id
int64 1
935
| text
stringlengths 50
309
| audio
audioduration (s) 2.54
18.7
| source
stringclasses 1
value | text_revised
stringlengths 50
309
|
|---|---|---|---|---|
1
|
If we don't ask how long do they last, but instead ask what's the probability that there have been any civilizations at all, no matter how long they lasted, I'm not asking whether they exist now or not. I'm just asking in general
|
adam
|
If we don't ask how long do they last, but instead ask what's the probability that there have been any civilizations at all, no matter how long they lasted, I'm not asking whether they exist now or not. I'm just asking in general.
|
|
2
|
about probabilities to make a technological civilization anywhere and at any time in the history of the universe.
|
adam
|
about probabilities to make a technological civilization anywhere and at any time in the history of the universe.
|
|
3
|
And that we were able to constrain. And so what we found was basically that there have been 10 billion trillion habitable zone planets in the universe. And what that means is that those are 10 billion trillion experiments that have been run.
|
adam
|
And that we were able to constrain. And so what we found was basically, uh, that there have been 10 billion trillion habitable zone planets in the universe. And what that means is that those are 10 billion trillion experiments that have been run.
|
|
4
|
And the only way that we're the only time that this is, you know, this whole process from,
|
adam
|
And the only way that we're the only time that this is, you know, this whole process from,
|
|
5
|
you know, abiogenesis to a civilization has occurred is if every one of those experiments failed, right? So therefore, you could put a probability, you could, we called it the pessimism line, right?
|
adam
|
you know, abiogenesis to a civilization has occurred is if every one of those experiments failed, right? So therefore, you could put a probability, you could, we called it the pessimism line, right?
|
|
6
|
We don't really know what nature sets for the probability of making intelligent civilizations, right?
|
adam
|
We don't really know what nature sets for the probability of making intelligent civilizations, right?
|
|
7
|
But we could set a limit using this. We could say, look, as if the probability per habitable zone planet is less than 10 to the minus 22, one in 10 billion trillion, then yeah, we're alone.
|
adam
|
But we could set a limit using this. We could say, look, as if the probability per habitable zone planet is less than 10 to the minus 22, one in 10 billion trillion, then yeah, we're alone.
|
|
8
|
If it's anywhere larger than that, then we're not the first. It's happened somewhere else. And to me, that was an annoying, that was mind-blowing. It doesn't tell me there's anybody nearby. The galaxy could be sterile.
|
adam
|
If it's anywhere larger than that, then we're not the first. It's happened somewhere else. And to me, that was an... that was mind-blowing. It doesn't tell me there's anybody nearby. The galaxy could be sterile.
|
|
9
|
It just told me that like, you know, unless nature's really against, has some bias against civilizations, we're not the first time this has happened. This has happened elsewhere over the course of cosmic history.
|
adam
|
It just told me that like, you know, unless nature's really against, has some bias against civilizations, we're not the first time this has happened. This has happened elsewhere over the course of cosmic history.
|
|
10
|
That's the question, right? The amazing thing is that after two and a half millennia of people yelling at each other or setting each other on fire occasionally over the answer, we now actually have the capacity to answer that question.
|
adam
|
That's the question, right? The amazing thing is that after two and a half millennia of, you know, people yelling at each other or setting each other on fire occasionally over the answer, we now actually have the capacity to answer that question.
|
|
11
|
So in the next 10, 20, 30 years, we're going to have data relevant to the answer to that question.
|
adam
|
So in the next 10, 20, 30 years, we're going to have data relevant to the answer to that question.
|
|
12
|
We're going to have hard data finally that will, one way or the other, you know, even if we don't find anything immediately, we will have gone through a number of planets. We'll be able to start putting limits on how common life is.
|
adam
|
We're going to have hard data finally that will, one way or the other, you know, even if we don't find anything immediately, we will have gone through a number of planets. We'll be able to start putting limits on how common life is.
|
|
13
|
The one answer I can tell you, which was an important part of the problem, is how many planets are there, right?
|
adam
|
The one answer I can tell you, uh, which was an important part of the problem, is how many planets are there, right?
|
|
14
|
And just like people have been arguing about the existence of life elsewhere for 2,500 years, people have been arguing about planets for the exact same amount of time, right?
|
adam
|
And just like people have been arguing about the existence of life elsewhere for 2,500 years, people have been arguing about planets for the exact same amount of time, right?
|
|
15
|
You can see Aristotle yelling at Democritus about this. You can see they had very wildly different opinions about how common planets were going to be and how unique Earth was. And that question got answered, right?
|
adam
|
You can see Aristotle yelling at Democritus about this. You know, you can see they had very wildly different opinions about how common planets were going to be and how unique Earth was. And that question got answered, right?
|
|
16
|
Which is pretty remarkable that in a lifetime, you can have a 2,500-year-old question. The answer is they're everywhere.
|
adam
|
Which is pretty remarkable that in a lifetime, you can have a 2,500-year-old question. The answer is they're everywhere.
|
|
17
|
There are planets everywhere. And it was possible that planets were really rare. We didn't really understand how planets formed.
|
adam
|
There are planets everywhere. And it was possible that planets were really rare. We didn't really understand how planets formed.
|
|
18
|
And so if you go back to, say, the turn of the 20th century, there was a theory that said planets formed when two stars passed by each other closely and then material was gravitationally squeezed out.
|
adam
|
And so if you go back to, say, the turn of the 20th century, there was a theory that said planets formed when two stars passed by each other closely and then material was gravitationally squeezed out.
|
|
19
|
In which case, those kinds of collisions are so rare that you would expect one in a trillion stars to have planets. Instead, every star in the night sky has planets.
|
adam
|
In which case, those kinds of collisions are so rare that you would expect one in a trillion stars to have planets. Instead, every star in the night sky has planets.
|
|
20
|
That actually we're able to do now. There is, you can run simulations of the formation of planetary system.
|
adam
|
That actually we're able to do now. There is, you can run simulations of the formation of planetary system.
|
|
21
|
So, if you run the simulation, really where you want to start is a cloud of gas, these giant interstellar clouds of gas that may have a million times the mass of the sun in them.
|
adam
|
So, if you run the simulation, really where you want to start is a cloud of gas, these giant interstellar clouds of gas that may have, you know, a million times the mass of the sun in them.
|
|
22
|
And so, you run a simulation of that. It's turbulent.
|
adam
|
And so, you run a simulation of that. It's turbulent.
|
|
23
|
The gas is roiling and tumbling. And every now and then, you get a place where the gas is dense enough that gravity gets hold of it and it can pull it downward. So, you'll start to form a protostar.
|
adam
|
The gas is roiling and tumbling. And every now and then, you get a place where the uh the gas is dense enough that gravity gets hold of it and it can pull it downward. So, you'll start to form a protostar.
|
|
24
|
And a protostar is basically the young star of, you know, this ball of gas where nuclear reactions are getting started.
|
adam
|
And a protostar is basically the young star, you know, this ball of gas where nuclear reactions are getting started.
|
|
25
|
But it's also a disk. So, you, as material falls inward, because everything's rotating, as it falls inward, it'll spin up and then it'll form a disk. Material will collect in what's called an accretion disk or a protoplanetary disk.
|
adam
|
But it's also a disk. So, as material falls inward, because everything's rotating, as it falls inward, it'll spin up and then it'll form a disk. Material will collect in what's called an accretion disk or a protoplanetary disk.
|
|
26
|
Once you get into the disk itself and you want to do planets,
|
adam
|
Once you get into the disk itself and you want to do planets,
|
|
27
|
things get a little bit more complicated because the physics gets more complicated. Now you got to start worrying about dust because actually dust, which is just dust is the wrong word. It's smoke, really. These are the tiniest bits of solids.
|
adam
|
things get a little bit more complicated because the physics gets more complicated. Now you got to start worrying about dust because actually dust, which is just dust is the wrong word. It's smoke, really. These are the tiniest bits of solids.
|
|
28
|
They will coagulate in the disk to form pebbles, right?
|
adam
|
They will coagulate in the disk to form pebbles, right?
|
|
29
|
And then the pebbles will collide to form rocks. And then the rocks will form boulders, et cetera, et cetera. That process is super complicated.
|
adam
|
And then the pebbles will collide to form rocks. And then the rocks will form boulders, et cetera, et cetera. That process is super complicated.
|
|
30
|
But we've been able to simulate enough of it to begin to get a handle on how planets form, how you accrete enough material to get the first proto-planets or planetary embryos, as we call them.
|
adam
|
But we've been able to simulate enough of it to begin to get a handle on how planets form, how you accrete enough material to get the first proto-planets or planetary embryos, as we call them.
|
|
31
|
And then the next step is those things start slamming into each other to form planetary-sized bodies.
|
adam
|
And then the next step is those things start slamming into each other to form, you know, planetary-sized bodies.
|
|
32
|
And then the planetary bodies slam into each other. Earth, the moon, came about because there was a Mars-sized body that slammed into the Earth and basically blew off all the material that then eventually formed the moon.
|
adam
|
And then the planetary bodies slam into each other. Earth, the moon, came about because there was a Mars-sized body that slammed into the Earth and basically blew off all the material that then eventually formed the moon.
|
|
33
|
Yeah, so the temperature of the material in the disk depends on how far away you are from the star. So it decreases, right?
|
adam
|
Yeah, so the temperature of the material in the disk depends on how far away you are from the star. So it decreases, right?
|
|
34
|
And so there's a really interesting point. So like, you know, close to the star, temperatures are really high.
|
adam
|
And so there's a really interesting point. So like, you know, close to the star, temperatures are really high.
|
|
35
|
And the only thing that can condense, that can kind of freeze out, is going to be stuff like metals. So that's why you find Mercury as this giant ball of iron, basically.
|
adam
|
And the only thing that can condense, that can kind of freeze out, is going to be stuff like metals. So that's why you find Mercury as this giant ball of iron, basically.
|
|
36
|
And now you can start getting things like water to freeze, right? So there's something we call the snow line, which is somewhere in our solar system out around between Mars and Jupiter.
|
adam
|
And now you can start getting things like water to freeze, right? So there's something we call the snow line, which is somewhere in our solar system out around between Mars and Jupiter.
|
|
37
|
And that's the reason why the giant planets in our solar system, Jupiter, Saturn, Uranus, and Neptune, all have huge amounts of ice in them or water and ice.
|
adam
|
And that's the reason why the giant planets in our solar system, Jupiter, Saturn, um, Uranus and Neptune, all have huge amounts of ice in them or water and ice.
|
|
38
|
Actually, Jupiter and Saturn don't have so much, but the moons do. The moons have so much water in them that there's oceans, right?
|
adam
|
Actually, Jupiter and Saturn don't have so much, but the moons do. The moons have so much water in them that there's oceans, right?
|
|
39
|
We've got a number of those moons have got more water on them than there's water on Earth.
|
adam
|
We've got a number of those moons have got more water on them than there's water on Earth.
|
|
40
|
So, you know, one part is like trying to just figure out how to, how planets form themselves and doing the simulations, like that, that cascade from dust grains up to planetary embryos.
|
adam
|
So, you know, one part is like trying to just figure out how to, how planets form themselves and doing the simulations, like that, that cascade from uh dust grains up to planetary embryos.
|
|
41
|
Once you get up to a planet-sized body, then you know, you kind of have to switch over to almost like a different kind of simulation.
|
adam
|
Once you get up to a planet-sized body, then you know, you kind of have to switch over to almost like a different kind of simulation.
|
|
42
|
There, often what you're doing is you're doing, you know, sort of you're assuming the planet is this sort of spherical ball, and then you're doing what, you know, like a 1D, a radial calculation.
|
adam
|
There, often what you're doing is you're doing, you know, sort of you're assuming the planet is this sort of spherical ball, and then you're doing what, you know, like a 1D, a radial calculation.
|
|
43
|
And you're just asking, like, all right, how is this thing going to,
|
adam
|
And you're just asking, like, all right, how is this thing going to,
|
|
44
|
And then you get, you know, a silicate kind of a rocky mantle and then a crust. All of those details, those are kind of beyond being able to do full 3D simulations from ab initio from scratch. We're not there yet.
|
adam
|
And then you get, you know, a silicate kind of a rocky mantle and then a crust. All of those details, those are kind of beyond being able to do full 3D simulations from ab initio from scratch. We're not there yet.
|
|
45
|
Atmosphere, do you think? Hugely important. So I'm part of a collaboration at the University of Rochester where we're using the giant laser. It's literally, this is called the Laboratory for Laser Energetics.
|
adam
|
Atmosphere, do you think? Hugely important. So I'm part of a collaboration at the University of Rochester where we're using the giant laser. It's literally, this is called the Laboratory for Laser Energetics.
|
|
46
|
We got a huge grant from the NSF to use that laser to like slam tiny pieces of silica to understand what the conditions are like at, you know, the center of the Earth, or even more importantly, the center of super-Earths.
|
adam
|
We got a huge grant from the NSF to use that laser to like slam tiny pieces of silica to understand what the conditions are like at, you know, the center of the Earth, or even more importantly, the center of super-Earths.
|
|
47
|
Like the most common, this is what's wild. The most common kind of planet in the universe we don't have in our solar system, which is amazing, right? So we've been able to study enough or observe enough planets now to get a census.
|
adam
|
Like the most common, this is what's wild. The most common kind of planet in the universe we don't have in our solar system, which is amazing, right? So the uh we've been able to study enough or observe enough planets now to get a census.
|
|
48
|
You know, we pretty, you know, we kind of have an idea of what, who's average, who's weird.
|
adam
|
You know, we pretty, you know, we kind of have an idea of what, who's average, who's weird.
|
|
49
|
And our solar system is weird because the average planet has a mass between somewhere between a few times the mass of the Earth to maybe, you know, 10 times the mass of the Earth.
|
adam
|
And our solar system is weird because the average planet has a mass between somewhere between a few times the mass of the Earth to maybe, you know, 10 times the mass of the Earth.
|
|
50
|
And that's exactly where there are no planets in our solar system. So the smaller ones of those we call super Earths. The larger ones we call sub-Neptunes.
|
adam
|
And that's exactly where there are no planets in our solar system. So, um, the smaller ones of those we call super Earths. The larger ones we call sub-Neptunes.
|
|
51
|
And they're anybody's guess. Like, we don't really know what happens to material when you're squeezed to those pressures, which is like millions, tens of millions of times the pressure on the surface of the earth.
|
adam
|
And they're anybody's guess. Like, we don't really know what happens to material when you're squeezed to those pressures, which is like millions, tens of millions of times the pressure on the surface of the earth.
|
|
52
|
So, those details really will matter of what's going on in there because that will determine whether or not you have, say, for example, plate tectonics.
|
adam
|
So, those details really will matter of what's going on in there because that will determine whether or not you have, say, for example, plate tectonics.
|
|
53
|
We think plate tectonics may have been really important for life on Earth, for the evolution of complex life on Earth.
|
adam
|
We think plate tectonics may have been really important for life on Earth, for the evolution of complex life on Earth.
|
|
54
|
So, it turns out, and this is sort of the next generation where we're going with the understanding the evolution of planets and life.
|
adam
|
So, it turns out, and this is sort of the next generation where we're going with the understanding the evolution of planets and life.
|
|
55
|
It turns out that you actually have to think hard about the planetary context for life.
|
adam
|
It turns out that you actually have to think hard about the planetary context for life.
|
|
56
|
you know, and then some interesting chemistry happens in the warm pond. You actually have to think about the planet as a whole and what it's gone through in order to really understand whether a planet is a good place for life or not.
|
adam
|
you know, and then some interesting, you know, chemistry happens in the warm pond. You actually have to think about the planet as a whole and what it's gone through in order to really understand whether a planet is a good place for life or not.
|
|
57
|
There's a bunch of different things. One is that, you know, the Earth went through a couple of phases of being a snowball planet. Like we, you know, we went into a period of glaciation where pretty much the entire planet was under ice.
|
adam
|
There's a bunch of different things. One is that, you know, the Earth went through a couple of phases of being a snowball planet. Like we, you know, we went into a period of glaciation where pretty much the entire planet was under ice.
|
|
58
|
The oceans were frozen. You know, early on in Earth's history, there was no, there was barely any land. We were actually a water world, you know, with just a couple of Australia-sized cratons, they called them, proto-continents.
|
adam
|
The oceans were frozen. You know, early on in Earth's history, there was no, there was barely any land. We were actually a water world, you know, with just a couple of Australia-sized cratons, they called them, proto-continents.
|
|
59
|
So those, we went through these snowball earth phases. And if it wasn't for the fact that we had kind of an active plate tectonics, which had a lot of volcanism on it, we could have been locked in that forever.
|
adam
|
So those, uh, we went through these snowball Earth phases. And if it wasn't for the fact that we had kind of an active plate tectonics, which had a lot of volcanism on it, um, we could have been locked in that forever.
|
|
60
|
Like once you get into a snowball state, a planet can be trapped there forever, which is, you know, maybe you already had life form, but then because it's so cold, you may never get anything more than just microbes, right?
|
adam
|
Like once you get into a snowball state, a planet can be trapped there forever, which is, you know, maybe you already had life form, but then because it's so cold, you may never get anything more than just microbes, right?
|
|
61
|
So what plate tectonics does is it, because it fosters more volcanism, is that you're going to get carbon dioxide pumped into the atmosphere, which warms the planet up and gets you out of the snowball earth phase.
|
adam
|
So what plate tectonics does is it, because it fosters more um uh volcanism, is that you're going to get carbon dioxide pumped into the atmosphere, which warms the planet up and gets you out of the uh the uh Snowball Earth phase.
|
|
62
|
But even more, there's even more really important things. I just finished a paper where we were looking at something called the hard steps model,
|
adam
|
But even more, there's even more really important things. I just finished a paper where we were looking at something called the hard steps model,
|
|
63
|
which is this model that's been out there for a long time that purports to say intelligent life in the universe will be really rare.
|
adam
|
which is this model that's been out there for a long time that purports to say intelligent life in the universe will be really rare.
|
|
64
|
And it made all these assumptions about the Earth's history, particularly at the history of life and the history of the planet, or have nothing to do with each other.
|
adam
|
And it made all these assumptions about the Earth's history, particularly the history of life and the history of the planet that have nothing to do with each other.
|
|
65
|
And it turns out, as I was doing the reading for this, that Earth probably early on had a more mild form of plate tectonics. And then somewhere about a billion years ago, it ramped up.
|
adam
|
And it turns out, as I was doing the reading for this, that Earth probably early on had a more mild form of plate tectonics. And then somewhere about a billion years ago, it ramped up.
|
|
66
|
And that ramping up changed everything on the planet. Because here's a funny thing. The Earth used to be flat. What I mean by that, right? So all the flat earthers out there can get excited for one second. Clip it.
|
adam
|
And that ramping up changed everything on the planet. Because here's a funny thing. The Earth used to be flat. What I mean by that, right? So all the flat earthers out there can get excited for one second. Clip it.
|
|
67
|
The beginning of, I think the term is orogenesis, mountain building, the true Himalayan style giant mountains didn't happen until this more robust form of plate tectonics where the plates are really being driven around the planet.
|
adam
|
The beginning of, I think the term is orogenesis, mountain building, the true Himalayan style giant mountains didn't happen until this more robust form of plate tectonics where the plates are really being driven around the planet.
|
|
68
|
And that is when you get the crusts hitting each other and they start pushing, you know, into these Himalayan style mountains.
|
adam
|
And that is when you get the crusts hitting each other and they start pushing, you know, into these Himalayan style mountains.
|
|
69
|
The weathering of that, the erosion of that puts huge amounts of nutrients, you know, things that microbes want to use into the oceans.
|
adam
|
The weathering of that, the erosion of that, puts huge amounts of nutrients, you know, things that microbes want to use, uh, into the oceans.
|
|
70
|
And then what we call the net primary productivity, the, you know, the photo, the bottom of the food chain, how much sugars they are producing, how much photosynthesis they're doing.
|
adam
|
And then what we call the net primary productivity, the, you know, the photo, the bottom of the food chain, how much sugars they are producing, how much photosynthesis they're doing.
|
|
71
|
Shot up by a factor of almost a thousand, right? So, the fact that you had plate tectonics supercharged evolution in some sense.
|
adam
|
Shot up by a factor of almost a thousand, right? So, the fact that you had plate tectonics supercharged evolution in some sense.
|
|
72
|
You know, like we're not exactly sure how it happened, but it's clear that the amount of life, the amount of living activity that was happening really got a boost from the fact that suddenly there was plate this new vigorous form of plate tectonics.
|
adam
|
You know, like we're not exactly sure how it happened, but it's clear that the amount of life, the amount of living activity that was happening really got a boost from the fact that suddenly there was this new vigorous form of plate tectonics.
|
|
73
|
Yeah, that's actually really true. Because what happens is if you look at the history of life, that's a really, you know, it's an excellent point you're bringing up.
|
adam
|
Yeah, that's actually really true. Because what happens is if you look at the history of life, that's a really, you know, it's an excellent point you're bringing up.
|
|
74
|
If you look at the history of life on Earth, we get abiogenesis somewhere around at least 3.8 billion years ago.
|
adam
|
If you look at the history of life on Earth, we get uh, you know, abiogenesis somewhere around at least 3.8 billion years ago.
|
|
75
|
But then you go through this period they call the boring billion, where like it's a billion years and it's just microbes. Nothing's happening, it's just microbes.
|
adam
|
But then you go through this period they call the boring billion, where like it's a billion years and it's just microbes. Nothing's happening, it's just microbes.
|
|
76
|
I mean, microbes are doing amazing things. They're inventing fermentation. Thank you very much.
|
adam
|
I mean, they're they're doing the microbes are doing amazing things. They're inventing uh um fermentation. Thank you very much.
|
|
77
|
We appreciate that. But it's not until sort of you get probably this continents slamming into each other, you really get the beginning of continents forming and driving changes that evolution has to respond to.
|
adam
|
We appreciate that. But it's not until sort of you get probably this these continents slamming into each other, you really get the beginning of continents forming and driving changes that evolution has to respond to.
|
|
78
|
That on a planetary scale, this turmoil, this chaos is creating new niches as well as closing other ones. And biology, evolution has to respond to that.
|
adam
|
That on a planetary scale, this turmoil, this chaos is creating new niches as well as closing other ones. And biology, evolution has to respond to that.
|
|
79
|
And somewhere around there is when you get the Cambrian explosion, is when suddenly everybody plan, you know, evolution goes on an orgy, essentially. So, yeah, it does look like that chaos or that turmoil was actually very helpful to evolution.
|
adam
|
And somewhere around there is when you get the Cambrian explosion, is when suddenly everybody, plan, um, you know, evolution goes on an orgy, essentially. Uh, so, yeah, it does look like the that chaos or that turmoil was actually very helpful to evolution.
|
|
80
|
Well, I think what's, I'm not sure if that's true. I don't know if it needs to be like an almost extinction event, right?
|
adam
|
Well, I think what's, I'm not sure if that's true. I don't know if it needs to be like an almost extinction event, right?
|
|
81
|
Because it's certainly true that we have gone through almost extinction events, right? We've had, you know, five mass extinctions, but you don't necessarily see that like there was this giant evolutionary leap happening after those.
|
adam
|
Because it's certainly true that we have gone through almost extinction events, right? We've had, you know, five mass extinctions, but you don't necessarily see that like there was this giant evolutionary leap happening after those.
|
|
82
|
So, you know, with the comet impact, the KT boundary, certainly, you know, lots of niches opened up. And that's why we're here, right? Because, you know, our ancestors were just little, basically rodents, rats, living under the footsteps of the dinosaurs.
|
adam
|
So, you know, with the comet impact, um, the KT boundary, certainly, you know, lots of niches opened up. And that's why we're here, right? Because, you know, our ancestors were just little, basically rodents, rats, living under the footsteps of the dinosaurs.
|
|
83
|
But what we found with this hard steps paper, because the whole idea of the hard steps paper was.
|
adam
|
But what we found with this hard steps paper, because the whole idea of the hard steps paper was.
|
|
84
|
It was one of these anthropic reasoning kinds of things where Brandon Carter said, Oh, look, the intelligence doesn't show up on Earth until about, you know, almost close to when the end of the sun's lifetime.
|
adam
|
It was one of these anthropic reasoning kinds of things where Brandon Carter said, Oh, look, the intelligence doesn't show up on Earth until about, um, you know, almost close to when the end of the sun's lifetime.
|
|
85
|
And so he's like, Well, there should be no reason why the sun's lifetime and the time for evolution to produce intelligence should be the same.
|
adam
|
And so he's like, Well, there should be no reason why the sun's lifetime and the time for evolution to produce intelligence should be the same.
|
|
86
|
And so, therefore, and he goes through all this reasoning, anthropic reasoning, and he ends up with the idea that, like, oh, it must be that the odds of getting intelligence are super low.
|
adam
|
And so, therefore, and he goes through all this reasoning, anthropic reasoning, and he ends up with the idea that, like, oh, it must be that the odds of getting intelligence are super low.
|
|
87
|
And everybody loves a good probability distribution, and they went a long way with this.
|
adam
|
And everybody loves a good probability distribution, and they went a long way with this.
|
|
88
|
on one, you know, when you look at it, of course, the time scale for the sun's evolution and the time scale for evolution on life are coupled because life and the time scale for evolution of the earth is coupled,
|
adam
|
on one, you know, when you look at it, of course, the time scale for the sun's evolution and the time scale for evolution on life are coupled because life and the the the time scale for evolution of the earth is coupled,
|
|
89
|
is about the same time scale as the evolution as the sun. It's billions of years. The earth evolves over billions of years.
|
adam
|
is about the same time scale as the evolution as the sun. It's billions of years. The earth evolves over billions of years.
|
|
90
|
And life and the earth co-evolve. That's what Brandon Carter didn't see: is that actually the fate of the earth and the fate of life are inextricably combined. And this is really important for astrobiology too.
|
adam
|
And life and the earth co-evolve. That's what Brandon Carter didn't see: is that actually the fate of the earth and the fate of life are inextricably combined. Uh, and this is really important for astrobiology too.
|
|
91
|
Life doesn't happen on a planet. It happens to a planet. So, this is something that David Grinspoon and Sarah Walker both say. And, you know, I agree with this. It's a really nice way of putting it.
|
adam
|
Life doesn't happen on a planet. It happens to a planet. So, this is something that David Grinspoon and Sarah Walker both say. And, you know, I agree with this. It's a really nice way of putting it.
|
|
92
|
These things, you know, these are things that are happening where life and the planet are sort of sloshing back and forth.
|
adam
|
These things, you know, these are things that are happening where life and the planet are sort of sloshing back and forth.
|
|
93
|
And so, rather than to your point about do you need giant catastrophes, maybe not giant catastrophes, but what happens is as the earth and life are evolving together, windows are opening up, evolutionary windows.
|
adam
|
And so, rather than to your point about do you need giant catastrophes, maybe not giant catastrophes, but what happens is as the earth and life are evolving together, windows are opening up, evolutionary windows.
|
|
94
|
Like, for example, life put oxygen into the atmosphere. When life invented this new form of photosynthesis about two and a half billion years ago, that broke water apart to, you know, work, to do its shenanigans, chemical shenanigans.
|
adam
|
Like, for example, life put oxygen into the atmosphere. When life invented this new form of photosynthesis about two and a half billion years ago, that broke water apart to, you know, work, to do its shenanigans, chemical shenanigans.
|
|
95
|
That opened up huge possibilities, new spaces for evolution to happen.
|
adam
|
That opened up huge possibilities, new spaces for evolution to happen.
|
|
96
|
So the introduction of oxygen photosynthesis changed the planet forever and it opened up a bunch of windows for evolution that wouldn't have happened otherwise.
|
adam
|
So the introduction of oxygen photosynthesis changed the planet forever and it opened up a bunch of windows for evolution that wouldn't have happened otherwise.
|
|
97
|
Like, for example, you and I, we need that amount of oxygen. Big-brained creatures need an oxygen-rich atmosphere because oxygen is so potent for metabolism. So you couldn't get intelligent creatures 100 million years after the planet formed.
|
adam
|
Like, for example, you and I, we need that amount of oxygen. Big-brained creatures need an oxygen-rich atmosphere because oxygen is so potent for metabolism. So you couldn't get intelligent creatures 100 million years after the planet formed.
|
|
98
|
Life hijacks a planet in a way that the sum total of life creates these feedbacks between the planet and the life such that it keeps the planet habitable. It's kind of a homeostasis, right?
|
adam
|
Life hijacks a planet in a way that um the sum total of life creates these feedbacks between the planet and the life such that it keeps the planet habitable. It's kind of a homeostasis, right?
|
|
99
|
I can go out like right now outside, it's 100 degrees, right?
|
adam
|
I can go out like right now outside, it's 100 degrees, right?
|
|
100
|
And I go outside, but my internal temperature is going to be the same.
|
adam
|
And I go outside, but my internal temperature is going to be the same.
|
End of preview. Expand
in Data Studio
README.md exists but content is empty.
- Downloads last month
- 2