SPEAKER_1: Welcome to StarTalk, your place in the universe where science and pop culture collide.
SPEAKER_1: StarTalk begins right now.
SPEAKER_1: Welcome to the Hall of the Universe.
SPEAKER_1: I'm Neil deGrasse Tyson, your personal astrophysicist, and tonight we're talking about the scientific search for extraterrestrial intelligence.
SPEAKER_1: Are they out there?
SPEAKER_1: If they are, where are they?
SPEAKER_1: Are we listening?
SPEAKER_1: Those questions and more tonight.
SPEAKER_1: So let's do this.
SPEAKER_1: Let's do this.
SPEAKER_1: As you know, I never do this alone.
SPEAKER_1: My comedic co-host tonight, Michael Ian Black, welcome.
SPEAKER_1: You've been on with us before.
SPEAKER_1: Thanks for continuing to do this.
SPEAKER_4: My pleasure.
SPEAKER_4: I'm boldly going where a lot of people have gone before.
SPEAKER_1: And this is a show on the search for aliens, and I got one of the world's experts on it, Seth Shostak, friend and colleague.
SPEAKER_5: Welcome.
SPEAKER_1: You're a senior astronomer at the SETI Institute in Mountain View.
SPEAKER_1: How long have you been looking for aliens?
SPEAKER_5: Goes way back.
SPEAKER_5: I mean, I'm an astronomer by training, and this is just using the same techniques we use to study galaxies to try and eavesdrop on aliens.
SPEAKER_1: And now it's mainstream science.
SPEAKER_5: I think that it is.
SPEAKER_5: To begin with, there's the big effort by NASA and the space agencies to find nearby life, like on Mars, some of the moons of Jupiter and Saturn.
SPEAKER_5: Those are all places where you might find life.
SPEAKER_5: If you find life there, you'd need a microscope to see it because it's going to be bacteria.
SPEAKER_5: But SETI, where you're looking for life that can hold up its side of the conversation, that goes back to 1960s.
SPEAKER_5: It's not necessarily a very new idea.
SPEAKER_5: It's just that today we have much better equipment.
SPEAKER_1: There was a jump in public enthusiasm for the search for alien intelligence after a particular movie hit the screens.
SPEAKER_1: Check out this clip.
SPEAKER_1: So that's of course a clip from the movie Contact.
SPEAKER_1: So that was a film adaptation of Carl Sagan's 1985 novel, and we saw there Jodie Foster playing the lead character Ellie Arroway, first hearing a signal coming through the radio telescopes converted into sound.
SPEAKER_1: And once they decoded it, they found that it was a sequence of prime numbers.
SPEAKER_4: Wait, if you're converting it to sound at SETI, why not make it sound a little nicer than wah, wah, wah?
SPEAKER_5: But you never convert it to sound, actually, you never do.
SPEAKER_1: They did it for the film, but it's basically radio wave light that you are analyzing.
SPEAKER_5: If you converted it to sound, Michael, what you would hear is the same as you would hear by turning on your kitchen faucet.
SPEAKER_5: It would just be white noise, pssh, not very interesting.
SPEAKER_1: Yeah, and so they sent us prime numbers.
SPEAKER_1: I think in the novel they sent digits of pi, but it's the same idea here.
SPEAKER_1: So what's interesting for me is, Carl Sagan, who is not himself professionally a novelist, has to gather raw data to assemble the story that he ultimately composed.
SPEAKER_1: And there were rumors that Jodie Foster's character was based on a real person that Carl Sagan knew.
SPEAKER_1: And you wonder, might it have been Jill Tarter, one of the co-founders of the SETI Institute?
SPEAKER_1: Let's go to my interview with the former head of SETI, Jill Tarter.
SPEAKER_1: Check it out.
SPEAKER_1: It's been rumored that the lead character of Contact, Ellie Iroway, might have smelled like you a little bit.
SPEAKER_1: What's there?
SPEAKER_2: So, I was back at Cornell, and Carl said...
SPEAKER_1: Carl Sagan.
SPEAKER_2: I'm sorry, Carl Sagan said, come over, we're having a cocktail party tonight.
SPEAKER_2: Come on up to the house.
SPEAKER_2: And when I got there, he and his wife, Ann Druyan, took me aside.
SPEAKER_2: And they said, Carl's writing a science fiction book.
SPEAKER_2: And they said, well, you might think you recognize someone in the book, but I think you'll like her.
SPEAKER_2: I said, oh, come on.
SPEAKER_2: All right, as long as she doesn't eat ice cream cones for lunch, nobody's gonna think it's me.
SPEAKER_2: Because at that time, that was something that I was quite noted for, and everyone teased me about.
SPEAKER_1: Okay, so the character did not eat ice cream cones for lunch.
SPEAKER_2: She did not.
SPEAKER_1: So it couldn't have possibly have been you.
SPEAKER_2: No, everybody is wrong.
SPEAKER_1: But she was a strong female character in a male-dominated world, trying to get her ideas out there, trying to make the discovery.
SPEAKER_2: A woman who does what I do.
SPEAKER_1: So Seth, how long have you known Jill?
SPEAKER_5: I've known Jill for, let me think about it, almost 40 years, I think.
SPEAKER_1: Would you agree with this sense that there's overlap in the two characters?
SPEAKER_5: Oh, absolutely, there's overlap.
SPEAKER_5: I have to say, Sagan, I think probably made an amalgam of female astronomers that he knew.
SPEAKER_5: I've heard other female astronomers saying, no, I was the prototype.
SPEAKER_5: I don't know.
SPEAKER_1: So people vying for...
SPEAKER_5: Yes, they all want to be the prototype.
SPEAKER_1: Now he's dead, so there's no...
SPEAKER_5: You can ask him, but he doesn't say much.
SPEAKER_5: So in fact, but I think that Jill is it.
SPEAKER_5: To me, it's Jill.
SPEAKER_1: So beyond that, the movie, I think honestly, in an honest manner, tries to portray issues that would arise upon the discovery of extraterrestrial intelligence.
SPEAKER_1: Dealing with the religious consequences, philosophical consequences.
SPEAKER_1: I'm impressed by how much the film explored this, the fallout of the contact with extraterrestrial intelligence.
SPEAKER_1: And I don't think your institute has a branch of itself thinking about this.
SPEAKER_5: Well, I think you're largely right, but not entirely.
SPEAKER_5: We had a fellow on staff who was actually trained in psychology because one of the most interesting things about the whole SETI enterprise is not the technology.
SPEAKER_5: That's interesting, of course.
SPEAKER_5: Or even the astronomy, where you're going to point your antennas, all that.
SPEAKER_5: That's something we worry about day to day.
SPEAKER_5: But what the public is very interested in is, well, suppose next Wednesday, you find a signal.
SPEAKER_1: Tuesday, these things happen on Tuesdays.
SPEAKER_5: They usually do.
SPEAKER_5: So you pick up a signal.
SPEAKER_5: The first question they ask is, would you even tell us?
SPEAKER_5: A lot of Americans are not even convinced we would tell them because it was a NASA project up until 1993 and then Congress killed it.
SPEAKER_1: But you're still in business, so where are you getting your money?
SPEAKER_5: Donations.
SPEAKER_1: Private money.
SPEAKER_5: Private money.
SPEAKER_1: Okay, so interested, by the way, in the movie Contact, that same thing happened.
SPEAKER_5: Exactly.
SPEAKER_1: Government money got pulled by the natural, oh, yeah, thank you.
SPEAKER_5: Don't stop, Michael.
SPEAKER_4: Here's $22.
SPEAKER_5: You know what?
SPEAKER_4: Make it last.
SPEAKER_1: Getting back to my interview with Jill Tarter, she began life coining the term brown dwarf because she was active in the life cycle of stars, and that's a kind of star that she figured must exist and we should look for them.
SPEAKER_1: And so I asked her about her decision to throw away her career, her promising career looking for brown dwarfs and searching for aliens.
SPEAKER_1: Let's check it out.
SPEAKER_2: For millennia, we've been asking the priests and the philosophers, what should we believe about life beyond earth?
SPEAKER_2: Suddenly, there were some tools, radio telescopes, computers, scientists and engineers could get in this game.
SPEAKER_1: And the priests and the philosophers were not asking, what happens if a star fails for being too low on the Earth?
SPEAKER_1: So, these two questions are very different in their magnitude or in their relevance to pop culture.
SPEAKER_2: Sure, well, as I was walking down the street as a post-doc working on brown dwarfs, I always felt a little bit, why should the public be paying me to do this fun stuff?
SPEAKER_2: But once I started working on SETI-
SPEAKER_1: Because working for NASA, that's tax-based sources.
SPEAKER_2: Absolutely.
SPEAKER_2: But once I started working on SETI, God, this is a question everybody's interested in.
SPEAKER_2: And so, it was fantastic to be privileged to try and answer this whole question.
SPEAKER_1: How inevitable, in your judgment, is what we call intelligence given the formation of life on a planet?
SPEAKER_2: That's a question that we don't have an answer to, but there are several schools of thought that say a predator-prey relationship, evolutionarily, will ratchet up intelligence.
SPEAKER_1: Because you don't want to get eaten.
SPEAKER_2: I think that's a good theory.
SPEAKER_1: And you want to eat something.
SPEAKER_1: So you have kind of an arms race.
SPEAKER_2: That's right.
SPEAKER_1: Between the two.
SPEAKER_2: Yep.
SPEAKER_1: Okay, so predator-prey.
SPEAKER_1: Why does that matter to anything?
SPEAKER_2: Well, if as a piece of prey, you get smarter to elude the predator, you do well.
SPEAKER_2: If the predator doesn't get its act together and gets smarter yet, they're gonna get hungry and starve.
SPEAKER_2: So it really does.
SPEAKER_2: Smart begets smarter begets smarter.
SPEAKER_2: Perhaps.
SPEAKER_2: That's a theory.
SPEAKER_2: It seems to have worked on this plan.
SPEAKER_1: I mean, it doesn't have to be how smart you are.
SPEAKER_1: It can be how strong you are.
SPEAKER_1: How powerful is your bite.
SPEAKER_2: Yes, but if you are small and weak in a prey, it really does help you to get smarter to avoid those big teeth.
SPEAKER_2: Because you can't out fight them.
SPEAKER_1: Plus, big teeth with brains is surely better than just big teeth.
SPEAKER_1: I'm guessing.
SPEAKER_2: Probably so.
SPEAKER_2: Seems to have worked that way here.
SPEAKER_1: All right, so then you have this inevitability of intelligence, that's hypothesized.
SPEAKER_1: Completely sensible, but you said there are other schools of thought, other camps?
SPEAKER_2: Yeah, we look at toothed whales, right?
SPEAKER_2: And we look over geological time, and we try and say.
SPEAKER_1: This would be billions of, well, hundreds of millions.
SPEAKER_1: Hundreds of millions of years.
SPEAKER_2: And say, are these things getting smarter?
SPEAKER_2: At least are their brains getting bigger?
SPEAKER_2: And we can actually see both directions.
SPEAKER_2: Yes, a lot of them got bigger brains and apparently smarter, but some of them actually went the other way.
SPEAKER_2: So it doesn't always have to go in one direction.
SPEAKER_1: Okay, so all branches don't always have to go in the smart direction.
SPEAKER_1: You just need some branches to go in the smart direction.
SPEAKER_1: That's all you...
SPEAKER_1: Okay.
SPEAKER_1: So this gives people confidence that if you find a planet with life, you wait long enough, there'll be something there that has intellectual capacity.
SPEAKER_2: It'll give them...
SPEAKER_2: It gives them expectations.
SPEAKER_1: Expectations, okay.
SPEAKER_1: So what gives you the confidence that life could be out there?
SPEAKER_5: Well, the number of planets in the Milky Way, it's like a trillion.
SPEAKER_5: Now, most of them are kind of worthless.
SPEAKER_1: Just to be clear, we're starting with at least 100 billion stars.
SPEAKER_1: So you're counting a trillion planets in orbit collectively around these 100 billion stars.
SPEAKER_5: That's a lot of planetary places.
SPEAKER_1: Yes, it is.
SPEAKER_5: And it turns out that maybe one in five stars actually has a planet that might have oceans and atmosphere, the kind of place you would build condos on.
SPEAKER_1: In recent months, there's been a lot of news about the planet around Proxima Centauri, Proxima b, in the Alpha Centauri star system.
SPEAKER_1: Important because that's the nearest star system to the sun.
SPEAKER_1: So were you guys jumping for joy when this happened or not?
SPEAKER_5: Well, it's great to know that there's a planet, and it might even be an Earth-like planet.
SPEAKER_5: I mean, we don't know much about it.
SPEAKER_5: But it's more or less the right size.
SPEAKER_1: Could be rocky.
SPEAKER_5: It could be rocky, and it's also at the right distance from Proxima Centauri, which is the name of the star, so that the temperatures there, under some reasonable assumptions, might be just as attractive as they are here on the East Coast.
SPEAKER_1: In the Goldilocks Zone.
SPEAKER_5: So that makes it interesting.
SPEAKER_5: And, you know, there might be life there, there might not be life there.
SPEAKER_5: But one thing you can say is that that planet will be in the textbooks forever because it will always be the closest, maybe, Earth-like planet to us.
SPEAKER_1: So you can run the numbers on how long it would take to get there.
SPEAKER_1: Our fastest probes ever aimed at Proxima B, I think I got 40,000 years.
SPEAKER_1: Is this consistent with what you got?
SPEAKER_5: Well, I just took the New Horizons spacecraft.
SPEAKER_5: The one to Pluto.
SPEAKER_1: Aim it to Proxima B.
SPEAKER_5: 75,000 years.
SPEAKER_1: 75,000.
SPEAKER_5: But, you know, 40,000 years in a middle seat, 75,000 years in a middle seat.
SPEAKER_5: And it's pretty much the same, right?
SPEAKER_1: The point is, if it's 35,000 years and a generation is 35 years, that's a thousand generations.
SPEAKER_1: So if you were to send people on this journey by conventional methods and you wanted living humans on the other side, they'd have to be really fertile people and sustain this flow for a thousand generations.
SPEAKER_1: That's not realistic.
SPEAKER_1: So the fact that it's closest to us is kind of meaningless given the life expectancy of our species, of individuals in our species.
SPEAKER_5: Well, yes.
SPEAKER_5: But on the other hand, there are plans to send something to this star system, using really powerful lasers.
SPEAKER_5: And if you're willing to send something the size, I don't know, of a dollar, a silver dollar, or maybe your iPhone or something like that, if you're willing to just send that to Proxima Centauri, you can get it there in 20, 30, 40 years if you build this giant laser.
SPEAKER_5: The trouble is I don't know what you...
SPEAKER_1: The laser, it gives, sends momentum to it from light pressure.
SPEAKER_5: Right, you have a big sail.
SPEAKER_5: This thing has got strings to a big sail and you hit the sail with this laser and it kicks it up to high speed.
SPEAKER_1: Okay, so you get there in less time, but you still didn't go there.
SPEAKER_5: No.
SPEAKER_1: You're not sending a telescope there.
SPEAKER_1: You're not, so it's just the, it's an exercise and can I put some of my hardware junk in the atmosphere of this other planet?
SPEAKER_1: Worth it.
SPEAKER_1: So there's already been some thinking on how to actually search for aliens occupying other worlds.
SPEAKER_1: We'll get to that when StarTalk returns.
SPEAKER_1: We're on StarTalk, the American Museum of Natural History, and we're talking about the scientific search for alien intelligence.
SPEAKER_1: Featuring my interview with SETI co-founder, Jill Tarter.
SPEAKER_1: Let's check it out.
SPEAKER_1: How much of the galaxy have we actually searched for life?
SPEAKER_1: Because every time I'm out in the street, someone says, we haven't found any, are we alone?
SPEAKER_1: And I'm trying to find a way to tell them we're not likely alone, but they know we've been looking for a while.
SPEAKER_1: So how do you deal with this?
SPEAKER_2: So I try and tell people about all the different ways you might have to look to get it right.
SPEAKER_2: All the different frequencies, be at the right time, looking at the right place.
SPEAKER_1: All this has to come together.
SPEAKER_2: Right, now, that big volume that you need to search through, set that equal to the volume of the Earth's oceans.
SPEAKER_2: All that water.
SPEAKER_2: So how much have we sampled in the last 50 years?
SPEAKER_2: One 12-ounce glass.
SPEAKER_2: It's not a lot.
SPEAKER_2: And so if you were looking for fish in the ocean, are there any fish in the Earth's ocean?
SPEAKER_2: Here's a glass.
SPEAKER_2: I'm going to scoop up a glass and I'm going to look at it.
SPEAKER_2: And there aren't any fish in there.
SPEAKER_2: Can you claim that there are no fish in the ocean?
SPEAKER_1: Yeah, it'd be stupid to do so.
SPEAKER_2: Yeah.
SPEAKER_1: Short-sighted.
SPEAKER_2: Stupid.
SPEAKER_1: You're sticking with stupid.
SPEAKER_2: Yeah, you were right in the first place.
SPEAKER_1: You're short-sighted.
SPEAKER_1: You'd be inexcusably egocentric.
SPEAKER_2: That's right.
SPEAKER_2: And so it's the fact that it's hard to comprehend how big the search is.
SPEAKER_2: So you can't understand how little we've done.
SPEAKER_2: However, exponentials will save us.
SPEAKER_2: Because our ability to search may be through computing.
SPEAKER_2: The growth of technology.
SPEAKER_1: Exponential growth of storage, retrieval of information.
SPEAKER_2: All that stuff.
SPEAKER_2: It gets faster and better all the time.
SPEAKER_2: And all the good stuff is at the end.
SPEAKER_2: It's really getting fast.
SPEAKER_1: So next we might get a garbage pail of water.
SPEAKER_2: Swimming pool.
SPEAKER_1: Swimming pool of water.
SPEAKER_2: Yeah, that could be.
SPEAKER_2: And then a lake.
SPEAKER_2: And then very soon, an ocean.
SPEAKER_1: So Seth, how do you calculate the likelihood of finding intelligent life out there?
SPEAKER_5: It's a very simple thing.
SPEAKER_5: It's saying, look, how many societies are out there in our own galaxy that are broadcasting signals that are going through our bodies as we sit here?
SPEAKER_5: You know, is it one?
SPEAKER_5: Is it a thousand?
SPEAKER_5: Is it a million?
SPEAKER_5: Because that gives you some idea of whether you ought to spend a lot of time looking for it.
SPEAKER_1: So you're giving a verbal version of the Drake equation right now.
SPEAKER_1: We can put up the Drake equation just so we have it.
SPEAKER_1: So this is an organization of probabilities, basically.
SPEAKER_1: For me, the most interesting terms in this equation are the f's.
SPEAKER_1: The f's are the fractions of all stars that would have planets.
SPEAKER_1: The f sub l is the fraction of stars that would have life.
SPEAKER_1: The f sub i is the fraction of planets that have intelligent life.
SPEAKER_4: Can I guess?
SPEAKER_4: Can I guess the t?
SPEAKER_1: F sub t.
SPEAKER_4: Time?
SPEAKER_1: No.
SPEAKER_1: Damn.
SPEAKER_1: F sub t is the fraction.
SPEAKER_4: Transporters?
SPEAKER_1: I'll set you up for one.
SPEAKER_1: The f sub t is the fraction of all that we've computed that has technology because you can have intelligent-
SPEAKER_4: You didn't set me up.
SPEAKER_4: You just told me what it was.
SPEAKER_1: Because you could have intelligent civilizations out there with no technology.
SPEAKER_1: People could be trying to communicate with Earth in the Roman times and they're clearly intelligent but they're not talking to aliens.
SPEAKER_1: They don't have radio telescopes.
SPEAKER_4: They're setting up triangles on the ground and lighting them on fire with squares.
SPEAKER_5: It's a bit like asking how many students are there at Stanford University?
SPEAKER_5: You could say, well, what's the rate of admitting freshmen and how long do they, maybe it's a thousand a year, and how long do they stay there on average?
SPEAKER_5: Four years.
SPEAKER_5: So there are 4,000 students.
SPEAKER_5: It's the same thing here.
SPEAKER_5: How often do new societies arise and then we'll multiply that by L at the end of the equation which is the average lifetime of an intelligent civilization before they do something terrible and disappear.
SPEAKER_1: Which we have no idea what that would be.
SPEAKER_5: No, but we don't have very much idea about a lot of the terms in the Drake Equation.
SPEAKER_5: So you can't really compute it very well.
SPEAKER_5: All you can do is say, well, this kind of organizes the problem.
SPEAKER_1: Okay, so what is the best estimate now for how many civilizations there might be in the galaxy?
SPEAKER_5: Well, best estimate.
SPEAKER_5: I mean, Carl Sagan himself thought there were millions, right?
SPEAKER_5: There are plenty of people who think there's one and we're it.
SPEAKER_5: And Frank Drake who came up with this equation back in 1961, he says 10,000.
SPEAKER_1: So there's some signals that exist in the record books, right?
SPEAKER_1: And to some that means the aliens have already tried to contact us.
SPEAKER_5: In 1977, the Ohio State University had a big radio telescope.
SPEAKER_5: It's been turned into, I think, a golf course now.
SPEAKER_5: But one morning, one of the astronomers, a guy by the name of Jerry Amon, he comes in and he looks at the last night's observing, which is all printed out on paper.
SPEAKER_5: That's the way computers used to work.
SPEAKER_5: And he's gone to this paper.
SPEAKER_5: Remember paper?
SPEAKER_5: Okay, and he finds this big signal and he writes with a magic marker, he writes, wow, next to it.
SPEAKER_5: So that's become known as the wow signal.
SPEAKER_5: Now the big question was, could this have been the aliens trying to get in touch with Ohio?
SPEAKER_5: And the answer is we don't know the answer.
SPEAKER_5: Because that instrument automatically looked again 70 seconds later, a little over a minute later and didn't find the signal.
SPEAKER_5: People have continued to look for it.
SPEAKER_5: We've been looking for it and we haven't found it either.
SPEAKER_5: So, what do you conclude from that?
SPEAKER_5: It could be that the aliens broadcast once and then went on vacation.
SPEAKER_5: It could be.
SPEAKER_5: But you would never call that science.
SPEAKER_5: If you don't find it another time.
SPEAKER_1: We can't repeat it.
SPEAKER_1: So, that's one.
SPEAKER_1: And how about the Kepler object that had this weird eclipsing material in orbit around the host star?
SPEAKER_5: Yes.
SPEAKER_5: KIC 846 2852.
SPEAKER_5: It kind of rolls off the tongue.
SPEAKER_1: It's at its phone number.
SPEAKER_5: Anyhow, this is a star that's quite far away, actually.
SPEAKER_5: It's almost 1500 light years away.
SPEAKER_5: That's pretty far from most stars.
SPEAKER_5: And it is seen, you know, Kepler measured its brightness over the course of years, really.
SPEAKER_5: And you know, stars don't change their brightness very much.
SPEAKER_5: But this one suddenly dipped in brightness by more than a fifth, 22 percent.
SPEAKER_5: Very unusual.
SPEAKER_5: The sun never does that, thank goodness, okay.
SPEAKER_5: It wasn't because there was a planet going in front of it.
SPEAKER_5: That would never dim it that much.
SPEAKER_5: So the question is, what was it?
SPEAKER_5: And one suggestion made maybe semi-seriously was, well, maybe there's a civilization there and they build some astro-engineering project which is blocking some of the light.
SPEAKER_1: And they're taking that energy and feeding their planet with it.
SPEAKER_5: For example, they could be doing that, so-called Dyson Sphere.
SPEAKER_5: Yeah.
SPEAKER_1: Okay, so now, just keep it in the list here.
SPEAKER_1: A few months ago, Russians made an announcement of possible, a radio signal that could represent intelligent life.
SPEAKER_5: Indeed, the Russians back in 2015 had used a big antenna and they found a signal coming from the star HD 164595, another wonderfully named star.
SPEAKER_5: That star is known to have planets and they thought maybe this is it.
SPEAKER_5: But they didn't make any noise about it.
SPEAKER_5: They didn't tell people.
SPEAKER_5: And that's a strong indication that they themselves thought it might be interference.
SPEAKER_5: But somebody wrote a blog about this and so, you know, for a week the media went nuts about this star.
SPEAKER_5: We tried to check out the signal, the Berkeley people tried to check out the signal, no signal.
SPEAKER_5: The Russians were kind of forced to announce, look, we think it was a military satellite.
SPEAKER_1: Okay, so basically contaminated signal that masqueraded to those who are gullible as alien intelligence trying to talk to us.
SPEAKER_1: Now, here's something I always wonder.
SPEAKER_1: We're spending all this time listening and seems to me less time transmitting, which seemed unfair to me that we require alien intelligence to send signals to us when we are not doing the same back to them.
SPEAKER_1: I had to ask our listener in chief, Jill Tarter, why is it that we are always listening and not playing our dutiest role by also sending signals out to others who might want to find us?
SPEAKER_1: Let's check out what she said.
SPEAKER_2: We're the youngest kids on the block, right?
SPEAKER_2: And we're not very good at 100 or 1,000 or 10,000 year plans.
SPEAKER_2: And if you're gonna transmit, you gotta do it for a long time because your signal, if you transmit for a year, is gonna go on by the receiver in a year and they have to be looking at you exactly the right way, exactly the right time, if they're gonna catch that.
SPEAKER_2: So transmission is a long-term strategy.
SPEAKER_2: But if we listen first, you might get a signal that was already transmitted and, in fact, it would be more like a conversation that you can have today with Shakespeare or the ancient Romans than a hi, how are you, I'm fine, yes, a real slow two-way conversation.
SPEAKER_2: Information transfer, if it's ever going to happen, is going to be one-dimensional through time.
SPEAKER_2: They will transmit a lot of information or ultimately we will transmit a lot of information.
SPEAKER_1: So it's not witty repartee?
SPEAKER_2: How are you doing today?
SPEAKER_2: Not snappy conversation.
SPEAKER_1: So Seth, what's your take on active SETI?
SPEAKER_1: Sending signals, you agree with Jill, I presume?
SPEAKER_5: Well, I tell you, I think it's actually worth doing, this idea of not just listening, but having a broadcast experiment.
SPEAKER_5: There are people who think it's dangerous, right?
SPEAKER_5: I don't think it's dangerous.
SPEAKER_4: Isn't Stephen Hawking one of those people?
SPEAKER_5: He is.
SPEAKER_5: He has said, you know, well, every time, because you're giving away the fact that we're here.
SPEAKER_5: And then your tombstone reads, was responsible for the destruction of Earth.
SPEAKER_5: That'd be a bummer.
SPEAKER_1: So what's interesting to me is, the I in SETI stands for intelligence.
SPEAKER_1: And we're all operating on the assumption that we even know what intelligence is and that we somehow have it perfectly defined for this exercise.
SPEAKER_1: When we come back, we will explore what it means to be intelligent at all.
SPEAKER_1: Welcome back to StarTalk from the American Museum of Natural History.
SPEAKER_1: Tonight, we're talking about the search for alien intelligence.
SPEAKER_1: And I asked my colleague, astrophysicist, Jill Tarter, how we even define the intelligence that we're looking for in the first place.
SPEAKER_1: Let's check it out.
SPEAKER_1: Given the challenges we have in our species, even defining intelligence among ourselves, who are we to say that we'd even know intelligence if we found it somewhere else?
SPEAKER_2: Well...
SPEAKER_1: Who are you to say?
SPEAKER_2: Ah, I'm going to tell you that the intelligence that I would find has the ability to build and operate a transmitter of some kind.
SPEAKER_2: Otherwise, I wouldn't be able to find them.
SPEAKER_2: So there could be planets out there that are inhabited by intelligent dolphins, whales, these kinds of creatures.
SPEAKER_2: I don't have a way to find them.
SPEAKER_1: They don't have opposable thumbs to make stuff.
SPEAKER_2: That's right.
SPEAKER_2: And they live in the water.
SPEAKER_2: It's hard to have a fire and make metal and transmitter and stuff like that.
SPEAKER_1: They live in the water.
SPEAKER_1: That's right, there are no fireplaces under water.
SPEAKER_2: Hard to do.
SPEAKER_1: Right, right.
SPEAKER_1: So by that definition, most of human history where we've had what we call civilization, you would not have called intelligent.
SPEAKER_2: Absolutely correct.
SPEAKER_1: So I think you just need another word, because it's misleading.
SPEAKER_2: Well, we have...
SPEAKER_1: The Romans were intelligent, but they didn't have radio telescopes to transmit into space.
SPEAKER_2: Right, and we often say it's a misnomer.
SPEAKER_2: It should be the search for extraterrestrial technology.
SPEAKER_1: You invented the term brown dwarf.
SPEAKER_1: Why can't you invent a new word?
SPEAKER_2: Because the Russians already got there with CETI, and it was CETI in Russian, the C for communication, or a C as a Cyrillic S, or CETI.
SPEAKER_2: It was there before I got there.
SPEAKER_1: So the communication with extraterrestrial intelligence.
SPEAKER_2: That's what started.
SPEAKER_1: There you go.
SPEAKER_1: All right, so Seth, you're not searching for alien intelligence.
SPEAKER_1: You're searching for alien communicators.
SPEAKER_5: Well, yeah, right.
SPEAKER_5: Exactly, actually, you're looking for the signals.
SPEAKER_1: So this ought to tell you what the aliens might look like, because if they live underwater, they're not making machines.
SPEAKER_1: And so you're not looking for aquatic intelligence, presumably.
SPEAKER_5: No, I don't think so.
SPEAKER_5: Yeah, Jill's right.
SPEAKER_5: I mean, you know, it's really hard to build high-tech stuff underwater, right?
SPEAKER_4: That's an obvious point.
SPEAKER_4: So it's the search for thumbs, essentially, in the end, is what we're looking for.
SPEAKER_4: Opposable thumbs.
SPEAKER_1: This, right.
SPEAKER_1: So if this is the argument here, it may be that since we are on the cusp of inventing artificial intelligence that could itself invent new machines without our help, maybe you are searching for artificial intelligence.
SPEAKER_1: Ultimately.
SPEAKER_5: Well, I think we are, actually.
SPEAKER_5: I think it's much more likely if we pick up a signal that it's not coming from some soft, squishy gray guy with big eyeballs, right, that it's coming from some machine.
SPEAKER_5: Just looking at the time scale.
SPEAKER_5: We invented radio, what, 100 years ago?
SPEAKER_1: Radio waves, radio wave communication, yeah.
SPEAKER_5: Right.
SPEAKER_5: And we will probably invent thinking machines by 2050.
SPEAKER_5: If you talk to people in the artificial intelligence biz, right, and if you ask them, hey, how long will it be before we have a computer that can write the great American novel, just for example?
SPEAKER_5: And they'll say 2050.
SPEAKER_5: Now, they might be wrong.
SPEAKER_5: Maybe it's 2150.
SPEAKER_5: It really doesn't matter.
SPEAKER_5: Because that means you invent radio and within a few centuries, you've invented your successors.
SPEAKER_5: That's what we're doing in this century.
SPEAKER_5: We're inventing our successors.
SPEAKER_5: And they will invent their successors, not us.
SPEAKER_5: At which point, some of them get up, they leave, they go out, who knows what they do.
SPEAKER_5: But if you pick up a signal, the dominant intelligence in the cosmos is probably machines, anyhow.
SPEAKER_5: And that's where I figure the signal will be coming from.
SPEAKER_4: So is that the Borg?
SPEAKER_4: Is that the Borg?
SPEAKER_1: Maybe.
SPEAKER_1: But Borg is still, but it's a communal life.
SPEAKER_1: In your case, it's still individuals.
SPEAKER_5: Well, who knows?
SPEAKER_5: Who knows?
SPEAKER_5: I kinda like that idea.
SPEAKER_1: Yeah, who knows?
SPEAKER_1: It could just be a-
SPEAKER_5: Swarm intelligence.
SPEAKER_1: A swarm, that's right, that's right.
SPEAKER_1: So we can actually expand our definition of intelligence beginning now, because we've got neuroscientist, Lori Marino, standing by live on video call for that very purpose.
SPEAKER_7: Hi Neil, how are you?
SPEAKER_1: Well, thanks for being on StarTalk.
SPEAKER_1: You gained international prominence by your sort of non-invasive research into dolphin and whale brains.
SPEAKER_1: So how do you think about this whole landscape of intelligence as it applies to SETI, or to life on earth in general?
SPEAKER_7: Well, I think about it very differently.
SPEAKER_7: I come at it from the other end.
SPEAKER_7: Instead of looking for extra-terrestrial technology, I see the landscape of intelligence as being very broad.
SPEAKER_7: And I don't think you can have life without intelligence.
SPEAKER_1: So you have expanded our general concept of intelligence to include life forms that previously no one would have added to the list, right?
SPEAKER_7: Right, exactly, but from a biologist's point of view, from an evolutionary point of view, you have to include them because it turns out that really, you know, something like the human brain didn't just pop up.
SPEAKER_7: It evolved and it's sitting within a whole nest of other species on the planet.
SPEAKER_1: I was going to ask you, what's your evidence, your best evidence that dolphins are truly intelligent?
SPEAKER_1: But if your definition of intelligence is really, really broad, then the obvious answer is just yes.
SPEAKER_1: But so I should re-ask that question, how intelligent are dolphins?
SPEAKER_7: Well, you know, it's so hard to know where to put them, but let me say this, that they have the second largest size brain next to modern humans, so they are huge brains.
SPEAKER_7: Their brains are really complex.
SPEAKER_7: And then when you look at their behavior, you see very complex behavior.
SPEAKER_1: Yeah, but do they know their times table?
SPEAKER_1: That's what I want to know.
SPEAKER_7: Well, knowing your times table is a pretty anthropomorphic or anthropocentric, rather, way of putting it.
SPEAKER_7: They probably know things that we don't.
SPEAKER_1: One of my favorite quotes from Carl Sagan, I have it here, I have to read it.
SPEAKER_1: It's of interest to note that while some dolphins are reported to have learned English, up to 50 words, used in a correct context, no human being has ever been reported to have learned dolphinese.
SPEAKER_7: Well, you know, that's absolutely the case.
SPEAKER_7: We've been trying for decades now.
SPEAKER_7: We can't figure it out.
SPEAKER_7: And I think it's because it's very complex, but also it's probably very different.
SPEAKER_7: So we really don't even know how to begin.
SPEAKER_1: So if we cannot even communicate with another highly intelligent species on Earth, why do any of these SETI people have any confidence at all that we're going to communicate with an intelligence on another planet with whom we have no DNA in common?
SPEAKER_1: Have you thought about that, Lori?
SPEAKER_7: Yeah, I've thought about that.
SPEAKER_7: Sure.
SPEAKER_7: And I don't think that the SETI people are searching for life in the wrong way.
SPEAKER_7: They're searching for a particular type of signal that we have the capability to pick up right now.
SPEAKER_7: But I think you have to appreciate the fact that, you know, if we don't get a signal, that doesn't mean there is an intelligence out there.
SPEAKER_1: Okay.
SPEAKER_1: So, Lori, just thank you for piping in.
SPEAKER_1: I'm just glad to know that somebody such as you exists just to give animals their fighting chance to show up on our intelligence scale.
SPEAKER_1: So, coming up, former co-founder of this SETI institute, Jill Tarter, will share a story about a time she actually saw a UFO when StarTalk returned.
SPEAKER_1: We're talking about the scientific search for aliens, featuring my interview with the former director of that search effort, Dr.
SPEAKER_1: Jill Tarter.
SPEAKER_1: Let's check it out.
SPEAKER_1: You must get no end of emails, written mail, people telling you that they saw a UFO, and they want your validation of it.
SPEAKER_2: And they come, they show up at the office with their video cameras, and they're this, and they're that, and I'm going to set it up, and see, see, see.
SPEAKER_2: Yeah, I see a cobweb floating in and out of focus on your security camera, right?
SPEAKER_2: It's crazy.
SPEAKER_2: This whole idea that UFOs have anything to do with alien spacecraft when there are no data, no evidence to back it up.
SPEAKER_2: Sure, people see things on the sky.
SPEAKER_2: Sure, there's science that we don't yet understand.
SPEAKER_2: But the link between seeing something and an alien spacecraft, that's just not there, Neil.
SPEAKER_1: And how do we know you're not just covering it up?
SPEAKER_2: Oh yeah, that's right.
SPEAKER_2: I've actually seen a UFO.
SPEAKER_2: Actually, it's the freakiest experience because I'm a skeptic, right?
SPEAKER_2: So my husband and I fly a small airplane.
SPEAKER_2: We're flying back to our home airport at night.
SPEAKER_2: Suddenly, a bright light at two o'clock position.
SPEAKER_2: A big, bright light.
SPEAKER_2: As if the headlight of another airplane was flying towards us.
SPEAKER_1: Bad situation.
SPEAKER_2: Bad, yeah, yeah.
SPEAKER_2: So we call the tower and we say, what do you see at our two o'clock position?
SPEAKER_2: What's the traffic?
SPEAKER_2: The tower says, we don't have any traffic anywhere near you.
SPEAKER_1: Wait, why didn't you say, I've got a bogey at two o'clock.
SPEAKER_1: Give me a read.
SPEAKER_1: Call STRATCOM.
SPEAKER_2: Right?
SPEAKER_1: Throw some military terms in there.
SPEAKER_2: And we watched it long enough to see a hole in the clouds.
SPEAKER_2: We didn't know the clouds were there and we didn't know that there was a little hole in them through which the moon was shining.
SPEAKER_2: And finally the hole opened up and we could see and understand what we'd been seeing.
SPEAKER_2: But yes, people see things all the time and they don't necessarily attribute them to the correct cause.
SPEAKER_1: Seth, a lot of people, they think UFOs and alien visits are the same thing.
SPEAKER_1: So what's up with that?
SPEAKER_5: Well, I think that most people who are into the UFO phenomenon, and by the way, that's not a small percentage, it's one third of the public.
SPEAKER_5: One third of the public thinks there's his guy.
SPEAKER_1: One, two, three.
SPEAKER_5: There are 10,000, 20,000 sightings reported per year in the US, so that's a lot.
SPEAKER_1: So you know, there's a lot of people out there who are just hoping that we make contact with aliens sometime, someday.
SPEAKER_1: And I always wondered like how many people that is and how preoccupied.
SPEAKER_1: And so we need data on this.
SPEAKER_1: And anytime we need data, we need Mona.
SPEAKER_1: Mona, can I get some data, please?
SPEAKER_1: So Mona Chalabi, she's a data journalist, we call you that, for Guardian, the newspaper, and they have a New York office.
SPEAKER_1: And she's, I didn't even know until we met her that there's such a thing as a data journalist.
SPEAKER_1: So Mona, what kind of data do you have for us on aliens?
SPEAKER_6: So we're looking at public involvement in this stuff.
SPEAKER_6: And unlike some other scientific questions, actually when it comes to extraterrestrial intelligence, a lot of people try to find answers for themselves.
SPEAKER_6: So since 1974, the National UFO Reporting Center has existed and they've tallied up over 100,000 reports of UFOs.
SPEAKER_6: But as Jill said, actually the link between UFOs and aliens is misleading at best.
SPEAKER_6: But there is some cause for optimism here.
SPEAKER_6: There's one project to detect intelligence that seems to be offering some promise.
SPEAKER_6: It's called SETI at home.
SPEAKER_6: And just like Seth's SETI project, they use radio telescopes to listen out for radio signals from space.
SPEAKER_1: So SETI at home.
SPEAKER_6: Exactly, SETI.
SPEAKER_6: Let's call it SETI.
SPEAKER_6: So much easier than SETI.
SPEAKER_6: And no risk of saying STI by accident as well, which is quite good.
SPEAKER_6: So, it's called SETI at home.
SPEAKER_6: And just like Seth's SETI project, they use radio telescopes to listen out for radio signals from space.
SPEAKER_6: But doing that requires a ton of computer power, right?
SPEAKER_6: So they ask for volunteers to give them access to their own home computers to really, really up their game and be able to process all of that data.
SPEAKER_6: So far, 1.6 million...
SPEAKER_1: Wait, just to be clear, they commandeer your home computer while it's otherwise doing nothing.
SPEAKER_6: Right, with your permission.
SPEAKER_1: Yeah, with your permission.
SPEAKER_1: And it's in sleep mode or something, and so you might as well put it to use, because what else are you doing?
SPEAKER_1: You were having dinner while your computer happens to still be on.
SPEAKER_6: Exactly, and it's the first project of its kind, which is why the University of California Berkeley has done this, right?
SPEAKER_6: It's not just all about the search for extraterrestrial intelligence.
SPEAKER_6: And in that way, it's kind of been a huge success because 1.6 million people in 233 different countries have signed up.
SPEAKER_6: But you could argue that we shouldn't really be leaving this down to the enthusiasts.
SPEAKER_6: So in countries like France, Denmark, Sweden, and New Zealand, governments have transparent programs that allow people to find out about the search for ET.
SPEAKER_6: Maybe if the US government did the same, that would be a pretty cool thing.
SPEAKER_6: Until then, the search continues, thanks in part to an active citizen volunteer group.
SPEAKER_1: And the fact that that's open to the public in a way that's not embarrassing and that is some measure of the enthusiasm that the public has for this search.
SPEAKER_6: Absolutely, yeah.
SPEAKER_1: And so this kind of computing power, it's basically parallel processing, right?
SPEAKER_1: Because you have all computers doing this simultaneously.
SPEAKER_6: And you wouldn't be able to do it unless you were able to harness that many computers, right?
SPEAKER_1: Okay, so that's encouraging that people care in those numbers, which Seth, I think is well beyond the numbers of people who say they were abducted or otherwise come up with suspicious reports.
SPEAKER_1: So I'm just trying to account for the fact that we do have genuine interest in people's knowing whether we are alone in the universe.
SPEAKER_5: I think so, and there have been polls that show that 80% of the population of the country believes that they're out there.
SPEAKER_5: So it's hard not to be interested in something that you think is out there, and that might be as clever as your next door neighbor.
SPEAKER_4: Has that number gone up over time?
SPEAKER_5: It hasn't changed much, to be really honest, yeah.
SPEAKER_1: Well, thank you, Mona.
SPEAKER_1: Once again, Mona Chalabi.
SPEAKER_1: Tonight, we're talking about listening to the skies for a chance to make contact with an alien civilization.
SPEAKER_1: Yeah, and right now, it's time for Cosmic Queries.
SPEAKER_1: These are questions called from the internet, and they're all about the search for life in the universe.
SPEAKER_1: And anything I can't answer, I'm handing over to this guy.
SPEAKER_1: Okay, so let's do it.
SPEAKER_4: David Hamilton, Mayagas, Puerto Rico.
SPEAKER_4: Would it be more likely that any intelligent signal we detect is simply an echo of life now long gone?
SPEAKER_4: How could we tell the difference?
SPEAKER_4: And if we couldn't, can we still claim we aren't alone?
SPEAKER_1: Seth.
SPEAKER_5: Yeah, well, look, people ask that.
SPEAKER_5: You pick up a signal, it took, you know, who knows how many years to get here.
SPEAKER_5: Maybe they're gone.
SPEAKER_5: Well, maybe they are gone.
SPEAKER_5: But you know what?
SPEAKER_5: The time it takes for a signal to get here might be tens, hundreds, thousands of years.
SPEAKER_5: You know, the US.
SPEAKER_5: Post Office might give me a letter from my aunt tomorrow.
SPEAKER_5: And maybe my aunt has died since she sent that letter.
SPEAKER_5: It's possible.
SPEAKER_5: But the lifetime of aunts is pretty long compared to the function of the postal service.
SPEAKER_5: So the chances are she's still around.
SPEAKER_5: I think that if we pick up a signal, yeah, maybe it's a hundred-year-old signal.
SPEAKER_5: But I'd like to think that they haven't self-destructed in the last century.
SPEAKER_4: But I think it's a good question because ultimately does it matter?
SPEAKER_4: I mean, we're receiving this signal.
SPEAKER_4: That answers a fundamental question.
SPEAKER_5: Yeah, I think this is an important point because we've talked about the fact that maybe there's different kinds of intelligence and maybe we'll never understand the signal.
SPEAKER_5: I think that's pretty likely actually, but it doesn't matter because what you've learned is that what's happened on this planet has happened in many other places.
SPEAKER_4: Denny North, New Orleans, Louisiana.
SPEAKER_4: Could we send entangled particles to an extraterrestrial intelligence to communicate with them in real time?
SPEAKER_5: Well, you could send the particles, but the facts are that, you know, quantum entanglement, very appealing, but it doesn't allow faster-than-light communication, despite what many people think.
SPEAKER_5: Physics doesn't allow you to send information faster than the speed of light, unless Al Einstein is wrong, and he's never been shown to be wrong.
SPEAKER_5: Sorry.
SPEAKER_1: Yeah, even when he was wrong, he was right.
SPEAKER_4: Well, you're talking about the cosmological constant.
SPEAKER_1: Yes, exactly.
SPEAKER_1: Yeah, the cosmological constant, he put it in his equations, which would represent some kind of negative gravity in the universe, and turned out it wasn't necessary to be in his equation for the universe to expand, which he discovered a few years later after Hubble discovered an expanding universe.
SPEAKER_1: He said it was the biggest mistake, biggest blunder of his life.
SPEAKER_1: And then we would find the cosmological constant in the actual universe is called dark energy.
SPEAKER_1: And so I've concluded that Einstein's biggest blunder was saying that that was his biggest blunder.
SPEAKER_1: So even when he was wrong, he was right.
SPEAKER_1: That's how you know you're badass.
SPEAKER_1: Next.
SPEAKER_4: James Coltis Bentonville, Arkansas.
SPEAKER_4: If SETI discovered extraterrestrial intelligence, how long would it take to share the discovery to the public and what is the process involved with making it public?
SPEAKER_1: I would say a billionth of a second.
SPEAKER_4: Do you tell the president first?
SPEAKER_4: Does the president get to know first?
SPEAKER_5: No.
SPEAKER_5: Look, we don't have a call list.
SPEAKER_5: You know, start with this, William.
SPEAKER_5: I mean, we have had false alarms.
SPEAKER_5: In 1997, we had a false alarm that for most of the day looked like the real deal.
SPEAKER_5: And I kept waiting for the Pentagon to call, the White House to call, somebody to call.
SPEAKER_5: The only people that called were the New York Times.
SPEAKER_5: And the facts are that they were calling within hours of us finding the signal.
SPEAKER_1: Yeah, so this notion that the government is somehow in control, and no, this is not the case.
SPEAKER_1: The government is not that high functioning.
SPEAKER_1: That was it?
SPEAKER_1: Got the questions?
SPEAKER_1: We've been featuring my interview with SETI scientist, my colleague and friend, astrophysicist, Jill Tarter.
SPEAKER_1: And in this last clip, Jill shares with us some parting thoughts about the search for aliens and what that means in the cosmic perspective.
SPEAKER_1: Let's check it out.
SPEAKER_2: Our galaxy is 10 billion years old.
SPEAKER_2: We've had technology for 100 years.
SPEAKER_1: Technology to do this.
SPEAKER_2: To do this, yes.
SPEAKER_2: And so any other technology out there, statistically speaking, is going to be older than we are.
SPEAKER_2: So as the young kids on the block, as the newcomers, we should listen first.
SPEAKER_2: When we grow up, then we should take on the job of transmitting, the responsibility.
SPEAKER_1: When we grow up thousands, tens of thousands of years from now.
SPEAKER_2: When we can maintain ourselves as a sustainable, stable population and take care of the planet.
SPEAKER_2: Oh yeah, but I think that's what SETI is all about.
SPEAKER_2: I think in fact, that's the reason to do SETI.
SPEAKER_2: Because it requires you to think outside this planet, to have a bigger cosmic perspective, and to understand that relative to something out there, we're all the same.
SPEAKER_1: It's a search that feeds the growth of the cosmic perspective that lurks within us all.
SPEAKER_2: That's right, all for the good.
SPEAKER_2: I think we can't end up having a long future unless we all adopt that perspective.
SPEAKER_1: Seth, what's your take on that?
SPEAKER_5: It's exploration.
SPEAKER_5: It's exploration, it's like sitting around in the bars of Europe, you know, 300, 400 years ago and saying, what do you think, Ralph?
SPEAKER_5: Do you think there's a continent at the bottom of the globe, right?
SPEAKER_5: And you can say, well, what good is it gonna do to find it if it's there?
SPEAKER_5: What we will learn is that we're unique, yes, but we're not special.
SPEAKER_4: I'm special.
SPEAKER_4: But if we are actually alone, it would seem to me that our responsibility is even greater because if the universe has no other consciousness in it other than ours, it seems like we owe it to the universe to keep ourselves going.
SPEAKER_4: If there is no intelligent life other than us, then the universe itself loses meaning in a way because there's nothing to observe it.
SPEAKER_4: That was beautiful what I just said.
SPEAKER_1: Well, before we wrap this up, we want to make sure we get to hear from Bill Nye, the Science Guy.
SPEAKER_1: And so let's see if we can tune into our radio frequency to get Bill Nye here and now.
SPEAKER_1: Let's check it out.
SPEAKER_3: With technology like this, perhaps we can answer one of the oldest, deepest questions asked by all of humankind.
SPEAKER_3: Are we alone in the universe?
SPEAKER_3: Now the problem is the distance.
SPEAKER_3: The vast, hugely, enormously vast distances between our star, the sun, and say, the next one over.
SPEAKER_3: Which is four years away.
SPEAKER_3: At the speed of light.
SPEAKER_3: That's why scientists speculate that an alien civilization will not send a spaceship.
SPEAKER_3: Instead, they'd send a radio signal or a beam of light at some logical frequency.
SPEAKER_3: And after 50 years of listening, we haven't detected any signal.
SPEAKER_3: But if we did, it would be profound.
SPEAKER_3: It would change the way each and every one of us feels about being a living thing here in the cosmos.
SPEAKER_3: And one way to make sure that we never receive a signal is to stop listening.
SPEAKER_3: Back to you, Neil.
SPEAKER_3: Neil, can you hear me?
SPEAKER_3: Neil, Neil.
SPEAKER_1: You know, I think every one of ours, especially here in the United States, perhaps our first encounter with what aliens might be like is a movie.
SPEAKER_1: And can I count one or two movies on one hand that portrayed aliens as peace-loving creatures?
SPEAKER_1: All the rest just want to kill us.
SPEAKER_1: And I think there's only one explanation for that.
SPEAKER_1: Because in our own civilization, we know the consequences of a more advanced culture coming upon a less advanced culture.
SPEAKER_1: They get enslaved, they get disease-ridden, they get put in camps, or they get slaughtered.
SPEAKER_1: So, it disturbs me a bit, as an astrophysicist, to have we humans portray aliens based on how we know we would treat one another, rather than on how they might otherwise treat us given our highest and noblest causes.
SPEAKER_1: So, I don't fear sending out our return address to aliens.
SPEAKER_1: Maybe aliens are beyond us in every way, including their capacity to treat one another kindly.
SPEAKER_1: That's the movie I haven't seen yet.
SPEAKER_1: I'll be looking for it as part of the cosmic perspective.
SPEAKER_1: You've been watching StarTalk.
SPEAKER_1: I've been your host, Neil deGrasse Tyson.