StarTalk Radio - Extended Classic: Cosmic Queries – A Stellar Sampling

Episode Date: June 30, 2017

Extended Classic: Cosmic Queries – A Stellar Sampling by Neil deGrasse Tyson 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. This is StarTalk. I'm your host, your personal astrophysicist, Neil deGrasse Tyson. I'm here in studio with Eugene Merman. Eugene, welcome back. Great to be here, Neil. That sounded way too rehearsed.

But it's true. It is great to be here. Okay. But you're right. It sounded terrible. It sounded like a fake announcer. We are in a Cosmic Queries edition. Yeah.

That's one of my favorite kinds of Star Talk. And this one, people writing questions, and this is the cosmic queries edition that's one of my favorite uh yeah kinds of star talk and this one people writing questions and this is the grab bag this is a grab bag of all sorts of questions all sorts of we that we collect them in the bottom of the bin and we still think about you these are questions from all of our fans and yeah i mean this is literally from denmark why would you even bother merlin no this is what merlin asks merlin from denmark i know okay cool let's do it i recently found an article describing a relatively recently found uh quasar cluster which which apparently is too big to exist in the universe according to our current state of understanding i am wondering now of course how an object could be even be too large for the entire universe and also

what that exactly means for our understanding of the cosmos. No, so that's a great question. So I think there's a mix up of information there. So if there's an object, you have like galaxies out there, right? Sure. And then you have like pairs of galaxies and they know about each other because they orbit one another. They can have clusters of galaxies and they orbit like a bees in a hive would.

And so you can see that galaxies can know about the existence of other galaxies that are nearby and they create what we call a cluster. Now, if you have a cluster of quasars and they know about each other, but they're too far away from one another for the age of the universe to have allowed them to know about one another at the time they were created. Uh-huh. That's a problem. Yes. So.

It's definitely a problem. So, in other words, it's a coherent structure. Uh-huh. That is larger than the universe at the time would have allowed to have existed. Right, but now it's fine. No. Well, now it would have been fine, but back then, we're talking about quasars in the early universe. The early universe back then, the universe was smaller.

It was the size of like a pan, the size of a Marshalls. Pick a time and we can find a time in the universe where, pick a size, there's a time in the universe when it was that size. Marshalls. Marshalls, yes. A marble and adam yes a football stadium yes i see so so it's so it's a challenge when you have this it's you know the universe brims with mysteries we don't have it we don't have answers to name of of your band um all right here's a question from Nick. Christoph Wetterich, theoretical physicist at the University of Heidelberg in Germany. If he's a theoretical physicist, he should have no questions for me whatsoever.

Well, it's too late. This guy is quoting him. It's too late for me. Oh, he's quoting the other guy. Yeah, yeah. Oh, I thought there was a question from him. Oh, yeah, yeah. No, Nick is like expanding universe, and then this is the message. Christoph, a theoretical physicist at the University of Heidelberg in Germany, has recently.

That would be Heidelberg. Yeah. Just testing you. Okay. Has recently proposed an idea that the universe isn't expanding, but instead gaining mass. gaining mass. If the entire universe is gaining mass at the same proportions, it makes his theory impossible to test, though it remains mathematically possible. Nature News ran the article with a couple of opinions. Cosmologist Hong-Ang Sheng-Zhao, who thought it should be entertained and naish ashfordy an astrophysicist in canada who preferred the standard ocam razor approach have you read this paper whether you have or have not what are

your thoughts on or initial reaction to it okay thank you for having me read all these names that i have tried to do justice to. But you didn't even get the city right, so. Yeah, but that's because I was terrified that I was going to say Hong Kong Zhang Zhao incorrectly. So what we have going on here is a new idea that someone puts forth that could explain what we already know to be true, but in a new and novel way, right? There's a time-honored history of this going on in the sciences. In fact, Copernicus, who put the sun back in the middle of the known universe,

turning our geocentric world into a heliocentric world, his book called De Revolutionibus, that book, which is one of the most coveted books in the history of publishing that goes for millions of dollars at auction, if you want to pick up one from the original first edition. I would love to. Maybe I'll start a Kickstarter to buy it. edition, that idea was so heretical. To put the sun in the middle and not the earth, it is clear and obvious from any read of the Bible that earth is in the middle of all motion and everything goes around the earth. That's how any movement is described. And earth is stationary. So to say something that's not that is heretical and at the time punishable by trial and the inquisition.

punishable by trial and the Inquisition. So at the beginning of it, there's a disclaimer. And the disclaimer not written by Copernicus. It says, this is probably not true, but it makes the math a little easier. So for that reason alone, it's worth publishing so that the mathematicians can calculate where the planets are in the night sky. That's a good, great way around it. So the point is, if you have a new idea, it could be completely radical from what was prevailing at the time. And it could be right. It could be wrong.

First, you want to make sure it doesn't predict something that you already know is not true. And you want it to predict something that you haven't discovered yet. And that'll give you confidence that it's a real idea. And it's not just exactly mapping onto what you already know is true. If that's all it is, it's not useful. It's just somebody else's other idea. And you don't want it to turn it into a Rudyard Kipling- Just a big idea party. A Rudyard Kipling just so story. That's how the leopard got the spots. It got before this way. And here's how the elephant got its trunk.

You could just come up with another explanation. Right. That doesn't make it right. It's just another explanation. Right. And it's got to survive the testing. So you're not a fan of multiple origin stories. No, you want to make a prediction that we can test it.

And if the prediction fails, then we discard the idea. So I don't know the idea well enough to know what kind of predictions it makes. If it makes no predictions, it's not useful to anyone. Not anyone scientifically. Sounds like you're not a huge fan of theoretical physicists. No, that's why. Or they're fine. On a scale of one to 10, where would you put them? They're 11. That's a very disingenuous 11.

My wife is a mathematical physicist. I've got to say nice things. Okay, right. I don't want to ruin your marriage. What else you got? Okay. Well, is it a long question? Because we're running out of time in this segment. Yeah, it's longer than nine seconds.

You could do an outro. Okay. You are listening to StarTalk Radio Cosmic Queries Edition. I'm here with Eugene Merman. We'll be right back. We're back. StarTalk Radio Cosmic Queries Edition. Grab bag.

Stuff we found at the bottom of the bin. Yeah. Bottom of the bin questions. Every question matters. Each one from a conspiracy nut. Give it to me. Here it is. There are no conspiracy nuts who listen to StarTalk Radio.

No, there aren't. There are people with valid questions. All right. So what do you got? Gareth asks, I've read some theories that harp can be used to manipulate the weather is this possible yeah harp is uh high altitude radio pension i always forget i always forget the acronym yeah uh there are people who are sure that the government is stockpiling aliens and controlling everything about anything we would ever think about. And they clearly have never worked for the government because the level of

incompetence in the government and inefficiency knows no bounds, for starters. It's true that you could manipulate the weather like they did during the Olympics in China. It's not that you can't manipulate the weather. It's that whether you would really have any serious control. Well, weather happens in many places. So it comes about from the heat balance, from the energy coming from the sun, what it reflects off of, what it gets absorbed by, what the up currents do, what the downdrafts do, what the rotation of the earth is doing, all of this factors in. And so I have not been convinced by any of the reports to suggest that experiments in the upper atmosphere, physics experiments, are having any effect on our weather whatsoever. Right.

And it would be tragic if we wanted to say, oh, that's why it's getting hotter in the world. Okay? Because there's some experiment happening. That would be tragic because we would be missing the 900-pound gorilla in the room. Right. And then, but can you- The carbon dioxide gorilla. Yes.

Yes, the 900-pound carbon dioxide gorilla. All right. Here's another question. By the way, I don't think gorillas can weigh 900 pounds. Is that true? Yeah. The biggest one I've seen, so not 900 pounds. 500 pounds, yeah.

Not 900. So 900-pound elephant. Like a pumpkin i bet there's like a pumpkin that someone has made with a gorilla like a 500 gorilla holding a 400 pound pumpkin that would work yes that would be in the room which would also should attract attention um here's the question i don't know who it's from yeah is it possible to somehow direct pollution through our atmosphere and dispose of it in space all without harming our atmosphere love your show by the way thank you it depends on what kind of pollution you're talking about the dust so what you're saying is rather than pollute your rivers or your oceans you want

to pollute the space environment well since it wouldn't be since we'll throw it into space throw it at well you would you'd want to actually get rid of it either you drop it into a black hole drop it down into the sun yeah you'd want to actually get rid of it. You drop it into a black hole, drop it down into the sun. You'd want to actually remove the thing entirely. But would it matter to throw it into space? Would that be bad to someone? You have to calculate the energy it takes to throw it into space versus the energy it takes to completely break it down on Earth

into some non-pollutant ingredient. You don't want to send a whole thing of sporks into space because that's the way to dispose of it. And I don't know that sporks are destructible at all but so you'd want to not just scatter it into space space we might want to travel that one day so yeah but we wouldn't put so much pollution into space that we'd be like oh we can't get to mars i think they said that when they had built smokestacks. Oh, it's just a little bit of dirty air. Look how big the atmosphere is. Don't worry about it. Yeah.

All right. All right. I won't throw my trash into space. Let's have some foresight here. Next. Okay. George asks, if we take an open jar into space, to outer space, and close it once up, thereby filling it with the vacuum of space, what would happen if we bring it to Earth-level atmosphere

and even to the International Space Station? It would be the best vacuum we would have ever encountered on Earth, ever. Really? Yes. We can't make vacuums as good as space vacuums. Really? Yeah. Last I checked, we can't do it.

Unless somebody last week pulled one off. We can't have it as much as space is just top-notch. Space is a far better vacuum than anything we've been able to create in our laboratory. So why don't we always bring back jars of vacuum? I now have a new business where I'm going to sell jars of the best vacuum you've ever seen. But I like the way the question was worded. When the vacuum gets inside the jar, what happens is the air inside the jar escapes. By the way, once you put the vacuum in it

and then you bring it back to earth, what will happen is the inner surface of the glass and presumably a metal lid will outgas into that volume. Their gas is dissolved on the surfaces of all solid objects and it just stays there. It's molecules that are just stuck in the jaggedy surface of every solid object. If you now evacuate the center of that jar,

it dislodges those gas molecules, and so it'll then put some kind of gas pressure back in. If you're ever trying to create a perfect vacuum, you first vacuum it out, then you heat the sides of the container. That releases the gas that's attached. Then you vacuum it out again. So what would you bring into space to bring

the vacuum back home? Something that has a really, really smooth surface with hardly any gases attached to it. More smooth than glass. Oh, yeah. Oh, yeah. So glass is, yeah, way more smooth. And you could preheat it before you did this. You'd bring like Jon Hamm, just somebody who's super smooth.

He'd be like, yeah. All right. Oh, by the way, you might ask if, quote, unquote, nature abhors a vacuum, which, of course, it doesn't because most of the universe is vacuum. How come all Earth's atmosphere doesn't just rush out into the vacuum of space? It's true.

You might ask. Why doesn't it? A vacuum on Earth, we think of nature abhorring it because air wants to get inside the vacuum. Air wants to go into the vacuum. Air wants to go in because you are in a place where there's air pressure that wants to get inside. As you get higher up in the atmosphere, the air pressure gets less and less and less and less and less. Because there's less air above it pressing down.

And when you get less and less and less and less and less, the air doesn't want to do anything. It's got no forces. There's no air pressure to make it. It's just going to float away. Okay. So our atmosphere goes out thousands of miles getting ever so thinner as it gets out there. And so it's not that earth is holding the atmosphere down, although it is because earth has gravity and the gravity keeps the atmosphere

separate from the rest of the vacuum of space. But the air pressure out there has no urge to go anywhere other than just staying right where it is. yeah okay so uh here's the question uh from uh kyle kyle uh it is the same exact time everywhere in the universe like i know you've talked about how the moon and space station is on uh houston time because that's uh who they talk to but is the whole of the universe within the same a unit of time at the same time? Or did the vast expansion of the universe do something funky with that? Yeah.

I mean, different parts of the universe are moving at different rates and time has some relative aspects to it. So for example, the GPS satellites, the clocks on them tick at a different rate than clocks on earth's surface. Because when you move far away from a source of gravity, your time speeds up. So the clocks on the GPS satellites are not ticking at the rate of the clocks that they are informing down here on Earth. down here on earth.

The military puts a correction into the clock time you get from a GPS satellite so that it matches the time we need it to have here on the earth surface. So if you're in motion, if you're near a gravity source or far from one, your clock is ticking at a slightly different time from everybody else's. Then what time is it on Jupiter?

Well, so you go to Jupiter and set up a- Is it like 3.15? No, you set up a time system. So the way you want to answer that in an interesting way is you take two identical clocks, you put one on Earth and one on Jupiter, and watch what happens. The one on Jupiter will tick slower than the one on Earth. Really? Because of Jupiter's gravitational field slows down the ticking of the clock.

So one way to live forever is to go to Jupiter and sit there. No, you'll just live longer than you would on Earth. Right, right. Not forever. Sorry. Longer. Yeah, you'll suffocate and die of pressure. You would bring a jar of air.

Ignoring that complication, yes. You can go to Jupiter and live slightly longer than you would here on Earth. How much longer, actually? Let's say your life is 100 years. Oh. Like minutes or years yeah no minutes oh oh that's really not worth it sorry i got excited you're like yeah you'd live for 100 years in 10 minutes oh that's super not worth it it's minute i mean off the top

of my head i think it's the answer is minutes yeah yeah yeah all right here's a question yeah i'm writing you from kabul afghanistan and my question is we know the speed of light do we know the speed of dark and what is dark oh okay so philosophers like batman philosophers like asking questions such as that yeah the problem is if you align the verbs and nouns so that it makes something that sounds like a question doesn't mean that it's an actual legitimate question it's like saying what flavor cheese is the moon made of right that's a question it's a question it's a lit it's a literate watch out you're gonna spark a war in afghanistan i'm just saying so what is the speed of dark if dark is the absence of light dark has no speed at all so there's an answer it's zero well while the moon is not breathe so so just because we have a word for something that is the absence of light doesn't

mean the absence of light is a thing for you to then ask questions about right that's the point physically like i said philosophers go you know what is the sound of one hand clapping you know if it's doing it well it's still like this i don't know if you can hear it but that is literally one hand clapping it's not so bad clapping itself yeah yeah So then that's the backdoor answer to that. So dark has no speed because it, in fact, does not exist as an entity. What we call dark is the absence of light. We are StarTalk Cosmic Queries Edition. We'll be right back. StarTalk Radio, Cosmic Queries Edition.

Neil Tyson here. Eugene Merman there. Eugene. Yes. Comedian extraordinaire. Always great to have you on StarTalk. Always wonderful to come. We are Cosmic Queries edition grab bag.

Grab bag? Oh, you had more about darkness. Oh, yeah, yeah. Somebody asked from Kabul, Afghanistan. Yeah, what's the speed of dark? The speed of dark. By the way, at night. Great metal band.

In Afghanistan, where there are very few city lights, at night it gets really dark. So interesting that someone from Afghanistan is asking about dark and no one from New York city would ever ask about dark because they don't experience the, they don't experience the dark. So there's an interesting question kids sometimes ask. You can pose the question when you turn on the light, how do you know that light comes out of the bulb rather than darkness leaves the room and enters the bulb. Yes.

Is there an experiment that you can conduct? And the answer is yes. You can put up a thing in the middle of the room and detect light hitting one side of that object and you will not detect anything else going back towards the light bulb. If dark was a thing that had speed, you'd be able to... You'd measure it. You'd be able to measure it. Right.

And this is one of the hallmarks of science that is underappreciated. In science, we measure stuff. Yeah. And when you measure it, you can tag and bag it. You can... It's why you know that the universe

is probably not 5,000 years old. That's exactly right. You can't prove it, but you've measured that it's unlikely. What else you got? Okay, here's a question from Rafa from Norway. Let's suppose you encounter... I love these questions.

Yeah, I feel like we know that Europe listens. Okay, let's suppose you encounter an alien race. It looks like a three-meter-tall gummy bear. It has discernible anatomy parts but you don't have any idea of what uh what does what it makes sounds but of course you don't understand anything you are not sure that it has eyes you are not sure it has ears you're not sure if you touch it he would you are you do know it's a guy though you're like definitely a guy uh you you're not sure if it would react uh overreact and uh disintegrate you with a phaser or if uh it would be just toxic and make

you uh make you die instantly but you know that it is very intelligent and he understand at least college he understands at least college level mathematics physics chemistry and in general has a good background in sciences. How would you proceed in order to communicate with it? Yeah, okay. So what would you say if there's a – I see now that the question is what would you do to a three-meter tall gummy bear that's intelligent and studied our earth sciences? What, is it three meters tall? Is that the name?

Three meters tall, yeah. Three meters. So that's bigger than us, right? Yeah. Tall human. Three meters. So that's bigger than us, right? Yeah. Yeah, tall human is two meters. Yeah, and he's like, if you touch it, it might hurt you, which you would instantly already assume. Right. So, yeah, I wouldn't go for the appendages.

Plus, you know, if it extended something to shake your hand, you don't even know what part of its anatomy you're touching. Yeah, yeah. But it's a gummy bear, which actually is, he doesn't realize. No, he's just saying. It's shaped like a bear. It looks like a gummy bear. It doesn't mean it is a gummy bear. But it does have legs, arms, a torso, and a head.

I guess it would, but you don't know what the torso does versus the head. So you just don't even go there. So what I would do is I would take the vocabulary of the universe. By the way, even if I didn't know that he got A's in his astrophysics. He didn't say he got A's. He just said he had a pretty good student and made him B pluses. I would not have to know that he, this he, Gummy Bear, took these classes. I wouldn't have to know that.

I would know if he arrived here in a spaceship, the dude knows physics. Okay? So I would set up certain physics demos. You can't imagine somebody would put a dummy into a spaceship, send them here, and they'd be like, how'd you get here? And the dummy would be like, I don't, I have no idea. I really, I just walked into it. It was a bright light. All I have is this soup I brought from my world I mean think about Tom Brokaw famously said you

know I was at Tom I think it was Tom Brokaw you know I've been news anchor for 30 my whole my whole career and I still don't know how a TV works and most people don't know how to stuff works so it'd be unfortunate if they sent, you know. Someone who couldn't explain it. Someone who was impressed by our old cathode ray tubes. So if they got here, the dude knows some physics, right? So I would take out simple physics experiment, like, you know, the swinging ball experiment. I'd take some out, make sure they knew what that was. And you'd start to build a science vocabulary.

Because that is the only thing that is not only international on Earth, it is intergalactic. Right. You don't start speaking French. You don't start asking etiquette. You start understanding science and math. Understanding science. You start throwing up. You start your first things, or you throw up, and loud sounds upset you.

So I would start building a vocabulary of scientific methods and tools. And that way, we have a common place to to start and then you increment your way from there that's what anyone does even on a speed date right you start with you start with a science whether you do a science example on a speed date yeah um all right here's another question from gwendolyn uh gwendolyn wants to know is it possible to use quantum teleportation to explore inside a black hole since a teleported to explore inside a black hole? Since a teleported particle is not a light particle, it does not have to obey. Therefore, uh, would it be possible to send a particle in a black hole and get data from it?

Oh, uh, no. Black holes don't distinguish matter from energy. You want to go into a black hole? Oh, well, so what's happening? What if you wore a helmet? If you, so a black hole, you want to go in and then come back out again. Hawking radiation allows this. All the particles that enter a black hole will come out eventually

as the black hole evaporates by way of Hawking radiation. So that's a really slow way to find out what the inside of the black hole was doing. Could you go in a black hole, wait 10,000 years, and come out and be alive and fine? No, because your particles will go in one by one and they'll come out one by one. You'd have to reassemble who and what you were as well as your brain and your memory. We don't have that power yet. Not yet.

So just briefly Hawking radiation is particles get spontaneously created in the gravity field outside the black hole. The particle pairs, one falls back in the other escapes all the particles that escape. It's the same inventory as the particles that it had eaten over its entire life. It's an awesome fact of the universe. You're listening to Cosmic Queries Star Talk. We'll be right back.

StarTalk Radio. These questions came from the internet, StarTalkRadio.net, from Twitter, StarTalk Radio, from Google+. Yeah. Some of these emailed. Facebook. So give them to me.

This one's from Australia. And I haven't seen any of them. No. This one's from Australia, from Dave Willis. So if I don't have an answer, I'll tell Yeah. Yeah. Some of these emailed. Facebook. So give them to me. This one's from Australia. And I haven't seen any of them. No. This one's from Australia from Dave Willis. So if I don't have an answer, I'll tell you. Not the one who created Aqua Teen Hunger Force. So anyway, here's a question from Australia. Would you be able to explain the differences between black holes, supermassive black holes, quasars, and white holes?

I'm very interested in this subject, but any information I find is vague and sometimes contradicts previous info. In the 1970s, the black hole formula that told us what a black hole is and how it works, it was discovered had a second solution to it. And the second solution was the mathematical opposite of the solution that described a black hole. So a black hole, nothing comes out,

anything always goes in. The white hole, everything only ever comes out. Oh. And so people wondered, could a black hole be connected to a white hole through a wormhole in the fabric of space? I think you're describing zebras now. So anything that goes into a black hole

would then come out a white hole. And if that were the case, a white hole would be a highly radiant thing. And if it is, what are these radiant things at the edge of the universe? They're quasars. Could a white hole be a quasar? Mm-hmm.

So we mapped out what a white hole should look like. We looked at what quasars look like, and they don't match at all. No. So we have no evidence for white holes. So white holes might not exist. They likely don't exist in this universe. And if they do, they're full of stuff that would be awesome to have. That would be so awesome.

It would be energy. That's just pouring out of nowhere. Pouring out of awesome to have. That would be so awesome. It would be energy. That's just pouring out of nowhere. Pouring out of nowhere, exactly. That would be fun. So quasars, our current model for quasars, which is stable and we all sort of agree what's going on here, is that there is a black hole in the center of a galaxy. And it is dining upon material that comes too close. And the act of dining upon it, swirling down toilet bowl style, heats up the stars, the gas, and everything else, and it radiates profusely.

That is what we call a quasar phenomenon. And quasar stands for quasi-stellar radio source. It's a loose acronym for that because the energy is coming from such a tiny spot on the sky because it's the volume of a black hole in the center of a galaxy. They call it quasi-stellar because stars are points of light. These are points of light, even though they have nothing to do with stars themselves.

They're supermassive black holes dining upon matter that came too close. And there you have black holes, white hearts, white holes, quasars. All right. So here's a question. It's from Jay with enough resources and energy.

Would we be able to move the sun? And if so, would we come along for the ride? This is how diabolical evil people are. Yeah, this is how he's like, I'm building a machine. I don't think I have enough copper for it. All right. So yeah, and would we go along with it if we did i would just wonder why one would want to do this uh but if you move the sun yeah uh that would be hard yes the planets

would come along but you would disturb their orbits briefly they would resettle but in a slightly disturbed way so in other words we're orbiting where the sun is right now now you move the sun yeah we still orbit where the sun was right now. Now you move the sun. Yeah. We still orbit where the sun was for 8 minutes and 20 seconds because that's how long it takes gravity to reach us. Then we figure out, oh, the sun is now in a different place. Yeah. Our orbit no longer applies to the sun in the new place. So the Earth starts moving.

So then we say, well, we got to find a new orbit. It works. All the planets have to find new orbits if you're going to start accelerating the sun. The fact is the sun is already moving in orbit around the galaxy with all the planets and comets and moons and Pluto in tow. So we are already a moving system. And in fact, if you plotted this through space, the sun would make a sort of a straight line and all the planets would stay around the sun as they move forward. And you get this helical, beautifully artistic spirals. So the sun is already moving. We don't need to push it.

You don't need to push it. How much energy would it take to push the sun? Without blowing it up, I wouldn't want to put in the sun's worth of energy into it. Well, the sun is four times 10 to the 33 grams. So you do the math. So four to the 34 grams would that be enough neil no you have to find out how to do you can't push a gas so you have to figure out how to do this

you'd need a giant hand yeah all right this sounds complicated um all right one minute left okay here's a question uh from michael if hot air rises why is the temperature at the height that airplanes fly so cold? Ooh. Solid question. Nice. Michael Burns. Nice question. Well, the sun doesn't heat the air.

The sun heats the ground. Uh-huh. Basically, that's how that works. And there's a little time delay. The heat on the ground then heats the air. And that's why the hottest time of day is not 12 noon. It's a couple hours later. It takes time for the ground.

Yeah, it can be as late as in Texas, 4 o'clock, depending on where you are in the time zone. And so that can happen. Also, it delays the hottest month of the year from otherwise being June to being July and August. June has the most direct sunlight on the first day of summer. But otherwise, it's delayed. So these are the effects of what happens when the sun is heating the Earth. The hot air doesn't rise enough. When we come back, you'll find out why it's cold in airplanes.

Star Talk, Cosmic Clarity's Star Talk. Grab bag edition. We left off, someone asked a great question. How come it's cooler up in the sky, up in the atmosphere where airplanes fly if hot air rises? Yeah. The reason why hot air rises

is because it's less dense than the air around it. That's the only reason why it rises. So as it rises, it is looking for air that has the same density as it. Mm-hmm. And where does it find it? And where does it find it? And where does it find it? It could find it at any altitude.

But while that's happening, that pocket of air is expanding and cooling. So there's no such thing as a free lunch here. And this hot air does rise up, and that gives you thunderheads. Right. Thunderclouds or hot, unstable air. And you look at the clouds in stop action, you see the top of the cloud roiling as it rises up. And if this happens in a big way, you get cumulonimbus clouds and rainstorms and even hail.

But it'll reach the point where it's equal, and that point is not as high as where planes fly. Planes fly higher. We are in the lightning round. Eugene, I take too long to answer all the other questions. We're going to blow through this list. Yeah, good. This is an easy question. If the multiverse theory is true, is it possible to travel to other universes?

How would it be possible for us to exist in those universes if they have different laws of physics? Okay, it may be possible to travel to another universe, but I would not be the volunteer to do so. If it has different laws of physics, you could end up in a pile of goo because the forces that guide and control your molecules and atoms, if they're different, you don't want to be the first one to go. So you'd go to the second. Even if you could go to that universe, send somebody else. Great. Are there any plasma rockets that are close to being ready to go to Mars?

What is the time frame? How do they work? Yeah. He's like, is it true? Tell me how to build one. So that's my lightning round question. Yes, we do have plasma rockets. They're ion drives.

And they are not good for sort of launching things. They're good for slowly changing the direction. And they're good for very long trips. Yeah. Or if you're going to send cargo to Mars and you can take years to get it there, a high shelf life product, go ahead. But if you're going to move people, the ion drive is not a good option for people at this point. Would you ever use an ion?

It takes too slow to move you. Would you? Oh, okay. You would use it on Earth? No. No, no. Next. Good.

Great. If we could manage to build a spaceship that could accelerate at a constant 1G, could we leverage time dilation to reach the nearest galaxy within the lifetime of a human on the spaceship? The nearest galaxy within the lifetime of a human on the spaceship? The nearest galaxy, no. But you can definitely, if you could accelerate at 1G, and that way you can walk around in the spaceship as though you're on Earth, because you'd have a 1G acceleration, that would be cool.

No bone mass loss or anything, all these problems you hear about being in 0G. We can go ahead and do that. Go to the nearest stars and come back. And yes, time dilation, you'll eventually reach near the speed of light. Time dilation will allow you to not age very much, but people on earth will continue to age. And when you come back, everyone will have forgotten about you. Next.

Okay. It's my understanding that a black hole will just vanish and disappear. And at the end of its life, if that is so, and equals MC squared, what happens to the energy of all the particles the black hole has consumed? Ooh, so there's no such thing as a free lunch. So all the energy of the stuff that fell in, in Hawking radiation, it all comes back out again, and you leave nothing left behind. Great. Not even the smile of the black hole.

Next. Okay, a galaxy. Next. A galaxy several hundred thousands of light years across. How do we know what a galaxy actually looks like if we are not seeing the same time from the entire galaxy? Oh, great point. So the point is, if our galaxy is 100,000 light years across, and you're on one edge, you don't see the whole galaxy at once.

You see the nearby stuff as it was yesterday, the stuff farther away as it was a week ago, the stuff at the other edge of the galaxy as it was 100,000 light years, 100,000 years ago. You're not seeing the whole thing at once. So the best way to do it is to come above it and then all the light comes to you at once. Okay. And we have galaxies out there that are face on to us.

We see them all at once. And the galaxy is not doing nasty things over the 100,000 years that that takes. Galaxy lived for billions of years. It's not going to do anything really drastic in 100,000 years. Next. What will building the square kilometer array allow us to see in space? Oh, so what you want is huge, huge telescopes to make big buckets to see, get more light of any kind, radio waves, microwaves, X-rays.

In astrophysics, bigger is better. Mm-hmm. Period. Yes. So the square kilometer ray sees radio waves and microwaves, and you will look into the universe seeing things dimmer than you could have ever seen before because this will be the bigger telescope

than we've ever made before. So what we'll see is a lot more. That's what you're saying. Because you can see things that are bright or you can see dim things that you would not have even otherwise shown up.

Right. And so that's where discovery is made. So we'll be able to use it to see the movie Grown Ups 2. So you see it to see stuff

you could not have seen before. One more. Go. Okay, excluding size and distance from the sun, does Venus have more in common with the gas giants than the terrestrial planet? Venus is like our twin.

It is about the same size, the same gravity, nearly the same composition, except that it's 900 degrees Fahrenheit, and we are not. It has a runaway greenhouse effect, a carbon dioxide atmosphere that is nearly 100 times the pressure of what you have here on Earth.

If you go there, you will die. But it is otherwise a twin to Earth, appropriately called Earth twin, Earth's sister planet. You're listening to StarTalk. Stay tuned for another segment. This is StarTalk Cosmic Queries Edition. I'm your host, Neil deGrasse Tyson, your personal astrophysicist. I've got with me, as always, my co-host. Not as always, as sometimes. As sometimes.

As always. As sometimes alwayshost, not as always, as sometimes. As sometimes, as always. As sometimes, always. I'm always. Sometimes. Eugene Merman. And this topic today is science literacy. And I've got with me a YouTube star who is a science educator herself, Vanessa Hill. Vanessa, welcome.

Thank you. It's lovely to be here. You're up from down under, apparently. For a few years. I'm not so fresh, but I still... Do I sound fresh? Yeah. A little. You sound a little Aussie.

Good. I'd like to keep it that way. I don't know what else I would become. We'd love ourselves some Aussies here in the United States. Welcome. You've got a YouTube channel. We are here in YouTube Studios. Yes, I do.

That's the connection. It's called BrainCraft. BrainCraft. Very nice. Very nice. Yes, just the connection. It's called BrainCraft. BrainCraft, very nice. Very nice. Just like that. PBS Digital Studios. It's a PBS Digital Studios show. So they're in the game. Very nice to hear that. Yeah, doing lots of cool educational content and it's just youtube.com forward slash BrainCraft. Go watch. Okay, all right. And so this set of questions pre-solicited are on science literacy. So we'll get to compare our notes being both kind of in the business, right? All right.

So Eugene, what do you have? Adam Fazio from Facebook asks, In the information overload era, how do we determine what to pay attention to? How do we convince others to pay attention to impartial database information when it's not as sexy or scary as the mainstream media or advertising, which is carefully engineered to play to our psychology.

I wish I had just a short and concise and really good answer for this, but it's so complicated. That sounds completely like a question you should answer. Well, I think in the internet age as well and on YouTube, clickbait and sexy thumbnails and things like that play into this so much where with pbs like how can we get our pbs information

over through all of that well through the the buzz feeds of the world right and it's really really difficult and it's a i think a fine line between education and entertainment to try and get that information out to people edutainmentment. Yes. Possibly. But isn't that a horrible word? You don't have to say the word. You can just do it. Yeah. Yeah. So what's your answer?

Ask me the question again. How do you get people to focus on the data and the information? How do you make basically science, I guess, science sexier and more fun. Yeah, I guess the way that we do it is just, I mean, as YouTube shows, just through sexy visuals in a way. Like we have lots of cool animation.

We like to try and draw analogies to things. You do this every week? I do. We have a lot of shows. How do you have it in you every week? I'm a shell of a human. Man. I don't have that much in me.

I hate the words information overload because I'm like, I can't fit a single thing into my brain. It's full. But, I mean, it's interesting, though, because there is so much information out there. And sometimes the credible news sources aren't the sexiest news sources. So I think it's hard. I don't think there's a perfect answer for it. I think we can possibly just try to share credible news and not this fake news that we keep hearing so much about. But then sometimes it's hard to spot. So I think we need to think critically. We need to be discerning. And I think we need to be open to information sources that maybe aren't just like

little pieces of candy right yeah longer yeah like a more of like a piece of chicken yeah yeah less candy more chicken something substantial yes yeah so i have two reactions to that question one of them is the older you are the more likely you are to say the following sentence. Yeah. I suffer from information overload. I thought you were going to say back in my day. Yeah. So what I found is older people cannot keep pace with the level of information that's coming out.

Right. keep pace with the level of information that's coming out. Right. The emergent. Whereas younger people, whether or not they can or can't keep pace, they don't feel overloaded by it. I don't know anyone 20 and under who walks away from their computers and say, I'm overloaded by information. This is not their state of mind.

Right. It is a playground. It's an information playground to them and they embrace every bit of it. I remember before the Google search engine, there was a big joke that went around. The internet is great. It's a great library, except all the books are scattered on the floor. And you didn't know how to make sense of them. Google search it. So now that's not a joke anymore. It's all right. So now we can search it. But now you can search something that's not true and find everyone else in the world who

believes that not true thing, thereby affirming your not true idea, making you think that it's mainstream. That's one of the problems of the search engines. So there ought to be a way to rank the integrity of information in a search so that you can then choose, do I want high integrity information or low integrity information? And maybe some days you want low integrity information and just have fun there. It's got to be a playground of weird cockamamie ideas. I would love to learn a bunch of lies and then apply them to my life. But really, I think it's right now the educational system doesn't have as any part of it, internet intelligence. So you think that the educational system should prepare us to appreciate or to hear.

To be discerning. So that when it is time to learn what is true, you put in your truth filter and then you know how to interact with all of this information. So we need to build a truth filter into the curriculum. Into the curriculum. That is our answer. That is our answer. That's definitely going to happen. Okay. So we need to build a truth filter into the curriculum. Into the curriculum. That is our answer. That is our answer. That's definitely going to happen. Okay. All right. So optimistic. Jamie Robertson asks, a lot of science journalism is faulty,

using hyperbole, misconstruing findings, and giving the people the impression that the evidence is stronger than it is, and can create the illusion that scientists are always changing their minds, and thus have no idea what they're talking about. How can we combat this? I think this feeds perfectly into the last question because a lot of writers report on science who aren't specialized science writers. And then a lot of science writers just need to get clicks on their articles to get paid. So they put the hyperbole in. So it makes the article seem more appealing. Because if we're thinking about science journalism and reporting super accurately on things,

you can report a study, you can talk to someone else, and then at the end it's like, well, we're not quite sure because we need to do more research. Yeah, it doesn't make a good lead-in. Yeah, and it's not a good conclusion. So you almost need to take a side in a way to make it an interesting article. I've had a lot of trouble with this professionally because all of my- Where you write a bunch of lies because it's a little more fun. Where my conclusions have been, well, everything in moderation. Oh, we're not quite sure.

We need to do more research. And it doesn't make a good story. So I think it's a problem between balancing the facts and the realities of the process of science, which is slow. And it's not that sexy sometimes because it takes years and years and years with something that makes a good story that will get clicks on articles or sell newspapers or whatever. And by the way, the rabbit hole goes even deeper than that. where they issue a press release based on research that was conducted by the research community, there's usually a little bit of extra hyperbole there or certainty that is not actually there. So the source press release on which journalists base their story has some of that already built into it. And so I think my community at the community of scientists

in general and our institutions that want the publicity yeah you know you're you want your university be mentioned in the New York Times or the LA Times yeah I'd like my university or I'm coming up for tenure and if you write about my you do a story on me that's that's always looks good, right? So I think there are two sides to that fence that need to be tended to. And so I think, again, getting back to the educational pipeline, not only do we need to be internet savvy, but we also need to know what science is and how and why it works. So you're saying education can solve all of our problems. What a concept! That is the theme of the half-day. Was that brilliant of me? Yeah. It was so innovative of me to tell you that. So no but if you learn

that science is a way of querying nature, and it takes multiple scientific experiments to arrive at an emergent truth. Then the article that says, new scientific result changes everything. No, it doesn't. It hints that maybe if it's confirmed by other experiments, it changes everything, but no one experimented. But the journalists jump after those single papers. A lot of the popular news media do as well. You can watch every breakfast TV

program. There will be study says, red wine's good for us and chocolate's good for us. Please watch my TV show. Please don't change the channel. I'm just going to report on all of these single studies. Wine. Wine. Pretty good for you. Next question. I'm not giving up the wine and chocolate.

I want to believe. The wine and chocolate. I don't care what they say about the wine and chocolate. No, no, but here's the thing. Here's the thing. So if they say wine and chocolate is bad for me, then my response should not be, I don't believe it. My response should be, and if that's a truly emergent scientific truth my response should be thank you for letting me know i will fold that into my behavior but i will knowingly still drink wine and eat chocolate

the way people who smoke cigarettes they all know it's gonna get it can give them cancer yeah so it's awareness of the causes and effects of things that i think are important definitely and you don't go and say i choose not to believe it like anyone who denies an emergent scientific truth, be it global warming or anything else. Yeah. Yeah. We've got to wrap this up. That was quick. Oh, is that it?

That was quick. I have so many questions, so much I want to learn. Oh, well. But we had very thorough answers to the one or the two questions that we had. Yeah. I feel good about those, too. I feel very good about it. Education.

Those largely the questions. Education. That's it. Education. Education. Uh-huh. Those largely. Education. That's it. Education. Education. Education. Yeah, exactly. Yeah, you've learned a lot.

Yeah, yeah, I have. So, Eugene, thanks for being my co-host. Thank you very much for having me. On StarTalk. And, of course, we had this woman here, Vanessa Hill. She's got her own YouTube channel. Nobody ever gave me a YouTube channel. She's got her own YouTube channel.

If you put your mind to it, you can do it too. Is that what it is? Yeah. If I put my mind to it, that's all it takes. And you work every single day of the year. So, BrainCraft. BrainCraft, yes. At a channel near you. No, you can search for it easily on YouTube. Just put BrainCraft into Google, into YouTube search. It'll find it. It will pop up. You'll see my face. And you know why it comes up in a Google search? Because Google owns YouTube. It'd probably come up in a Bing search. No, I wouldn't.

Maybe it's third. I would not recommend Bing. Don't Bing it. Bing it. Bing it. You're never allowed in this building again. You can't use that. We are in the YouTube studios.

Is that even still a... Anyway. AltaVista, the number one... I remember AltaVista. Ask Jeeves knows who Frank Kraft is. Ask Jeeves, that's like 15 years ago. Yep, it did well. I'm older than I look.

There's a planetarium called the Ask Jeeves Planetarium. Really? Yeah, and they had to change that up real quick. Can I end the show, please? No, I want to mention WebCrawler. You've been watching, possibly even only listening to, StarTalk. I've been your host, Neil deGrasse Tyson. Thanks again to Vanessa and, of course, to Eugene for helping making this show what it was.

That was McQuarrie's Science Literacy Edition.