Sean Carroll and Joe Rogan debate humanity’s blind spots in disaster preparedness, like solar flares capable of crippling global power grids, while NASA’s speculative Yellowstone drilling plan highlights the disconnect between long-term risks and funding priorities. Carroll clarifies quantum mechanics—electrons as probability clouds collapsing upon interaction—not consciousness—dismissing pseudoscience like What the Bleep Do We Know! as misguided. They explore black holes’ unproven evaporation, dark matter’s 25% cosmic dominance (despite WIMP failures), and AI’s existential threats, from opaque neural networks to potential transcendence beyond biology. Carroll’s firsthand accounts reveal systemic sexism in physics, where subtle biases push women out, while Rogan probes free speech tensions. The episode underscores how science grapples with unseen forces—cosmic, social, and technological—while public perception often lags behind reality. [Automatically generated summary]
There's all sorts of disasters that could happen to us that we don't really plan for because human lifetime is 100 years, technology is a few hundred years, but maybe there are disasters that happen every 1,000 or 10,000 years.
Right.
And they could be very bad.
I think solar flares are the ones to really worry about, to be honest.
It's not my professional concern, but I was once sitting next to a hotshot lawyer who had just been finished visiting Washington, D.C. to campaign for, we've got to start hardening up the electrical grid because one kind of solar flare that he says happens every thousand years could wipe out electricity in the United States or the world for weeks or months.
Millions of people would die, right?
So a few billion dollars and we can harden it and fix things, but who's going to spend a few billion dollars for something that happens once every thousand years?
So Hawaii's another good place to put telescopes, but that's gotten in trouble with local resistance, and astronomers just not even trying to take that into consideration and therefore getting themselves in trouble.
Canary Islands are okay, but yeah, Chile is one of the best places.
I've been to the Keck Observatory a couple of times.
I've been three times, and every time I go, like, the first time I nailed it, and every time I've been since then, I just haven't gotten, like, one time we went, and I didn't plan for the moon, and I was like, oh, there's too much moon out, and it just wasn't, it was just too bright, the sky was too bright, and then the next time, unfortunately, we got it when it was rainy and kind of cloudy, and we didn't get a good vision, but the first time, First time changed my life.
I mean, I really felt like I was on a spaceship looking through a window.
Yeah, you see like these faint little flickering things.
You don't see like a full, the view of like the Milky Way where you actually look up and you see that white sort of stripe across the sky and you realize, oh my god, that's stars.
Quantum mechanics, I think, that's the subject of the next book that I'm writing, the book I'm working on right now.
So I'm just starting thinking about it.
But it's not just the people on the street.
It's my professional colleagues with PhDs in physics who don't understand quantum mechanics.
And rather than being embarrassed by that, you know, rather than thinking, wow, this is, you know, a terrible thing that we should devote all of our resources to understanding, They flip it.
It's like Aesop's fox and the grapes, you know, the parable where the fox is trying to get the grapes and he realizes he can't reach them.
I've always assumed when I was younger that when you get to the highest levels of science or any sort of intellectual pursuit, that the people that are really involved, there wouldn't be any ego issues.
You know, see?
As an outsider, I was like, well, there's ego in every other part of the world, but those super smart dudes that are figuring everything out, they got all that stuff locked down.
I'll explain quantum mechanics eventually, but you are right.
This ego thing...
The one thing about academia, being a professor, right, whether it's science or anything else, is that you are constantly being evaluated by every other person you meet.
There's a hierarchy.
There's a rank, how good you are at everything, right?
And it's not written down, necessarily.
There's not a rankings that appear in the sports pages, but everyone is judging you all the time.
And, you know, my students and so forth, they say, well, I don't like to ask questions in a seminar because I worry that someone's going to be judging me.
And all I can say is that, yes, they are going to be judging you.
Yeah, and in your field, there is a big issue, I guess, with people disregarding other people's discoveries, or wanting to, rather, like wanting to poo-poo things.
Yeah, you know, I think this is a very complicated issue that I don't really have clear, because certainly scientists can be very, very supportive of each other under the right circumstances, but they're human beings.
There's all sorts of...
Cognitive biases that they have, prejudices, Bayesian priors for what's likely to be true, what's not likely to be true.
And it's not just perfect reasoning, perfect rationality, right?
People come in with their prejudices.
And if you go and tickle their preconceived notions, they'll think you're great.
And if you say something that doesn't quite fit into what they're thinking about, then they'll sort of look somewhere else.
Do you tell them about the potential pitfalls and maybe plant a seed in their head?
Like, hey, you can avoid this.
You can still be competitive, but avoid all these traps that are essentially like these intellectual rabbit holes that can go down that are really not beneficial to anybody.
Yeah, I mean, if I'm formally teaching a class, if I'm standing up there in front of the lecture hall, 98% is teaching the material pretty straightforwardly.
I try to dribble in little words of wisdom here and there, and especially if I think that There is a way that we always teach the subject that is wrong and wrongheaded and we should be doing it right.
I try to highlight the differences.
But if I'm advising students, like my graduate students or my undergraduates, then I, you know, lay on very hard my own perspective on how it is to be a scientist and what is the good way to do it and what's the bad way to do it, what are the pitfalls, and also just, you know, how to not make mistakes and trip up your own career.
There's the thing that makes quantum mechanics, which is our single best theory of the universe in some sense, The thing that makes it difficult to understand is that it's the only theory you've ever invented where there is a difference between what the world is and what we see when we look at the world, right?
In every other theory, if we look closely enough, we would see the world.
As it is.
And quantum mechanics has this fundamental rule that says you can't see the world as it is.
If you have an electron, right, a particle that can be spinning clockwise or counterclockwise, you think that's what can happen because every time you look at it and you say, is it spinning clockwise or spinning counterclockwise, you get one answer or the other.
But the rules of quantum mechanics say when you're not looking at it, it's in a superposition of both.
And you can calculate the probability that you're going to get one answer or the other.
And this drives people crazy because they think that what they see is what is real and therefore they have very, very difficult times figuring out how to make a sensible theory of quantum mechanics that explains what you actually see.
So exactly what you're doing right now, you're saying that there are things that it can be still in motion, this place, that place, and somehow it's in both at once or something like that.
And what quantum mechanics says, it's not in either.
Like, if you ask, where is the position of the electron?
There's no such thing.
As the position of the electron.
If you look at the electron, you will see it in a position, but that is not the fundamental essence of the electron.
There's something called the quantum state or the wave function.
There's a mathematical way that we have of representing the reality of it, but the answers it gives us to questions are just not, here it is, how fast it's moving, etc.
That was when I first started really paying attention to this stuff.
And then I was reading criticisms of what the bleep, and that's when I got an understanding, like, oh, okay, well, this is kind of horseshit, and this lady is kind of a channeler?
But when you look at an atom and realize that most of it is space, like most of the things that we're looking at are mostly space, and that subatomic particles really do kind of blink in and out of existence, and you look at...
All the various quantum weirdness that is real and observable by people like you that actually study this stuff, it looks crazy.
Yeah, in fact, so I hate to be that guy, but both the claim that atoms are mostly space and the claim that particles popping out of existence are both entirely bullshit.
And so if you have an electron in an atom, we have a mathematical way of describing it.
And it's a cloud.
It's not located anywhere.
It's not empty space and here's the electron and most of the rest of it is empty.
It's not like a little miniature version of the solar system, right?
The solar system is mostly empty.
There's empty space in between the planets.
And if you draw a picture of the atom or look at one from your high school science book, an atom looks just like the solar system, right?
A nucleus at the center and these things moving around it.
That's not what it is.
It's a smooth cloud that is everywhere inside the atom.
And that cloud is the answer to the question, were I to look for the electron, where would I most likely see it?
And so the leap that is very, very hard to make is what the electron truly is, is that cloud.
It's not what you see.
You never see the cloud when you look at it.
You see the electron in position.
But what it is, is that cloud.
And people just can't And so that's why they talk about particles popping in and out of existence.
What there is is this wave function, this probability cloud that tells you how likely it is that you'll see a particle.
And if the answer is, well, it's very unlikely, it's 0.001% chance if I look here and look here again and look here again, then when you do see it, you're tempted to say, aha, a particle has popped into existence.
The reality is there was the cloud that was there all along.
It was sitting there.
It was not fluctuating.
It was not changing.
But it's not what you see.
And everyone from Einstein on down has had a real tough time wrapping their heads around that.
So there's this sort of very difficult to describe property to it.
Yeah, that's right.
So are we looking at things sort of in a very material sense, like, you know, this mug is ceramic, this table is wood, and we think about the composition of it.
If we cut into the ceramic, we know what it looks like.
So we're trying to apply those principles to, like, maybe an atom system.
And they just don't apply because it's the other way around.
Like we think that our world that we see every day is sort of basically how things work.
And we're going to sort of translate other extremes of existence into that language, whether it's far away or way back in time or very, very small or whatever.
But there's no reason to think that our everyday life experience has equipped us with the vocabulary to talk about these things in any sensible way.
And in fact, it hasn't.
So we have a very completely viable way of talking about the atom.
We have very, very rigorous mathematical ways of describing what happens.
And then quantum mechanics says what you see when you look at the atom is different.
And we just sit there and insist that what we see is the real way to talk about it, no matter how anti-quantum mechanical that viewpoint really is.
That's got to be incredibly frustrating to you, because I've heard, like, legitimate mainstream scientists on television talking about the atom and describing it in that way.
So I think that people disagree about what the fundamental nature of quantum mechanics is.
And I have no problem with that.
I mean, I have a point of view, and I actually believe in the many worlds interpretation of quantum mechanics, and we can explain that.
And I think it is perfectly sensible and coherent and fits together.
But if you have another point of view on quantum mechanics that is also perfectly sensible and coherent and fits together, that's fine.
We can disagree and we can ask about what experiments to do.
The sad thing is that most physicists, especially ones that go on TV and talk about this stuff, just don't think about it that hard.
And therefore, they're sloppy when they talk about it.
And therefore, people come away going, I don't really get it.
It's very gettable.
It's totally understandable.
Again, we can disagree about what the understanding will ultimately be, but physicists contribute just as much, you know, not on purpose, but they allow, they open up the space for what the bleep do we know people to insert their woo in there because they're not doing a very good job of measuring up to the reality themselves.
So, it seems like it's something that's intensely complex that almost needs to be described with mathematics, which would require you to have a deep understanding of that mathematics to really completely grasp it.
What we need is to have the willingness to let go of our intuition a little bit, to accept the idea that the way the world works at a fundamental level is very different than the typical ideas about space and time and stuff that we are born with.
I have a friend, it was a really sad sort of story.
I have a friend who was really into The Secret.
Mm-hmm.
And, uh...
She was actually a friend of a friend, more than a friend.
And, um, I ran into her at the comedy store, and we were talking, and she was explaining to me how...
She has sort of used the the power of the secret to map out her life And it was all gonna take place right and I didn't see her again for like like a year or so later And then the next time I saw her, she was like, I don't understand.
You know, I really thought this was going to work.
So my last book, The Big Picture, I actually devoted, even though it's mostly about physics and philosophy and cosmology and biology, I devoted a little bit to the fundamental principles of reasoning, and especially Bayesian reasoning.
I don't know if you've ever heard of Bayesian reasoning.
Someone tells you a good idea or you come up with a good idea yourself.
The usual thing that people will do is either say, that sounds right, it's true, or that sounds wrong, it's false.
And what Bayesian reasoning says is, no, to every possibility, you say, okay, maybe it's true, maybe it's false.
I will assign a probability to it being true or false, call that the prior probability, and then I will go collect data.
I will say, well, what would the world be like if this were true?
And then I'll go, look, right?
Does this woman over here like me?
Is she romantically attracted to me?
Well, maybe that would affect what she says if I say hi to her, and therefore I'm going to do the experiment, right?
And this is everything from going through your everyday life to being a professional scientist.
So, look, fine.
Read the secret.
Be told that there is this law of attraction.
If you understand how physics works, you know that it's completely nonsense, but if you were tempted to believe it, Say to yourself, all right, let me test it.
Let me figure out whether it's true or false by saying if it were true, the following things would happen.
If it were false, the following things would happen.
I think that everyone thinks they work that way, but almost no one really does.
And people generally think that the probability something is true is either zero or 100%.
They don't like the idea that something is 70% true, and therefore they can sort of improve that or disprove that or whatever.
It's just hard going through life thinking about probability distributions for every possible version of reality, but that is the best way to do it if you can.
And I'm not, you know, there's some version of the scientific method that says every idea should be treated seriously, and you should sort of write down what the evidence for and against this is.
But come on, I've done that.
I know the universe is expanding.
I'm not going to waste my time.
That's okay.
And that's why we can get through our everyday lives perfectly well without being very good Bayesians at all.
You know, it was, to their credit, it was quite polite and, you know, we know you don't believe this, but let's come on and have a conversation and we'll talk to you.
And we're just about, you know, questioning things and getting at the truth and not accepting dogma.
No, the crucial thing that you notice whenever you talk to the many, many physics and astronomy crackpots out there is that they're never asking questions.
Well, it's super easy to start questioning things, but it's very difficult to get a degree in astrophysics or to get a degree in astronomy or to just really read books about it.
Getting through Lawrence Krauss' last book, man, there's chapters that I had to go, okay, let's go through this one more time.
When he came here, I had to ask him one of the first things we did.
It was probably a mistake because it was so complex.
I tried to get him to explain gauge symmetry to me.
No, yeah, it's super complex, and I guess that makes sense.
It makes sense that it would be.
Now, when someone boils it down to something that's really woo-woo, like, you know, what in the bleep do we know?
Is that very frustrating to you?
I mean, that must make...
You communicating with people that have seen that and have these ideas that are false assumptions based on it, sort of like I said to you that atoms are mostly hollow.
But it's weird that that stuff is all sort of kind of in that...
Sort of genre of people that are trying to improve their life or be spiritual.
They love that Deepak Chopra shit.
I had this conversation with a friend of mine who gave me a Deepak Chopra book, and I started going through it, and I go, you know this guy's crazy, right?
But he's also ignoring the actual scientists that study all this stuff, and he's sort of pitching this thing, what it is like this Deepak Chopra-ism, this sort of spiritual pseudo-quasi-spiritual view of the world that he's pitching to these middle-aged housewives that are looking for some sort of meaning to life, but they don't like going to church.
Yeah, and Daniel Dennett, the philosopher, came up with a great word for it.
He calls them deepities, when you string some words together in a way that sounds extremely profound, but you look closely at it and it doesn't actually mean anything at all.
I guess there's similar issues with the reason why Deep Rock can do that is because most people don't understand what he's talking about.
So if you say a lot of stuff about things that people don't understand.
There's been a bunch of videos that we played on this podcast about fake martial arts practitioners.
There's a whole business in these people that have these fake martial arts techniques, and they use all these huge words.
That are very rare about the central nervous system and about the structure of the body.
And they'll use all this stuff to try to get you to think, like, oh, well, this guy obviously has an enormous vocabulary and a deep understanding of anatomy.
He must, therefore, be this chi master that he's pretending to be.
And it's kind of very similar.
So I kind of recognize that pattern in the woo-woo people.
I'm like, oh, I kind of see what you're doing.
You're throwing a bunch of very complicated words that aren't in most people's vernacular, and you're saying them in a way that makes me feel like you have some sort of a connection to the chi and to the chakras and to the inner whatever that everybody's trying to reach to be happy.
And another problem is just that whenever there is a field, whether it's physics or medicine or whatever, where we know something, but it's hard, complicated, counterintuitive, when we explain it, we translate it, right?
You know, in physics, we have mathematical equations that are quite unambiguous as to what they say, but then we use words.
We say, well, there's a cloud, there's a probability, etc.
And every translation is inaccurate in some sense.
Well, if you're thinking about the electron, what the wave function is, sort of, how we use it is, you ask the question, if I were to look For the location of the electron, there's a machine that tells me the answer.
There's a probability of seeing it here with a certain number, a probability of seeing it there, a probability of seeing it somewhere else.
And so at every point in space, there's a number, the probability you will see the electron there, right?
And so if you visualize all those probabilities all at once, it looks like a cloud that is filling up all of space.
And then the leap is to say there's no such thing as where the electron is.
There's only the cloud.
It's not like the cloud is expressing your ignorance of where the electron really is.
Yeah, it's something like that, exactly, because we're used to stuff, coffee cups, bottles of water, they have locations in space, they have a shape, a size, things like that.
What do you think about the very uber-bizarre theory that the universe is incredibly fractal in the sense that what we're looking at when we're looking at the universe is essentially some sort of subatomic particles for a much larger atom.
And then it goes bigger and bigger and then there's a human out there that's also a part of another galaxy that's also part of another universe.
Let's ask if maybe what we think of as atoms could be alive with little people in substructure that we just don't know about.
Right.
If you're an honest, conscientious scientist, you always say we don't know for sure, right?
But everything that we think we know about quantum mechanics says that things like electrons and quarks are completely featureless.
That if you tried to put little wrinkles and make them different, like the Earth and Venus and Mars are very different from each other.
Every electron is exactly the same as every other electron.
And if you tried to give it any distinguishing features, it would cost an enormous amount of energy, energy that's just not there.
So there's fundamental principles of physics that says that there are no people living on atoms, okay?
And so what we're like with our solar system, even though it kind of vaguely resembles an atom in some sense, we are nothing like real atoms.
We could not be packed together to make a solid object in this bigger world or anything like that.
So our existence is sufficiently different from the subatomic realm that I see no way that we could be the same thing as the subatomic realm to some bigger people.
I do think we could be living in a simulation, as Elon Musk famously suggested.
We could be all living in a computer simulation.
I don't think it's likely, but it's completely plausible given what we know right now.
The real issue is that one day we most likely will have something, as long as technology continues to exponentially advance, we'll one day have something that's indiscernible from the reality.
They'll be able to interface, more than likely, to be able to interface with your senses, with the way the mind perceives reality, and create something that passes that uncanny valley and literally feels like Like real life, like the Matrix or whatever.
I think there are people who make us think more deeply, right?
I remember seeing a panel discussion with Murray Gelman, who was a famous physicist, and Isaac Asimov.
This was like 30 years ago.
Asimov is still alive.
And there was someone else who was on the panel, I forget it was, another physicist.
And the amazing thing was the science fiction author was by far the most conservative thinker up there in terms of what he thought would really be happening a thousand years from now.
Right.
The physicists had these way out ideas and Asimov was like, yeah, I don't think it's going to be all that different.
Right.
And it's just hard to predict the future accurately.
And there's a role served both by trying to be as realistic as possible and careful and Bayesian and saying, what are the probabilities and so forth?
There's another role served by just being the provocative and saying, well, maybe this crazy thing is going to happen.
Maybe we'll cure death in the next hundred years and life will change for everybody dramatically.
Yeah, I think that there's a difference between, you know, what is potentially possible, given arbitrary amounts of time and resources, and what is realistic in the relatively near term.
I'm exaggerating what's going to be possible in the next 50 or 100 years, because they underestimate how little we know about how the brain works, how important it is for the brain to be in our bodies, right?
One of the breakthroughs in artificial intelligence over the last couple of decades was to realize that if you tried to build an artificially intelligent computer, It becomes much more realistic if you give it a body, if you give it a face and it can interact with people.
I mean, we underestimate the extent to which having a body is an important part of how we think and who we are.
And this is just like such baby steps in understanding this stuff that to imagine that in a matter of decades we'll have it all figured out and have downloadable consciousnesses is not realistic to me.
The problems that can be solved by things that we design are just a different set of problems than the thing that evolution naturally made us do, right?
Like, evolution built a very, very general-purpose machine That is inefficient and irrational in all sorts of ways.
Like, anyone's pocket calculator since the 1970s can multiply numbers way better than your brain can, right?
Your brain has enormously more computational capacity than a pocket calculator.
Why can't we multiply numbers?
That ability was not important back when we were evolving these things, right?
So the set of things that it is easy to design is just very, very different than what the brain does.
So who knows?
I don't know exactly what it will look like.
I actually think that the more important thing will be blurring the distinction between human beings and machines, you know, the crossovers.
There's another one of Elon Musk's project.
It's called the neural link.
The idea of, you know, basically a neural lace, something that is just interfacing with your brain very, very, very fast so that you have access to the entire Internet or whatever peripherals you want in real time.
So, like, Wikipedia is part of your memory, essentially.
And that's just who you are and how you walk around.
And you can multiply numbers as fast as you want to.
It's a laptop bag that also is, you have a passport bag and a laptop bag and then a carry-on and then a check and stow, you know, for airplane luggage.
And all of it is Bluetooth and all of it is location coordinated with GPS. So that if somehow or another your bag gets lost, you literally can go on a computer and it'll show you where your bag is.
Another thing I wanted to talk to you about with quantum mechanics that came out of that movie, What the Bleep, that was very confusing to a lot of people, was the whole observer effect.
Now that is something that I've tried to explain to people that the issue is...
Well, please, if you could explain it.
The thing is that people believe that in quantum physics it's been proven that if you look at things, that you looking at things changes those things.
But the way it's been described to me, it's like, no, it's actually because you are measuring those things, and that's what changes it.
Want to describe what you see when you look at an electron.
What you see is different than what it is.
You do change it by looking at it.
And therefore, back in the bad old days, a lot of people wondered whether there was something special about consciousness or human perception or something that was helping us explain the laws of quantum mechanics.
So as you are pointing toward, no.
The answer is no.
There's nothing special about quantum mechanics and consciousness in any way.
A rock could do the same thing, or a video camera, or a speck of dust.
The quantum mechanics rules says that things change when systems interact with each other.
The way that you describe a system is different when it's all by itself than when it interacts in some interesting way with some other system.
And that system can be a person, but it can be anything else also.
So, in that famous experiment that's in that cartoon that gets passed around by people every two or three years, when they're like, wow, the world's made of magic.
And they pass this around.
It's usually a yoga teacher.
That shows that, you know, there's the particles and the waves.
And so what happens when you let an electron go through?
The answer is you get an interference pattern.
It's more like a wave than a particle.
But the real weird thing that they're going to get to eventually is if you let an electron go through two slits but You put little detectors on the slits.
So you say, which slit did the electron go through?
Then it always says it goes through one or the other.
It never goes through both.
And the interference pattern on the other side disappears.
You only see the two lines that you would have seen if they were marble-like.
So the point is, when you're not looking, the electron is acting like a wave.
And when you look at it, the electron acts like a particle.
And this is where you get into my favorite version of quantum mechanics, which is the many worlds interpretation.
The right way to think about the electron was that cloud, that wave going through.
That's the natural thing.
The weird thing is that when you look at the different slits, you only see it go through one or the other and it acts like a particle.
So how do you explain that?
So in other words, our natural intuitive way of thinking about electrons is as particles, little marbles.
And quantum mechanics says, no, no, no, it's naturally a wave.
The weird thing is when it acts like a particle.
And if you're a many-worlds person, the answer you give is the following.
When you look to see, did the electron go through one slit or the other, you, or whatever video camera you had or whatever, becomes entangled with the electron.
And what that means is that the wave function of the whole universe, the wave function of both the electron but also your camera and you and the stars and galaxies and so forth, splits in two.
And there's now one branch of the wave function, which acts like its own separate world, which says the electron went through the left slit, and your camera saw it go through the left slit, and it made a little line on the other side.
And there's another branch, which says the electron went through the right slit, and your camera saw it go through the right slit, and it makes a line on the other side.
And so they're both still there, but the world's split in two, and now you're only in one of them, you don't see the whole world anymore.
Well, I get it now, though, in talking to you, why, you know, you have the Deepak Chopras of the world and why you have, like, the what the bleeps, because it's so intensely confusing.
It's against every little bit of our everyday experience.
It's a set of concepts that we're not equipped with, that we're not born with, that we have to struggle to get into our heads over many, many years, and it shouldn't be surprising.
And I think that it's certainly true that we don't understand quantum mechanics if, by understand, you mean both understand and everyone else agrees that you understand it.
So when it comes to the people that you were talking about, like scientists who sort of dismiss quantum mechanics, what are they dismissing and how are they doing it?
Well, to be very, very clear, they're not dismissing quantum mechanics.
They use quantum mechanics every day.
They love quantum mechanics.
Quantum mechanics is a recipe for For calculating what's going to happen in your experiment that is of unprecedented precision.
It's really the best way we have of knowing what's going to happen in the lab that we've ever invented, and there's no reason to think that it's wrong.
But then when you press them on, okay, what was really happening?
What is the description of reality that corresponds to the calculation you just did?
They get annoyed and frustrated with you rather than give you an answer to the question.
You go to an office or a cafe, and you sit down with one of these yellow legal pads, and you write all that chicken scratch that nobody understands but you guys.
So you say that the world really is some quantum wave function, but you and I observe things like space and tables and stuff like that, right?
So what does that mean?
What does it mean to say that there's a table?
Lurking in the wave function of the universe.
Or there's stars and galaxies.
So that means that there's some way of writing the wave function of the universe that is sort of, here's a table, here's the rest of the universe.
So I might write down on a piece of paper, well, here is a toy model, like a simple representation of the wave function of the universe that includes one piece and another piece, and they're interacting with each other.
How would I know that that was table-like?
Or how would I know...
Tables are not really what we care about, but why is space three-dimensional, right?
This is the kind of question we would worry about.
So what would a wave function look like that represented three-dimensional space?
Is that natural?
Could I poke at it and kind of make a prediction for what the early universe was like on the basis of that?
It is if you believe what we think is already true about general relativity, the curvature of space-time, and quantum mechanics, then Hawking says it follows from those assumptions that black holes are not completely black.
Now, what about the theory, and I've heard this fairly recently, that there is potentially another universe inside of a black hole, that as you go into a black hole, you may in fact be going into another universe That's filled with hundreds of millions of galaxies that have hundreds of millions of black holes in the center and perhaps hundreds of millions of universes inside of them.
So, Carl Sagan was a brilliant guy, but he was not a physicist.
He was a planetary scientist.
He studied life on other planets and things.
So, in his novel, he had this idea.
He wanted his heroine, Ellie, to get across the galaxy very, very quickly, faster than the speed of light.
And so in the first draft, he said she falls into a black hole and then she gets spit out somewhere else in the galaxy.
And he knew that that's not exactly right.
That didn't sound right.
So he called up his friend, Kip Thorne, who's a very famous physicist at Caltech, who, by the way, will be winning the Nobel Prize in a couple months in October.
When you're looking up in the sky and you're seeing something that's a million light years away, when you're looking through a telescope, you're seeing something that might not even be there anymore.
When, like, when you try to make these visual representations of something that is, like, essentially, you're only interpreting, you're getting the gravitational wave, you're getting the information, the data, and then you try to make a visual representation of this thing.
So if you could also, though, see the event happen using visible light or using your regular telescopes, that would give you enormously more information, so that's always a good thing to aim for.
So as they do, like, this array that they're putting together in Chile and all these different new, more advanced super-telescope arrays, they're trying to get more and more actual visual information so that people could see this stuff or something, something bizarre.
I was watching a documentary, and they were talking about hypernovas, and they were talking about the initial discovery of hypernovas, that they detected this gamma radiation, these bursts in the sky, and they originally had one working theory that there was some sort of an alien war going on.
Like, astronomers, bless their hearts, they, you know, are happy to at least contemplate some of the more way-out speculations, like when pulsars, which are just spinning neutron stars, when they were first detected, they were called LGMs for little green men, because they were these very, very regular pulses, and people said, what could it be?
One of those planets that we've observed recently had something that was orbiting it, and they were trying to figure out if it was some enormous space station that was causing this.
Which is basically something that is bigger and colder than you would expect, but maybe if it were some structure surrounding a star, that's what it would look like.
So when they first initially discovered these gamma ray bursts, and they thought there was some sort of an alien war going on in space, I mean, so far, nothing, right?
So far, there's no detectable evidence whatsoever of anything out there other than us.
I think that we're not very realistic about these.
I think that it could happen, but just like with quantum mechanics or artificial intelligence or whatever, we tend to put everything in the frame of what we're immediately used to.
So we can beam out radio signals into space.
We're really good at that, right?
So we tend to think that aliens will either be discovered or actually contact us by beaming radio signals at us.
But that's a horrendously wasteful way to do interstellar communication, right?
For one thing, radio waves move at the speed of light.
So imagine you're a thousand light years away.
You have no idea what's going on on Earth.
But you say, well, there's a promising location for life to arise.
I know what I'll do.
I'll beam a signal at them.
Well, how long are you going to beam it?
Are you going to turn the telescope on for a month?
Then in the whole history of humankind, they better be listening at the exact right month, otherwise they're not going to hear it.
It's actually way more efficient to send a spacecraft.
Even though it's much slower, that's okay.
You have plenty of time.
Send a spacecraft and park it in the system that you want to know about, and then wait for life to arise in that system.
So, honestly, if we're going to detect evidence for aliens, it's much more likely we're going to find a monolith on the moon or something like that than we're going to hear them in our telescopes.
And you want to keep an open mind because if there was a unique event where an alien spacecraft did enter our atmosphere and observe us and then take off, it would be quite fascinating if you could actually get a good read on someone.
Well, we also have this weird way of defining intelligence by the ability to change your atmosphere, your environment, to build things.
Like, that's what we think of as intelligent.
Whereas dolphins are obviously extremely intelligent, but they don't really impact their environment much at all, other than biological life, like eating things and waste and things along those lines.
Like, even here in the solar system, you wouldn't necessarily look to Earth first if you didn't already know.
The moons of Jupiter and Saturn are very plausible places to look for the beginning of life, even though they're outside the Goldilocks zone, because it's just different conditions.
So I think we should be very, very open-minded about...
And part of that is, you know, I think the response to that would be, well, life started in fairly benign conditions and then evolved to survive in these harsher conditions.
But I just think that our ability to understand chemistry and biology is not that good, especially hypothetical speculative chemistry and biology.
We should be very humble about saying how life needs to be on other planets.
Yeah, those are weird things that are somehow or another linked together because they're...
I don't want to be mean in saying this, but they're bullshit.
You know, like, there were psychic powers or aliens, and when you bring up the fact that it's very likely these things are bullshit, people get very upset.
There's a video I saw literally this morning on the web of these people stood outside a little mart on the corner of a street in New York where people were buying Powerball tickets.
Okay.
So the people buy Powerball tickets and it's like 10 bucks and they come out and they were offered, can I buy your Powerball ticket from you for $20 for twice what you paid for it?
And 11 out of the 14 people last said, no, I'm holding on to my ticket, right?
Because they thought that this ticket was the winner.
And they're like, this is $700 million that I'd be giving you for $20, right?
With no rational justification.
But they, you know, it's in some sense innocent.
If you just, okay, you're wishful thinking about your own little ticket, that's fine.
But it leads us to be not completely rational when planning our futures.
But what if you give it to them, you give them the ticket, you get the $20, you go buy some useless tickets, and it turns out the ticket you gave them was $700 million.
You know, calibrate your odds of winning the Powerball or saying, you know, just play the numbers 1, 2, 3, 4, 5, 6. And people will go like, well, that's never going to come up.
Now, have you ever read anything compelling at all that leads you to think that maybe somebody might have observed something that could potentially have been something from another planet or some sort of an...
I mean, I think that astronomers do have a set of things that they don't understand very well.
The most recent example are these things called fast radio bursts, which are a little bit different than the gamma bursts, gamma ray bursts.
But, you know, as always, the more we think about it, the more we say, oh, actually, I can come up with a perfectly plausible explanation for that.
There's nothing to do with aliens.
Going back to this sort of uploading consciousness thing, there's a very real possibility that once civilizations or intelligent species become sufficiently advanced, they upload themselves and they realize there's not really any motivation to go exploring in the universe and maybe die anymore.
Well, if we can create artificial intelligence, too, that's what's very bizarre.
It's like, if we can create artificial intelligence and somehow or another corral it into existing only in this virtual world that we've created, and then inside this virtual world, you're interacting with these artificially intelligent creatures that are disembodied, right?
And then in this world, you would give them some sort of a body, and you would interact with them.
I think that, again, the thing that we underappreciate about that is what is the motivation that these artificially intelligent entities would have?
We human beings, like it or not, we get hungry.
We want to have sex.
We want to have power or whatever.
But if you're just a virtual being in an environment without these energetic constraints or need to eat and sleep and so forth, why do you do anything at all?
I don't know.
I have no idea what the psychology would be like for something like that.
And again, I get in trouble on Twitter for saying that I agree with him.
But because people who are actually doing artificial intelligence have this very real appreciation for how far away we are from something that you would classify as intelligent in any real sense.
And so therefore, from their day-to-day perspective, the worry about super-intelligent AIs taking over the world is laughable.
But my argument, I think Elon's, is that, yeah, but...
What does the percentage chance have to be that this is going to happen before you start worrying about it if the consequence is really the ruination of the world, right?
There are only so many things that we do for which the worst case scenario is quite that bad.
That's what makes it a special circumstance.
And it might be very, very unlikely.
But are you willing to say, like, okay, 1% chance that all human beings get destroyed?
I don't think that's actually the worry, but we should just do our due diligence, right?
We should think about what the possibilities are.
We should plan for them.
Probably no big deal.
When I said this on Twitter, people, knowing that I was a physicist, were like, well, what did you think about people who were worried that the Large Hadron Collider was going to destroy the world?
I said, well, what do you mean?
Physicists did many, many studies checking to see whether or not it would destroy the world.
We don't want to be destroyed any more than anybody else.
And so I think that's a very sensible thing to do for artificial intelligence also.
When you see articles like, did you see the recent article with the Google AI that they had to shut down because they were starting to communicate with each other in some sort of a language they invented?
But to me, that's like a scene in a horror movie, and then you go to blank screen ten years later, and we're all dressed up like Mad Max with fucking bandanas over our face, and we're running from Terminator bots.
Again and again, we're coming to this theme that our imaginations are not quite up to the task, because our imaginations about super-intelligent AI are something like that, something Frankenstein-esque, just in Robots, or something out of Asimov.
But the, I think, much more realistic worry are things like currently existing neural networks and deep learning algorithms.
So basically, there's all sorts of problems like pattern recognition, facial recognition, right?
We are very, very bad at sitting down and writing a program that recognizes faces.
Human beings are not very good at figuring out how to do that.
But we have ways of building programs that can teach themselves to recognize faces and they're amazingly good.
So we have programs like when you go onto Google or your iTunes or whatever and your iPhoto is recognizing your face.
There is some neural net that is doing that, and there is no human being alive that understands what it's doing.
All we know is that it's getting the right answer.
And that kind of logic can go very, very far.
And so I'm not worried about a robot like Ultron taking over.
I'm worried about all of our infrastructure being run by programs that no human being understands.
I've always wondered whether or not what human beings are doing with our insane lust to innovate and to constantly create new and more spectacular things and to always look for the next version of something.
I mean, we're not satisfied with the iPhone 6. We want the iPhone 7. We're not satisfied with that.
Unless you're a classic car advocate or devotee, really what you want is like, oh, this new car stops faster, it handles better, it accelerates quicker.
We always want things to constantly improve.
When you look at human beings, like if you looked at us objectively, that's one of the main things that we do.
We produce better technology, better objects, better engineering.
It's like constantly improving and accelerating.
And then there's this potential artificial intelligence thing.
I've always wondered if that's really what our focus or what our purpose is on this planet, that we're like some sort of an electronic caterpillar.
It's going to become a butterfly.
That we recognize in some sort of a weird way, or nature recognizes, the biological limitations of flesh and tissue, and that it can advance far better with something that we create.
So that we don't even realize what we're doing by making this cocoon.
That we're just building it up, building it up, and we're not even thinking about what we're doing.
And by buying this, and by this materialism that we all have, right?
People have this innate sort of desire for new and shinier objects that that is fueling this innovation and that's pushing along this and that one day we're going to give birth to this new version of life.
We can call it artificial life, but it's not artificial if it's right there.
It's just created by human beings, which obviously are created by this intense and very long evolutionary process.
Yeah, so I would tend to want to remove from that the sort of anthropomorphic or teleological aspects of the language, like that it's a purpose or we're meant to be here.
But I completely agree with the idea that there's a threshold that has been crossed.
Whether you want to say it's the last 500 years or the last 10,000 years, human beings have developed the ability to do something that has never been done before.
And that has this sort of recursive, self-reflective thing that we can build things that can build things, and we can build things that can learn, and we can build things that are like living things.
And we are just at the very, very beginning of exploring the space of what's going to happen because of that.
And the idea that we human beings are going to be around 10,000 years to enjoy the fruits of that...
I have no idea whether that's true or not.
I don't even know if that's bad.
I mean, maybe it'll still be human beings.
Maybe 100 years from now, we'll cure death and aging, and we'll stop having kids, and the people who are alive 100 years from now will live for another million years.
Maybe human beings will just become more and more melded with artificial things, and they'll have artificial bodies and so forth.
Or maybe, you know, another underappreciated thing, I think, is that at the very, very small scale, where we do like nanotechnology and so forth, There is a whole bunch of problems that have already been solved at that scale, namely biology, cells, right?
Like, cells do many, many things really, really well, and they also repair themselves.
They're much less brittle than things that we build using metal, okay?
So synthetic biology, just programming existing biological organisms or designing new ones, but we would still recognize them as biological, But they might be very, very different than anything that naturally appeared through the course of evolution so far.
That could be the thing that takes off, and 100 years from now, that's all the living beings or all the beings with higher intelligence left on Earth.
I mean, I don't know what the actual thing that's going to happen is, but what I know is that the pace of change is just accelerating.
Do you ever sit around and try to extrapolate and try to, like, look at where we are now as opposed to where we were at the turn of the century, you know, 20th century?
And just try to think, like, where is this going?
I mean, it seems like...
Any day now, some new invention could be put forth that changes the way we interface with reality.
If you wanted to make a movie and set it 50 years ago, right?
So in the 1960s.
It wouldn't be that hard to film, you know, outside and in certain areas, certain suburbs.
It kind of looks more or less like it looked in the 1950s.
Whereas it actually would be harder to make something that was in the 1960s look like it did the 1910s, right?
There's sort of more obvious visible change just because cars were different and so forth.
But you don't see the sort of Technological change that might have a far bigger impact in electronics and artificial intelligence and so forth that happened in the last 50 years.
So just because there's no visible sign of the change doesn't mean that the changes cannot be eventually very profound.
It's always amazing, too, when you look back at science fiction movies from the 80s, where they were predicting 2017. They thought we were going to be flying around in space constantly.
We'll just, you know, like I remember what I had for lunch, I'll remember what the population of Malta was in the year 1500. What am I looking at here, Jamie?
But that movie in 1979, their idea of what 21, 22 was going to be like, they had weird lights flashing in the cabin that didn't really seem to make a lot of sense, but they looked electronic.
I don't know how well they work because I've only seen them out in commercials and whatnot, but real-time in-ear translations in French, Spanish, English.
It says, Bluetooth and Wi-Fi, out of the range of Bluetooth and Wi-Fi, translate one-to-one, can still work just as well.
As the first device on the market for language translation using AI that does not rely on connectivity to operate, it offers significant potential for its unique application across airlines, foreign government relations, and even not-for-profits working in remote areas.
Yeah, so essentially it'd be like there's these map applications, like Onyx Maps and stuff like that.
You can download like sort of a Google Earth-type topographical map of areas, and you could look at it.
Say if you're hiking, you could look at these on your phone.
Even if you don't have cell service, you could just pull them up and get a Google image of like, oh, hey, here's the creek that we have to go down to to get water.
In Italy, I mean, it's like you barely need to understand anything other than saying thank you and saying, you know, hello and good evening, things along those lines.
When you travel to a place like France, people have this, French people in particular, there's always this stereotype that you hear that French people think that Americans are rude.
I would try to go way out of my way to make sure that no one thought I was a rude American.
Because there's always this reaction that they have.
The worst case scenario is the American goes over there and is pissed off that they don't speak English and they start...
It's a great privilege, what I do for a living, right?
Like, I can't believe that I get paid to do this.
And it's hard.
I have to tell my incoming graduate students, if you get a PhD in theoretical physics from Caltech, and you probably want to be a physics professor, because that's the only thing you can do with that degree, and your chances are maybe 25% of...
These days, all the money is being made by algorithms that study the stock market and destroy human beings picking stocks, right?
Renaissance technologies and places like that.
I mean, like we were just talking about, but soon the entire stock market will just be dueling algorithms, trying to sell something a microsecond before something else does.
And there's just no question that, you know, I'm in an area of theoretical physics where there's a very tiny fraction of women, an even tinier fraction of African Americans and so forth, but that's kind of...
Less surprising because they just don't come up usually in economic circumstances that put theoretical physics as one of the plausible future research careers.
But, you know, I see an enormous amount of discrimination against women in my field.
And it's there and women leave.
And some of the complaints against it are overblown, but many of them are very, very real.
It's usually you're taken a little bit less seriously if you're a woman.
I mean, there's all sorts of tests that have been done, right?
Like people handed out mathematics papers and then all they did was change the name of the author, James Smith versus Jennifer Smith.
And they were always ranked much worse when it was Jennifer Smith who was the author, even if it's exactly the same paper.
Really?
And, you know, there's a certain style of aggressive, in-your-face egotism that serves you well in academia generally, and in physics in particular, putting yourself forward, asking questions, being loud and noisy.
And women are less good at that for whatever reason.
They're not trained to do that, or it's innate, I have no idea.
But they can sort of get bullied into silence or just say, like, this is not worth it.
And I think that, you know, honestly, if I were giving advice to young women whose primary goal was to become a successful theoretical physicist, you know, if that was your only goal, then don't raise a fuss about sexism or discrimination,
because just like worrying about the interpretation of quantum mechanics, Wow.
And so I think that it's kind of the job of guys to raise a little bit of a fuss about this.
And, you know, I saw it at Caltech where this guy recently got fired.
How many people were willing to make excuses for his really, really, really bad behavior?
Right.
You know, it's unseemly to talk about these things.
We hope it's not true.
Like, this is our friend.
This is someone we worked with.
We don't want to believe this about him.
We want to protect him.
So...
Physics, philosophy, astronomy, all these areas are now having these examples of famous big-name professors that it's finally being revealed for the last 20 years have been regularly harassing graduate students and pushing them out of the field.
And I think maybe finally that's coming to light enough that it hopefully will go away a little bit.
It's a lot of like what we were talking about earlier with the people that don't necessarily understand quantum physics, and so they sort of dismiss what's important about it, or people that, you know, use their—they rely too much on ego, or it's too much of a part of their life.
I mean, the human folly that sort of— It gets involved in everything.
And, you know, I'm not the broader question of identity politics, etc.
I mean, I'm pretty lefty justice warrior about this stuff, to be honest.
I think that the number of women, for example, women are just the most obvious example in my field, who have been pushed out of my field because of bias and discrimination in very, very...
Obviously, you know, verifiable ways is just that's the big embarrassment, you know.
But at the same time, I'm kind of a free speech absolutist.
If some crazy person who has very retrograde views wants to say those retrograde views, then I think that if someone else wants to invite them on campus to do it, I think they should be allowed to say all the craziness that they want.
I don't think that's the right solution to these problems.
Well, that's great, you know, because I know that they have an issue there with Ben Shapiro coming, who's a very reasonable guy and sometimes gets lumped into the alt-right and gets lumped into these.
He's not that at all.
He just happens to be conservative and young and very articulate.
For a while, they were trying to limit his participation there and putting him in the same category that they would put Milo Yiannopoulos or some of these other guys there.
We're very weird with free speech in that we love free speech as long as it's in line with how we think.
I mean, I don't know Ben Shapiro, but Larry Summers is another example.
He gave this famous speech at Harvard.
He was the president of Harvard and a world-famous economist.
And he gave this speech saying, well, maybe the reason why we don't have as many women physicists as male physicists is because of a different distribution of innate abilities.
Now, I think that you could make a very, very good case that his substantive claims were entirely bullshit.
Like he misread data and he was making excuses.
And it's one thing if that's a guy on the street.
It's another thing if it's the president of Harvard.
OK.
Right.
But then after that, like people were saying, well, he shouldn't be invited to give talks about economics at other universities because he said this bad thing.
I think that's ridiculous.
He's a world-class economist.
Like, he was wrong and you should criticize him.
But I want to hear what he has to say about economics.
Isn't there an issue with someone who's a professor who's constantly used to really not being questioned and giving lectures and being able to talk in front of students and you develop sort of a general hubris about your own opinions?
Well, I would hope that, I don't know, in my areas of academia, you can't get through lunchtime without having all of your opinions questioned all the time.
Like, that's just what we do, right?
Like, you never sit around and say something and everyone agrees.
To be very, very fair, there's, like we said before, there's still prejudices about purely physics topics.
Like, you can talk about quantum mechanics or the nature of the dark matter, and discussions get very, very heated and emotional, and people's jobs depend on it and the whole bit.
But the idea that things go unchallenged is not—that just doesn't fly very far in this field, yeah.
I think this is a really, really good question because we might be in flux right now.
For a long time, like basically from the 1980s to today, There was a leading candidate for what the dark matter was, something called the WIMP, the Weakly Interacting Massive Particle.
So if you indulge me for just a second, we have the particles we know and love.
There are four forces that push these particles around.
There's gravity, there's electromagnetism, and then there's the strong and weak nuclear forces, two nuclear forces.
And the nuclear forces are distinguished by being short range, like you don't notice them in your everyday life.
You've got to be down there at the atomic scale.
So, it turns out that if you imagine a new particle that obviously interacts through gravity, because everything interacts through gravity, but doesn't interact through the strong nuclear force, like a proton does, or through electromagnetism that will be charged, but it interacts through the weak nuclear force.
Okay?
So you imagine a particle interacts through the weak nuclear force, relatively heavy, and you calculate how much of those should be left over from the Big Bang.
You get the right amount to be the dark matter.
So this is called the WIMP miracle, the idea that if you just hypothesize out of the blue a new particle that is invisible and stable and interacts through the known force of nature that we call the weak nuclear force, that could easily be the dark matter.
So that seemed so natural and simple, and there were many more complicated theories that predicted that such particles would exist.
I would say that many people 10 years ago or so would have said there's a 90% chance that WIMPs, weakly interacting massive particles, are the dark matter.
Here's the problem.
If the dark matter is WIMPs, we can build detectors and look for them.
And we have done that.
We've built these giant detectors deep underground.
You're shielded from all the cosmic rays that are just noise and contaminating your experiment.
And you wait for a little weakly interacting massive particle to pass through your detector and bump into an atom.
So the first evidence, well, you know, it comes in drips and drabs.
My Caltech predecessor, Fritz Zwicky, a famous astrophysicist, back in the 1930s pointed out that galaxies were orbiting each other too fast.
In what are called clusters of galaxies.
You look out there in the sky, you see like these bunches of galaxies that are orbiting each other.
You calculate how heavy the galaxies should be from what you see.
You can calculate using Newtonian laws of physics how fast they should be orbiting.
They're actually orbiting much faster.
And he said the only way for that to happen is if they're much more massive than you thought, if there's much more mass in there.
There's some missing mass, okay?
But at the time, we didn't know it could just be stars that we didn't see, or gas, or dust, or whatever.
It wasn't really until the 1970s that Vera Rubin, a famous astrophysicist, looked at how individual galaxies are rotating, and she found that it's a similar kind of thing.
The edges of the galaxies are moving way faster than they should be.
Given the amount of matter that is inside, and she concluded that there's a lot of dark matter causing a gravitational pull that we didn't see, but is causing the edges of the galaxies to spin a lot faster than they should be.
So there's certainly this idea that is on the market that because all of our evidence for dark matter is indirect, because it's through its gravitational influence, not by directly touching it or seeing it, Maybe we just don't understand gravity.
Maybe gravity is a little bit different.
Now, I would argue, and I think I'm right, not everyone agrees with me, sadly, but that idea has basically been killed off by our observations of the microwave background radiation.
You know, we are 14 billion years after the Big Bang.
The Big Bang was very, very hot and dense, and it was glowing to beat the band everywhere, but it was also opaque.
The light didn't get very far.
And about 400,000 years after the Big Bang, it cooled down enough it became transparent.
And then these photons of light just stretched, traveled through the universe unimpeded, and we can see that, the leftover radiation.
We can see these faint patterns.
These oscillations in the microwave background, which look exactly like they would look if dark matter were causing them.
And they don't look what they would look like if gravity were modified.
So there's a much longer version of that story, but the basic thing is, if I can just pull authority and say, trust me on this, I was totally on board with the idea that there was something wrong about gravity.
That would be a very cool thing if it were true.
That would be a big mind-bending discovery.
But we've tested that.
And the microwave background, there were predictions.
It would look this way if you modified gravity, that way if there were dark matter.
And the answer is spot on to the dark matter predictions.
Very different from the modified gravity predictions.
You need something that tells you that dark matter is influencing the motion of stuff in this vicinity of space.
So in a galaxy, it's just like the stars at the edges of the galaxy.
And most of the mass in our galaxy is dark matter.
Like, we see these pictures of galaxies that you see that look very beautiful.
The actual size of the galaxy is much bigger than that, but it's all dark matter.
The galaxy you see is a tiny little puddle, you know, one-fifth of the total mass, that sort of settled down to the center of this big, puffy cloud of dark matter.
And when people say, well, there's a galaxy that is only dark matter, what they really mean is it's almost only dark matter.
It's a puffy cloud of dark matter where most of the stars have been pushed out by something, but some of the stars or the gas you can still see orbiting around, and that tells you there's some concentration of dark matter there.
WIMPs were the biggest theory, but there's alternatives.
There's one alternative.
It could be small black holes that were made in the very early universe.
That seems unlikely.
There's another kind of subatomic particle called the axion.
Which is nice because people invented it for totally different reasons and they also worked out that could give you exactly the right abundance to be the dark matter.
And there's dozens of different theories out there for what it could be.
So with this WIMPS detection theory, where they've developed these detectors deep into the ground, that would be able to detect something that's actually prevalent here on Earth?
Now, the Big Bang one is another weird one, because I was watching this thing on television that was proposing alternative theories to the Big Bang, and one of them was that the universe is next to another universe, and that somehow or another it collided with this universe, and that this is probably a process that repeats itself.
Say if something like that comes up, one of your colleagues has this idea, so then you go to the cafe with your legal pad and go, all right, how do we do this?
So here's the thing, and I think this is actually not always communicated very well.
The Big Bang...
The phrase the Big Bang is used in two different senses.
One is what we call the Big Bang model, which is the whole history of the universe for the last 14 billion years from an original hot, dense state, expanding, cooling, galaxies form, here we are.
That's true.
That's settled art.
We know that that's right, okay, the Big Bang model.
But then there's also the Big Bang event, the beginning of that story.
Time equals zero, the initial singularity.
It's a prediction.
Again, if you remember we talked about in black holes, you have general relativity, Einstein's theory of gravity.
It makes predictions.
And one of those predictions is if you trace the universe backward in time, you hit a singularity.
You hit a moment when everything was infinitely dense, infinitely fast expanding, etc., etc.
That's the Big Bang moment, and it is certainly not true.
It's the opposite of true.
You have no right to believe that that actually happened because it's a prediction of general relativity, but general relativity is not right in that regime because you're ignoring quantum mechanics once again.
So if you don't think that you understand the fundamental quantum mechanical rules of the universe, you have no right to say what happened at the Big Bang.
And what physicists should say, if they're being honest, is that could be That there was a first moment in the history of the universe, a first moment of time, a day without a yesterday.
And once we understand quantum mechanics and gravity and how they play well together, that will all be very clear.
Or there could have been something before.
You know, what we call the Big Bang may have been just a phase the universe goes through occasionally.
And this bouncing universe idea that you were talking about with the two different universes hitting each other, that would be an example of a scenario in which the universe actually was eternal, that it lasted forever.
What do you take of the idea that the Big Bang is a process, a continual expansion and contraction process, and that it starts with the Big Bang, the universe expands, and then somehow another pulls back into itself until it becomes this infinitely dense small point again, and then the whole process starts from scratch?
There's this extra dimension and two universes smacking into each other.
They later realized the same people, very well-known, respectable physicists, realized they could just play the game over and over again.
So you could have this smacking together, call that the Big Bang, it expands and cools, but then it re-contracts, and there's another bounce, and this goes on an infinite number of times.
I am personally not that fond of this idea.
Number one, there's no evidence whatsoever or reason to believe that our universe will ever contract.
It's not only expanding, but it's expanding faster and faster.
It's doing the opposite of what you'd expect if it were going to contract.
So I don't think that's very likely.
And number two, the single most...
The impressive empirical fact about the universe is the difference between the past and the future, what we call the arrow of time, right?
You remember the past but not the future.
You make choices now that affect the future but not the past.
So this difference between the past and future is nowhere built into the laws of physics as we know them.
All the laws of physics that we know treat the past and future the same.
The reason why there's a difference is because of the Big Bang.
Because the Big Bang was a very, very special, organized state that the universe could be in.
And ever since then, we have been expanding and cooling and sort of winding down.
And that's the fact you have to explain if you want to explain the origin of the universe, in my view.
And the idea that there's an infinite number of cycles doesn't explain that fact at all.
It's one light year per year is the way to remember it, right?
So if the universe had a beginning, a finite number of years ago, then there's only so far out that light can get between now and then.
That's all there is.
So there are things far away that are so far away we can never possibly see them at this current age of the universe because it would take longer than 14 billion years for light to get from there to here.
If there is a point where the Big Bang begins, right, there is a single origin point, and it explodes outward, and we are seeing it from some position, so we're seeing this explosion 14 billion years ago, does it move in the opposite direction as well?
So the thing is that as far out as you look, even if you look at, you know, with your God's eye view faster than the speed of light, there's still stuff out there.
It's uniformly spread, let's say, okay?
So, but it's closer together.
It's the relative size, the relative distance between galaxies and stars is smaller in the past than it is today.
But the whole size of the universe is still infinity.
And that's still true all the way back 14 billion years right up to the Big Bang.
The universe could have been infinitely big, but the density, the amount of stuff in a cubic centimeter goes to infinity.
Actually, when I was a kid, like, it was 10 years old or so when I first got interested in this stuff.
And so, yeah, when I was 11 or 12, the thing that would stop me from sleeping was I'd be, you know, dreaming about, you know, the Big Bang and the universe.
And I would come to the beginning and I'd go like, but what if the universe had just chosen not to exist?
Yeah.
No sleep for me that night.
I know better now.
I moved on to other more worldly concerns keeping me awake at night.
And that, I mean, causes and effects work themselves out over time.
Right.
So there was a time when there wasn't a Big Bang, and then there was something that caused the Big Bang to occur.
So what I want to suggest is that that's just not the metaphysical framework in which to think about the origin of the universe.
Don't ask what caused it.
Ask what were the laws of physics that can be compatible with both the universe we see today and with the universe having a beginning 14 billion years ago.
We don't know the answer to that, but that's the question we should ask.
Well, it's complex, but more importantly, it's a realm that is just so far outside our experience and our toolkit for dealing with the world that we have no guidance, right?
We're kind of at sea, like, what are the kinds of things we should be asking about?
What are the answers that would satisfy us, right?
If we come up with a picture of the universe, a set of laws of physics and a story for the history of the universe that says, well, the universe started this way and then that happened, etc., and someone says, well, why did it happen that way?
And I would say there is no answer to that question.
This is just what it is.
I might change my mind if you convince me, but there's no right to demand that there is a reason why things are one way rather than another.
The Big Bang could be just one of these moments, one of these things that happens.
One possibility is that there's another universe that is sort of big and quiet and empty, but through a quantum mechanical fluctuation, a little part of the universe could pinch off and become a separate baby universe and then grow by itself, and that could be the origin of our universe.
When you look at the universe, if a universe is finite in size, you know, we were talking about it could be infinitely big, it could be finite in size.
But if it is finite in size...
We think that a finite universe has zero total energy, zero total charge, zero total velocity, etc.
So making a universe costs nothing.
Alan Guth, who's a famous cosmologist at MIT, says the universe is the ultimate free lunch.
Universes are not an expendable resource.
If you can make one universe, you can make an infinite number of universes just as easily.
People have a hard time even thinking of there being more than one universe.
You start thinking about the fact that there's a hundred million galaxies in this, or a hundred million, at least a hundred million solar systems, right?
In this galaxy, this is one of hundreds of billions of galaxies in the known universe, and that there might be more than one universe.
And again, just looking up into the sky, you know, unless the purpose was to make a pretty sky, boy, anything that we're seeing here on Earth could have been done with much less effort than making 100 billion galaxies, right?
There's no evidence in anything that we've learned about science or the universe that gives us a reason to believe that there's a purpose behind it all.
If anything, as time goes on, the entropy of the universe is increasing and the universe is becoming more random and disorderly.
I think that we're, you know, riding a wave of a universe that is growing and expanding and cooling and becoming more and more disorderly, and that's a finite amount of time.
So 14 billion years, from the Big Bang to today, sounds like a lot.
That's 1.4 times 10 to the 10 years.
But the future of the universe is enormously longer than that, according to our best current theories.
It's potentially infinitely long.
Anyway, the last star is not going to burn out until a quadrillion years from now.
We are very close to the beginning of the history of the universe.
But it's not forever.
It doesn't last an infinite amount of time.
So the universe is ephemeral.
We human beings and living creatures are temporary structures within it, and the idea that it's all for some big cosmic purpose seems to hold very little water.
And honestly, this is very, very small amounts of data.
But from what I can tell, when personal tragedies strike, people who are atheistic cosmologists and scientists deal with it way better than people who think that we're embedded in a matrix with a bigger purpose or a spiritual reality.