Adam Frank
speaker
594 appearances
1 recordings
1 series
first heard Dec 2024
last heard Dec 2024
Adam Frank’s voice in public audio — every appearance, attributed to the second.
Trend
recordings per month · last 12 monthsNo recordings in the last 12 months.Older appearances are listed below; set an alert to hear about the next one.
Appearances
You know, I'm not sure where my paper fits in on those. I'm saying, you know, one should be careful about what you're using it for. But in terms of understanding the problem that that astrobiology faces, this really broke it up in a useful way.
Yeah, 92 and 95. 95 to me was really, that was the discovery of the first planet orbiting a sun-like star. To me, that was the water, the dam being broken.
You can. All you need is one. Like right now, it's an any, you know, our understanding of life. We have one example. We have N equals one example of life. So that means we could be an accident, right? It could be that we're the only place in the entire universe where this weird thing called life has occurred. Get one more example and now you're done.
Because if you have one more example, you don't have to find all the other examples. You just know that it's happened more than once. And now you are, from a Bayesian perspective, you can start thinking like, yeah, this life is not something that's hard to make.
So the paper, there was this paper we wrote, Woody Sullivan and I, in 2016, where we said, look, we have all this exoplanet data now, right? So the thing that exoplanet science and the exoplanet census I was talking about before have nailed is, F sub P, the fraction of stars that have planets, it's one. Every fricking star that you see in the sky hosts a family of worlds.
I mean, it's mind boggling because every one of those, those are all places, right? They're either, you know, gas giants, probably with moons. So the moons are places you can stand and look out. Or they're like terrestrial worlds where even if there's not life, there's still snow falling and there's oceans washing up on shorelines.
It's incredible to think how many places and stories there are out there. So, right, the first term was F sub P, which is how many stars have planets. The next term is how many planets are in the habitable zone. Right? On average. And it turns out to be 1 over 5. Right? So, you know, we're on 0.2. So that means you just count five of them. Go out at night and go 1, 2, 3, 4, 5.
One of them has an Earth-like planet, you know, in the habitable zone. Like, whoa! So what defines a habitable zone? Habitable zone is an idea that was developed in 1958 by the Chinese-American astronomer Xu Sheng. And it was, it was a brilliant idea. It said, look, this is there, you know, I can do this simple calculation.
If I take a planet and just stick it at some distance from a star of what's the temperature of the planet, what's the temperature of the surface. So now you're all, you're going to ask, you give it a standard kind of, you know, earth-like atmosphere and ask, okay, Could there be liquid water on the surface, right? We believe that liquid water is really important for life.
There could be other things that's happening. Fine. But you know, if you were to start off trying to make life, you'd probably choose water as your solvent for it. So basically the habitable zone is the
band of orbits around a star where you can have liquid water on the surface you could take a you know glass of water pour it on the surface and it would just pool up it wouldn't freeze immediately which would happen if your planet is too far out and it wouldn't just boil away if your planet's too close in so that's the formal definition of the habitable zone so it's a nice strict definition there's probably way more going on than that but this is a place to start
Right.
Well, for example, we know in our own solar system, we have say Europa, the moon of Jupiter, which has got a hundred mile deep ocean under 10 miles of ice, right? That's not in the habitable zone. That is outside the habitable zone. And that may be the best place. It's got more water than Earth does. All of its oceans are, you know, it's twice as much water on Europa than there is on Earth.
So, you know, that may be a really great place for life to form. And it's outside the habitable zone. So, you know, the habitable zone is a good place to start and it helps us. And there's reason, there's reasons why you do want to focus on the habitable zone because like Europa, I couldn't, I won't be able to see from across telescopic distances across light years.
I wouldn't be able to see life on Europa because it's under 10 miles of ice. So with the important thing about planets in the habitable zone is that we're thinking they have atmospheres. Atmospheres are the things we can characterize for across 10, 50 light years. And we can see biosignatures as we're going to talk about.
So there is a reason why the habitable zone becomes important for the detection of extrasolar life.
Yeah, I think that's not unreasonable to say. I mean, especially since the formal definition, you get one in five, right? One in five is a lot. There's a lot of stars in the sky. So yeah, saying that in general, when I look at a star, there's a pretty good chance that there's something habitable orbiting it is not a unreasonable scientific claim.
Okay. The Fermi Paradox. Let's talk about... I love talking about the Fermi Paradox because there is no Fermi Paradox. Dun, dun, dun, dun. Yeah. So the Fermi Paradox, let's talk a little about the Fermi Paradox and the history of it. So Enrico Fermi, it's 1950. He's walking with his friends at Los Alamos Nuclear Weapons Lab to the cantina. And there had been this...
cartoon in the new yorker they all read the new yorker uh and the cartoon was trying to explain why there had been this rash of uh uh garbage cans being disappearing in new york and this cartoon said oh it's ufos because this is already you know it's 1950 the first big ufo craze happened in 47 so they'd all they were laughing about this as they're walking and they started being physicists started talking about interstellar travel interstellar propulsion blah blah blah you know conversation goes on for a while conversation turns to something else you know
they've gone to other things about 40 minutes later over lunch, Fermi blurts out, well, where is everybody? Right. Typical Fermi sort of thing.
Showing 101–120 of 594 · page 6 of 30
← Previous
Next →