SPEAKER_1: Chuck, that might have been the best Cosmic Queries ever.
SPEAKER_2: Yup.
SPEAKER_1: Grab bag.
SPEAKER_2: It was certainly entertaining.
SPEAKER_2: And if you want to know what happened, well, you're gonna have to listen.
SPEAKER_2: That's all there is to it.
SPEAKER_2: Not giving anything away.
SPEAKER_1: That's cold.
SPEAKER_2: No, that's how good it was.
SPEAKER_2: It's worth the listen.
SPEAKER_1: All right, coming right up.
SPEAKER_1: Welcome to StarTalk, your place in the universe where science and pop culture collide.
SPEAKER_1: StarTalk begins right now.
SPEAKER_1: This is StarTalk, Neil deGrasse Tyson, your personal astrophysicist.
SPEAKER_1: Chuck, you're the grab bag man.
SPEAKER_2: I'm the man with the bag.
SPEAKER_2: This is Youssef Kazwini, who says, greeting StarTalkers, Youssef from Damascus, Syria here.
SPEAKER_1: Damascus?
SPEAKER_2: That's right.
SPEAKER_1: Whoa.
SPEAKER_2: That's right.
SPEAKER_2: Ancient, ancient city Damascus.
SPEAKER_2: I found your podcast recently and I joined the club.
SPEAKER_2: Welcome aboard, my friend.
SPEAKER_2: Here's my question.
SPEAKER_2: You often mention photons travel at the speed of light at all times.
SPEAKER_2: Working as an optics engineer and dealing with TIRF microscopes, I wonder how evanescent waves during total internal reflection, TIR, is thought of from a particle physics perspective.
SPEAKER_2: Are the photons moving at the speed of light but somehow without propagating?
SPEAKER_2: Or the photons don't exist at all.
SPEAKER_2: But then, what is interacting with the sample on my microscope?
SPEAKER_2: Thank you.
SPEAKER_2: I love your work, PS.
SPEAKER_2: Chuck.
SPEAKER_2: You surely deserve an honorary Ph.D.
SPEAKER_2: by now, my brother.
SPEAKER_2: Oh, look at that.
SPEAKER_2: My brother.
SPEAKER_1: Optics is a huge field that does very important work on a lot of frontiers.
SPEAKER_1: Okay.
SPEAKER_1: Optics is what do you do with electromagnetic waves?
SPEAKER_1: Do you bend them?
SPEAKER_1: Do you reflect them?
SPEAKER_1: Do you trap them?
SPEAKER_1: Do you heat with them?
SPEAKER_1: What do you do with them?
SPEAKER_1: An entire branch of physics and engineering addresses those questions.
SPEAKER_1: So I don't know how specific the example is that he's giving and how that would lend itself to my explanation.
SPEAKER_2: Okay.
SPEAKER_1: Okay.
SPEAKER_1: So what I will otherwise say is the speed of light is not just a good idea.
SPEAKER_2: It's not just a good idea.
SPEAKER_2: It's the law.
SPEAKER_1: It's the law.
SPEAKER_1: Thank you.
SPEAKER_1: That's a dated reference to 55 miles an hour speed limit.
SPEAKER_1: When we went out and said we're not going to go fast anymore.
SPEAKER_1: So that doesn't mean light always travels at that speed.
SPEAKER_2: Exactly.
SPEAKER_1: It means it will never travel faster than that speed.
SPEAKER_2: Right.
SPEAKER_2: Because you can slow it down.
SPEAKER_1: So let's see how you do that.
SPEAKER_1: Okay.
SPEAKER_1: Turns out you sort of can slow it down.
SPEAKER_2: Right.
SPEAKER_2: I got you.
SPEAKER_2: So the medium itself can slow the travel.
SPEAKER_1: Yes.
SPEAKER_1: However.
SPEAKER_2: The medium.
SPEAKER_1: Okay.
SPEAKER_1: But the way it slows it down is fascinating.
SPEAKER_2: Interesting.
SPEAKER_1: Okay.
SPEAKER_1: So I'm gonna beam a light.
SPEAKER_2: Just going on about my business.
SPEAKER_1: Going about my business.
SPEAKER_2: Look at me traveling at the speed of light.
SPEAKER_2: Nothing can be faster.
SPEAKER_1: Nothing can be faster.
SPEAKER_1: Then you hit the air, or you hit a piece of glass or a piece of water.
SPEAKER_1: This is for visible light going through what we would say are transparent objects.
SPEAKER_1: If you're transparent, it means the light stays coherent as it goes through.
SPEAKER_2: Okay.
SPEAKER_1: So that the waveform maintains its structure.
SPEAKER_1: If it does not maintain its structure, light can still get through, but we would not call it transparent.
SPEAKER_2: Right.
SPEAKER_2: Yes.
SPEAKER_1: The other little word we have for that.
SPEAKER_2: Translucent.
SPEAKER_1: Translucent.
SPEAKER_2: Yes.
SPEAKER_1: And lucent means light in Latin.
SPEAKER_2: Latin, yeah.
SPEAKER_1: Luce is light.
SPEAKER_1: Luce.
SPEAKER_1: So the light comes up to the boundary.
SPEAKER_1: Some light will get reflected.
SPEAKER_2: Yes.
SPEAKER_1: And optics people know and understand that, okay?
SPEAKER_1: That happened no matter, you can't do anything about that.
SPEAKER_1: You can try to minimize it by having what are called these coatings that will delete any attempt for the light to reflect back.
SPEAKER_2: Bounce that, right.
SPEAKER_1: Right?
SPEAKER_2: Yeah.
SPEAKER_1: And you know, it's fun the way they do that.
SPEAKER_1: So you have a coating that's half the wavelength of the light that you're using.
SPEAKER_2: Interesting.
SPEAKER_1: Okay?
SPEAKER_1: So then the light goes through, and by the time it wants to reflect back, the light that's coming in is out of phase with it.
SPEAKER_2: Oh, so it creates a disruption.
SPEAKER_1: And it flattens out.
SPEAKER_1: It flattens the light.
SPEAKER_2: Look at that.
SPEAKER_2: I never knew that.
SPEAKER_1: Isn't that brilliant?
SPEAKER_2: God, people are smart.
SPEAKER_1: Yeah, so a coated lens prevents the reflections off of surfaces.
SPEAKER_2: Interesting.
SPEAKER_1: Okay?
SPEAKER_1: And cameras, especially zoom lenses and other big industrial cameras, they have many, many lenses in them.
SPEAKER_2: Yes, they do.
SPEAKER_1: You can't have light reflecting off of shiny surfaces at every time there's a surface.
SPEAKER_1: Okay.
SPEAKER_2: You just end up with a blob at the end.
SPEAKER_1: Just a blob at the end and all the light will be scattered everywhere.
SPEAKER_1: You got nothing.
SPEAKER_1: And when I say it reflects, because light will reflect off of practically any surface, whether or not it's a mirror.
SPEAKER_2: Yeah.
SPEAKER_1: That's what I'm saying.
SPEAKER_2: As a matter of fact, in photography, they have something called a bounce board, and it's just a stark, stark white.
SPEAKER_2: I forget the color of white.
SPEAKER_1: So it diffuses the light that it comes back to you.
SPEAKER_1: Otherwise, a flash can be very harsh.
SPEAKER_2: Exactly.
SPEAKER_2: So you bounce it off of there, and you get the light without the harshness.
SPEAKER_1: Without the harshness.
SPEAKER_1: So now you took care of that.
SPEAKER_1: Now the light enters the medium.
SPEAKER_1: Between molecules, light is moving at the speed of light.
SPEAKER_2: Gotcha.
SPEAKER_1: But it hits a molecule.
SPEAKER_1: I gotta deal with the molecule.
SPEAKER_1: I gotta go in and come out.
SPEAKER_2: Damn it.
SPEAKER_1: Yeah.
SPEAKER_2: Excuse me.
SPEAKER_1: Pardon me.
SPEAKER_2: Pardon me.
SPEAKER_2: Excuse me.
SPEAKER_2: I'm so sorry.
SPEAKER_1: Now I'm speed of light again until I hit the next molecule.
SPEAKER_2: Right.
SPEAKER_2: Oh, God.
SPEAKER_2: Here we go.
SPEAKER_2: It's like walking in New York City street behind tourists.
SPEAKER_2: Yes.
SPEAKER_1: Tourists are just in the way.
SPEAKER_1: In the way the New Yorkers are not.
SPEAKER_2: That's right.
SPEAKER_1: And I figured I analyze that.
SPEAKER_2: Go ahead.
SPEAKER_1: I figured out why.
SPEAKER_2: Why?
SPEAKER_1: May I say it?
SPEAKER_2: Please go ahead.
SPEAKER_1: I'll try to relate it to light going through a medium.
SPEAKER_2: Okay.
SPEAKER_1: Okay.
SPEAKER_1: Here's why.
SPEAKER_1: New Yorkers anticipate each other's trajectories because we've done this with each other before.
SPEAKER_2: It's a dance that we know.
SPEAKER_1: It's a dance we know.
SPEAKER_1: Whereas a tourist, they might step left unannounced.
SPEAKER_1: Nobody told you to step left because I'm about to pass you on the left.
SPEAKER_2: Who does that?
SPEAKER_1: But a tourist who is just ambling, looking up, ambling.
SPEAKER_1: And so you can't predict what their next move is, but for other New Yorkers you can.
SPEAKER_2: It's true.
SPEAKER_1: Not only that, there are people who are, I've walked perpendicular to people, they're on the sidewalk and I'm crossing the street.
SPEAKER_1: You time it so that you perfectly, you know exactly.
SPEAKER_2: No, it's a dance.
SPEAKER_2: It's a dance.
SPEAKER_2: You gotta live here to know the dance.
SPEAKER_1: Whereas the tourists will stop.
SPEAKER_1: Well now they just messed up my timing.
SPEAKER_2: Exactly.
SPEAKER_1: Okay, they'll look, they'll say, excuse me, pardon me.
SPEAKER_1: And you get people, I'm trying to get in the subway, okay?
SPEAKER_1: And a train just lets out.
SPEAKER_1: Tourists will wait for everyone to clear from the stair.
SPEAKER_2: No, you don't do, dummy.
SPEAKER_1: You make your path.
SPEAKER_2: They know you're coming down.
SPEAKER_2: They will move aside as they come down and you're going to, right, exactly.
SPEAKER_1: Just because it's a massive, you don't mean it.
SPEAKER_2: You just made me miss my train.
SPEAKER_2: You know that, right?
SPEAKER_2: That's what you did.
SPEAKER_2: Waiting in line to get on the damn stairs.
SPEAKER_2: What the hell is wrong with you?
SPEAKER_2: I'm late for work.
SPEAKER_2: And by the way, stand back from the doggone platform.
SPEAKER_2: Not that I'm worried about you or concerned about your safety.
SPEAKER_2: I'm late for work.
SPEAKER_2: You fall on the damn tracks.
SPEAKER_2: Guess what?
SPEAKER_2: Now I'm late.
SPEAKER_2: Okay.
SPEAKER_1: Anyway.
SPEAKER_1: How to give New Yorkers a bad name.
SPEAKER_2: I know.
SPEAKER_2: Anyway, so the light in the medium is bumping into the molecules.
SPEAKER_1: The molecules of the medium.
SPEAKER_2: But in between, it's traveling at the speed of light.
SPEAKER_1: Correct.
SPEAKER_1: So the combination of getting through the molecule plus the speed of light between molecules on average slows down the propagation of light through the medium.
SPEAKER_2: Look at that.
SPEAKER_1: This is called the index of refraction.
SPEAKER_1: And it's a beautiful mathematical construct.
SPEAKER_2: I love it.
SPEAKER_2: The index of refraction.
SPEAKER_2: Yeah.
SPEAKER_1: Yeah.
SPEAKER_1: So.
SPEAKER_2: Oh, I love it.
SPEAKER_1: And I'll tell you how it works.
SPEAKER_1: The index of refraction, you can use that in a formula to tell you how much the light will bend coming in or out of that medium.
SPEAKER_1: That's how you make a lens at all.
SPEAKER_1: Okay.
SPEAKER_1: But the index of refraction, if you take the speed of light and divide by the index of refraction.
SPEAKER_2: Go ahead.
SPEAKER_1: That's the speed of light in that medium.
SPEAKER_1: Ain't that something?
SPEAKER_2: That is really cool.
SPEAKER_1: Okay.
SPEAKER_1: So let's do the math.
SPEAKER_1: The index of refraction of diamond is 2.4.
SPEAKER_1: What is one divided by 2.4?
SPEAKER_1: One is like the speed of light.
SPEAKER_1: Divided by 2.4, what's the number?
SPEAKER_2: Point four something.
SPEAKER_1: Exactly, about point four.
SPEAKER_1: So light in diamond is going 40% as fast as it goes in a vacuum.
SPEAKER_2: In a vacuum.
SPEAKER_2: That's awesome.
SPEAKER_1: Isn't it?
SPEAKER_2: Oh, I love it so much.
SPEAKER_1: Yeah.
SPEAKER_1: And so diamond is one of the hardest natural substances known.
SPEAKER_1: It's hard for light to get through as well.
SPEAKER_2: Yes, it is, yeah.
SPEAKER_1: And even though it's transparent.
SPEAKER_2: Right.
SPEAKER_1: And before we get all emotional about light trying to get through the medium, visible light can't get through most mediums.
SPEAKER_1: Like a brick wall.
SPEAKER_1: The light just didn't go through at all.
SPEAKER_2: Yeah, it's just like, damn it.
SPEAKER_2: That's light trying to get through a brick wall.
SPEAKER_2: God damn it.
SPEAKER_1: If light were giving a voice.
SPEAKER_2: Right.
SPEAKER_1: Let's try the brick, no, no, let's try the steel, no, no.
SPEAKER_1: Damn it.
SPEAKER_1: But other wavelengths of light are transparent in these other substances, as you know.
SPEAKER_1: So your cell phone works in here because the walls are transparent to microwaves.
SPEAKER_2: Microwaves, right.
SPEAKER_1: Microwaves come right on through.
SPEAKER_2: No problem.
SPEAKER_1: No problem.
SPEAKER_2: They don't travel well through plaster, though.
SPEAKER_1: What are you talking about?
SPEAKER_2: Because my house, the walls are plaster.
SPEAKER_2: My house was built in 1898.
SPEAKER_1: I think there might be something else in your walls.
SPEAKER_2: Oh, you know what?
SPEAKER_2: You're right.
SPEAKER_2: You might have a metal lathe.
SPEAKER_2: Metal lathe, plus, so here's what it is.
SPEAKER_2: It's plaster, then it's wood, then it's lathe, then it's metal.
SPEAKER_1: I bet there's a metal mesh.
SPEAKER_2: It's a mesh.
SPEAKER_1: To hold up the plaster.
SPEAKER_2: To hold up the plaster.
SPEAKER_1: So you're in a Faraday cave, my son.
SPEAKER_2: Oh, my God.
SPEAKER_1: Faraday cave.
SPEAKER_2: That's what it is.
SPEAKER_1: That's right.
SPEAKER_1: If you're surrounded by a metallic anything, A metallic, yeah.
SPEAKER_1: Okay.
SPEAKER_1: Then the electrons in the metal will conspire to prevent electromagnetic energy from entering.
SPEAKER_2: That's why I can only hear the voices when I go outside.
SPEAKER_1: So that's why.
SPEAKER_1: Don't blame the plaster.
SPEAKER_1: Damn.
SPEAKER_1: Plaster ain't nothing to do with this.
SPEAKER_2: That's, wow, look at that.
SPEAKER_2: Okay.
SPEAKER_1: Yeah, back then they would put up the mesh.
SPEAKER_1: Yeah, you put the mesh.
SPEAKER_1: And hold the plaster up, because all of the little, the grid of the metal.
SPEAKER_1: So if you have multiple internal reflections, that's the light just going back and forth.
SPEAKER_1: By the way, by the way, check this out.
SPEAKER_1: Check this out.
SPEAKER_2: Are you ready?
SPEAKER_1: Okay.
SPEAKER_1: So if I have two media, two media with different indices of refraction, okay?
SPEAKER_1: So I have light coming up from one, it crosses the border, and it bends.
SPEAKER_1: Any time you go between two media, the path of light bends.
SPEAKER_1: The light bends.
SPEAKER_1: It will bend, okay?
SPEAKER_2: Right.
SPEAKER_1: That's why sunset happened five minutes ago.
SPEAKER_2: Right.
SPEAKER_1: Because the light bends.
SPEAKER_1: Going from the vacuum of space to our atmosphere, and it gave us an extra five minutes of sunlight because it refracted around your horizon.
SPEAKER_2: Nice.
SPEAKER_1: Okay.
SPEAKER_1: So it will bend.
SPEAKER_2: Okay.
SPEAKER_1: Now watch this.
SPEAKER_1: It comes up and it bends.
SPEAKER_2: Right.
SPEAKER_2: Yes.
SPEAKER_1: Suppose I take the angle of the light and make it steeper, like this.
SPEAKER_1: Then that will keep this come further and further down.
SPEAKER_1: There is an angle at which the light never enters the next medium.
SPEAKER_2: Oh.
SPEAKER_1: Because this bend now takes it backwards into the medium itself, and it's called total internal reflection.
SPEAKER_2: Oh, wow.
SPEAKER_2: That's something I avoid at all costs.
SPEAKER_2: That's why I can't sleep at night.
SPEAKER_1: So here, so that's that angle.
SPEAKER_1: It's still in the other medium.
SPEAKER_2: Bam!
SPEAKER_1: Now it's total internal reflection.
SPEAKER_2: That's pretty cool, man.
SPEAKER_1: It's very cool.
SPEAKER_2: I love that.
SPEAKER_1: And you can know exactly what that angle is, how to do that.
SPEAKER_1: And so if you have an optical system where the light is just bouncing back and forth, it is within the parameters of, or you can have just a reflective surface as well.
SPEAKER_1: Right.
SPEAKER_1: Just a mirror would do that.
SPEAKER_1: Yeah, just a mirror.
SPEAKER_1: So what you do inside your medium is your business.
SPEAKER_1: And what that then does to a beam of light.
SPEAKER_1: But yeah.
SPEAKER_2: Interesting.
SPEAKER_1: There it is.
SPEAKER_1: That's all I can do to illuminate.
SPEAKER_2: See what I did there?
SPEAKER_1: To illuminate that question.
SPEAKER_1: There may be other places to go in the physics of optics that I would not have known to touch.
SPEAKER_2: Very cool, man.
SPEAKER_2: What a great question and thanks, Yousef.
SPEAKER_2: And welcome to the club.
SPEAKER_2: All right, this is Vic G.
SPEAKER_2: He says, Hey there, Lord Nice, Dr.
SPEAKER_2: Tyson, Vic G.
SPEAKER_2: Here from California with a question for each of you.
SPEAKER_2: Are there any cosmic mysteries that you are most looking forward to knowing their resolutions, but sadly may not be resolved in our lifetimes?
SPEAKER_2: Bonus points, if you can name mysteries that we are so close to resolving, but it's probably just beyond our reach.
SPEAKER_1: Okay, you go first.
SPEAKER_2: Well, see, mine is the easiest because I just want to know what exactly is causing the acceleration and the expansion of the universe.
SPEAKER_1: Like everybody else wants to know that.
SPEAKER_2: Because that's everybody else's.
SPEAKER_2: But the reason is because I believe that it's a pressure from outside of our universe that bleeds through.
SPEAKER_2: That's what I think it is and I just-
SPEAKER_1: You think there's a puppet master.
SPEAKER_2: No, well, I'm not going to call it a puppet master.
SPEAKER_2: I think there's a bleeding.
SPEAKER_2: That's what I'll call it.
SPEAKER_1: An injured puppet master.
SPEAKER_2: An injured puppet master.
SPEAKER_2: Leakage.
SPEAKER_1: A leakage of pressure.
SPEAKER_2: Because if we were to find that out, now we have to explore the leak.
SPEAKER_2: And that means we're looking at a whole other universe.
SPEAKER_2: And to me, that's fascinating.
SPEAKER_1: That's interesting.
SPEAKER_2: Yeah, yeah.
SPEAKER_1: You have to then explore the leak.
SPEAKER_2: You gotta explore the leak now.
SPEAKER_1: Okay, I can't top that.
SPEAKER_1: That's good.
SPEAKER_1: No, I would say, I don't think we're gonna know, for sure, if there's life in the universe in my lifetime.
SPEAKER_2: Whoa.
SPEAKER_1: Intelligent life in the universe.
SPEAKER_2: Well, then you win the bonus points because that is something we are very, very close to.
SPEAKER_2: But it's very possible we may not find in our lifetime.
SPEAKER_1: Yeah, I don't think in my lifetime we will know that.
SPEAKER_1: What we will know in our lifetime is if there's any life at all.
SPEAKER_2: Outside.
SPEAKER_1: No, in our own solar system.
SPEAKER_2: In our own solar system.
SPEAKER_1: Okay, because we're looking at Europa.
SPEAKER_2: Right.
SPEAKER_1: We did a whole episode.
SPEAKER_1: We went to JPL, Cheprapulsion Lamps, NASA in Pasadena, talked to the Europa Clipper people, talking about what are they gonna do, what are they gonna measure it, what's beneath the ice.
SPEAKER_1: So, we will know whether or not there has ever been or is currently life in our solar system other than on Earth.
SPEAKER_2: Yes.
SPEAKER_1: I think that will happen.
SPEAKER_1: But, it would be sad if there is no life other than life on Earth.
SPEAKER_1: You know what has been said?
SPEAKER_1: How profound it would be if we discovered intelligent life in the universe.
SPEAKER_1: But, how more profound it would be if we discovered that we are alone.
SPEAKER_2: Listen, the second one is far scarier.
SPEAKER_1: It's a little scarier, isn't it?
SPEAKER_2: Than the first.
SPEAKER_2: Because that means...
SPEAKER_1: You kind of want neighbors, don't you?
SPEAKER_2: All of this was a mistake.
SPEAKER_1: No, it would feed many religious thinking that the whole universe is just for us.
SPEAKER_1: That's a face mistake.
SPEAKER_1: Some branches of Christianity, and perhaps other religions as well, require that life on earth be the sole object of God's creation.
SPEAKER_2: Okay, I'm just going to say it, and please don't judge me here.
SPEAKER_2: I'm being logical, and I'm thinking like God, all right?
SPEAKER_2: That's the dumbest crap I ever heard, and here's why it's stupid.
SPEAKER_2: I don't need to do all this, okay?
SPEAKER_2: I don't need to do...
SPEAKER_1: You're God, you're God speaking.
SPEAKER_2: I'm God right now.
SPEAKER_2: I don't need to do all this to show you that you're the only thing necessary, and good, and my central and crowning creation.
SPEAKER_2: As a matter of fact, all I really need is the sun, and the earth, because that's the energy system that makes all of this happen.
SPEAKER_1: Nothing else matters.
SPEAKER_2: Nothing else matters.
SPEAKER_2: So, if the sun, like a hydrogen atom, had just the earth going around it, then I would say, there is a God, and he made this just for us.
SPEAKER_2: But when you look at the vastness of the universe, and the trillions of galaxies, all of which containing stars, billions and billions of stars in each galaxy, to a place where we can't even fathom the number of celestial bodies that are out there, then what you're saying to me is, I'm stupid and I like to waste my time.
SPEAKER_2: I like to waste my time.
SPEAKER_2: That's what I'm doing.
SPEAKER_1: I'm saying that God is an inefficient manufacturer of worlds.
SPEAKER_2: Right, it doesn't make any sense.
SPEAKER_2: So either there's a lot more of us out there, not meaning us, but life, all over the place.
SPEAKER_1: This was Giordano Bruno's argument.
SPEAKER_2: Who was that?
SPEAKER_1: You don't know Giordano Bruno?
SPEAKER_2: I never talked about him.
SPEAKER_2: We never talked about Bruno.
SPEAKER_1: Bruno.
SPEAKER_2: Who's Bruno?
SPEAKER_1: He's a monk.
SPEAKER_2: I'm sorry, that just sounds funny.
SPEAKER_2: But go ahead.
SPEAKER_1: A 16th century monk.
SPEAKER_2: No, really?
SPEAKER_1: In Italy.
SPEAKER_1: Yeah, yeah.
SPEAKER_1: He had just read Copernicus' book, De Revolutionibus, which puts the sun back in the, I say back because the Greeks knew this, but it got lost in the Dark Ages.
SPEAKER_1: But the sun back in the middle of the known universe.
SPEAKER_1: He, religious man, God-fearing man said, hmm, if the sun is in the middle and not Earth, that means Earth is a planet.
SPEAKER_1: Going around the sun like Jupiter and Mercury and Mars and Venus.
SPEAKER_1: If the sun has planets, and we're life on a planet, maybe these stars in the night sky are just like our sun.
SPEAKER_1: And if they are, maybe they have planets.
SPEAKER_1: And if they have planets, maybe they have life.
SPEAKER_2: Right.
SPEAKER_1: Heretical.
SPEAKER_2: Oh, they killed him.
SPEAKER_2: They killed him.
SPEAKER_1: Because that meant Earth was not the object of God's creation.
SPEAKER_2: There you go.
SPEAKER_1: So they put him on trial, sentenced him to death.
SPEAKER_2: Oh my God.
SPEAKER_1: Burned him upside down, naked, in the Campo di Fioro, the piazza in Rome.
SPEAKER_1: And I think that's in Rome, not Florence.
SPEAKER_1: And they drove a steak into his mouth.
SPEAKER_2: To shut his ass up.
SPEAKER_1: So that even in the afterlife, he would not preach such a heresy.
SPEAKER_2: We don't deserve to be a species running for us.
SPEAKER_1: Okay, you know what one of his last words were?
SPEAKER_2: Let me guess.
SPEAKER_1: Okay, before that, okay?
SPEAKER_1: Okay, what was his last word?
SPEAKER_1: He says, he had a few good last words.
SPEAKER_1: My favorite among them was, your god is too small.
SPEAKER_2: Yes!
SPEAKER_2: Way to go out!
SPEAKER_1: Way to go out.
SPEAKER_2: Way to go out, man.
SPEAKER_2: Your god is too small.
SPEAKER_1: Too small.
SPEAKER_1: Your god is just earth and the sun?
SPEAKER_2: Yes!
SPEAKER_2: Yes.
SPEAKER_1: Yeah, so anyhow.
SPEAKER_2: Oh my god, okay.
SPEAKER_2: First of all, I'm gonna read up on this guy.
SPEAKER_2: Bruno is his name, huh?
SPEAKER_1: Giordano Bruno.
SPEAKER_1: Cool name, too.
SPEAKER_2: So check this out.
SPEAKER_2: Some people know my background, but one of my last words before I left my other life, my religious life, was over this whole idea of homosexuality.
SPEAKER_2: I never understood it.
SPEAKER_2: I still don't understand it.
SPEAKER_2: Like, why people have a problem with it, and why would God have a problem with it?
SPEAKER_2: I couldn't get around it as I'm studying to become, you know, a minister.
SPEAKER_1: But it's because it's in Leviticus.
SPEAKER_2: Yeah, but Leviticus is full of shit.
SPEAKER_2: Anyway, I mean, honestly, you know how many people have read Leviticus?
SPEAKER_2: Me being one.
SPEAKER_2: Okay, so anyway, so I, one of my last words.
SPEAKER_1: You know what someone told me?
SPEAKER_1: A Jewish person told me, Leviticus are just suggestions.
SPEAKER_1: Kind of.
SPEAKER_1: If they were important enough, they would have been a commandment.
SPEAKER_2: They would have been a commandment, right.
SPEAKER_2: No, seriously, the Levitical law, and by the way, it's a Levitical law for the priests.
SPEAKER_2: Okay, anyway, anyway, I said, a God that needs me to fight this battle for him is not a God I want to serve.
SPEAKER_1: Ooh.
SPEAKER_2: If God needs me to fight this battle.
SPEAKER_1: Almost sexuality.
SPEAKER_1: Yeah, right.
SPEAKER_2: If that's the battle that I gotta fight.
SPEAKER_1: Interesting.
SPEAKER_2: I gotta be worried about two dudes doing it.
SPEAKER_2: Like, that's what my God is all about.
SPEAKER_1: Two consenting dudes.
SPEAKER_2: Two consenting dudes doing it.
SPEAKER_2: Like, that's what I gotta worry about?
SPEAKER_2: I can't serve that.
SPEAKER_2: I gotta be out.
SPEAKER_2: Anyway, so I love this Bruno dude, and I'm gonna.
SPEAKER_1: Yeah, check him out.
SPEAKER_2: I'm gonna check him out.
SPEAKER_1: All right.
SPEAKER_2: Awesome.
SPEAKER_1: Oh, by the way, there's a memorial to him in the square.
SPEAKER_2: I'm sorry.
SPEAKER_1: Looking very.
SPEAKER_1: A little late.
SPEAKER_1: Sorry.
SPEAKER_2: God damn.
SPEAKER_1: He's got his monk robe on and he's very solemn there.
SPEAKER_2: Dear Darno Bruno.
SPEAKER_1: Yeah.
SPEAKER_2: Oh, I can't wait.
SPEAKER_1: I think it was 1601, something like that.
SPEAKER_1: Yeah.
SPEAKER_2: That's amazing.
SPEAKER_2: Wow, what a great, great story.
SPEAKER_2: I love it.
SPEAKER_2: Okay, this is Keith Coensburg.
SPEAKER_2: Coensburg.
SPEAKER_2: Coenigsburg.
SPEAKER_2: Yes, Keith.
SPEAKER_1: It was a K.
SPEAKER_2: It was a K.
SPEAKER_1: Yeah, yeah.
SPEAKER_2: Keith says, hello, Team Star Talk.
SPEAKER_2: This is Keith here, writing from New York, New York, big city of dreams.
SPEAKER_2: Here's a question I've been wrestling.
SPEAKER_1: It's like the first one we've gotten from New York, New York.
SPEAKER_2: That's so true.
SPEAKER_2: We don't get a lot of New York people.
SPEAKER_1: Right here in my office in the Hayden Planetarium, and we're getting from Syria, from Pakistan, from all kinds of Chile.
SPEAKER_2: That's cool.
SPEAKER_2: He says this, LIGO has used light waves to detect the shrinking and expanding of space caused by passing gravitational waves.
SPEAKER_2: But wouldn't the waves be in and out of the material of space?
SPEAKER_2: If space expands, don't your light waves stretch along with it?
SPEAKER_2: And any other measuring rod, as Einstein would say, and cancel out the change.
SPEAKER_2: So.
SPEAKER_1: Yes.
SPEAKER_2: Yes.
SPEAKER_2: Okay.
SPEAKER_2: Explain to me.
SPEAKER_1: What the hell he was actually saying?
SPEAKER_2: What the hell he's really asking?
SPEAKER_2: Cause I'm confused.
SPEAKER_1: What he's saying is we have a laser that bounces back and forth.
SPEAKER_2: Right.
SPEAKER_1: Okay.
SPEAKER_1: We measure the trip of that laser with very high precision.
SPEAKER_2: Very high precision.
SPEAKER_1: What he's asking is, if a gravitational wave washes over the measuring device, how's the measuring device gonna know if everything about it moves with it?
SPEAKER_2: I got you.
SPEAKER_1: Okay.
SPEAKER_1: So if I'm measuring your height, how tall are you?
SPEAKER_2: 5'10.
SPEAKER_1: You're lying, my foot.
SPEAKER_2: No, I'm 5'10.
SPEAKER_1: Okay.
SPEAKER_1: I'll give you 5'9.
SPEAKER_1: That's it.
SPEAKER_1: Okay.
SPEAKER_1: So you're 5'9, and I have a 5'9 tape measure, and you look at it and it says 5'9, right?
SPEAKER_1: Okay.
SPEAKER_1: Then we stretch both you and the tape measure.
SPEAKER_1: You're still 5'9.
SPEAKER_1: True.
SPEAKER_1: Unless you have some other way to measure what just happened.
SPEAKER_2: They're called Ron DeStantis heels.
SPEAKER_2: Anyway, sorry.
SPEAKER_2: Go ahead.
SPEAKER_1: Okay.
SPEAKER_1: That's like a news item from the eight years ago.
SPEAKER_2: Last year, but okay.
SPEAKER_1: Feels like eight years.
SPEAKER_2: Yeah, it does, doesn't it?
SPEAKER_1: So you're absolutely right.
SPEAKER_1: If I stretch you and the tape measure, you're still 5'9.
SPEAKER_2: Right.
SPEAKER_2: But we're talking about something washing over the measurement system.
SPEAKER_1: That's right.
SPEAKER_1: So now watch.
SPEAKER_1: It's because of that fact.
SPEAKER_1: That LIGO, Laser Interferometer Gravitational Wave Observatory, has two lasers at right angles to each other.
SPEAKER_1: So if one of them stretched moving that way, it's not stretching the other way.
SPEAKER_1: And it's those two path lengths that we compare with each other.
SPEAKER_1: That's how we know if a gravitational wave watched over us.
SPEAKER_1: We've got smart people designing this.
SPEAKER_2: That, first of all, is a brilliant question.
SPEAKER_2: And secondly, those people, they deserve the money.
SPEAKER_1: What money?
SPEAKER_2: Whatever money we gave them, they make LIGO.
SPEAKER_1: Oh, the funding.
SPEAKER_2: Yeah, whatever the funding was, they deserved it.
SPEAKER_1: The National Science Foundation, yeah.
SPEAKER_2: They deserve that, because that, first of all, what a simple, simple little answer to what could be altered results.
SPEAKER_1: Right, right, right.
SPEAKER_2: Interesting.
SPEAKER_2: I love it.
SPEAKER_1: So, 1915, Albert Einstein puts forth the general theory of relativity.
SPEAKER_1: A year later, he uses the general theory of relativity to predict the existence of gravitational waves.
SPEAKER_2: Right.
SPEAKER_1: But he doesn't think we'll ever detect them.
SPEAKER_2: Of course.
SPEAKER_1: Because the energy level is so low.
SPEAKER_2: How would you detect them?
SPEAKER_1: It was 1916, for goodness sake.
SPEAKER_1: That same year, he publishes a paper on the stimulated emission of radiation, which is the foundation for the laser.
SPEAKER_2: Right.
SPEAKER_1: One hundred years later, in 2016, or was it 2015?
SPEAKER_1: Ninety-nine or a hundred years later, we discover gravitational waves using lasers.
SPEAKER_2: Damn.
SPEAKER_2: Bro, Einstein was gangster.
SPEAKER_1: Gangster.
SPEAKER_2: He was gangster.
SPEAKER_1: Gangster.
SPEAKER_2: Okay.
SPEAKER_1: Gangster.
SPEAKER_2: That's like a chicken laying an egg so you can discover an egg.
SPEAKER_1: Okay.
SPEAKER_1: You made it way less profound.
SPEAKER_1: Normally, you would digest it into something more profound.
SPEAKER_2: I know, and poetic.
SPEAKER_1: But that was worse.
SPEAKER_2: It probably is, yeah.
SPEAKER_2: That's Einstein.
SPEAKER_2: He was gangster.
SPEAKER_1: Gangster.
SPEAKER_2: Oh, yeah, that's dope.
SPEAKER_2: That's really...
SPEAKER_2: God, if you...
SPEAKER_2: See, this is...
SPEAKER_2: You don't love science.
SPEAKER_2: If you get angry with people...
SPEAKER_2: If this does not make you love science, I swear.
SPEAKER_2: I'm gonna go kick your ass.
SPEAKER_2: You know what?
SPEAKER_2: You should go...
SPEAKER_2: You should get a dumb ass poker.
SPEAKER_2: Bang!
SPEAKER_2: Right up.
SPEAKER_2: That's what a big poker that's...
SPEAKER_2: Brands...
SPEAKER_2: Anyway, God, help me.
SPEAKER_2: So good.
SPEAKER_2: That is so good.
SPEAKER_2: Okay.
SPEAKER_2: Scott Jarbo says this.
SPEAKER_2: Hello, Dynamic Duo.
SPEAKER_2: My name is Scott Jarbo from Seattle, Washington.
SPEAKER_2: And you mentioned, I believe recently, that we cannot gather data from sending a probe into a black hole, as we would have no way to transmit any data collected because it could not escape the gravity of the black hole.
SPEAKER_2: Okay.
SPEAKER_2: So my question is, understanding we can't at this time, if we quantum entangled the instrumentation of the probe with a twin probe that was kept external, could we not record that data that way?
SPEAKER_2: And in fact, in general, would that not be a feasible mechanism for interstellar communication in faster than light speed?
SPEAKER_2: The state of each should instantaneously mirror.
SPEAKER_2: Is that correct?
SPEAKER_2: Quantum entangled.
SPEAKER_1: I'm not a black hole entangled expert.
SPEAKER_2: Okay.
SPEAKER_1: So it feels plausible that you should be able to entangle particles even though you lose one of them into the black hole.
SPEAKER_2: Right.
SPEAKER_1: It feels like you should be able to do that.
SPEAKER_2: They should know what the other particle is doing even though it's inside of a black hole.
SPEAKER_1: It should, but, and so, someone interacts with the particle that just went into the black hole, which then triggers the measurement of your, the one outside the black hole.
SPEAKER_2: You entangled the particle outside of the black hole.
SPEAKER_1: And that way you knew something happened in the black hole.
SPEAKER_2: Right.
SPEAKER_1: I don't see why that wouldn't be possible.
SPEAKER_1: I don't know what to say.
SPEAKER_2: Oh, you know I don't know what to say.
SPEAKER_2: You don't know what to say.
SPEAKER_1: I don't see why not.
SPEAKER_1: Okay.
SPEAKER_1: No, no, but they want to talk about faster than light communication.
SPEAKER_1: The problem is you're not, your thing has the information already built into it.
SPEAKER_1: Right.
SPEAKER_1: You can't after the fact change that information.
SPEAKER_2: Now that we know.
SPEAKER_1: So normally communication happens where, oh, turn left instead of right.
SPEAKER_1: All right.
SPEAKER_1: And if it's already built in, I can't do that.
SPEAKER_2: Right.
SPEAKER_1: And so there's still some jury that's out on how we will fully exploit quantum entanglement as a communication mechanism going forward.
SPEAKER_1: And from what I have read, it's less favorable than you want to believe it is.
SPEAKER_2: Okay.
SPEAKER_1: For these reasons.
SPEAKER_2: All right.
SPEAKER_1: Okay.
SPEAKER_2: All right.
SPEAKER_1: All right.
SPEAKER_2: This is James Peterson.
SPEAKER_2: Hello to my personal astrophysicist and personal science comedian.
SPEAKER_2: My name is James Peterson from Lacey, Washington.
SPEAKER_2: Here are my scenarios and related questions.
SPEAKER_2: Two manned spacecraft are approaching each other at a constant rate within a huge cosmic void.
SPEAKER_2: Neither one is accelerating or decelerating.
SPEAKER_2: They are no, there are no other visible or detectable objects within this cosmic void.
SPEAKER_2: Just the blackness of the vacuum of space.
SPEAKER_2: Neither of them knows if they are moving or stationary.
SPEAKER_2: They only know that they are approaching each other at roughly 20% the speed of light.
SPEAKER_2: What would be the reference point for each of them to determine their individual velocities assuming that they could compare rates of time on their clocks as they pass?
SPEAKER_2: Could the relative speed of their clocks be used to determine their individual velocities and individual velocities relative to what?
SPEAKER_2: Everything is relative, you know?
SPEAKER_1: Do all these people have jobs?
SPEAKER_2: Do they?
SPEAKER_1: To have the time to come up with questions like this?
SPEAKER_2: I know, it's just like, this guy, weren't you satisfied with two trains leave the station at the same time?
SPEAKER_2: One in Chicago, one in DC?
SPEAKER_1: He didn't stop there.
SPEAKER_2: He didn't stop there.
SPEAKER_1: So, what he's not getting right in the question, the simple point, is each of them does not know if they're moving.
SPEAKER_1: As far as they're concerned, they're stationary.
SPEAKER_1: So, he's saying, well, they approach each other.
SPEAKER_1: I don't know that.
SPEAKER_1: As far as I'm concerned, I am still in a void and I see this other craft coming towards me.
SPEAKER_1: There it is.
SPEAKER_2: That's the only thing that matters.
SPEAKER_1: That's it.
SPEAKER_1: And so, I will measure how fast he's moving.
SPEAKER_1: There'll be time dilation relative to me as a function of how fast it's going.
SPEAKER_1: It's not more complicated than that.
SPEAKER_2: That's it.
SPEAKER_1: We don't have to do a double calculation or anything.
SPEAKER_1: We will each measure exactly the same thing about each other.
SPEAKER_2: Because it's relative to the observer.
SPEAKER_1: It's relative to the observer.
SPEAKER_2: And so, each one of us will see the other ship coming.
SPEAKER_2: We will measure that.
SPEAKER_1: And we will think we are not moving along.
SPEAKER_2: And we're gonna still stay stationary as far as we're concerned.
SPEAKER_1: Correct.
SPEAKER_2: And when the ship goes by, it's like, whoa, did you see that?
SPEAKER_2: And that's gonna be the end of it.
SPEAKER_1: That's the beginning and end of it.
SPEAKER_1: And there were jokes back in 1905 when Einstein came out with this for the first time, Special Relativity, they try to ag them on, say, hey Einstein, when does Grand Central Station arrive at the next train?
SPEAKER_2: That's actually kind of funny.
SPEAKER_2: Damn, boy, haters no matter, there's haters no matter what.
SPEAKER_2: I know, even Einstein had haters, look at that.
SPEAKER_2: All right, so this is Vexonar, who says, greetings, Dr.
SPEAKER_2: Tyson.
SPEAKER_1: What's his, who?
SPEAKER_2: Vexonar.
SPEAKER_1: Vexonar, okay.
SPEAKER_2: Vexonar, who says, greetings, Dr.
SPEAKER_2: Tyson and Lord Nice.
SPEAKER_2: What are you putting in your time capsule for the next generation to open?
SPEAKER_1: Oh, so, so, so.
SPEAKER_2: Yeah, yeah, yeah.
SPEAKER_2: So.
SPEAKER_1: Go ahead.
SPEAKER_1: I just gotta say this, okay?
SPEAKER_1: And there's a book written on this, I forgot the name of it, forgive me, and I don't remember the author, but there's nothing less interesting to a subsequent generation than an earlier generation's time capsule.
SPEAKER_2: Wow.
SPEAKER_1: And the evidence of this is nobody remembers where any of the time capsules were buried.
SPEAKER_1: There's ceremony, there's mayor speaks, and then as things move on and culture advances and technology advances, no one cares what your sorry ass from 40 years ago thought was modern.
SPEAKER_2: Right.
SPEAKER_2: Exactly.
SPEAKER_2: Wow, look at this, a phonograph.
SPEAKER_1: I was in Flushing Meadow near the Unisphere.
SPEAKER_1: Tell everybody what the Unisphere is.
SPEAKER_2: It's the thing outside of the old World's Fair Stadium.
SPEAKER_2: It's a big giant globe, right?
SPEAKER_1: Yeah, yeah.
SPEAKER_1: I mean, it's the one that it's what anyone thinks of when they think of the Flushing Park.
SPEAKER_1: Okay, it's Earth.
SPEAKER_1: US.
SPEAKER_1: Steel created this for the World's Fair.
SPEAKER_1: And these three rings around it, evocative of John Glenn's Three Orbits around the Earth.
SPEAKER_2: I did not know that.
SPEAKER_1: I'm just saying, I'm just saying.
SPEAKER_1: So there I am, this is maybe 15 years ago.
SPEAKER_1: I'm just sitting on a bench.
SPEAKER_1: I forgot why I was there.
SPEAKER_1: I don't remember, forgive me, I don't remember why I was sitting on a bench in Flushing Meadow, because I don't live in Queens.
SPEAKER_1: Usually I'm just driving through Queens.
SPEAKER_1: But I'm sitting there, and I look down, and under the brush, here is a time capsule from 1965.
SPEAKER_1: It was like a time capsule buried in that spot.
SPEAKER_1: No one cared.
SPEAKER_2: And they just put a bench on it.
SPEAKER_1: No one cared.
SPEAKER_2: Nobody gave a damn.
SPEAKER_1: There's no memorial around it, no ceremony, nothing.
SPEAKER_1: We have a time capsule for the Rose Center here.
SPEAKER_1: And they asked me, what do I want to put in the time capsule?
SPEAKER_1: So I thought about it, I said, okay, I'll tell you what I put in it.
SPEAKER_1: I put a Metro card in it.
SPEAKER_2: Oh, and guess what?
SPEAKER_2: That's a good thing to put in it, because they don't exist anymore.
SPEAKER_2: So you weren't ahead of your time.
SPEAKER_1: So I put in a Metro card.
SPEAKER_1: I think I put in an iPod.
SPEAKER_2: Oh, okay.
SPEAKER_1: Okay.
SPEAKER_2: And interesting.
SPEAKER_1: This was modern stuff at the time.
SPEAKER_1: We're all excited about it.
SPEAKER_1: But who cares?
SPEAKER_2: Right, because both of those things are non-existent now.
SPEAKER_1: They're non-existent, and no one wants one.
SPEAKER_2: And nobody wants one.
SPEAKER_1: No one cares about them.
SPEAKER_1: No one wants one.
SPEAKER_1: We moved on.
SPEAKER_2: Right.
SPEAKER_1: So for me, time capsules, though they mean well, I think are one of the greatest misplaced investment of our attempt to communicate with the future.
SPEAKER_2: Okay, that's very cool.
SPEAKER_1: I don't want to be victim of that.
SPEAKER_2: I don't, right.
SPEAKER_1: No, I ain't putting nothing in it.
SPEAKER_2: I'm putting the transcript of every speech given by President Trump.
SPEAKER_2: Just the transcript, no audio and no, just the transcript.
SPEAKER_1: Just the words.
SPEAKER_2: Just the words.
SPEAKER_1: Okay.
SPEAKER_2: So that they could read it and go, what the?
SPEAKER_2: What the?
SPEAKER_1: Words of the most powerful person in the world.
SPEAKER_1: Exactly.
SPEAKER_2: The most powerful man in the world said these words.
SPEAKER_2: Okay.
SPEAKER_2: Let's see it.
SPEAKER_2: Thomas says this.
SPEAKER_2: Dr.
SPEAKER_2: Tyson, Lord Nice, greetings from Hungary.
SPEAKER_1: Hungary, love it.
SPEAKER_2: Yeah, way to go.
SPEAKER_2: In an earlier episode, Dr.
SPEAKER_2: Tyson said that mathematically, the horizon of the universe has all the same properties as the event horizon of a black hole.
SPEAKER_2: That got me thinking, if our universe would be a black hole, knowing that gravity has no limits on range, could the continuous falling in of matter into our black hole universe explain accelerating expansion of our universe?
SPEAKER_2: And if that would be the case, is there any possible way to detect such matter, since it would be at the edge of our known universe?
SPEAKER_2: Thank you for your work.
SPEAKER_1: That would be true, good question.
SPEAKER_1: That would be true if we were not expanding exponentially.
SPEAKER_1: Expanding, right.
SPEAKER_1: Okay, so the fabric of the universe is expanding, and because of that, there's nothing falling in.
SPEAKER_2: Right.
SPEAKER_1: It's taking it with it out to the edges.
SPEAKER_2: Yes.
SPEAKER_1: But if we were not that way, we just had our horizon, an object moving could just kind of cross our horizon and show up.
SPEAKER_1: It'll just show up, okay, if it moves in that way.
SPEAKER_1: Or you wait enough time, I should say that differently, wait enough time, that horizon washes over the next set of galaxies that are sitting there waiting to be seen by you.
SPEAKER_1: Because right now the horizon is 14 billion light years away.
SPEAKER_1: Wait a billion years, then it's 15 billion.
SPEAKER_1: That's a whole extra universe that's in your horizon.
SPEAKER_1: You know what the scariest day of them all will be?
SPEAKER_1: You wait another billion years, and there's no new galaxies to reveal themselves.
SPEAKER_1: It meant you reach the actual edge of the universe.
SPEAKER_2: Yes, not just the observable universe, but the edge.
SPEAKER_1: Of the whole universe itself.
SPEAKER_1: That's a scary day right there.
SPEAKER_2: That's kind of a cool day, though.
SPEAKER_1: It is kind of cool.
SPEAKER_2: Yeah.
SPEAKER_1: But it also means cosmology will evaporate, because at that distance we're seeing things that are that old getting born, but if there's nothing there, then the galaxies that a billion years ago were just born, they're now a billion years old.
SPEAKER_2: Right.
SPEAKER_1: And another billion years, they're two billion years old, and there's nobody new coming in that's just being born.
SPEAKER_1: Gone is cosmology.
SPEAKER_2: Look at that.
SPEAKER_1: Yeah.
SPEAKER_2: Wow.
SPEAKER_2: That is a scary day.
SPEAKER_1: I have it on my calendar.
SPEAKER_2: All right, this is Bill.
SPEAKER_1: This might be the last question, I think.
SPEAKER_2: Okay, last question.
SPEAKER_2: Bill gets the last question.
SPEAKER_2: Bill says, hi Dr.
SPEAKER_2: Tyson, Lord Nice.
SPEAKER_2: This is Bill.
SPEAKER_2: I made it easy for Chuck to say, shut up, Bill.
SPEAKER_1: This is how you pronounce Bill.
SPEAKER_2: He says from Banach, Banach, Scotland.
SPEAKER_2: And he says, I need some cheering up, considering the state of the earth in a few hundred years, maybe sooner if he whose name we shall not mention gets his way.
SPEAKER_2: From now, when humankind has finally turned Mother Earth against us, which species that exists just now, would you imagine will pick up the cloak of dominance that we humans held for a few thousand years?
SPEAKER_2: Will they have, will they be land-based, sky or sea-based or even amphibious?
SPEAKER_2: What is it about the species that leads you to that conclusion or do you see a bright future for us?
SPEAKER_2: And what that future would look like in the event we are still here in 25, 25?
SPEAKER_2: Ooh.
SPEAKER_2: A question that is, I'll say, laced with hope but yet very dark.
SPEAKER_2: Very dark and daunting.
SPEAKER_1: Yes, yes, is both hopeful and darkful.
SPEAKER_2: Yes.
SPEAKER_1: So I have some important replies to that.
SPEAKER_2: Go ahead.
SPEAKER_1: So first, there's a book written, forgive me, I don't remember the author, it's called After Man.
SPEAKER_2: After Man.
SPEAKER_1: Something like that.
SPEAKER_2: Okay.
SPEAKER_1: Okay.
SPEAKER_2: And is that like?
SPEAKER_1: What it does is it renders humans extinct and it looks at other animals to see what would become of them.
SPEAKER_2: Oh, I thought it was a woman who left her husband for a lesbian relationship.
SPEAKER_2: After Man.
SPEAKER_2: I am so much happier, I can't tell you how much better it is with no man.
SPEAKER_2: With no man.
SPEAKER_2: Which by the way, seems to be the consensus, by the way.
SPEAKER_1: Apparently, yeah.
SPEAKER_2: Anyway.
SPEAKER_1: So, so.
SPEAKER_2: After Man.
SPEAKER_1: And so I looked it over, I didn't read every word, but it's highly illustrated, it's intriguing.
SPEAKER_2: It is.
SPEAKER_1: Okay.
SPEAKER_1: What to think about.
SPEAKER_1: Okay.
SPEAKER_1: Now.
SPEAKER_2: Cause who would have bet on us?
SPEAKER_1: Consider.
SPEAKER_1: What's the largest animal there ever was?
SPEAKER_2: From what I understand, it is the blue whale.
SPEAKER_1: And it is alive today.
SPEAKER_2: It's alive today.
SPEAKER_1: And what kind of animal is it?
SPEAKER_2: It is a mammal.
SPEAKER_1: Mammal.
SPEAKER_2: Yes.
SPEAKER_1: Okay.
SPEAKER_1: Do you know the size of the smallest mammal?
SPEAKER_2: I don't, but I think it's pretty small.
SPEAKER_1: It can fit inside of like a teacup.
SPEAKER_2: Yeah.
SPEAKER_1: It's like this big.
SPEAKER_2: Yeah.
SPEAKER_1: I think it's a marsupial.
SPEAKER_2: Yeah, it's like a little shrew or something.
SPEAKER_2: Those are mammals, I think.
SPEAKER_2: Marsupials are mammals.
SPEAKER_1: It's some little thing, this big and the whale.
SPEAKER_1: So mammals have the capacity to not only occupy practically any size range, but practically any place on earth, they can figure out how to live there.
SPEAKER_2: And we are on every place on earth.
SPEAKER_1: Basically.
SPEAKER_1: We saw bacteria, but there's animals.
SPEAKER_2: We're a different kind of bacteria.
SPEAKER_2: We're more like a virus.
SPEAKER_2: I'm talking human beings.
SPEAKER_1: So, unlike reptiles and other cold-blooded creatures, they can't exist in cold climates, right?
SPEAKER_1: Because they would just freeze and die.
SPEAKER_1: But we maintain our body temperature no matter where we are.
SPEAKER_1: All right.
SPEAKER_1: The reason why I'm saying this is this book said, if that's the case, what's limiting the size of rats?
SPEAKER_2: I don't know.
SPEAKER_2: I'm gonna tell you.
SPEAKER_1: You ready?
SPEAKER_2: Go ahead.
SPEAKER_1: I could be wrong, but just put it out there.
SPEAKER_2: Cats?
SPEAKER_1: The size of, not New York rats, the size of the hole they will run into so that you don't harm them.
SPEAKER_2: Really?
SPEAKER_1: Okay?
SPEAKER_1: Just think about that.
SPEAKER_1: Yeah.
SPEAKER_1: Look in the subway.
SPEAKER_1: You see rats?
SPEAKER_2: Yeah.
SPEAKER_1: They'll crawl in.
SPEAKER_1: There's a hole they go into.
SPEAKER_2: There always is.
SPEAKER_1: There always is.
SPEAKER_2: No matter what rat you're talking about.
SPEAKER_1: There always is.
SPEAKER_1: All right.
SPEAKER_1: There's a hole.
SPEAKER_2: Yeah.
SPEAKER_1: Okay.
SPEAKER_1: If humans aren't here, they don't need the hole.
SPEAKER_2: Oof.
SPEAKER_2: Which is why you get some, they're not rats, but they are a part of rodentia in certain parts of the world where they're as big as like a small horse.
SPEAKER_2: Like a coppibari.
SPEAKER_1: The biggest rodent is, right, small horse.
SPEAKER_1: So rodents, which are one of the most successful branches in the tree of life, for how many they are and how many species they are, okay?
SPEAKER_1: How many species are there in the branch called Homo?
SPEAKER_2: I don't know.
SPEAKER_2: One, it's Homo sapiens.
SPEAKER_2: We're the only ones left.
SPEAKER_2: Because when you say how many species, I was trying to think of Denisovians and Homo erectus.
SPEAKER_1: That makes us quite fragile on the tree of life.
SPEAKER_1: Rodents.
SPEAKER_2: So many of them.
SPEAKER_1: So many of them.
SPEAKER_1: Okay, so this book foresees that basically rodents take over and they become huge.
SPEAKER_1: Like, people sized.
SPEAKER_2: Oh.
SPEAKER_1: Like rats that are people sized.
SPEAKER_2: That's scary.
SPEAKER_1: And there's nothing to...
SPEAKER_2: And nothing to stop them.
SPEAKER_1: Nothing to stop them.
SPEAKER_2: You dirty rat.
SPEAKER_1: And it talks about the aquatic creatures.
SPEAKER_1: What is it?
SPEAKER_1: The penguin gets really large or something.
SPEAKER_1: Right.
SPEAKER_1: So when you take away a predator, there's no longer a limit on the size of what it is.
SPEAKER_2: Okay.
SPEAKER_1: So, Earth after humans.
SPEAKER_1: I picture a natural history museum.
SPEAKER_2: With a bunch of giant rats walking through.
SPEAKER_1: Walking through.
SPEAKER_2: Looking at us.
SPEAKER_2: I know!
SPEAKER_1: And it's like, mommy, daddy, what is that?
SPEAKER_1: And there's like human skeletons.
SPEAKER_2: Oh, those were called dumbasses.
SPEAKER_2: They used to run the Earth at one point, sweetie.
SPEAKER_1: That's what I was talking about, the dinosaur.
SPEAKER_2: They ruled the Earth.
SPEAKER_2: So these dumbasses, what they liked to do was burn stuff.
SPEAKER_2: Dig it out of the ground and burn it, sweetie.
SPEAKER_2: And they would burn it and it would release something called carbon into the atmosphere.
SPEAKER_2: And then they all died and now we were-
SPEAKER_1: And then they kill each other for any reason at all?
SPEAKER_2: Oh yeah, and they also like to kill each other.
SPEAKER_1: You know?
SPEAKER_1: So that's the future of Earth.
SPEAKER_1: Because Earth and other life forms are going to survive us.
SPEAKER_2: Right.
SPEAKER_1: For sure.
SPEAKER_2: Right, exactly.
SPEAKER_1: All right, so don't stop there.
SPEAKER_1: This green movement, save Earth?
SPEAKER_2: No, Earth's gonna be fine.
SPEAKER_2: Save your ass.
SPEAKER_2: That's what you need to do.
SPEAKER_2: Earth gonna be fine.
SPEAKER_2: Save your ass.
SPEAKER_2: Your ass.
SPEAKER_1: That makes a lesser poster in March.
SPEAKER_1: Exactly.
SPEAKER_1: Save your ass.
SPEAKER_2: Save your ass, okay.
SPEAKER_1: So, but in terms of hope?
SPEAKER_2: In terms of hope.
SPEAKER_1: Here's the hope.
SPEAKER_1: Our boy here is from Scotland.
SPEAKER_2: That's right.
SPEAKER_1: I gave a public talk a few nights ago.
SPEAKER_1: Someone asked me what was my favorite song ever.
SPEAKER_2: Really?
SPEAKER_1: And you know what I told them?
SPEAKER_2: What?
SPEAKER_1: Amazing Grace.
SPEAKER_2: Okay.
SPEAKER_1: I think that's a song on a millennium.
SPEAKER_1: Amazing Grace.
SPEAKER_2: It's a beautiful song.
SPEAKER_1: It's a beautiful song.
SPEAKER_1: And you know how it's most beautiful-est?
SPEAKER_2: Okay, no.
SPEAKER_1: In bagpipes.
SPEAKER_2: Okay.
SPEAKER_2: I'm not a fan of bagpipes.
SPEAKER_1: You would be if you heard it in Play, Amazing Grace.
SPEAKER_2: You know.
SPEAKER_1: That's all I'm saying.
SPEAKER_1: Okay.
SPEAKER_2: I'm going to.
SPEAKER_1: And bagpipes, that's a Scottish thing.
SPEAKER_2: It really is.
SPEAKER_1: So what I'm saying is, when life in the world gets us down, we should hear chorus of bagpipes performing Amazing Grace.
SPEAKER_1: How sweet the sound.
SPEAKER_2: The Savior rich like me.
SPEAKER_1: Because we're all riches and we need saving.
SPEAKER_2: It's true.
SPEAKER_2: From each other.
SPEAKER_1: So Scotland may be the Savior of us all.
SPEAKER_2: Well, look at that.
SPEAKER_1: All right, we gotta go.
SPEAKER_2: We gotta go, right?
SPEAKER_2: Oh, man, man.
SPEAKER_2: That was fun.
SPEAKER_2: That was so much fun.
SPEAKER_1: All right, this has been yet another Cosmic Queries.
SPEAKER_1: What kind of addition?
SPEAKER_2: This is Cosmic Queries, grab bag.
SPEAKER_1: Grab bag with Chuck Nice, of course.
SPEAKER_1: Neil deGrasse Tyson here, your personal astrophysicist.
SPEAKER_1: Always good to have you, Chuck.
SPEAKER_2: Always a pleasure.
SPEAKER_1: As always, keep looking up.