StarTalk Radio - Cosmic Queries: More Space and Science with Bill Nye

Episode Date: May 31, 2014

Get schooled on space and science by guest host Bill Nye and Chuck Nice when they answer your Cosmic Queries about everything from evolution and carbon dating to gravity and the Doppler effect. Subscribe to SiriusXM Podcasts+ on Apple Podcasts to listen to new episodes ad-free and a whole week early.

Welcome to StarTalk, your place in the universe where science and pop culture collide. StarTalk begins right now. Welcome, welcome, welcome, ladies and gentlemen, boys and girls, kids of all ages to Star Talk Radio. Bill Nye here, sitting in for Neil deGrasse Tyson. And I'm here today with none other than Chuck Nice. Hey, Bill. And we are going to have cosmic queries. Yes, we are.

Questions from the cosmos submitted by you to Chuck. And Chuck, you not only have the questions, you have what they want to look like. That's right, I do. What they want to look like, because these are their avatars from Facebook and Twitter and what have you. And we have questions from all over the internet,

wherever we find a home. And... Before you go any further, I just want to point out that we are excited to have ge as a partner for this inaugural video cosmic queries head over to their youtube page to check out videos of how they are bringing imagination to life i'm talking about www.youtube.com slash ge yes we have a query yes we do let's jump right into this and go to Justin Connors, who's coming to us via Facebook. And Justin says this.

Since Mars' core cooled off much faster than Earth because of its higher surface area, wouldn't it have had a much earlier start than that of Earth? That is to say, how much sooner could Mars have been habitable than Earth? Also, what kind of period of time could Mars have had to develop and sustain life, and could you compare that to Earth? First of all, this is a fabulous question. It is a great question. And let me say, he worded it as best as he could, but it's not just that Mars has more surface area. It has more surface area relative to its mass.

It's a smaller thing. It has about as much surface area as the land of the Earth, the dry land of the Earth. Okay. And so the number that I hear people work with quite a bit for Mars is 4 billion years ago, it would have cooled off enough to have liquid water running around on mars okay so that would be pick a number half a billion or half a billion years before the earth so maybe it is just not it's not crazy but it's extraordinary to say that life started on mars mars was hit with an impactor about three billion years ago stuff

got tossed off into space through home and orbits a little mathematical fabulous thing uh these rocks with living things in them landed on earth and you and i are descendants from from those particular microbes so we are really martians it It could be. It's possible. It could be, but I'll tell you what it is. It is worth finding out. It is worth mounting a human mission to Mars to go look for signs of water and life. If we were to discover evidence of life on Mars on that other world, it would utterly change this one. In the same way astronomy has humbled us through the ages. Right.

We found out that we go around the sun, not the same way astronomy has humbled us through the ages right we found out that we go around the sun not the other way around right we find out that planets are if i made a dime a dozen maybe even cheaper than that maybe and so we're no big deal our star is no our sun is no big deal star wise and maybe life happens all the time and it's worth knowing as they say your world is getting smaller and smaller and you didn't even know it uh i didn't write this joke it's a good one go ahead it may be a small world but i wouldn't want to have to paint it so uh okay that's really actually a great question and uh pretty fascinating stuff let me ask you about the mars rover though as an addendum

to this question the curiosity rover the curiosity, as an addendum to this question. The Curiosity rover. The Curiosity rover. Because there's Opportunity Spirit and Sojourner. But right now we've got Opportunity running and Curiosity. Curiosity. Take it. Okay. So have they been able to determine whether or not there's been any, not life, of course,

but rivers, streams, things of that nature? Well, the place used to be very wet. Okay. And the Curiosity rover landed in essentially a stream bed. It's crazy. You see these rocks embedded in what was ancient mud that's solidified into rock. And then opportunity stumbled or rolled up to a layer of gypsum. This is the rock that you make wallboard out of right and

it is a mineral that only shows up when things are really wet like clays and so geologists you know they just can't get enough they're going crazy out of their minds but what we want to do is go to some place if i may even more interesting but to get to such an interesting place you have to be able to land more accurately the places we land these rovers are wide open spaces so that we can not crash very much right yeah because those are some expensive stuff let me tell you something okay opportunity curiosity together about three and a half billion dollars right spirit they're not even locked. Okay, anybody could just walk up to those rovers. It's weird.

You think somebody's up there with the club. The keys are in them. They're just sitting there with the keys. Yes. They're virtually bait cars is what they are. That's what I'm saying. They're like virtually bait cars. Surprise, the wheels are still on them after all this time.

All right, let's move on. I'm doing Doug McKenzie. Doug. And Doug wants to know this. I'm doing Doug McKenzie. Doug. And Doug wants to know this. I understand Doppler effect with sound, but give light speed properties. How does it catch up or pull away from itself to create red and blue ships? Oh, it's fabulous. So here's the cool thing.

Another good question. It's a fabulous question. This is the great thing to grasp about the Doppler effect. And by the way, full disclosure, my brother still dreams of starting a band called Christian Doppler and the effects. But his first name's not Christian. Oh, well. Anyway, that aside. It's like Hootie and a Blowfish.

Yes. That's right. Darius Rucker is actually Hootie. So tell your brother he could do that. It's totally fine. It is crazy. Okay, with this said, here's the thing to grasp, is the frequency is what changes, not the speed.

So it's a fabulous, subtle thing. When we do experiments on light to observe waves, we observe waves. Right. And if you can show or accept that sound travels in waves then you can by perfect analogy you'll have light travel in waves and get the right answer so as an object like a star moves away from us at extraordinary speeds dozens and hundreds of kilometers a second it stretches the waves of light and so they go to lower frequencies and it's you have trouble remembering this,

I strongly encourage you just to do a little Latin. Ultra means beyond. Ultraviolet is beyond violet. Infra means below. Infra is below red. So the red is the longer wavelength, and blue and violet are the shorter wavelengths. So when you go faster and faster away, your wavelength is stretched out.

The speed of light's the same. The wavelength is stretched out. And so the color, as we perceive it, the color changes. Fabulous question. That is really fantastic. So I suppose that's where we get Ultraman. That's right. Ultraman was beyond man.

Ultraman was beyond man. If the blinking light stops, I remind you, Ultraman. That's right. Ultraman was beyond man. Ultraman was beyond man. If the blinking light stops. That's right. I remind you, Ultraman may never rise again. Hyatta and the Science Patrol, Chuck and I will be back right after this. Welcome back to StarTalk Radio. Bill Nye, guest hosting for our beloved Neil deGrasse Tyson. I am here with Chuck Nice. That's right.

And you know what's cool, Chuck? What? Slow-mo. Even cooler, super slow-mo. Head over to GE's YouTube channel and get a look at what GE's up to with their super hydrophobic materials. And watch what it looks like when a T-1000 gets built. That's right. www.youtube.com slash GE.

That's it, ladies and gentlemen. That's it, ladies and gentlemen. That's it. With that said, before the break, Chuck and I got off on a little Ultraman tangent. Yes. Ultraman, for those of you unfamiliar, is a Japanese superhero. Yes, he is. And that he was Japanese was a big part of it. Yes, it was.

Because he was fluent in karate. He was a giant guy. He was a giant guy. He was from the science patrol. He was from the science patrol. Hayata was his civilian name, like our Clark Kent. Correct. Takes out his beta capsule.

Correct. He would become Ultraman. And for some reason, Ultraman had a light that flashed on his chest. Every week, Chuck, there's a monster. Every week there was a monster. And just shows you. From somewhere. From the bottom of the sea.

A monster would appear. Mountains, yes. And Ultraman had to be called. It's very stressful. Yeah. And it shows you something about our deepest fears. Right. That the unknown and monsters are trouble.

And I got to think it's related to the Japanese island's tendency to have earthquakes. I thought it was the fact that we dropped a bomb on them that was 100 million megatons. Well, it was about 30 kilotons. 30 kilotons. And so I think the monster thing goes back in Japanese culture way before that. Way before us. And can I name the artist you dropped a bomb on me? Was it – you dropped a bomb on me? Was it you dropped a bomb

on me and then you'd hear the bombing? I want to say Kool and the Gang. No, no, no. We have work to do. We've got work to do. It's on the tip of my tongue. Gap band. Gap band. You dropped a bomb on me. Okay. Here we go. With that, another question.

A cosmic query, actually. Oh, man. And just think what it was like conducting warfare without aircraft. Now we can't imagine it. And the whole world, as of this broadcast, the whole world is fascinated with whatever became of Malaysia Flight 370. Absolutely. Our fascination with flying is deep within us. And space flight is perhaps the ultimate expression of flying i would agree all right let's uh let's um take one from saeed uh who wants to know this all right saeed

saeed uh and his last name is roshan saeed roshan wants to know this will the earth ever increase or decrease in its size over life over its life over its life not our well i gotta think yeah now geologists i'm sure have pondered this question deeply it's a question of timing time timing will the sun expand and heat the earth before the earth has a chance to cool off? See, when you cool the metal of the inside of the earth, your nickel, your iron, your molten earth core, are you going to, you're going to shrink, but will the sun come out here and cook things up before that happens? I think the sun's going to beat us. As far as cooling the earth off, I wouldn't worry about it.

And let me remind you, one of the tremendous insights into the nature of geology, the nature of our place in space, people wondered quite reasonably, how could you have evolution happen over 3 billion years? How could the earth stay hot as it seems to have all this time? And you can tell the earth's hot inside when you have a volcano. Absolutely. Which we have now and then. That and the way Venus looks at us lets us know we're hot. I'm sorry.

Go ahead. I'm sure you're right, Chuck. I'm sure you're right. I've always kind of had a thing for Venus myself. I don't blame you. But that said, Venus stays really hot for other reasons. Anyway, the inside of the Earth has fission going on, nuclear fission, and that keeps it really hot. But eventually you would think, hypothetically, theoretically, things would cool off. But I think the sun's going to heat up and cook us before then.

Venus stays hot because of all its carbon dioxide in the atmosphere, which has run away with the greenhouse effect. So Venus, please, could that be our future? Will you talk about the greenhouse effect? Could it be? No, I don't think so. Venus is so hot. How hot is it? Thank you.

It's so hot that the ground, you would melt lead on the ground. You take your fishing weights. What? They would melt. Oh, my goodness. Your stainless steel cutlery would just bend, yield. So, furthermore...

Like a Salvador Dali painting. It would be. Really? But you'd be dead before you could appreciate it, probably. I mean, instantly. And then, furthermore, not only...

Wait, wait, there's more. It rains acid rain. Wow. Sulfuric acid. This sounds like an environmental disaster, this place. Well, Venus is like hell. And the guys who did the first in the modern era, not the people from the 1700s and the early 1900s. In the modern era, the people who discovered climate change on Earth, James Hansen.

Okay. June of 1983. All right. Testified in front of Congress. It was studying Venus, the atmosphere of Venus with telescopes, that people discovered the real effect of greenhouse gases. The deleterious effects of greenhouse gases. Too much carbon dioxide.

Wow. Wow. And by too much, we're talking about just a little bit too much. Just a little bit. Just a little bit. And that's all we need here is just a little bit too much. That's right. And it's game over.

Yes. But I think it's going to happen even if I whisper about it. Chuck, we have another query. You know I'm laughing because we do have a tendency to do that. When something's bad, we have a tendency to whisper

like, that's going to make it okay. But I remind you, the Earth can still hear you. We're now over 400 parts per million of carbon dioxide in the Earth's atmosphere. There you go. Even if you whisper about it. It's still going to happen. All right, let's move on to Matt Milligan.

And this is what Matt wants to know. Let's move on to Matt Milligan, and this is what Matt wants to know. Why does the light from stars go on for billions of light years, but the light from my flashlight will only go two feet? Oh, no. Oh, it does go. What's up with that? Good question. But first of all, let's remind us the light year is a unit of distance, not a unit of time.

It's speed of light times time. And that gets you the distance. And by the way, everybody, if you're out there having trouble with your distance equals rate times time problems, just relax. Just look at the units. If you're going meters per second times seconds, you're going to get meters. If you're going miles per hour times hours, you're going to get miles. Cheer, it's happy. Speed of light times years, you get a long way.

A light year. Right. All right. Now your flashlight. I used to sit on the beach particularly, and sometimes the forest, and shoot the light straight up, the flashlight straight up,

and wonder if there was somebody else out there on another planet, pick one, Rigel 12. Rigel 12. Who's doing the same thing. Here's lovely in the spring, by the way. It could be with the Rigelians. And is there a Rigelian out there shooting her or his flashlight back at me? And yes, the photons do go on forever. It's just they get so dim, your eyes can't

detect them. Now, in a room where you shine your light around, that light will get absorbed by your quilt in your bedroom. Got you. Even the paint of your walls is absorbed. What if you set up mirrors everywhere on all the walls and you turn on the light?

Would it bounce around forever? No. Even at 99.99999%, at the speed of light, things bounce around very quickly and it's all absorbed. And it's all absorbed. Turned into heat. Okay. Sorry, man. Reradiated in another form of light, but in general-

So it's still there. It's just kind of- Energy doesn't go away. Energy doesn't go away. It's still there. It's just like, hey, baby, this is what I am now. Gotcha. In those terms. I'm very scientific that might have been how the gap band would have expressed it

or people from that era from that era hey baby i'm just something else now i'm just all right i'm just an energy man all right let's Why? You know, we really don't have to. Okay. Oh, wow. This is a question directly for you. Okay. Let me see. Okay. I think we might have enough time. Hey, Bill, Matt here, student at Sacramento State University, California. Sac State. There you go. When we see an object of light away from us, we are seeing it in a year in the past. An object a light year from us, we're seeing it a year in the past. Okay. A reasonable way of reckoning. That's a reasonable way of reckoning.

Theoretically, if we are able to grow a tree, say five light years tall, with the aid of a telescope, would we be able to see the different ages of the tree as we look at its farthest branches? Say, for example, the tree begins to die near the ground, blah, blah, blah. The short answer is no. Okay. Because you can only see it at the speed of light. In other words, you can't detect that it's dying out there on the end of its five light year away branch.

Right. Unless you're looking at the light bouncing off the branch. So along this line, another interesting thing to interestingly think about. You say you're looking at light on distant stars. What's ever happened there has already happened. Right. Be that as it may, it hasn't happened here yet until the light gets here. Right.

And this gets into this thing of information theory. Like, although the thing landed on Mars 11 minutes ago, it hasn't landed on Mars here until the light gets here. Do-do-do-do-do-do-do-do. We will discuss this further right after this. Welcome back to StarTalk Radio. Bill Nye here, guest hosting, if I can use that verb, for Neil deGrasse Tyson. And people, check me out because I'm with Chuck Nice.

Yes. And it is fabulous. I don't think he's going to change his name. Not going to change my name. To Fabulous. Not to Fabulous. But he could. That's what I'm saying. Nah, that sounds too much like a rapper. Chuck Fabulous. What does Chuck Nice sound like? You know what?

A wimp. That's what it sounds like, young man. Certainly. He's nice. No one is afraid of Chuck Nice. That is for sure. And they should be. This guy will cut you. It's good, though. It's good. Oh, that's great.

Chuck, Cosmic Queries, your queries from the electric interweb that the kids are using. Yes. Very happy that you all took the time to write to us. And your questions, this show especially, have been just outstanding. We really have had some great questions. We have another one. Before we go on to the next question, very quickly, you didn't finish this because we had to come back for the break but we were talking the break very quickly about uh i said i think that we're so

science averse in our country because there's certain people who benefit from that because they have it gives them power some power it gives them power i mean that's just my own personal opinion and so this is especially true of military hardware. Okay. Historically, these scientists have been pressed into service. You know, Galileo, I guess Fraunhofer was pressed into service in science, in the military, using science in the military, making these extraordinary lenses and stuff. With that said, science democratizes knowledge.

Chuck, this may mean this more to me than it should, but it doesn't matter who shows you the earth goes around the sun. The man does not control what makes the earth go around the sun. Science is true for everybody. Science is knowledge outside of us. Everybody. True. Science is knowledge outside of us. What we hope to find in science are rules or laws or ways of looking at things that are true everywhere in the universe.

It doesn't matter where you're from, your ethnic background, how much money your ancestors made. The man does not control the facts of science. There you go. And that is an elegant, beautiful thing. So you and I and the regular host, Neil deGrasse Tyson, are working to change the world. So everybody listening to the broadcast right now, turn it up loud

as we take another Cosmic Query. Fantastic. That was outstanding, sir. Let's move on. Jerry Yitzi Sandberg wants to know this. If you could pour to the center of the Earth and not get burned to a cinder, let's suspense

some disbelief here, and hollow out a sphere in the geometric center of the Earth, how would gravity affect you then? Oh, it's cool. There'd be no gravity. So you'd be zero G? Zero G.

So what we recommend to you all is- Get yourself a drill. Well, take physics. Take physics. And a classic physics problem, which is every bit as much fun as what you just described, is drilling a hole, a hypothetically imaginary hole, through the center of the earth, and then big enough for pick an enchanting object a bowling ball okay and drop it through the hole in the center of the earth what happens

as the ball goes all the way through and then comes out the other side what happens uh does it shoot off into space no it falls back falls back through over and over with no aerodynamic drag and not bring burn to a cinder. Right. And this is a fabulous problem. And wait, wait, there's more. I'm a mechanical engineer. And one of my really satisfying technical jobs was working on this navigation system for drill bits.

This would be the technology that is the ancestor of modern fracking drills. No kidding. Where you can guide the drill, steer it underground. be the technology that is the ancestor of modern fracking drills, no kidding, where you can guide the drill, steer it underground with extraordinary precision. Like when they had this oil well leak in the Gulf of Mexico and it had to come in sideways. You can guide drill bits very accurately. And the moment you start going down inside the earth, there's less gravity. Wow. Do, do, do, do, do, do, do, do, do, do, do.

And these were detected by our accelerometers. This was at a company called Sunstrand Data Control, which is now part of Honeywell. And these accelerometers or excels, because we're so cool, these excels would detect micro Gs, millionths of a G. Millionths of a G. And so when you have a shell of material, this is a mathematical shell of material above you, it all cancels out. Wow. And so to those of you listening who have not taken physics and have not tried this

math problem, I encourage you to do it. These are both just outstanding, cool, insightful math problems that would come to us really from the discoveries made by isaac newton where were you when i was taking physics in school i don't know man man physics it is off it is all science is either physics or stamp collecting but that turns out that's from a different era it turns out now life science is so fantastically complicated that it kind of overwhelms physics, much as I love my physics. Take it. Sorry, I digress.

Imagine me digressing. We have a minute left in this segment, so I've got Derek Wilson here who has a really cool question. I think I know why he's asking this. How accurate is carbon dating really? Very accurate. The least long time ago where it was, the better, more accurately it is. This is to say-

See, that's what I was about to say. I think he's asking this- So here's how it works. Carbon-14 is formed in the air when you are a living thing and you stop breathing or stop transpiring if you're a plant. The carbon-14 changes to nitrogen and then back then down to carbon-12. And so the moment you die or stop breathing, this process happens. See, carbon-14 doesn't get refreshed. Right. And so it's extraordinarily accurate.

But do not confuse carbon-14 dating with how we've determined the age of the ancient dinosaurs. That's potassium-argon and uranium-uranium. And rubidium-strontium. We'll be back after this. Welcome back to StarTalk Radio. Bill Nye here, guest hosting for Neil deGrasse Tyson. And wait, wait, there's more, everybody. I'm not here by myself.

No, no, I'm here with Chuck Nice. That's right. Good to be here, too. And it's all that. It is. It's so good to have you here, Chuck. Oh, man, we're having a blast. What are we doing today?

We are taking what? Cosmic queries. These are queries. From the internet. Well, from the here, Chuck. Oh, man, we're having a blast. What are we doing today? We are taking what? Cosmic queries. These are queries. From the internet. Well, from the cosmos, Chuck. They are from the cosmos via the internet. Yes. They are.

Precisely. And we have quite a few people who've actually written in to ask specific questions of you, Bill. Wow, people got a lot of free time out there. I know because they're saying hey bill you know like will burke who wants to know this are there any locations in the solar system that you think we should focus more on sending a mission what benefit would we gain from doing so well we at the planetary society the world's largest non-governmental space interest organization advancing space science and exploration for the betterment of humankind, where we want everyone on Earth to know the cosmos and our place within it.

That Planetary Society encourages missions to all these worlds. Enceladus, moon of Saturn, that seems to have an ocean, and Europa, which has got an ocean. Saturn, that seems to have an ocean, and Europa, which has got an ocean. We want to go to Titan, where there are tides of methane and ethane, these natural gas kind of liquids. They're liquid because it's so crazy cold. Smells like a fragrant trip. And we would put sniffers on them, by the way.

Just keep in mind, if we were to discover evidence of life on one of these worlds, like Europa or Enceladus or Mars, it would change this world, utterly change this world. It would change the way everybody felt about what it is to be alive in the universe, alive in the cosmos. It would change us. And do you know what else we'd discover? What? Nobody knows. That's why we're going to go send missions to find stuff. If we send missions out there, we will make discoveries,

and we will have an adventure, an adventure shared by all humankind. If you talk to kids and you say, what's your favorite planet? They often, not so much as they used to, thanks to Neil, they'll say Pluto. That's so true. Pluto. Thanks to Neil. I'll tell you what. 2015, there is a mission going by Pluto, New Horizons.

It left in 2006. I was there at Cape Canaveral. It's the fastest rocket anybody's ever built, and it will get to Pluto nine years later in 2015, and we will make discoveries that will change things. Furthermore, when you invest in these missions, Chuck. Yes. You solve problems that have never been solved before. So true. So planetary science is what NASA does best right now. Yeah. missions chuck yes you solve problems that have never been solved before so true so planetary

science is what nasa does best right now yeah and nasa is the world's largest space agency by a factor of three so that is planetary science the line item within nasa which is in turn a line item within the federal budget which is in turn a economic entity in the world, that's where we invest to innovate and keep the United States in the economic game. Next question. Awesome answer, sir. All right. J.D. Prevost wants to know this.

If a planet had a slower axis rotation allowing the star that it's orbiting to heat the planet over a longer day, could a planet be further out of what we consider the habitable zone and still sustain life at similar temperatures as Earth? So bigger planet, farther out, longer day. Do all those things factor into- Let's back up. The Earth's day used to be, before we had clocks as far as it used to be, 18 hours in the ancient dinosaur days.

So that's a fact that's like 30% that the Earth is going a third slower than it used to. I did not know that. And we're here. We're alive. So you got to figure if you're farther out and turning slowly, if conditions are right, you could be a living thing. You got to, why not?

Who's to stop you? Wait, wait, there's more. The planet Mercury spins two thirds of a time for every orbit. And I don't think there are any Mercurians because it's too close to the sun from what we understand. Right. But there's ice in the craters of Mercury. Is there some place on some other world that's turning slowly that has some slush and there's living things in it i i don't know right

one way to find to make sure we never find out is to stay here not Not go looking. And not go looking. Exactly. Wow. That is very cool. That is, hey, hey, J.D., number one, great question. And number two, who knew that the Earth Day used to be 18 hours? Well, that's when you talk to the ancient dinosaurs, take a meeting with them. Well, really, they're the fossil ferns that are extant that are along with their fossils. Okay. You can infer a lot about the ancient environment. And then you look at silts and ice and things,

and you can infer a lot about how the earth is slowing down now, caused by tidal friction with the moon. And you can work backwards to how fast it must have been spinning in ancient times. Meanwhile, we've got to spin on out to a break. Welcome back to StarTalk Radio. Bill Nye here, your host, sitting in for Neil deGrasse Tyson. And I am here with none other than Chuck Nice. And tell you what, Chuck. Yes.

Yes, Bill. It's time for the lightning round. Yes, it is. Now, this is pure lightning round. That's all it is. No bells and whistles. Wait, wait. There are bells. That's all it is. No bells and whistles. Wait, wait. There are bells.

There are bells. There will be bells. So take it with a cosmic query in the lightning round, Chuck. And here we go. Let's jump right into this with Steve Hoseed, who wants to know this. I'm from Heartland, Wisconsin. My question is, when the New Horizons spacecraft reaches Pluto next year, what is the mission exactly? Take pictures.

Take pictures. Take pictures. Okay. Record some thermal data, radiation, some science instruments aboard, but pictures. Pictures that could, dare I say it, change the world. Change the world. Steve, I think the answer might be pictures. All right.

Jonathan Suto wants to know this. Bill, why do we give NASA so little money? How did that happen? If I were king of the forest, we'd give NASA more money. We at the Planetary Society getting

everyone in the cosmos to know our place within it and advancing space science and exploration lobby continually to get more money for NASA, the world's largest space administration, so that we will make discoveries that will not only change the world, but keep the United States in the economic game and lead the way. Not that the United States has to do everything, but space exploration is what the United States is good at. All right, next question from, I'm just going to say Ms. McNaughton because I can't pronounce her first name. And I'm sorry, Ms. McNaughton.

Here we go. Hi, from Binghamton, New York here. And my question is, what is your opinion of Stephen Hawking's time travel fourth dimension theory? Do you believe it is accurate? Don't know. Fantastic. It's cool to think about though Isn't it? It's riveting

And the fourth dimension Is time everybody It's not an extraordinary thing It's just time XYZ And time And time Alright here we go

With Jared Reese And Jared is from Minnesota Wants to know this Is it possible And or probable To use gravitational lensing With a Hubble-like telescope On the outer edge of our solar system.

What tangible benefits could there be to do this? I've heard that lensing could be enhanced with radio pictures. Radio pictures maybe. Wherever there's a lot of gravity, out, out, out there in deep space, like when you have a black hole, you can observe light, and in this case radio waves being bent by the gravity and that can give you tremendous insight into the whereabouts of black holes and their nature the more spacecraft we have out there the better as far as i'm concerned let's fly them fly them all there you have it all right philip brinkman would like to know this How do the advancements in technology affect our own evolution?

Are we still subject to natural selection, or do humans evolve only artificially now? P.S. Excellent job on the debate. Oh, thank you. Thank you for the postscript. Yes, humans are still evolving. The thing is, let's take me, for example. Please. No, I had appendicitis.

I'd be dead otherwise. If I run around having kids, that means those kids might have been not coming to existence. But wait, that's part of being in a tribe. As your tribe advances culturally, you have the potential for your individuals to advance culturally, and that's evolution. Could it be that if we go back in time and talk to the ancient Egyptians who built the pyramids, and they don't get any of our jokes, wouldn't that be weird because we've changed just in those 5,000 years? Whoa!

Nicely done. Here's what Susan Minogue wants to know. We don't get any of your jokes either, Bill. Take it, Chuck. Susan Minogue wants to know this. What happens to a black hole after it runs out of stuff to eat? That's very unlikely. So I guess it remains a very massive star sending material to other parts of the universe.

That's a good question. Good question. When the source of energy material stops coming in, people have speculated about what happens. It shrinks. And what I'd like to do is hold that thought, Chuck, till you have Neil deGrasse Tyson here who's so into his astrophysics. Whoa. All right.

James Lesperance wants to know this. Is it possible to have binary planet systems, much like a binary star system, with the gravitational pull of the star they orbit as with the pull of each other make it unfeasible? No, no. It's probably quite feasible. In fact, that's a fun physics problem. The old thing that we're crazy for, what's that? The three-body problem. Okay.

So the Earth and the moon the moon is like a traditional planet in a sense it's a gravitational body orbiting the earth and the earth and the moon are in turn orbiting the sun and it's nothing but fun to consider the earth and the moon as a system with a center of mass a center of gravity somewhere between us and that center of gravity is in turn orbiting the sun. So we do it all day. And when you get Jupiter with its four massive Galilean moons, I mean, that's like a whole binary, quaternary, quaternary, quaternary system. So, yes, it's possible.

Party on. Nice. All right, here we go. What engineering hurdles from Chris Noll, what engineering hurdles prevent us from traveling faster than the speed of light? Well, it's not engineering hurdles so much. As far as we know, the speed of energy is the speed of light. As far as we can tell.

You just can't go any faster. You just can't go faster. You start pumping in more energy, and instead of going faster, you become effectively more massive. That is to say you increase your momentum without increasing your speed very much. It's a complicated problem discovered in my father's lifetime, not that long ago. Hey, we're almost done. We are.

Thank you for listening to Star Talk. We've got to fly, Chuck. Bill Nye, the science guy with Chuck Nice. Bye.