Sean Carroll

And you can work out from the equations and from what you observe how much more matter you needed than antimatter in the early universe. And the answer is about one extra proton per billion protons. So for every 10 to the 9 protons and antiprotons, there was 10 to the 9 plus 1 protons for every 10 to the 9 antiprotons. But that's not equal, right?

And you can work out from the equations and from what you observe how much more matter you needed than antimatter in the early universe. And the answer is about one extra proton per billion protons. So for every 10 to the 9 protons and antiprotons, there was 10 to the 9 plus 1 protons for every 10 to the 9 antiprotons. But that's not equal, right?

So could you explain it just as an initial condition? Sure. I don't think you can explain it just as a fluctuation, because you have to say a fluctuation of what? You would need some theory of the early universe. Sometimes you have a theory of the early universe, like you have theories like inflation, right?

So could you explain it just as an initial condition? Sure. I don't think you can explain it just as a fluctuation, because you have to say a fluctuation of what? You would need some theory of the early universe. Sometimes you have a theory of the early universe, like you have theories like inflation, right?

So in inflation, there is a predictive theory for where the baryons and the antibaryons come from, and you can calculate that. what the fluctuations should be, they're much, much smaller than one part in a billion, okay?

So in inflation, there is a predictive theory for where the baryons and the antibaryons come from, and you can calculate that. what the fluctuations should be, they're much, much smaller than one part in a billion, okay?

One part in a billion is actually a huge difference by the scales that we're talking about here, because there are quantum fluctuations, but every—sorry, there really are not quantum fluctuations. It depends on models of physics that we don't yet have complete handles on, okay? So you could—what you want to do

One part in a billion is actually a huge difference by the scales that we're talking about here, because there are quantum fluctuations, but every—sorry, there really are not quantum fluctuations. It depends on models of physics that we don't yet have complete handles on, okay? So you could—what you want to do

is to create some theory of the initial conditions where there's an imbalance where, sorry, there's not an imbalance in the initial condition, but there's dynamically a preference for, you know, decaying into baryons or antibaryons. And you can invent that. Models of leptogenesis and things like that do that kind of thing.

is to create some theory of the initial conditions where there's an imbalance where, sorry, there's not an imbalance in the initial condition, but there's dynamically a preference for, you know, decaying into baryons or antibaryons. And you can invent that. Models of leptogenesis and things like that do that kind of thing.

It's a little bit tricky because even in the standard model of particle physics, baryon number is not conserved. B minus L, baryon number minus lepton number is conserved. So if that quantity is exactly zero, it stays zero. But you can still create or destroy individual baryons. And in fact, we also think that gravity does not conserve baryon number at all.

It's a little bit tricky because even in the standard model of particle physics, baryon number is not conserved. B minus L, baryon number minus lepton number is conserved. So if that quantity is exactly zero, it stays zero. But you can still create or destroy individual baryons. And in fact, we also think that gravity does not conserve baryon number at all.

And that hurts you for this particular question because if you started with an imbalance, but it's super-duper high energies, there was copious violation of baryon number, then you would tend to equilibrate. You would tend to get rid of the excess number of baryons over anti-baryons. So, you know, we don't know what the final answer is.

And that hurts you for this particular question because if you started with an imbalance, but it's super-duper high energies, there was copious violation of baryon number, then you would tend to equilibrate. You would tend to get rid of the excess number of baryons over anti-baryons. So, you know, we don't know what the final answer is.

We certainly don't know what the initial conditions are, but cosmologists are thinking about all of these things. And, you know, the thing is, it's not just like we don't know why there's more matter than antimatter and this makes us sad, right? That's not the motivation. The motivation is this is a clue that the universe is giving us. There's more matter than antimatter. Okay.

We certainly don't know what the initial conditions are, but cosmologists are thinking about all of these things. And, you know, the thing is, it's not just like we don't know why there's more matter than antimatter and this makes us sad, right? That's not the motivation. The motivation is this is a clue that the universe is giving us. There's more matter than antimatter. Okay.

does that tell us something about the laws of physics that we don't know? So, you know, it's nice to have those little puzzles out there in the universe for us to think about. Helen Edwards says, I love all the interviews you've been doing in some form or another on life, how to think about agency, multiple scales, computation, information, etc.

does that tell us something about the laws of physics that we don't know? So, you know, it's nice to have those little puzzles out there in the universe for us to think about. Helen Edwards says, I love all the interviews you've been doing in some form or another on life, how to think about agency, multiple scales, computation, information, etc.

Where has your intuition got to on whether AI could ever be alive? And how are you conceptualizing information and computation as a common root of synthetic versus organic systems? Well, computation and—sorry, information and computation, absolutely a central part of the commonality between synthetic and organic systems.

Where has your intuition got to on whether AI could ever be alive? And how are you conceptualizing information and computation as a common root of synthetic versus organic systems? Well, computation and—sorry, information and computation, absolutely a central part of the commonality between synthetic and organic systems.