SPEAKER_1: On the next episode of StarTalk, it's a Cosmic Queries edition with, of course, Chuck Nice.
SPEAKER_1: And we have as our guest, David Grinspoon, a friend and colleague.
SPEAKER_1: His expertise is on exoplanets, the search for life, and astrobiology.
SPEAKER_1: And we had some great questions coming up for you.
SPEAKER_1: Like, is carbon-based life the only kind of life that can exist?
SPEAKER_1: Is it the only kind of life we're searching for?
SPEAKER_1: Might we be missing something?
SPEAKER_1: And if we do find life, is there a protocol?
SPEAKER_1: Also, what would an Earth-like planet that sustained life be like if it had no atmosphere?
SPEAKER_1: And will Earth ever become Venus with a runaway greenhouse that's nearly a thousand degrees Fahrenheit on this next episode of StarTalk?
SPEAKER_1: Welcome to StarTalk, your place in the universe where science and pop culture collide.
SPEAKER_1: StarTalk begins right now.
SPEAKER_1: David, welcome back to StarTalk.
SPEAKER_2: Thank you.
SPEAKER_2: It's great to be here, great to see you both.
SPEAKER_1: Yeah, we count you as a friend.
SPEAKER_1: You've been on many, many times.
SPEAKER_1: And on your resume here, I've got you as Senior Scientist at the Planetary Science Institute.
SPEAKER_1: And that's in Arizona, is that correct?
SPEAKER_2: That's in Arizona.
SPEAKER_2: I'm in the Washington, DC area through the magic of the interwebs, where PSI, Planetary Science Institute is sort of distributed.
SPEAKER_2: We have people all over the place.
SPEAKER_1: And I'm reminded, you're author of Chasing New Horizons.
SPEAKER_1: I see what you did there because there is a mission to Pluto called New Horizons.
SPEAKER_1: And as well, inside the epic first mission to Pluto.
SPEAKER_1: Chuck, you see what he did there.
SPEAKER_1: He's very expectant that there will be more missions to Pluto.
SPEAKER_3: Right, right.
SPEAKER_3: By the way, the subtitle of that New Horizons was, Screw You, Neil.
SPEAKER_3: That was the...
SPEAKER_1: I see.
SPEAKER_1: That's implicated in the demotion of Pluto.
SPEAKER_2: Chuck, that's the implied subtitle.
SPEAKER_2: Come on.
SPEAKER_1: Oh, the actual subtitle.
SPEAKER_3: Yeah, but let's not forget about my favorite Dr.
SPEAKER_3: Funky's Spoon book, if I recall correctly, is Earth in Human Hands, because it's all about how we are shaping this planet.
SPEAKER_3: And if you want to know some great information about climate change and the Anthropocene, you should check out that book, man, because it helped me.
SPEAKER_3: It's really very cool.
SPEAKER_1: Wow, I didn't know you're now his agent.
SPEAKER_1: Okay, thanks.
SPEAKER_2: No, Chuck's just my prime audience.
SPEAKER_2: If he likes it, then I know I did something right.
SPEAKER_1: Well, tell us about that book, because if you are a planetary expert, then Earth is simply another planet, then you get to compare it, you know, its strengths and weaknesses.
SPEAKER_1: Look at Neil.
SPEAKER_1: Susceptibilities.
SPEAKER_3: He does that in a book, Ashley.
SPEAKER_1: I just want you to take me for a few minutes, David.
SPEAKER_2: Yeah, well, so I just thought it would be, I thought it would be cool to look at sort of the question of, you know, the perennial question of what are humans and what makes us different, if anything, from the perspective of astrobiology and planetary science and try to look at humans as this sort of thing that's happening to the planet and how that fits into history and then hopefully how that view of ourselves can help us in a constructive way think about our future, you know.
SPEAKER_2: So it's basically, it's the astrobiologist view of, you know, if you were an alien with a long attention span watching Earth, then in this recent stretch of time, you would have seen something really weird happen to our planet that has never happened to it before, you know, where the night side lights up and the atmosphere changes and everything changes, and what does that sort of look like from a planetary perspective?
SPEAKER_2: That was sort of the goal of Earth in Human Hands.
SPEAKER_1: Okay, cool.
SPEAKER_1: And when was that published?
SPEAKER_2: That was published in 2017.
SPEAKER_1: 2017, and the date on the New Horizons book?
SPEAKER_2: That was 2018.
SPEAKER_2: That was a busy little stretch for me.
SPEAKER_2: I'm still recovering from all that.
SPEAKER_1: Very cool.
SPEAKER_1: And we also have you listed here as a musician.
SPEAKER_1: Are you active or you just sort of play at home where no one's listening?
SPEAKER_2: Well, actually, one of the things that's wonderful for me and I think for a lot of people about this stage where the pandemic maybe isn't over but is easing up a little bit is the return of live music.
SPEAKER_2: And I've been really enjoying that both as a listener and fan and also as a performer.
SPEAKER_2: And I have been playing, I'm in a new band actually here in the DC area.
SPEAKER_2: We're called The Easy Way and it's kind of a funk soul thing.
SPEAKER_2: We've just started playing.
SPEAKER_2: We played four gigs now.
SPEAKER_3: And are there any other scientists in the band with you?
SPEAKER_2: No, but one of the other guys, our lead singer, he works at NASA.
SPEAKER_2: He's not a scientist, but he's a NASA dude.
SPEAKER_2: So NASA does represent.
SPEAKER_1: So Chuck, you've got questions for us.
SPEAKER_1: I haven't seen them yet.
SPEAKER_1: I don't know if David has.
SPEAKER_3: I'm sure.
SPEAKER_3: Listen, I haven't.
SPEAKER_3: I don't think anybody has.
SPEAKER_1: This is a Cosmic Query, so tell us what you got.
SPEAKER_3: Here we go.
SPEAKER_3: You want to jump into this?
SPEAKER_3: Let's do it.
SPEAKER_3: Let's pop things off with Trevor C.
SPEAKER_3: Mills.
SPEAKER_3: Trevor says, Hey, Dr.
SPEAKER_3: Tyson, Dr.
SPEAKER_3: Grinspoon, as well as Chuck, I hope this finds you well.
SPEAKER_3: This is Trevor from Augusta, Georgia.
SPEAKER_3: At what point in our search for extraterrestrial life do we start a search for non-carbon-based life?
SPEAKER_3: What are some good candidates aside from silicone?
SPEAKER_2: Yeah, good question.
SPEAKER_2: David, what do you got?
SPEAKER_2: The thing is, I would say there's not one specific point.
SPEAKER_2: It's almost like more a perspective we have to keep in mind and remember that this search needs to be conducted with the humility of the realization that we don't really know what we're looking for.
SPEAKER_2: We have some hunches about what's universal about life, and we know that carbon chemistry in water is a basis that can work, and we have a good reason to believe that that could be functioning elsewhere because the conditions are available for it other places.
SPEAKER_2: So it's a good thing to look for because we know it can work and we sort of know how to look for it, but we should keep in mind that we don't have any solid reason to believe that that's the only kind of life.
SPEAKER_2: We haven't thought of any other.
SPEAKER_2: Nobody's constructed or invented in a lab another kind of life that works as well, but that could be because we're dumb, not because the universe doesn't know how to do it.
SPEAKER_1: We do it in our movies.
SPEAKER_1: Our movies, we do it 100 times over.
SPEAKER_2: Yeah, it happens in movies.
SPEAKER_2: And there is this move in NASA astrobiology to look for what we call agnostic biosignatures, which means trying to assume as little as possible and looking for more universal things that may not depend on carbon.
SPEAKER_2: But then you get into this question, what do we even mean by life?
SPEAKER_2: And what does life do?
SPEAKER_2: But you could talk about chemical disequilibrium, life changing the chemical balance of its environment in a way that non-life probably doesn't.
SPEAKER_2: And if you go that route, it doesn't have to be carbon-based.
SPEAKER_2: It just has to be something that's multiplying itself and using energy.
SPEAKER_2: And so we do have ideas about how to look for non-carbon-based life.
SPEAKER_2: And I think it's good to be reminded.
SPEAKER_2: So thank you for the reminder that we should keep that in mind as we search.
SPEAKER_2: But our search does tend to be focused on life as we know it, partly because that's what we know how to look for.
SPEAKER_1: So often people will try to swap silicon for carbon in the molecule.
SPEAKER_1: And many sci-fi movies that have attempted other chemically-based life have done that with silicon.
SPEAKER_1: And can you tell me why silicon would be such an attractive next option?
SPEAKER_2: Yeah, because in some ways, silicon is a lot like carbon in that, if you look at the periodic table, we all remember the periodic table from the wall of our science classroom, and it's got, you know, in the upper left, it's got hydrogen, and below hydrogen are all the things that bond like hydrogen with like one electron.
SPEAKER_2: And sort of in the middle of that chart is carbon at the top, and then below it are all the things that bond like carbon.
SPEAKER_2: Carbon makes four bonds with other things, and that's the basis of organic chemistry, which is the basis of life.
SPEAKER_2: So you look right below carbon, the next thing down is silicon.
SPEAKER_2: You think, OK, silicon, that's going to be kind of like carbon.
SPEAKER_2: Maybe you can make biomolecules out of that.
SPEAKER_2: So there's a good logic to it, but the problem is silicon bonds are not like carbon bonds.
SPEAKER_2: What's great about carbon is not just that it bonds to four other things, so it can make this whole, you know, complex Lego set of molecules.
SPEAKER_3: Well, then it doesn't sound like it works.
SPEAKER_3: It doesn't sound like it.
SPEAKER_3: It sounds like it's people making a leap because it's similarities, but that's like me saying, you know, Obama has large ears, he's black, I could be president.
SPEAKER_3: No, no, Chuck.
SPEAKER_3: No, you can't.
SPEAKER_3: You cannot.
SPEAKER_2: It is kind of like that.
SPEAKER_2: It depends on what features you're focusing on.
SPEAKER_1: Don't agree with Chuck on that.
SPEAKER_2: Don't get him all.
SPEAKER_2: I'm sorry, Neil, but Chuck has a point here.
SPEAKER_2: It depends on what characteristics you're focusing on.
SPEAKER_1: You are under no obligation to agree with Chuck on this show.
SPEAKER_2: And the fact that silicon bonds support the things makes it like carbon, but the problem is the nature of those bonds.
SPEAKER_2: Carbon bonds are also kind of floppy and loose, and carbon can get into all these weird configurations, which make proteins and things.
SPEAKER_2: Silicon bonds tend to be really stiff, and they don't make those complex configurations the way carbon bonds do.
SPEAKER_1: For those who can't see, David Grinspoon was just voguing in the last few moments.
SPEAKER_1: Shaping his hands around his face.
SPEAKER_2: Chemical voguing.
SPEAKER_1: Imitating the flexibility or rigidity of carbon and silicon bonds.
SPEAKER_2: Silicon.
SPEAKER_2: Silicon likes to strike a pose to stick to it.
SPEAKER_1: Okay, gotcha.
SPEAKER_1: So that's less flexible when life is experimenting on the diversity of what it may need to thrive in an environment.
SPEAKER_2: Yeah.
SPEAKER_2: And I don't think it makes like, carbon makes polymers, you know, the big molecules where it's not just carbon, but it's attached to lots of other things.
SPEAKER_2: Silicon makes, you know, silicon oxygen chains and things like that, but I don't think it makes the kind of just diverse molecule set that makes carbon so good for life.
SPEAKER_1: I would add just from an astrophysical point of view, there's like five times as much carbon in the universe as there is silicon.
SPEAKER_1: So you don't even need to appeal to silicon because carbon is there for you and it's your friend.
SPEAKER_3: So to both of you with respect to this, are there any conditions in the universe under which circumstances cause different reactions to these elements where they might behave in such a way to do something like make life?
SPEAKER_3: Or is the periodic chart the same, no matter what, no matter where?
SPEAKER_2: The elements are going to be the same, but your question is good.
SPEAKER_2: Are there conditions in which the reaction types, the behavior is going to be different?
SPEAKER_2: And the answer is yes, there are conditions in which it's different.
SPEAKER_2: And that's why we have to be careful to not be too earth centric.
SPEAKER_2: But has anybody come up with a set of conditions that we're likely to find somewhere where you can show that silicon is going to do the right thing to make life?
SPEAKER_2: The answer is no.
SPEAKER_2: But that may be just again be a limit on our imagination.
SPEAKER_1: And as any good scientist, you got to sort of not only know your limits, but be prepared to shatter them as you take every next step going forward.
SPEAKER_1: Chuck, you got another question for Dr.
SPEAKER_1: Funguswoon here?
SPEAKER_3: This is Emily either Talas or Talas, one or the other, because there's a double L.
SPEAKER_3: So hi, Chuck and Neil.
SPEAKER_3: Greetings from Paris, France.
SPEAKER_3: So maybe not either one of those.
SPEAKER_3: Maybe not.
SPEAKER_3: And then she goes, oh, look at this.
SPEAKER_3: Chuck, feel free to butcher my name.
SPEAKER_3: I can't wait to hear what you got.
SPEAKER_1: Oh, people setting you up.
SPEAKER_2: That was a preemptive consideration.
SPEAKER_3: Yeah, tell me about it.
SPEAKER_3: She goes, I was wondering what would happen if we were to discover intelligent life outside of Earth, of course, but less advanced than we are.
SPEAKER_3: First, how would we discover it and confirm that it is indeed less intelligent?
SPEAKER_3: Well, that's pretty easy.
SPEAKER_3: And second, once confirmed, what would the next steps be?
SPEAKER_3: Is there a protocol for life discovery?
SPEAKER_2: First of all, I love the question, and it's not one we think about very much because there's a set of assumptions that are almost unspoken because of how long we've been assuming them and how frequently we assume them, which...
SPEAKER_1: Actually, David, they'll remain unspoken until we come back from this break.
SPEAKER_2: Yes.
SPEAKER_2: They will remain unspoken a little longer.
SPEAKER_1: Oh, just a little longer.
SPEAKER_1: Just a little longer.
SPEAKER_1: Let's find out about the unspoken protocol.
SPEAKER_1: That's the next installment of Mission Impossible.
SPEAKER_1: David's unspoken protocol about encountering life.
SPEAKER_1: We'll be right back after this first break.
SPEAKER_4: Hey, I'm Roy Hill Percival, and I support StarTalk on Patreon.
SPEAKER_4: Bringing the universe down to Earth, this is StarTalk with Neil deGrasse Tyson.
SPEAKER_1: We're back at StarTalk Cosmic Queries with David Grinspoon, a friend and colleague, and he's an expert on the solar system and astrobiology and all kinds of cool things such as that.
SPEAKER_1: David, how do we find you on social media?
SPEAKER_2: Well, I'm still on Twitter, at least today, and that's at Dr.
SPEAKER_2: Funky Spoon.
SPEAKER_1: That's why we call you that, Dr.
SPEAKER_1: Funky Spoon.
SPEAKER_2: Yeah, and I'm on Facebook, just under my name, and I'm on Mastodon now, too, which is I'm Dr.
SPEAKER_2: Funky Spoon at coto.org.
SPEAKER_1: Funky or Funky Spoon?
SPEAKER_2: Funky, F-U-N-K-Y.
SPEAKER_1: Oh, Funky Spoon, okay.
SPEAKER_1: All right, I'm Mastodon.
SPEAKER_2: I'm hedging my bets.
SPEAKER_1: Okay, so, Chuck, we left off with a question about what would happen.
SPEAKER_3: From Emily Talias.
SPEAKER_1: She's from France, so is it Emily?
SPEAKER_1: Emily?
SPEAKER_1: Emily, how do you Frenchify Francophile Emily?
SPEAKER_1: So, she wants to know what happens when we find life that's less intelligent than us.
SPEAKER_1: That's hardly ever addressed in sci-fi storytelling.
SPEAKER_3: Yeah, because no one could imagine that we could be smarter than anything else in the universe.
SPEAKER_2: It's hardly ever addressed in sci-fi, but it's also hardly ever addressed in SETI itself, because there's always this assumption that anybody we find is going to almost surely be more, quote, advanced than us or have been around as a technological species or civilization much longer.
SPEAKER_2: And there's a good logic for that, because, you know, on this for one thing, on a cosmic time scale, we're just babies, right?
SPEAKER_2: You know, four and a half billion years of Earth, four billion years of life, depending on where you start it, you know, a couple million years of being human and a few hundred years of being technological and less than a hundred years, or a hundred years of being radio friendly, you know, so we're babies.
SPEAKER_2: And so we always imagine that we are the neophytes and they're the wise ones and that there's an asymmetry in contact in that direction.
SPEAKER_2: And, you know, statistically, I think it's a pretty good argument, but it's an interesting question.
SPEAKER_2: What if we meet somebody who's, you know, there's a pretty narrow range there where they could be dumber than us and still considered intelligent, but what if we did?
SPEAKER_2: And how would we find them?
SPEAKER_2: Because presumably then they wouldn't have traveled here, so we have to stumble upon them.
SPEAKER_3: Or responded.
SPEAKER_3: So even if they're not traveling here.
SPEAKER_2: But what if we got, you know, what if we got lucky?
SPEAKER_2: It sort of stumbled on a civilization that was sort of just becoming technological, but hadn't become interstellar yet.
SPEAKER_2: It seems unlikely.
SPEAKER_1: No, that would just be a tech level.
SPEAKER_1: That's not an intelligence level.
SPEAKER_2: No, that's a good point, too.
SPEAKER_2: Because you can argue there's always the whales, right?
SPEAKER_2: And the dolphins, they're really intelligent.
SPEAKER_2: They arguably have a civilization and a culture.
SPEAKER_1: I saw that Star Trek movie.
SPEAKER_1: The Save the Whales, Star Trek movie.
SPEAKER_2: Yes, so we could certainly find intelligent life that is not technological at the level we are.
SPEAKER_2: And as far as protocols, it's pretty vague.
SPEAKER_2: There are protocols for SETI.
SPEAKER_2: If we think we found something, a radio signal, what do you do?
SPEAKER_1: SETI, the Search for Extraterrestrial Intelligence, just the general term for that.
SPEAKER_2: Yeah, so the SETI, the Search for Extraterrestrial Intelligence community, has protocols that if somebody thinks they found a signal, then you don't announce it immediately to the public.
SPEAKER_2: First, you verify it, and you get another observatory to also find it, so you make sure it's not some weird mistake that your observatory is making and some local interference.
SPEAKER_2: But then once you're sure, then the protocol is complete transparency.
SPEAKER_2: You alert everybody, you know, so...
SPEAKER_1: Unless the men in black get to you first.
SPEAKER_2: Yeah, that's right.
SPEAKER_3: Right.
SPEAKER_2: With a flashy thing, yeah.
SPEAKER_2: So, you know, and then if somebody comes and lands a spaceship on Earth and contacts us, there's no real official protocol for that because it's not something that's just been, you know, you can argue whether it should be or shouldn't be, but it hasn't really been taken seriously enough by the sort of SETI and scientific community to develop a protocol for that.
SPEAKER_1: All I know is that in today's world, if the aliens land and they say, take us to your leader, nobody's taking them to the White House.
SPEAKER_2: It would present a conundrum, where do you take them?
SPEAKER_1: You take them, get a beer at the corner pub, that's all you need to do.
SPEAKER_3: I imagine that my fantasy is that they would land and then we find out that we're so insignificant that they're actually filming a reality show.
SPEAKER_1: Oh, oh, with them among us?
SPEAKER_3: Yes, exactly.
SPEAKER_3: Like that is, that's what we rate as, like, hey, let's go down there and like, basically they're the Aston Kutcher of the universe and we're the ones that are being pranked.
SPEAKER_2: We're basically props.
SPEAKER_3: We're props.
SPEAKER_3: We're straight up props.
SPEAKER_1: Thank you, Chuck, for the happy thought there.
SPEAKER_3: I know.
SPEAKER_3: All right, here we go.
SPEAKER_1: By the way, I want to add something here.
SPEAKER_1: So David, I just want to add that if we count chimps as sort of the next smartest species to us, just for the sake of this, for this example, we can't have a meaningful conversation with them.
SPEAKER_1: Think about it.
SPEAKER_1: And we've got 99% identical DNA.
SPEAKER_1: So if we find another species that's sort of not as smart as us, what evidence do we have that we'd be able to communicate with them?
SPEAKER_1: Or worse yet, finding a species just that 1% smarter than us than we are to chimps, what hope do we have of them even being able to communicate with us because our simplest thoughts would transcend our most brilliant?
SPEAKER_2: And it kind of illustrates that something very recent has happened here on earth with humans that, for better or worse, where we have these qualities of language and culture and so forth.
SPEAKER_2: And, you know, not just, I mean, chimps, you can argue, have a kind of language, but the sort of syntactical language and ability to express abstract thoughts and not all that, you know, it's pretty, it's pretty new.
SPEAKER_2: And it underscores how unlikely it probably is that we would connect with somebody else out there who seemed like an intelligent civilization, but also was less capable than us.
SPEAKER_2: Because, you know, it really illustrates that maybe we've just passed some kind of threshold.
SPEAKER_2: And on the other direction, yeah, so what if somebody is to us, as we are to chimps, that may be possible, but it may also be that this sort of threshold is something that once you're over it, then maybe you sort of can communicate even if you recognize that these guys are geniuses compared to us.
SPEAKER_2: It's an interesting question.
SPEAKER_1: Chuck, that's David's human ego that just got into that sentence.
SPEAKER_1: Yeah, we hit that threshold that we could communicate with any intelligent species smarter than us.
SPEAKER_2: Maybe we're dumb as rocks compared to just about everybody in the universe.
SPEAKER_1: Thank you.
SPEAKER_3: That's mine.
SPEAKER_3: That's the one I like.
SPEAKER_1: Chuck, keep it coming.
SPEAKER_3: All right.
SPEAKER_3: This is Sandra Pagliani.
SPEAKER_3: Sandra Pagliani says, Good morning or evening, wonderful StarTalk hosts and listeners.
SPEAKER_3: This one came to me as I was flying to Seattle and looking out the window.
SPEAKER_1: Love it.
SPEAKER_1: Love looking out the window.
SPEAKER_3: Why are black holes generally situated in the center of galaxies?
SPEAKER_3: Why that specific area?
SPEAKER_3: And yes, this is the kind of stuff that I think about while I'm on planes looking out the window.
SPEAKER_1: That's good.
SPEAKER_1: Because a whole lot of other stuff, you can think of how they create anxiety and things.
SPEAKER_1: And if you can think about black holes on a plane and not feel anxious, that's good.
SPEAKER_2: So, David, I should probably take this one.
SPEAKER_2: We actually have an astrophysicist here and it's not me.
SPEAKER_1: So, a black hole, our understanding of black holes tells us that you can get it from the death of a very high mass star.
SPEAKER_1: The sun is not among them.
SPEAKER_1: And high mass stars are very rare.
SPEAKER_1: So, these would be stars that are dotted around the galaxy from black holes that is the remnant of a supermassive star that lived out its life and died.
SPEAKER_1: And in the final collapse, it collapsed all the way over a black hole.
SPEAKER_1: We expect those black holes to be pretty much rare, but everywhere, if you can picture that.
SPEAKER_1: So, in other words, wherever you had stars being born, you'd have like maybe one of these.
SPEAKER_1: So, there are fewer of them than all the total stars by far, but there's no part of the galaxy that would be without them.
SPEAKER_1: So, that's one kind, those are called stellar black holes.
SPEAKER_1: Then, just empirically, we discovered that the centers of galaxies have black holes in them.
SPEAKER_1: It was a discovery.
SPEAKER_1: In my life, while I was in graduate school, this discovery took root.
SPEAKER_1: And we say, well, we've got one in our galaxy and one in a nearby galaxy, and there's another galaxy over here, we can get data and we show a black hole.
SPEAKER_1: And so we extrapolated.
SPEAKER_1: We said, if it's in these three galaxies, it must be in all galaxies.
SPEAKER_1: It's hard enough to get those data.
SPEAKER_1: And those galaxies were very different from each other.
SPEAKER_1: So then we just went on the assumption that every big galaxy would have a supermassive black hole.
SPEAKER_1: And sure enough, Hubble Telescope gets launched, and every galaxy we look into and have the quality of data to know, they've all got a supermassive black hole, and we do not yet know how they were formed.
SPEAKER_1: And the James Webb Space Telescope is exquisitely tuned to see the birth of galaxies.
SPEAKER_1: And from those data, we might be able to see material collecting in the middle to form the supermassive black holes that dot the center of every galaxy.
SPEAKER_1: And again, in a sense of it, a black hole, stellar black hole might be five, ten times the mass of the Sun.
SPEAKER_1: But the supermassive black holes in the centers of galaxies is hundreds of thousands up to millions of times the mass of the Sun.
SPEAKER_3: So if it's consistent that it's the death of a star that makes that, do we see stars that have that mass in the universe that might be able to create the supermassive black hole that coalesces a galaxy?
SPEAKER_1: No.
SPEAKER_1: Stars give out at about 60 to 100 times the mass of the Sun.
SPEAKER_1: We don't find stars more heavier than that.
SPEAKER_1: So we're not going to find a billion times the mass of the Sun star.
SPEAKER_1: We just have never seen that.
SPEAKER_1: And so that's what we think something else is making them.
SPEAKER_1: That's all.
SPEAKER_3: The universe brims with mysteries.
SPEAKER_3: That's why David and I have a job.
SPEAKER_2: And I love the fact that for the supermassive black hole in our own galaxy, we can actually watch the stars orbiting it.
SPEAKER_1: And in a Nobel Prize winning observations, yes, you're watching these stars do these loops and loops, and there's nothing there in the middle.
SPEAKER_3: Nothing.
SPEAKER_2: It's enough to make you really believe.
SPEAKER_1: You run the math on the orbits and the speeds and the distances, and you get a black hole.
SPEAKER_3: You get a black hole.
SPEAKER_3: So cool.
SPEAKER_3: It's not a NASCAR track.
SPEAKER_3: It's a black hole.
SPEAKER_3: That's very cool.
SPEAKER_3: All right.
SPEAKER_3: Here we go.
SPEAKER_3: This is, his name is on another page, Gavin Mallow.
SPEAKER_3: And Gavin says, greetings from Beaver Creek.
SPEAKER_3: Hello, David, Neil and Chuck.
SPEAKER_3: And that's Beaver Creek, Ohio.
SPEAKER_3: I forgot the Ohio part.
SPEAKER_1: Okay.
SPEAKER_3: I'm curious about the possibility of life on an Earth-like planet that would lack the protective sleeve that Earth's atmosphere and magnetic fields supply us.
SPEAKER_3: What would life do to accommodate these relative extreme conditions?
SPEAKER_3: Could anything on Earth potentially be transmissible to an environment as such?
SPEAKER_3: Ha ha.
SPEAKER_2: Yeah.
SPEAKER_1: Yeah, David, we got these, we got these, you know, our atmosphere protects us from meteors.
SPEAKER_1: It protects us from UV light.
SPEAKER_1: It's, you know, so we're here by the grace of the atmosphere.
SPEAKER_1: And so if there's a planet out there, Earth size, Earth gravity, Goldilocks zone, maybe, and doesn't have these protectorates, I mean, these protect, these protecting forces, what do we do?
SPEAKER_2: Yeah, that's a great question.
SPEAKER_2: I'm less worried about the magnetic field part, which is the other thing that the questioner asked, because we're learning more that makes us wonder how important magnetic fields are in protecting the surface of a planet.
SPEAKER_2: We used to say that without, that it was the lack of a magnetic field that made Mars lose its atmosphere, for instance, but more recent observations have made us question that, and the role of a magnetic field in protecting the atmosphere itself is not so clear.
SPEAKER_2: And then there's the example of one of my favorite planets, Venus, which has no intrinsic magnetic field, but because it has a thick atmosphere, it's still protected.
SPEAKER_2: In fact, Venus develops what's called an induced magnetic field, where just the solar wind itself sort of makes the upper atmosphere charged in such a way that it starts acting like it has a magnetic field.
SPEAKER_1: So, David, if memory serves, you wrote a book on Venus, too.
SPEAKER_2: This is correct, yes.
SPEAKER_1: Wait, wait, sorry, you wrote a book on Earth about Venus.
SPEAKER_2: That's right, I was not on Venus when I wrote the book, but I wrote a book on the subject of Venus.
SPEAKER_1: And the title of that book was what?
SPEAKER_2: That's Venus Revealed.
SPEAKER_1: Revealed, there you go.
SPEAKER_2: Yeah.
SPEAKER_1: You've been at this for a while.
SPEAKER_2: Yeah, yeah.
SPEAKER_2: So, magnetic fields, I think life would find a way, but an atmosphere fills so many roles.
SPEAKER_2: Not only does it protect from dangerous radiation, ultraviolet light and cosmic rays, but of course it also serves to transport, think of Earth and the role of oxygen and carbon dioxide in plants and animal life, the transporting of chemicals that are involved in the metabolism of organisms, trading energy between molecules and so forth.
SPEAKER_2: It's hard to imagine life evolving on the surface of a planet without an atmosphere.
SPEAKER_2: Now, of course, there are places in the solar system without atmospheres where we think there might be life on the inside, like, say, Europa.
SPEAKER_2: And so one could imagine an Earth-like planet without an atmosphere that still had the chemical stuff happening and the energy transformations on the inside so that maybe you'd have internal life in the interior of the planet.
SPEAKER_2: But an atmosphere is so integral to the kind of life that we have on Earth that it really sort of stretches the imagination to think of how you would get a biosphere without an atmosphere.
SPEAKER_1: And there's nothing wrong with stretching the imagination.
SPEAKER_2: This is true.
SPEAKER_2: That's why we like these kinds of questions.
SPEAKER_1: Yeah, yeah, yeah.
SPEAKER_1: Chuck, we've got to take a quick break.
SPEAKER_1: And David will be back in just a moment for our third and final segment with David Funky Spoon Grinspoon on StarTalk.
SPEAKER_1: We're back, StarTalk, Cosmic Queries, all about the solar system and searching for life and astrobiology, with one of the world's leading experts on these very subjects, David Grinspoon, a friend and colleague at the Planetary Science Institute, itself based in Arizona, but he is distributed.
SPEAKER_1: He's part of the PSI at-large community based in Washington, DC.
SPEAKER_1: Always good to have you, David, you're a friend of our show, and thanks for responding to our calls.
SPEAKER_2: Oh, it's great to be here with you guys.
SPEAKER_1: So, let's make this kind of like a lightning round, all right?
SPEAKER_1: And we'll speed it up as we go along.
SPEAKER_1: Because we only got through like five questions, and we got more, tons of them.
SPEAKER_1: Let's keep going.
SPEAKER_3: All right, here we go.
SPEAKER_3: Eric Sharakan says, Hey, from Boston, what does Dr.
SPEAKER_3: David Grinspoon think about the James Webb Space Telescope's recent exoplanet discovery, particularly that it appears similar to Earth in size and in composition?
SPEAKER_1: Yeah, David, you know, when we designed the damn telescope, it was to look for galaxies at the edge of the universe.
SPEAKER_1: And then you planet people are starting to use it to like look at stuff right in front of our noses.
SPEAKER_1: So who went what in the dark of what night did that?
SPEAKER_1: Yeah, that portfolio.
SPEAKER_3: Who do you know that you were able to pull this off?
SPEAKER_3: Where did that happen?
SPEAKER_2: All right, well, first of all, Boston, my hometown, yay, go Celtics.
SPEAKER_2: And it's wonderful what I think of that is, you know, like as Neil implies, the web was not designed to look at exoplanets.
SPEAKER_2: It was designed for galaxies and other things like that, astrophysical targets.
SPEAKER_2: But, you know, I chalk it up to the fact that the universe is just so incredibly productive when it comes to planets, much more than we thought, even when people started designing the web.
SPEAKER_2: And so in a way, it's luck.
SPEAKER_2: You know, it turns out web is sort of marginal for exoplanets, but there's so many good targets that we're starting to find them.
SPEAKER_2: And the exciting prospect now is that we can start to see what their atmospheres are made of, even though, again, web is not the ideal instrument for that.
SPEAKER_2: And we've got other ones, of course, we want to build in the future that will be more ideal.
SPEAKER_2: We're going to learn some really cool and important things about our planets in nearby star systems.
SPEAKER_1: So you're being opportunistic.
SPEAKER_2: Absolutely.
SPEAKER_3: That's a good thing.
SPEAKER_2: Absolutely, yes.
SPEAKER_1: All right, Chuck, keep it coming.
SPEAKER_3: All right, let's just keep going.
SPEAKER_1: Nice, succinct answer, David, for this third round.
SPEAKER_1: Okay, go.
SPEAKER_3: Keeping it moving, Kyle Marston says, Hey, yo, hey, yo, hey.
SPEAKER_3: I didn't say that, he did.
SPEAKER_3: How many Earth-like planets do we know about currently that reside in habitable orbits?
SPEAKER_3: Is there a number?
SPEAKER_2: You know, there's a lot of marginal ones.
SPEAKER_2: I would say a handful, you know, which is pretty good, because when it comes to saying habitable orbits, some of them we're sort of guessing, because it really depends on whether they have an atmosphere or not and what the details of their climates, but there's a good dozen or so that seem like pretty good candidates.
SPEAKER_1: Wait, David, there are 5,000 planets in the catalog right now, and you're telling me there's only like a dozen?
SPEAKER_2: Well, I'm saying...
SPEAKER_1: Goldilocks planets?
SPEAKER_2: I'm saying ones that we...
SPEAKER_2: And it depends on what you mean by Earth-like, okay?
SPEAKER_2: These are all gray area terms.
SPEAKER_2: But I'm saying roughly Earth-sized and definitely good candidates to be in the habitable zone and maybe have liquid oceans and things like that.
SPEAKER_2: It's a small but growing number.
SPEAKER_1: Okay, all right.
SPEAKER_1: So that would be if we did it in percentages, what's 10 out of 5,000?
SPEAKER_1: So what is it?
SPEAKER_1: It's one out of 500.
SPEAKER_1: So that's still pretty low.
SPEAKER_1: That's like a fifth of 1%.
SPEAKER_2: Yeah, but a lot of those 5,000 are ones that will, could be.
SPEAKER_2: I'm giving a conservative number for ones that we can say, yes, that's earth-sized and yes, that is really.
SPEAKER_1: So there's some in the running.
SPEAKER_2: Absolutely.
SPEAKER_2: But it's still big news.
SPEAKER_2: It's still big news when we find one.
SPEAKER_2: That's why it's so exciting, you know, this one that was just mentioned.
SPEAKER_2: Because like, oh yes, that's earth-sized and it seems to be in the habitable zone.
SPEAKER_2: It's still news.
SPEAKER_1: Yes, yes.
SPEAKER_1: Which is a good thing.
SPEAKER_1: It means that people are still excited and aren't enough of them to get bored with it yet.
SPEAKER_1: Chuck, keep it coming.
SPEAKER_3: All righty, here we go.
SPEAKER_3: This is Zeki Majed.
SPEAKER_3: I think.
SPEAKER_3: I mean, maybe.
SPEAKER_1: You're the reader here, so it's always what you think.
SPEAKER_3: Zeki Majed.
SPEAKER_3: Okay, you're right.
SPEAKER_3: Yeah, I'm going to tell you the truth.
SPEAKER_3: I really don't think that, but that's about as close as I can come.
SPEAKER_3: He says, hey, Neil, hey, David and Seth MacFarlane, the Orville of 25th century life has progressed far into the galaxy, solved societal health and technological issues and eliminated money as a form of currency.
SPEAKER_3: Do you think this future is viable?
SPEAKER_3: And what steps do present day humans need to take individually as well as on a larger scale to walk towards that goal?
SPEAKER_3: How can we push for science literacy globally?
SPEAKER_1: So David, answer that in three sentences.
SPEAKER_2: I would say in three sentences, yes, I think it's possible, though not assured.
SPEAKER_2: And that the path is not going to be smooth between here and there.
SPEAKER_2: And that the key is some sort of a globally enlightened society where we guide ourselves with the recognition that we are one planetary species, despite all of our wonderful differences.
SPEAKER_1: Just as a guiding force operating on our future decisions.
SPEAKER_3: Well, there you go.
SPEAKER_3: Here's your answer.
SPEAKER_3: We're screwed.
SPEAKER_1: And I think just to remind people, I think the original Star Trek, after which so much of the Orville, so much of it is inspired forces operating within the storytelling of Orville, if I remember correctly, the reason why there's no money is because they somewhat developed a replicator where if you need another one of something, just make another one in it.
SPEAKER_1: So you didn't have to go out and buy it or earn money to obtain it.
SPEAKER_2: It's post-scarcity.
SPEAKER_1: Correct.
SPEAKER_1: A post-scarcity world where anything could just come out of a machine that you create.
SPEAKER_1: And so that changes what people care about, what they value and all the rest.
SPEAKER_1: But one of them is you don't need money.
SPEAKER_2: It's interesting because money is just a belief system anyways.
SPEAKER_2: We all fool ourselves into thinking it has value, so it does have value.
SPEAKER_2: So we can always change our minds collectively about that.
SPEAKER_3: And the other thing too is once they got rid of money, people started to do what they wanted to do.
SPEAKER_3: So you naturally end up with a passion for life because everybody's doing what they want to do.
SPEAKER_1: Rather than what they have to do in order to pay the rent.
SPEAKER_3: Exactly.
SPEAKER_2: Okay, but then how do you explain Ferengi's?
SPEAKER_3: They're just greedy little bastards.
SPEAKER_3: They don't care.
SPEAKER_3: They have it all and they still want more.
SPEAKER_1: But Chuck, what you said is deep.
SPEAKER_1: What it would do, it would liberate the creativity of every citizen of the world to contribute in whatever way best floats their boat.
SPEAKER_1: And they'll probably be better at that than anything else they would have done.
SPEAKER_1: Because they'll do it because they want to.
SPEAKER_2: I like it, I like it.
SPEAKER_2: I think we should just like start that world right now.
SPEAKER_2: What are we waiting for?
SPEAKER_3: Ah, that's great.
SPEAKER_3: And on January 17, 2023, a revolution took hold.
SPEAKER_3: Spread like wildfire across the base of the globe.
SPEAKER_3: All right, so this is Cameron Bellamy who says, Greetings from Baltimore, Maryland.
SPEAKER_3: What aspects of a planet's climate are planetary scientists looking for when evaluating planets for potential to support life?
SPEAKER_3: Additionally, how close do these planets need to be to Earth to look for these aspects in the planet's climate?
SPEAKER_1: I like that.
SPEAKER_2: Yeah, so it's a good question.
SPEAKER_2: So, I mean, the basic factor that we're always very focused on is a climate in the range where water would be predominately liquid.
SPEAKER_2: And again, that could just be our own bias because, you know, as we talked about earlier, maybe we're not smart enough to think of other kinds of life that don't need water.
SPEAKER_2: But Earth, so much of what makes Earth the way it is is because the climate balance is such that we live on a water planet.
SPEAKER_2: And that is in every cell of your body is liquid water interacting with organic molecules.
SPEAKER_2: So that's the number one thing.
SPEAKER_2: There's enough greenhouse gases, carbon dioxide.
SPEAKER_2: Yeah, exactly.
SPEAKER_2: A good amount of greenhouse gases, carbon dioxide, water, a little methane, sulfur dioxide, these are the gases that absorb infrared radiation and make a planet warm.
SPEAKER_2: But not so much that you have a Venus that's just too hot for liquid water.
SPEAKER_2: So that's the sort of prime directive, if you will, for habitability.
SPEAKER_2: And what was the second part of the question?
SPEAKER_2: Oh, how far away?
SPEAKER_3: How far away?
SPEAKER_2: Again, with the tools we have now, it's very difficult to tell what's in a planet's atmosphere unless it's not just distance, the geometry has to be right.
SPEAKER_2: If we have what we call a transiting planet, so it passes in its orbit right between us and its star, then you can look at the radiation coming from that star as it passes through the atmosphere and see how it's filtered out and what molecules are there.
SPEAKER_2: But it's easier to do that if you're within a few hundred light years than if you're thousands of light years.
SPEAKER_2: But if we, as we get better instruments that we want to build in the future, we'll be able to greatly expand the number of planets we can do that for.
SPEAKER_1: And just a quick addition here, I remember watching Star Trek, and you ever notice, David, Chuck, they never wore spacesuits when they went down to planet surfaces.
SPEAKER_3: Right.
SPEAKER_1: Have you ever thought about that?
SPEAKER_2: Yes.
SPEAKER_3: No, they never wore it.
SPEAKER_1: Because at some point, Spock would say, it's an oxygen-nitrogen atmosphere, Captain, and so then they go down.
SPEAKER_3: It's a classic planet, Captain.
SPEAKER_1: But I would hear that, and it was as though, all we have to do is find an oxygen-nitrogen planet to move to.
SPEAKER_1: And then I realized, and David, correct me if I'm wrong here, if it has oxygen, something's making the oxygen.
SPEAKER_1: So you are already looking for planets that had some kind of life forms on it to create that atmosphere in the first place.
SPEAKER_1: It's not that there's all kinds of random atmospheres that exist on all the planets, and pick the ones that you happen to be able to breathe.
SPEAKER_1: There's active stuff going on there.
SPEAKER_2: The reason why we have a breathable atmosphere is because there's life here.
SPEAKER_2: And so any planet you find with that kind of atmosphere would be very surprising.
SPEAKER_2: Like you say, Neil, what else would be making an atmosphere with just that mixture?
SPEAKER_2: It's hard to imagine that it's not brimming with life.
SPEAKER_1: Right, right.
SPEAKER_1: Okay, a couple more.
SPEAKER_1: Chuck, man, we're blowing through these.
SPEAKER_3: Oh, right.
SPEAKER_3: Yes, we are.
SPEAKER_1: Now, we got to speed up even more.
SPEAKER_1: So David, soundbite mode, okay?
SPEAKER_1: Remember, so ABC News just put a microphone in front of your lips, and they're going to soundbite you for the evening news.
SPEAKER_1: So here it is.
SPEAKER_1: Go, Chuck.
SPEAKER_3: Hello, Chuck.
SPEAKER_3: Hello, Neil.
SPEAKER_3: Hello, Dr.
SPEAKER_3: Funky Spoon.
SPEAKER_3: Okay, here we go.
SPEAKER_3: Does weed still work in space, or are the THC crystals too fragile for space?
SPEAKER_3: What temperature, what hemp crop would be best to grow on Mars?
SPEAKER_2: I'll say I don't know that the experiment's ever been tried, but in all seriousness, one thing I wonder about is...
SPEAKER_1: You told me NASA never took weed into the space station.
SPEAKER_2: Not that I know of, but I will say in all seriousness, one of the big problems with astronaut health is eye pressure, ocular pressure.
SPEAKER_2: And one of the things that is well established that cannabis does medically is good for glaucoma because it reduces eye pressure.
SPEAKER_2: Ocular pressure.
SPEAKER_2: So I've always thought, and I've kind of whispered this to a few people at NASA, but like, why don't you try that?
SPEAKER_3: Right on.
SPEAKER_3: Yeah.
SPEAKER_3: You don't have to smoke it.
SPEAKER_3: We have gummies.
SPEAKER_2: Exactly.
SPEAKER_1: Tell me about the soils of Mars.
SPEAKER_1: Can you grow anything there?
SPEAKER_2: Yeah.
SPEAKER_2: I mean, if you could grow anything, I mean, the thing, you know, cannabis is just another plant.
SPEAKER_2: So if you grow tomatoes, you're going to be able to grow cannabis there.
SPEAKER_2: The soil by itself as of now probably isn't very fertile, you know, because it doesn't have organics.
SPEAKER_1: As we learn from the book and movie, The Martian.
SPEAKER_2: But it could certainly...
SPEAKER_1: Poop.
SPEAKER_2: You can certainly mix in a little either human-generated or otherwise generated fertilizer and grow stuff on Mars.
SPEAKER_1: Human-generated fertilizer.
SPEAKER_3: Fertilizer.
SPEAKER_1: I always knew you were full of fertilizer.
SPEAKER_3: Exactly.
SPEAKER_2: We call that HGF.
SPEAKER_3: Nice.
SPEAKER_3: One last one, Chuck.
SPEAKER_1: That's all we got time for.
SPEAKER_3: This is Akshat...
SPEAKER_3: Oh, man.
SPEAKER_1: Why does it take you as long to read the name as the question itself?
SPEAKER_3: Who says this?
SPEAKER_3: Hey, hello and greetings from India.
SPEAKER_3: I was wondering whether Venus was once a habitable planet and their civilization was there, living on the planet, but unfortunately they destroyed themselves due to extreme climate change.
SPEAKER_3: What does the climate history have to say about the evolution of the entire planet?
SPEAKER_3: Thanks, and I love the show.
SPEAKER_1: This is from India.
SPEAKER_1: India has been growing their presence in space with satellites and space missions and things.
SPEAKER_2: Yeah, and they have a Venus mission.
SPEAKER_2: So now it's an Indian Venus mission that's going to be...
SPEAKER_1: That may be where that came from.
SPEAKER_1: So, welcome to the company of spacefaring nations, I say, to the nation of India.
SPEAKER_2: Yes, indeed.
SPEAKER_2: A short answer, I've often wondered that myself, but it's true that we think that Venus probably was habitable, although that's one of the motivations for our upcoming missions is to determine, was it really?
SPEAKER_2: We think it had oceans and lost them, but we want to gather the evidence to be sure of that.
SPEAKER_2: We generally don't talk about an ancient civilization on Venus, although one has to admit that we have not explored the planet well enough to rule that out.
SPEAKER_1: Wait, you said you don't talk about it.
SPEAKER_1: That implies you don't talk about it in public.
SPEAKER_2: No, no, no.
SPEAKER_1: You heard how we said that, Chuck.
SPEAKER_1: We don't talk about that.
SPEAKER_3: We don't talk about that.
SPEAKER_2: No, I just made this.
SPEAKER_1: We don't talk about that.
SPEAKER_2: That's not amongst our...
SPEAKER_3: Like Bruno in the Disney movie.
SPEAKER_3: We don't talk about Bruno.
SPEAKER_2: I meant that's not amongst our most favored hypotheses, but it's certainly not that big we could rule out.
SPEAKER_2: Thanks for getting me to clarify that.
SPEAKER_1: Yes, thank you very much there.
SPEAKER_1: But clearly Venus does have a runaway greenhouse effect, and they're just worried.
SPEAKER_1: Maybe Venus has knobs that got turned, had it become what it is, and we should look at those very same knobs here on Earth.
SPEAKER_2: Yes, a serious answer is that by studying what happened to Venus, we can be better prepared to understand changes in Earth's future, and that indeed is one of the big motivations for understanding what happened to the climate there.
SPEAKER_1: You got it.
SPEAKER_3: Now, is runaway greenhouse affect something that can happen under the conditions that we have?
SPEAKER_3: Like, our planet could undergo the same thing?
SPEAKER_3: Could that happen?
SPEAKER_3: I'm just saying, like, not that we're making that it is going to happen, but is it possible here?
SPEAKER_2: People have looked at this, and the answer is if you burned all the fossil fuels on Earth, of course you would make things awful and uninhabitable for humans, but you probably would not trigger a Venus-style runaway greenhouse effect where all the oceans boiled off.
SPEAKER_2: But in the future, as the sun warms up, which it is slowly, in a billion years or so, then there probably will be a runaway greenhouse effect on Earth like there was on Venus in the past.
SPEAKER_2: So if we wait long enough, then the sun will help us do that.
SPEAKER_1: So you hear that, Chuck, when an astrophysicist says in the future, his next phrase was, a billion years from now.
SPEAKER_3: A billion years, always, yes.
SPEAKER_1: There's some serious-ass future that we're talking about here.
SPEAKER_3: Exactly.
SPEAKER_2: We have more immediate problems, but nonetheless it's still interesting to picture that long-term future.
SPEAKER_1: Let me add something and get David's blessing on this comment before we close it out.
SPEAKER_1: So David, in all my readings on this, I agree, that if you extracted all fossil fuels and burned them all with none left, Earth would be hotter, but you would not have the runaway greenhouse effect experienced by Venus.
SPEAKER_1: What you would need to do is somehow dissolve all of the world's limestone and other repositories of carbon that's beyond just fossil fuels or fossils, right?
SPEAKER_1: And if you put all of that carbon added to the carbon that the fossil fuel burning would have, then we could become a twin of Venus in that way.
SPEAKER_1: Is that fair?
SPEAKER_2: Yeah, I think that's right.
SPEAKER_2: Because then, I mean, Venus has sort of like 100 bars almost of CO2, which is 100 times the atmospheric thickness of Earth.
SPEAKER_2: If you burned all of the fossil fuels, you're not going to get that much carbon in Earth's atmosphere.
SPEAKER_2: But yeah, if you dissolve all the limestone and sort of took all the carbon in Earth's crust and somehow put it in the atmosphere, I don't think anybody should try this, mind you.
SPEAKER_2: Don't try this at home.
SPEAKER_2: Then I think you probably could turn Earth into Venus.
SPEAKER_1: All right, so we're not doing that for sure.
SPEAKER_3: But the one thing we know for certain is that greenhouse effect is from carbon in the atmosphere.
SPEAKER_3: That is just the way it is.
SPEAKER_3: Carbon dioxide.
SPEAKER_3: So carbon dioxide in the atmosphere, done deal, greenhouse effect.
SPEAKER_3: And we know that we are doing that through burning fossil fuels here right now.
SPEAKER_2: Absolutely.
SPEAKER_2: We're going in that direction, and it's the wrong direction for us.
SPEAKER_3: There you go.
SPEAKER_1: For our survival.
SPEAKER_2: Yes.
SPEAKER_1: We got to call it quits there on that down note.
SPEAKER_1: Chuck, I had a high note.
SPEAKER_3: Kiss your kids goodnight.
SPEAKER_1: A couple of minutes ago, and then you had to just take it down.
SPEAKER_3: All right.
SPEAKER_2: A few minutes ago, we were abolishing all money and liberating human creativity.
SPEAKER_3: We saved humanity in the last question.
SPEAKER_3: Oh, man.
SPEAKER_3: And then, of course, we destroyed it with this.
SPEAKER_1: Those are the breaks.
SPEAKER_1: This is StarTalk Cosmic Queries, one of our favorite variants on the StarTalk franchise.
SPEAKER_1: Neil deGrasse Tyson here, your personal astrophysicist.
SPEAKER_1: I want to thank David for coming back to StarTalk.
SPEAKER_1: He's a friend of the show.
SPEAKER_1: And, of course, Chuck Nice, always good to have you there.
SPEAKER_3: Always a pleasure.
SPEAKER_1: As always, I bid you farewell.