3: of like Mayan. Mayan was cracked because there's still people
Speaker 3: speaking a variant of Mayan, and so understanding this like
Speaker 3: cultural expression, the way this is spoken and used, is
Speaker 3: absolutely essential to cracking any sort of alien language. And
Speaker 3: so if we get a message from aliens like that
Speaker 3: would be awesome, but it's hard to know, like even
Speaker 3: as a message and what does it mean, Like the
Speaker 3: wow signal is a great example, like maybe we did
Speaker 3: get a message, we just don't know how to decode it,
Speaker 3: or maybe we're getting messages all the time we don't
Speaker 3: even recognize them, right, And so unless aliens arrive and
Speaker 3: we can sit together and build some sort of cultural
Speaker 3: context to establish that real communication. Mind mild, I think
Speaker 3: it's going to be impossible.
Speaker 2: Yeah, you need the feedback, but I think the hieroglyphics
Speaker 2: is a great example of example to use because it's like,
Speaker 2: what you're doing throughout the book is an example of
Speaker 2: where an assumption that was holding us back is invisible
Speaker 2: to us. And it's not until we realized we had
Speaker 2: the incorrect assumption that we can actually make progress.
Speaker 3: And who knows how many more assumptions there are built
Speaker 3: in that we don't even recognize. It's not like we
Speaker 3: have a list of assumptions we can examine them and say, yeah,
Speaker 3: I'm pretty confident in those. The problem is that we
Speaker 3: don't know where the edge of that box is because
Speaker 3: we don't even know how things might be different. You
Speaker 3: know what kind of breakfasts they eat in Alpha Centauri.
Speaker 2: So I want to go on to the other big
Speaker 2: part of the communication question. Obviously, if we're going to
Speaker 2: be sharing information about physics and the laws that govern
Speaker 2: reality with them, our main language for doing that is math.
Speaker 2: And so you have a question a chapter called does
Speaker 2: one plus one equal to everywhere? This starts with a
Speaker 2: fun contact scenario or contact hypothesis about contact that is
Speaker 2: made with the star that's alive, that's kind of bioplasma,
Speaker 2: but doesn't seem to respond to mathematical or numerical information.
Speaker 2: And so you asked the question, is it plausible that
Speaker 2: there could be an intelligent species that maybe even has
Speaker 2: technology in some way we could think about it, or
Speaker 2: at least has you know, capabilities of contact with another species,
Speaker 2: but it doesn't have a concept of counting and arithmetic,
Speaker 2: the most basic numerical thing that we think there is.
Speaker 2: Could you explore that a bit.
Speaker 3: Yeah, this is where it becomes clear if you're reading
Speaker 3: the book that the book really is about the philosophical question.
Speaker 3: You know, is science human or is it universal? And
Speaker 3: this really comes into focus because this is an ancient
Speaker 3: question of philosophy of math. Right, is math something that
Speaker 3: we've discovered or invented? Is it part of the universe
Speaker 3: or is it a shorthand for the way that we think?
Speaker 3: And it's a surprisingly difficult question. You know, on one hand,
Speaker 3: it seems like the universe is awfully mathematical, and there
Speaker 3: are great moments of discovery in the history of physics
Speaker 3: where math has led us to the answer. And you know,
Speaker 3: one of my favorites is pretty recent. It's the Higgs boson.
Speaker 3: You know, Peter Higgs was looking at the structure of
Speaker 3: quantum field theory and he noticed that these particles were
Speaker 3: very similar, the photon and the W and the z,
Speaker 3: but they were different. One of them had mass and
Speaker 3: one of them had no mass. And why is that?
Speaker 3: And anyway, how do you give masses to all the
Speaker 3: fundamental particles without breaking this other symmetry. And he came
Speaker 3: up with a mechanism, a mathematical mechanism. He said, you
Speaker 3: know what, this whole theory is missing a piece and
Speaker 3: clicks together only if you add this one more element.
Speaker 3: And so this is a purely mathematical observation, saying like,
Speaker 3: there's a mathematical structure here, and it seems like it's
Speaker 3: missing something. Fifty years later, we go out and it's there.
Speaker 3: The Higgs boson is there in the universe. It's real.
Speaker 2: It's kind of spooky.
Speaker 3: It's spooky, right, And there's all these great quotes from physicists,
Speaker 3: you know, like Stephen Weinberg saying that physicists often discover
Speaker 3: that mathematicians have been there before them, you know, and
Speaker 3: it goes back deeper. Like Maxwell Maxwell was the same.
Speaker 3: Maxwell was assembling the equations of electromagnetism them and he
Speaker 3: noticed lots of beautiful symmetry, but he also noticed, Hm,
Speaker 3: hold on a second, this would be more symmetrical if
Speaker 3: we added one piece. But you can't just like add
Speaker 3: something to the laws of physics because it's prettier. And
Speaker 3: yet when he went out there to find if there
Speaker 3: is an element of the universe that corresponds to this
Speaker 3: missing piece, he found, Oh, yes, it is. It just
Speaker 3: had been overlooked. So again the math guided him. And
Speaker 3: to me, that's really powerfully suggestive to say, like, Wow,
Speaker 3: the universe isn't just described by math. It runs on math,
Speaker 3: like it is fundamentally mathematical. And I remember having this
Speaker 3: moment where I personally came to believe that as an
Speaker 3: undergrad learning like quantum mechanics and hearing about like bells
Speaker 3: inequality and all these experiments, and I was like, Wow,
Speaker 3: this is too accurate to be approximate, too accurate to
Speaker 3: just be a description, right, this is the rules, this
Speaker 3: is the source code of the universe. So I used
Speaker 3: to deeply, deeply believe that. But you know, the more
Speaker 3: you dig into the philosophy of math, the more you
Speaker 3: realize this sits on on a bunch of assumptions, assumptions
Speaker 3: which sound plausible, but when you dig into them, like
Speaker 3: do we really have good arguments for them? And as
Speaker 3: you say, some of them relate to like arithmetic. In
Speaker 3: the last couple of hundreds of years, philosophers of math
Speaker 3: have asked questions like, well, what are the basic foundations
Speaker 3: of math? Like what are the starting rules the few
Speaker 3: things you need to assume from which you can build
Speaker 3: everything else? And the goal of that is not just like, hey,
Speaker 3: let's be nerdy and figure out what the rules are,
Speaker 3: but like, let's examine those assumptions and wonder like could
Speaker 3: they have been something else? You know, the way we
Speaker 3: might like see the fundamental equation of the universe and
Speaker 3: ask like, is it this way? Could it have been
Speaker 3: the other way? You learned something by seeing the fundamental
Speaker 3: nature written down, And in the last couple hundred years
Speaker 3: we've learned We've made a lot of progress, Like, wow,
Speaker 3: most of mathematics is based on arithmetic, and arithmetic itself
Speaker 3: is based on a few basic axioms. They're called p
Speaker 3: and O's axioms, and those can be described in terms
Speaker 3: of set theory, like you know this is inside that,
Speaker 3: and a barber who shaves himselves can shave other barbers
Speaker 3: or whatever. But at the core of it, there's a
Speaker 3: question mark, like Godle's theorem tells us that we can't
Speaker 3: describe everything in math using those fundamental axioms. And then
Speaker 3: even if you have a bunch of fundamental axioms, there
Speaker 3: are always going to be things that aren't captured by it.
Speaker 3: You know, there are things in arithmetic that are true
Speaker 3: that cannot be proven with our axioms, which tells you, like,
Speaker 3: maybe we don't really fundamentally understand what's at the core
Speaker 3: of mathematics.
Speaker 2: Is it possible to do physics without numbers? You explore
Speaker 2: at least one scholar who's attempted to, I think, put
Speaker 2: together a version of Newton's laws of motion or gravitation
Speaker 2: without using numbers. You make it sound like it's kind
Speaker 2: of difficult and painful.
Speaker 3: I love this book. It's not easy to read. It's
Speaker 3: like not written for a popular audience. It's written for
Speaker 3: like nerves of philosophy. So I'll be honest, it was
Speaker 3: hard for me to get through it and to really
Speaker 3: digest it. But it's a great book. It's called Science
Speaker 3: Without Numbers. It's by heartree Field, and it's really an
Speaker 3: effort to give an example of like do we need
Speaker 3: mathematics or is it just really useful? And he puts
Speaker 3: together an alternative theory of gravity. You know. He starts
Speaker 3: with Newton's theory, which you can write in terms of
Speaker 3: like a gravitational potential and a gravitational field, which is
Speaker 3: very handy. And newton theory famously has an equation in
Speaker 3: it and you can like calculate things with numbers, and
Speaker 3: it's like, do we need that or is that just
Speaker 3: really helpful? So he put together this theory of gravity
Speaker 3: with no numbers. There is no gravitational field. He says,
Speaker 3: you can't observe that directly anyway. All you see is
Speaker 3: motion of particles. So maybe that's just like an intermediate
Speaker 3: step that's useful to us. And then he's like, maybe
Speaker 3: you don't need numbers at all. Maybe you don't need
Speaker 3: to say the field has a value here, and you
Speaker 3: know this has this the son has a mass of
Speaker 3: this number. Maybe all you need are relationships. You know
Speaker 3: this one has more mass than the other one. This
Speaker 3: is a greater distance than that one. If he structure
Speaker 3: in terms of relationships, he was able to recover the
Speaker 3: not the equations of motion right because it's not like
Speaker 3: he's not dealing with numbers, but a description of the
Speaker 3: behavior gravitationally without using Newton's theory and without using any numbers.
Speaker 3: So in the philosophy of mass, this approach is called nominalism.
Speaker 3: Essentially says that numbers are something we made up, you know, one, two, four,
Speaker 3: They don't exist anywhere in the world. Like where is
Speaker 3: the number four? It's sort of hilarious philosophy question that
Speaker 3: you could just brush off. It's like, well, it sounds
Speaker 3: like you've been smoking too many banana peels. But you know,
Speaker 3: if four exists outside of human knowledge and before us,
Speaker 3: then like where is it? It's sort of a reasonable question, Like,
Speaker 3: you know, if it's part of the universe, it should
Speaker 3: have a location. Everything else that's part of the universe
Speaker 3: has a location. So maybe it's just some thing we
Speaker 3: constructed to help us think about stuff. And so it's
Speaker 3: pretty hard to grow like a theory of physics without math,
Speaker 3: And that's his point. His point is like look, math
Speaker 3: is very useful, but that doesn't mean it's necessary the
Speaker 3: way like, yes, having a car in Los Angeles is
Speaker 3: very useful, but you could walk everywhere it would be
Speaker 3: a huge pain. Right. It's obviously an advantage, but it
Speaker 3: doesn't mean it's fundamental. And that opens up the door
Speaker 3: to like, well, maybe aliens found some other way to think.
Speaker 3: Maybe math reflects the way our minds work instead of
Speaker 3: the way the universe works, and if alien minds work differently,
Speaker 3: they might come up with something else we wouldn't call math.
Speaker 3: Or if aliens evolved in a similar situation where they
Speaker 3: have bodies that are easy to distinguish and so counting
Speaker 3: makes sense, and they have like, you know, interesting economies
Speaker 3: that are similar hours, they might have evolved the similar concepts.
Speaker 3: So it comes down to essentially how much we have
Speaker 3: in common with them evolutionarily and conceptually, whether or not
Speaker 3: we think they might have math, but it's definitely not necessary.
Speaker 3: And even here on Earth. I was surprised when I
Speaker 3: was doing my research to learn that different cultures here
Speaker 3: on Earth have different relationships with counting. You know, you
Speaker 3: might look at a bunch of stuff on a desk
Speaker 3: and I can ask you like, oh, how many things
Speaker 3: are on the desk and you say, oh, there's four things.
Speaker 3: But somebody who's Japanese, for example, they have different categories
Speaker 3: of counting, and they would never group together things that
Speaker 3: are like long and thin with things that are like
Speaker 3: flat and short. So if you're like pencils and CDs
Speaker 3: on a desk, they would say, oh, there's two pencils
Speaker 3: and two CDs. You can't say that's four things because
Speaker 3: they're different categories, right, And that's a hint where you
Speaker 3: can dig in and say, like, well, when do we
Speaker 3: group things together? Like why do I say this four things?
Speaker 3: What is the category of a thing? Like why do
Speaker 3: I say these things are similar enough that I can
Speaker 3: call them a thing? And in the end, that's a
Speaker 3: bit of an arbitrary distinction. Like if you look at
Speaker 3: a bunch of apples on a table, I could say
Speaker 3: there's ten apples, or I could say, well, there's this apple,
Speaker 3: and there's that apple, and there's the other apple, and
Speaker 3: they're all unique apple and so on what basis am
Speaker 3: I saying they're all the same. That's culture, that's I'm
Speaker 3: saying the differences are not important, and that's arbitrary and like,
Speaker 3: I'm probably right there are about ten apples. Like I'm
Speaker 3: not saying that every apple really is fundamentally different. But
Speaker 3: when you discover that the lines you're drawing are arbitrary,
Speaker 3: then that makes you wonder whether other people are drawing
Speaker 3: different arbitrary lines. And again, this isn't like to say
Speaker 3: math is useless or anything. It's just to point out
Speaker 3: that there are cracks here, that there are assumptions we're
Speaker 3: making that are human that might be made differently elsewhere.
Speaker 2: Okay, you ask some other really interesting questions along these
Speaker 2: lines about how our thinking versus alien thinking might influence
Speaker 2: different ways that we could relate to the universe or
Speaker 2: that science could arise. One is you talk about differences
Speaker 2: in perception like native sensory capabilities, and how that could
Speaker 2: probably determine what kinds of questions and answers make sense.
Speaker 2: Maybe we can come back to that, because I want
Speaker 2: to get to your question about your chapter on do
Speaker 2: aliens argue about planets? I found this really interesting because
Speaker 2: I don't think I'd ever considered it this way. But
Speaker 2: you start here with a with a contact hypothetical about
Speaker 2: the inhabitants of a subsurface ocean on Jupiter's moon Europa,
Speaker 2: who see everything in terms of Eddy's kind of swirling
Speaker 2: swarms of matter in motion, and that that's as fundamental
Speaker 2: to their physical view of reality as the idea of
Speaker 2: particles and discrete objects is to us. I thought that
Speaker 2: was really interesting, the idea that we could meet with
Speaker 2: another speci And of course from here you build up
Speaker 2: the idea that we could meet with this other specie.
Speaker 2: We could both have science and both be able and
Speaker 2: willing to communicate with each other, but end up finding
Speaker 2: each other's physical metaphors for describing reality uninteresting and not
Speaker 2: very useful. I don't think I don't think i'd ever
Speaker 2: that had never entered my mind. So could you elaborate?
Speaker 3: Yeah, you know, the goal here is like identify the
Speaker 3: assumptions that underpin our science and wonder if they could
Speaker 3: be different. And one of my goals in writing this
Speaker 3: book was to bring to more popular awareness that there's
Speaker 3: like a raging philosophical debate about some of these things
Speaker 3: that a lot of people aren't even aware of, and
Speaker 3: one of them is this principle of emergence. You know. Essentially,
Speaker 3: it asked the question, why can you make chicken soup?
Speaker 3: Without understanding quantum gravity. Like, we don't understand the fundamental
Speaker 3: nature of the universe for sure, we don't, you know,
Speaker 3: like we've zoomed down to electrons and quarks and whatever.
Speaker 3: We know that's not the final story, and we don't
Speaker 3: know how far below that is the final story. Is
Speaker 3: there even a final story? And yet people have been
Speaker 3: like calculating how to lob cannonballs over castle walls for
Speaker 3: a long time. And people live in the world, and
Speaker 3: you know, we have very fancy technology that describes the
Speaker 3: behavior of transistors and all this sorts of stuff. Why
Speaker 3: is it possible to understand the world world without understanding
Speaker 3: the basic rules of it. There's this sort of magic
Speaker 3: trick that all of our science relies on, and it's
Speaker 3: called emergence, and it says that the universe seems to
Speaker 3: operate at different levels, and you can understand the universe
Speaker 3: at sort of our level without knowing the details of
Speaker 3: what's going on inside. Right. We've been able to do
Speaker 3: biology and chemistry well before we were even doing particle physics. Right,
Speaker 3: So it's not like everybody was waiting, y Daniel, particle
Speaker 3: physicists tell us what is the rules so that we
Speaker 3: can then extrapolate upwards to biology, like you could just
Speaker 3: go ahead and do biology, you can go ahead and
Speaker 3: do chemistry, you can do lots of classical physics. But
Speaker 3: why does that happen? Why is that even possible? You know,
Speaker 3: if I told you I'm going to make up a
Speaker 3: bunch of random, arbitrary rules for the way the universe
Speaker 3: works at its fundamental level, you might think, okay, well,
Speaker 3: what are the consequences then for the macroscopic scale, you know,
Speaker 3: And it turns out it's weird that you don't have
Speaker 3: to know the microscopic to understand the macroscopic. And that's
Speaker 3: the thing that makes me wonder if we don't know
Speaker 3: why that works. And this is a deep question in philosophy,
Speaker 3: why does simplicity emerge from complexity and chaos? Then how
Speaker 3: do we know we're not imposing it on the universe?
Speaker 3: How do we know there's not a cultural bias where
Speaker 3: we're like, well, there's a seeding mass of chaos out
Speaker 3: there in the universe, and we're selecting the things that
Speaker 3: are interesting to us because they're relevant to us and
Speaker 3: they come out of the way we live, and we're
Speaker 3: expressing the universe in terms of those things. And so
Speaker 3: I chose this question of planets because talking to a
Speaker 3: mathematician friend of mine early on in his book, he
Speaker 3: was like, yeah, well, but I mean, aliens are going
Speaker 3: to agree with us, but like there are planets and
Speaker 3: stars and galaxies and we have some scientific cultural touch points.
Speaker 3: And I was like, well, I don't know, maybe what
Speaker 3: if they didn't evolve on a planet so they don't
Speaker 3: see like rocks through space as fundamental. I mean, one
Speaker 3: way to understand this is like, think about how we
Speaker 3: describe the Solar System. Is it to scale? It never is.
Speaker 3: Whenever you see a description of the Solar System, it
Speaker 3: takes the planets and it zooms them way out of proportion.
Speaker 3: Somebody looking at that would be like, whoa dude, you
Speaker 3: kind of biased towards planets here, Like, really, planets are
Speaker 3: irrelevant dust compared to the Sun. So if you're an
Speaker 3: alien species that evolves like in a solar atmosphere, you're
Speaker 3: going to think it's awfully weird that we think about
Speaker 3: solar systems the way that we do, where planets are
Speaker 3: front and center. And as I make the argument in
Speaker 3: the book, we don't even have a good definition of
Speaker 3: what a planet is. I mean, we've been arguing about
Speaker 3: it for decades and the definition we have is pretty absurd.
Speaker 3: And it's the reason, like for all this kerfuffle about Pluto,
Speaker 3: it's because we wanted to protect this category. We wanted
Speaker 3: to have something special that made us feel important. And
Speaker 3: anytime we've done that in the history of science, you know,
Speaker 3: like the Earth, this is the center of the universe,
Speaker 3: the Earth is the center of the Solar System. It's
Speaker 3: always let us down the wrong path. And so it's
Speaker 3: hard to imagine aliens who don't understand planets and don't
Speaker 3: think about the universe in terms of rocks orbiting stars.
Speaker 3: But if they evolve in subsurface oceans, maybe they just
Speaker 3: think about, you know, little chaotic vortices and they build
Speaker 3: up their explanation in the universe from that. So that's
Speaker 3: what this chapter is about. And I had a lot
Speaker 3: of fun talking to philosophers about emergence, and it realized
Speaker 3: that I had a lot of assumptions about the way
Speaker 3: emergence works. Like, for example, I assumed that the universe
Speaker 3: has a fundamental level, that there is some firmament where
Speaker 3: the rules are set and everything emerges from that, and
Speaker 3: maybe we don't know exactly how, and it's complicated the
Speaker 3: way that like hurricanes are complicated, but we think they
Speaker 3: follow rules, but that's not necessarily true. Like what if
Speaker 3: there is no firmament. What if it's just like layers
Speaker 3: of emergence all the way down, or what if you know,
Speaker 3: they don't follow from below, Maybe things don't bubble upwards.
Speaker 3: Maybe every layer has its own set of laws that
Speaker 3: are somehow independent. There's a lot of basic philosophical assumptions
Speaker 3: you make when you take a sort of particle physics
Speaker 3: point of view there.
Speaker 2: That gets into your chapter also about the idea that
Speaker 2: maybe there are no underlying laws of physics, but also
Speaker 2: just at the base level of you know, the objects
Speaker 2: we deal with when we're talking about planets and particles.
Speaker 2: There was a great example in this chapter where you're
Speaker 2: trying to illuminate the different zoom settings. I think a
Speaker 2: lot of people will be familiar with the idea that, yeah,
Speaker 2: chemistry maybe is an approximation and you can get more
Speaker 2: exact if you go down into particle physics, and and
Speaker 2: of course you know hire biology is more of an approximation.
Speaker 2: It's based on emergence. But I think a lot of
Speaker 2: people would have that in their head, but think, well,
Speaker 2: when you get down to you know, particles, that's the
Speaker 2: base level. But I love the example you use in
Speaker 2: the book of the charge of the electron and how actually,
Speaker 2: while we have good approximation for how that works, that
Speaker 2: still relies on zoom settings. Could you explain that example.
Speaker 3: Yeah, I wanted to dig into this because I think
Speaker 3: a lot of people think about it the way you
Speaker 3: just described that. They imagine that eventually you can get
Speaker 3: down to the fundamental truth, right And like number one,
Speaker 3: we don't know if there is and the zoomiest bit
Speaker 3: that we have so far is still kind of a mess.
Speaker 3: Like I make fun of astronomers having a silly definition
Speaker 3: of planet, but like definition of a particle is much
Speaker 3: more of a mess philosophically. You get ten particle theorists
Speaker 3: in a room and you ask them what is a particle?
Speaker 3: You're gonna get ten answers, Like it's crazy. Like this
Speaker 3: concept is historical, it's intuitive for us. It comes out
Speaker 3: of our need to describe the universe in terms of
Speaker 3: like little bits of stuff, and in many ways I
Speaker 3: think it's holding us back. You know, we have a
Speaker 3: glimpse now in quantum field theory that things work differently,
Speaker 3: but we're still sort of like clinging to this idea anyway.
Speaker 3: The current idea of a particle is hard to describe
Speaker 3: because particles are by themselves. Like you think of an
Speaker 3: electron as a tiny dot with a negative charge on it. Cool,
Speaker 3: little ball, Yeah, people think a little ball, right, And
Speaker 3: there it is. There's your intuition, your classical intuition. I
Speaker 3: live in the universe with rocks and little bits of stuff,
Speaker 3: and so everything is made out of little bits of stuff, right.
Speaker 3: It's the way you might laugh at the ancient Greeks,
Speaker 3: and we're still doing it. But you think of the electron,
Speaker 3: even if you like think, well, it's not a ball
Speaker 3: of stuff, it's a point, right, and it's got a
Speaker 3: negative sign on it. And where does that negative sign
Speaker 3: come from? Well, we measure it in experiments, right. We
Speaker 3: know the charge of the electron. We have the famous
Speaker 3: oil drop experiment that told us the mass to charge ratio,
Speaker 3: et cetera. But is that the charge of the electron itself?
Speaker 3: Because the electron, because it has a charge, is always
Speaker 3: interacting with the electromagnetic field. It makes a field and
Speaker 3: as it moves that field ripples, and so the right
Speaker 3: way to describe an electron either is in terms of
Speaker 3: a field around it, or equivalently as a cloud of
Speaker 3: virtual photons. Right, Photons are ripples in the electromagnetic field,
Speaker 3: and so from the particle point of view, you have
Speaker 3: the electron. It's surrounded by this cloud of virtual photons,
Speaker 3: and those virtual photons change the charge that you measure.
Speaker 3: So when you're measuring the charge of the electron, you're
Speaker 3: not measuring the charge of the pure bear electron. You're
Speaker 3: measuring the charge of the electron plus this cloud of photons.
Speaker 3: Because photons can fluctuate into like electrons and positrons, you
Speaker 3: have this cloud of charged particles, and say electrons charge
Speaker 3: polarizes that cloud, and depending on how far into that
Speaker 3: cloud you go, you get a different answer for what
Speaker 3: is the charge that we measure. So really far away
Speaker 3: from the cloud you get the charge that we know
Speaker 3: in loud that Ben Franklin discovered and that we measured
Speaker 3: one hundred years ago. But if you start to probe
Speaker 3: into that cloud, then you're not seeing as much of
Speaker 3: those photons. You're getting through it closer to the bare electron,
Speaker 3: closer to the real truth of the electrons charge, and
Speaker 3: you get a more negative number. And the deeper you
Speaker 3: probe in towards that cloud, the more or you're not
Speaker 3: being affected by those particles, the more negative that number gets.
Speaker 3: And if you extrapolate, what would it be like if
Speaker 3: you went all the way through the clouds, you went
Speaker 3: all the way to the electron. What number would you
Speaker 3: measure for the charge of the electron? The answer is
Speaker 3: negative infinity? Like what? This is another example in physics
Speaker 3: where you get a nonsense answer that tells you that,
Speaker 3: like your theory has been pushed beyond its region of applicability. Right,
Speaker 3: it doesn't make sense. We're not saying the electron really
Speaker 3: does have a negative charge. We're saying the concept of
Speaker 3: the electron on its own with the charge that is
Speaker 3: not an appropriate way to think about what's happening. Really,
Speaker 3: electrons are always tied together with photons. We're making this
Speaker 3: arbitrary dotted line between the electrons and the photons because
Speaker 3: we like to think of it that way, But fundamentally,
Speaker 3: these two are so deeply interwoven that it doesn't make
Speaker 3: sense to imagine the charge of the electron by itself.
Speaker 3: So even this concept of a particle, like the fundamental
Speaker 3: base this of all of our particle physics, and we
Speaker 3: think the universe and even if the electron isn't, we
Speaker 3: think that our particles within it. Right, this basic unit
Speaker 3: of our imagination is something that's not really an appropriate
Speaker 3: description of the universe. And so that to me smells
Speaker 3: of humanity, of cultural choices, of being linked to our intuition,
Speaker 3: the preference, the way that we like to hear the answers,
Speaker 3: and so the language that we express ourselves in. And
Speaker 3: I wonder if aliens argue about particles and argue about planets,
Speaker 3: and it would be amazing. It'd be amazing if they didn't,
Speaker 3: if they came with a completely different way of expressing
Speaker 3: and explaining the universe, that would be mind blowing. That's
Speaker 3: my real fantasy.
Speaker 2: Well, that actually does tie into a later chapter, the
Speaker 2: one where you're talking about alternative alien science. Could there
Speaker 2: be completely different theories of everything, complete theories of physics
Speaker 2: that both correctly predict the behavior of all matter, energy,
Speaker 2: and space time, and yet they're different theories? Is that
Speaker 2: actually possible? Are two different theories that always make the
Speaker 2: exact same predictions actually equivalent?
Speaker 3: Yeah, so this is a great example, like this is
Speaker 3: a question philosophers have been debating for decades and decades
Speaker 3: that's basically unknown in physics. Like I think most physicists
Speaker 3: and most people out there imagine if you find a
Speaker 3: theory that works and is simple and it's basic, like
Speaker 3: say string theory, figures it out and they have one
Speaker 3: equation and it describes everything and it predicts every experiment
Speaker 3: and it all works, then people are like, okay, well
Speaker 3: you're done right, Like that's it. But there's an assumption
Speaker 3: there that there's a unique description, that there's only one description,
Speaker 3: one way to answer this question, And it actually makes
Speaker 3: a lot more sense to imagine that there might be
Speaker 3: multiple descriptions. I mean, like, consider any time you have data,
Speaker 3: you measure something, you have data points, and then you
Speaker 3: try to describe it, describe it by like drawing a
Speaker 3: line through it. Maybe it's a straight line, maybe it's
Speaker 3: a wiggly line. Maybe you have some model you're fitting
Speaker 3: to your data. That model is describing things between your
Speaker 3: data points that you have not observed. And even if
Speaker 3: you take infinite amounts of data, there will always be
Speaker 3: multiple models that fit the data. So it actually kind
Speaker 3: of makes sense to imagine you could have multiple ways
Speaker 3: to describe the same universe, and I think this conflicts
Speaker 3: with your natural intuition. They're like, yeah, but there's a
Speaker 3: true answer. You know, the universe runs some way and
Speaker 3: we just have to figure it out. And maybe we're right,
Speaker 3: or maybe the aliens are right, and maybe our theory
Speaker 3: of quantum fields is wrong and maybe their theory of
Speaker 3: quantum fields is right or whatever. But there is a truth.
Speaker 3: And that's a philosophical assumption saying that there's a single
Speaker 3: objective truth that we could discover and it's unique. How
Speaker 3: do you know you don't know. That's exactly the kind
Speaker 3: of philosophical assumption I want to sort of reveal in
Speaker 3: this book, saying that we don't. I'm not saying that
Speaker 3: there isn't, but I'm saying that we can't be sure.
Speaker 3: And you know, there's lots of arguments in philosophy that
Speaker 3: say that there very well could be, and there's lots
Speaker 3: of great historical examples. You know, the history of our
Speaker 3: physics is the history of overthrowing one way of thinking
Speaker 3: about the universe for another one. You know, when Einstein
Speaker 3: upgraded on understanding of gravity, didn't just give us better
Speaker 3: equations that were more accurate. He completely revised the story
Speaker 3: of what's happening. You know, it's not masses pulling on
Speaker 3: each other. It's space itself is bending and curving, and
Speaker 3: gravity is not even a force. So there is history
Speaker 3: of overthrowing our ideas, which suggests that there are other
Speaker 3: ideas out there which could better or at least equivalently
Speaker 3: describe the universe that we see, that we could conceive
Speaker 3: of right now. If you are a super genius, you
Speaker 3: could sit down and come up with another way to
Speaker 3: describe gravity or quantity, fields or whatever that's equivalent or superior.
Speaker 3: And so it's certainly possible to have multiple theories. And
Speaker 3: so in the in the literature, they argue about this,
Speaker 3: and there's a whole group of people like this is
Speaker 3: Guy Norton who says that any alternative theory is quote,
Speaker 3: merely the same theory dressed in different clothes. Right that
Speaker 3: as you say, look, okay, maybe you have fields and
Speaker 3: we have shmields, but they must be equivalent because if
Speaker 3: they're doing the same thing, right, they're making the same predictions,
Speaker 3: how can they really be different? And you know, we
Speaker 3: don't know the answer to that. Because nobody has an
Speaker 3: alternative like this is theoretical. Philosophers say it should be possible,
Speaker 3: and other philosophers say, like, all right, show us, you
Speaker 3: know what are you talking about? Where is this alternative? Right?
Speaker 3: And we don't have that. So all we can do
Speaker 3: is look at our history, and we have some fascinating
Speaker 3: examples there, like you know, Newtonian mechanics was supplanted by
Speaker 3: the Rongen mechanics and Hamiltonian mechanics, which is a different
Speaker 3: way to think about like how things move. If you
Speaker 3: want to calculate, you know, how does the ball move
Speaker 3: with the parabola, you can use Newtonian mechanics and we
Speaker 3: do that. You know, F equals MA and that works.
Speaker 3: But as soon as it gets complicated, you have your
Speaker 3: ball and a string, and the string is being held
Speaker 3: by a squirrel and the squirrels on a roller coaster,
Speaker 3: it's way too hard to use Newton's laws, like it
Speaker 3: just becomes unsolvable. So these clever guys, Lagrange and Hamilton
Speaker 3: came up with more effective mechanics that rely essentially on
Speaker 3: energy as the fundamental principle, and you can derive Newton's
Speaker 3: laws from them, and Lagrange and mechanics and Hamiltonia mechanics
Speaker 3: are very similar, but they're all so different, and you
Speaker 3: can use both of them to describe these things. And
Speaker 3: for like more than one hundred years, people have been
Speaker 3: arguing about are these two theories just the same dressed
Speaker 3: in different clothes or are they fundamentally different? And last
Speaker 3: ten years or twenty years or so, they've been digging into, like, well,
Speaker 3: what does it mean to be different? You know, this
Speaker 3: is the way philosophy makes progress. They're like, well, what
Speaker 3: is the word? Meaning of the word is mean anyway?
Speaker 3: So it gets pretty nerdy and abstract. But fundamentally, we
Speaker 3: don't know. We don't know if it's possible to have
Speaker 3: multiple theories that describe the universe equivalently and are fundamentally
Speaker 3: categorically different that they tell different conceptual stories, or if
Speaker 3: both being effective means that they fundamentally have to be
Speaker 3: telling the same story. We just don't know, And we
Speaker 3: have examples on the other side, you know, like quantum mechanics.
Speaker 3: We had matrix equations and we had wave equations. You know,
Speaker 3: Schrodinger and Heisenberg and von Neumann showed okay, guys, these
Speaker 3: are actually the same thing. You know, just you have
Speaker 3: different operators and different kinds of math, and they seem
Speaker 3: pretty different, but actually they are the same, which is
Speaker 3: kind of hilarious because Schortinger and Heisenberg famously sort of
Speaker 3: hated each other and really didn't like the other's approached, Like, ough,
Speaker 3: I find it gross, but yeah, exactly. Yeah, there's some
Speaker 3: German dissing in the in the academic literature which is
Speaker 3: pretty fun to read. But they are fundamentally the same.
Speaker 3: So you can show that's not two theories, right, that
Speaker 3: is just one theory expressed in different clothing. So that
Speaker 3: would be fascinating. Right when the aliens show up with
Speaker 3: their theory, it might be very different and we might
Speaker 3: be able to show that it's essentially the same, or
Speaker 3: we might discover, wow, this is a very different story
Speaker 3: about what's happening in the universe. It really is a
Speaker 3: different way to explain things that can't be mapped to ours.
Speaker 3: And what would that mean? You know, what would that
Speaker 3: mean if the universe has multiple correct descriptions, it means
Speaker 3: something about the nature of truth, right, but what is
Speaker 3: really happening? If there is anything that you can say
Speaker 3: is really happening.
Speaker 2: So I think one reason people are tempted to think
Speaker 2: that aliens would have science and it would be similar
Speaker 2: to us, similar to our science, is because when we,
Speaker 2: at least I have this experience, I think a lot
Speaker 2: of people do. When you look back on scientific history,
Speaker 2: you somehow get this feeling that it's kind of faded,
Speaker 2: that it's like on track, maybe because it's not, because
Speaker 2: it feels like different than like artistic you know, creations
Speaker 2: where it's like the scientific discoveries and history are bound
Speaker 2: by nature, and so because they're discovering things about nature,
Speaker 2: just kind of feels inevitable that it would have developed
Speaker 2: in the.
Speaker 3: Way that it did.
Speaker 2: Could you talk about some reasons for thinking that actually
Speaker 2: the history of human science is somewhat contingent, and how
Speaker 2: that could undermine our belief that aliens would develop science
Speaker 2: along the same tracks.
Speaker 3: Yeah, this is really fun. I got to dig into
Speaker 3: a lot of the history here, and I agree with you.
Speaker 3: I used to think of the history of science as inevitable.
Speaker 3: I plead civilization for example, and you know you have
Speaker 3: to develop this, and then gunpowdern and then you can
Speaker 3: build this, and it feels sort of like a natural progression.
Speaker 3: But you know, there's a lot of moments in the
Speaker 3: history of science that were random, that were accidental, where
Speaker 3: we discovered something that we could have discovered much earlier,
Speaker 3: and it could have totally changed the path of our science.
Speaker 3: And this is one of the reasons I wrote the
Speaker 3: book in the structure I did with this Drake equation
Speaker 3: structure because it let me make some assumptions, Like at
Speaker 3: this point in the book, I'm saying, all right, let's
Speaker 3: push aside all of the philosophical questions. Let's assume aliens
Speaker 3: do science, they use math, they ask the same questions,
Speaker 3: they're interested in the same stuff as us. Even then,
Speaker 3: how similar or different might their science be? Or like,
Speaker 3: take aliens out of the equation, imagine running the earth
Speaker 3: a million times, you know, and even start from like
Speaker 3: humans have formed one hundred thousand years ago, When do
Speaker 3: they become technological? How long does that take? What does
Speaker 3: that civilization look like? What science do they develop? Are
Speaker 3: we typically late or early compared to that population? Love
Speaker 3: to know the answer to that question, you know, what
Speaker 3: is the path of science in all of those different earths?
Speaker 3: And so we can't know that, but we do have
Speaker 3: some glimmers, you know. I was able to like dig
Speaker 3: into ancient human civilizations Mayans and Chinese and the Greeks
Speaker 3: before they really talk to each other. It's sort of
Speaker 3: like a little mini experiment to compare proto scientific development
Speaker 3: to see how similar it was. But actually, before we gether,
Speaker 3: you asked about like more recent developments. One of my
Speaker 3: favorites is the discovery of X rays, which was you know,
Speaker 3: essentially just accidental. Guy left a source on top of
Speaker 3: a photographic sheet, came back over the weekend, found this thing,
Speaker 3: He wrote it up, published it the next day, beat
Speaker 3: some English guy by.
Speaker 2: I got his wife to stick her hand in front
Speaker 2: of it.
Speaker 3: Exactly, and you know, made this discovery. And all the
Speaker 3: tools were there, like people have been using uranium for
Speaker 3: a long time, and we had photography for a while,
Speaker 3: so you could have discovered that much much earlier. It
Speaker 3: was really just an accident. And so I like to imagine, well,
Speaker 3: what if we had what if we had made that
Speaker 3: discovery decades or centuries earlier, because that discovery is what
Speaker 3: kicked off like the Curees and their analysis of radiation,
Speaker 3: and then you know Rutherford and his analysis of the
Speaker 3: nucleus and like basically quantum mechanics right, that was the
Speaker 3: moment that kicked off everything that led to quantum mechanics.
Speaker 3: What if that had happened one hundred years earlier. What
Speaker 3: if little Einstein was taught quantum mechanics in the crib,
Speaker 3: then when he was developing his theory of general relativity,
Speaker 3: would he have come up with some quantum version. I mean,
Speaker 3: it's it's just one example, but it shows you how
Speaker 3: randomness affects the development of our science and it could
Speaker 3: have taken us on different paths. And so the fact
Speaker 3: that we're stuck right now unifying quantum mechanics and gravity
Speaker 3: and that even Einstein wasn't able to do it, maybe
Speaker 3: it's because we started too late with quantu caad And
Speaker 3: if quantum mechanics was more intuitive to the smarty pants
Speaker 3: in the last one hundred years, maybe we would have
Speaker 3: made more progress. Or maybe there's some other crazy and
Speaker 3: kind of obvious discovery we haven't made yet and on
Speaker 3: all the other earths they have and so they're like
Speaker 3: way far ahead of us because we just haven't like
Speaker 3: stumbled across XYZ, you know. Or maybe we're very far
Speaker 3: ahead and most earths they're still using stone tools. Who knows,
Speaker 3: but It would certainly affect what it's like to talk
Speaker 3: to aliens. You know, are they on the same single
Speaker 3: path that we are on? Are there multiple paths up
Speaker 3: this sort of mountain to figure out the nature of
Speaker 3: the universe? And where did their path diverge? You know,
Speaker 3: did they start totally differently from us or do they
Speaker 3: just like randomly discover things in a different order. Really
Speaker 3: really fascinating to learn that, and so that's why I
Speaker 3: dug into the sort of ancient history. You know, we're
Speaker 3: the Mayans being mathematical. If the Mayans, for example, had
Speaker 3: not been devastated by the Spanish, what would their mathematics
Speaker 3: and science be like right now? That would be fascinating
Speaker 3: to know. It's such a tragedy. You know, they might
Speaker 3: have a very different way to think about the universe
Speaker 3: and to express it. They certainly were on the road
Speaker 3: to doing that when the Europeans got there. Their predictions
Speaker 3: for like motions of stars and moons were more accurate
Speaker 3: than the European predictions. So you know, we certainly lost
Speaker 3: a whole thread there.
Speaker 2: Okay, if your game for this, here's the part where
Speaker 2: I would like you to speculate. I want you to
Speaker 2: voice your hunches, if you have a guess or a
Speaker 2: suspicion about what is most likely the limiting factor in
Speaker 2: the original Drake equation, like which of those variables you
Speaker 2: know may be multiple, but which of them is most
Speaker 2: likely to be near zero and is the reason we're
Speaker 2: not hearing from anybody? And then secondly, what do you
Speaker 2: think is most likely to be the filter preventing the
Speaker 2: alien physics conference?
Speaker 3: Yeah, my hunch, again not scientifically, is that there's life
Speaker 3: everywhere in the universe, that it's all over. You know
Speaker 3: that maybe the fraction of planets that have life is small,
Speaker 3: but it can't be that small. You know, it doesn't
Speaker 3: seem like we're that special. So I think there's probably
Speaker 3: at least microbial life everywhere. How often do you get
Speaker 3: like complex multicellular life, I don't know. But still my
Speaker 3: hunch is that the denominator is big enough to tolerate
Speaker 3: a small fraction and that the final result is still
Speaker 3: going to be large. So I'm going to imagine that
Speaker 3: the universe is filled with technological aliens, and you know,
Speaker 3: we haven't heard from them because we don't understand their signals,
Speaker 3: or because you know, time and space have prevented them
Speaker 3: from coming here or communicating with us. So I think that,
Speaker 3: you know, we're starting from a good number. I think
Speaker 3: that when they do arrive, that we are going to
Speaker 3: be shocked by how human are so sciences. I mean,
Speaker 3: I think I persuaded myself when I was writing this
Speaker 3: book that there's a lot of assumptions we're making that
Speaker 3: you know, they're not going to have coffee and croissants
Speaker 3: for breakfast. They're going to be so much weirder than
Speaker 3: we imagine, because even on Earth, life is always weirder
Speaker 3: than we imagine, always discovering super weird, gunky stuff, and
Speaker 3: so it's sort of it's really just hubris to imagine
Speaker 3: that our way of thinking and our way of doing
Speaker 3: things is the only way, is the best way to me.
Speaker 3: It's equivalent to like geocentrism, you know, to put ourselves
Speaker 3: at the center of the intellectual universe and say this
Speaker 3: is the only way. And I'm looking forward to that.
Speaker 3: I want my mind blown. I want it to be
Speaker 3: bizarre and difficult. I wanted to take decades to understand
Speaker 3: what they're even talking about and how they think about things,
Speaker 3: because then we're going to learn something about ourselves, not
Speaker 3: just the aliens. We're going to learn about what's unusual
Speaker 3: about us. Where do we stand? Is weird about being human?
Speaker 3: And it's going to help define what it means to
Speaker 3: be human and to be a human scientist. This is
Speaker 3: how we think about things, This is how we ask
Speaker 3: about things. These are kind of answers that we find
Speaker 3: satisfying and that we accept and don't ask more questions about.
Speaker 3: And these are the things that drive us and make
Speaker 3: us curious. You know, so I think, I hope, I
Speaker 3: guess I have a hunch, and I hope that aliens
Speaker 3: do science in a much weirder way than anybody imagines
Speaker 3: that even is imagined in this book, right. I don't
Speaker 3: claim that what we've described in this book spans the
Speaker 3: whole space of ideas. I just want to give people
Speaker 3: a flavor that there are many ideas out there that
Speaker 3: we haven't even imagined because we might not have the
Speaker 3: capacity to think outside of our little box.
Speaker 2: The book is called Do Aliens Speak Physics? Daniel Whitson,
Speaker 2: thank you so much for joining us today.
Speaker 3: Thank you very much, super fun and conversation. Thank you.
Speaker 2: All right, so much appreciation to Daniel Whitson, for joining
Speaker 2: us today. The book Do As Speak Physics is slated
Speaker 2: for release on November fourth, twenty twenty five, but you
Speaker 2: can pre order your copy now. And if you want
Speaker 2: to check out Daniel's podcast, it is called Daniel and
Speaker 2: Kelly's Extraordinary Universe. If you're new to the show, Stuff
Speaker 2: to Blow Your Mind is a science and culture podcast
Speaker 2: with core episodes publishing on Tuesdays and Thursdays of every week.
Speaker 2: Usually I'm joined by my regular co host, Robert Lamb
Speaker 2: for those, and then also on Fridays we do a
Speaker 2: different kind of show called Weird House Cinema, which is
Speaker 2: just about weird movies.
Speaker 3: They can be.
Speaker 2: Old, new, good, bad, well known, or obscure. The only
Speaker 2: real criterion is they've got to be weird, So we
Speaker 2: do that on Fridays. On Wednesdays we usually have a
Speaker 2: short form episode. On Saturdays and Mondays we feature older
Speaker 2: episodes of the shows. You'll get a rerun of a
Speaker 2: core episode from the Vault on Saturdays and a Weird
Speaker 2: House Cinema rewind on Mondays.
Speaker 3: Let's see.
Speaker 2: If you would like to follow us on social media,
Speaker 2: you can find us there. We're on I think most
Speaker 2: of the major places, some we're called something like blow
Speaker 2: the Mind or stuff to Blow your Mind, and I
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Speaker 2: again to Daniel Whitson for joining us. If you would
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