Super-Duper Novas with Michael Shara

When will the last supernova be? Neil deGrasse Tyson and Chuck Nice explore types of novas, freaky binary star systems, core collapse, standard candles, and the explosive future of Betelgeuse with astrophysicist Michael Shara.

Speaker names marked ? are inferred from speaking time and the show’s known hosts — they are not voice-verified.

• 0:00Neil deGrasse Tyson?

  Chuck, it's great to have colleagues who are the world's expert on something just arms reach down the hallway. Yeah, I would not know what that is like. In this case, stars that blow up. Cool. That is so cool. Coming up on StarTalk.

• 0:16Neil deGrasse Tyson?

  Welcome to StarTalk, your place in the universe where science and pop culture collide. StarTalk begins right now.

• 0:32Neil deGrasse Tyson?

  This is StarTalk. Neil deGrasse Tyson, your personal astrophysicist. We're going to do cosmic queries today. Chuck. Hey Neil. Did you collect the cosmic query? I did. And this not just random this time? No, they are not. They were solicited on the topic of stars that blow up. Oh, and by that we mean those nasty stars that are just mean to all the other stars. Oh, is that how that works? Yeah. I've checked the sociology of the galaxy lately. There's a friend and longtime friend and colleague of mine who works right down the hall, who is one of the world's experts on stars that blow up.

• 1:15Neil deGrasse Tyson?

  Dr., Professor, Curator, Michael Shara. Mike?

• 1:19Speaker 01

  Good afternoon.

• 1:20Neil deGrasse Tyson?

  Welcome back to StarTalk.

• 1:21Speaker 01

  It's a real pleasure to be here again.

• 1:23Neil deGrasse Tyson?

  Do you guys realize he was our first hire when we rebuilt the Rose Center? Really? So 25 years ago, the Rose Center's been here 25 years. Right. But we built the Department of Astrophysics to prepin that. We got Michael and we said, and now we can build around Michael. And you came from the Hubble Space Telescope Institute. I did. So you and Hubble go way back.

• 1:47Speaker 01

  I was there more than 40 years ago and I was in fact the first scientific hire without tenure, who got tenure at the Space Telescope Institute.

• 1:58Neil deGrasse Tyson?

  So you were there?

• 2:00Speaker 01

  Pre-launch.

• 2:01Neil deGrasse Tyson?

  That's the origin story of the Hubble Institute.

• 2:05Speaker 01

  I was hired there seven and a half, almost eight years before the launch of the telescope.

• 2:09Neil deGrasse Tyson?

  Wow, that's like being on Krypton before L was launched. So that's on the campus of Johns Hopkins University.

• 2:19Speaker 01

  Correct.

• 2:20Neil deGrasse Tyson?

  In Baltimore.

• 2:21Speaker 01

  That is right.

• 2:21Neil deGrasse Tyson?

  Right.

• 2:22Speaker 01

  3700 San Martin Drive.

• 2:24Neil deGrasse Tyson?

  Whoa, there it is. And we were delighted that you were ready for a change and you came to join us here.

• 2:32Speaker 01

  It's been 26 fabulous years. The only condition of my hire was that I not blow up like the stars I study. I'm still here, still having.

• 2:41Neil deGrasse Tyson?

  Plus, he wanted some opera tickets, I think, you know, I think that was in the deal that we cut with him.

• 2:47Chuck Nice?

  Okay, that works.

• 2:49Neil deGrasse Tyson?

  So, Mike, tell us about stars that blow up. First, first disentangle the fact that the word Nova and supernova looks like one is just a sort of a, uh, an extra version of the other, but they're two completely different things in the universe.

• 3:05Speaker 01

  They are completely different things, but there's not just novas or novi and supernovas. There are micro novas, there are dwarf novas, there are recurrent novas.

• 3:19Chuck Nice?

  Okay.

• 3:20Speaker 01

  Novas, supernovas, sub supernovas and hyper novas and they're all.

• 3:28Neil deGrasse Tyson?

  Now you're sounding like you're just making shit up right now.

• 3:31Chuck Nice?

  I was gonna say, once you get past supernova, you know.

• 3:35Speaker 01

  Well, if you find something that is more energetic and brighter.

• 3:41Chuck Nice?

  Right.

• 3:42Speaker 01

  Lasts longer and even more unexpected than a supernova, you gotta give it a title.

• 3:47Chuck Nice?

  Cause you're already titled super to supernova.

• 3:50Neil deGrasse Tyson?

  Because at the time you titled that, that was.

• 3:52Chuck Nice?

  That was that super.

• 3:53Speaker 01

  That was the ultimate. And now we know there are things that are a lot brighter and even more, in a sense, explosive than supernovas.

• 4:00Neil deGrasse Tyson?

  So had I been around at the search for that new term, I would have called it super duper nova. Way more fun.

• 4:08Speaker 01

  And when some of me and my explosive star friends are sitting around over a beer, that's what we refer to.

• 4:15Neil deGrasse Tyson?

  Super duper nova.

• 4:16Chuck Nice?

  Super duper nova.

• 4:17Neil deGrasse Tyson?

  So let's back up. So the stars, nova, literally from Latin means new.

• 4:23Speaker 01

  Right.

• 4:23Neil deGrasse Tyson?

  Yet it's the star at the end of its life or at end of, it's long lived a life before it goes nova. So it's really misnamed.

• 4:32Speaker 01

  Long before it goes supernova. There's a real difference because novas.

• 4:38Neil deGrasse Tyson?

  Let's, let's start with nova.

• 4:39Speaker 01

  Let's, okay, let's do in a sense, the simpler thing. Novas are stars that explode but don't die.

• 4:45Chuck Nice?

  Gotcha.

• 4:46Speaker 01

  Every nova explodes not just once or twice, but thousands of times.

• 4:51Chuck Nice?

  Oh, it's a Christian Bale star.

• 4:56Speaker 01

  These are things that explode over and over again, and there can be years between the explosions of novas.

• 5:05Chuck Nice?

  Mm-hmm.

• 5:06Speaker 01

  These are called recurrent novas, or centuries.

• 5:08Chuck Nice?

  Right.

• 5:09Speaker 01

  Millennia, even a million years. Because something has to be rebuilt. The explosive part has to be rebuilt, and then it explodes again.

• 5:20Neil deGrasse Tyson?

  Because the star's still there.

• 5:21Speaker 01

  The star, the underlying star, and it turns out that every nova is a binary star. So the stars, plural, are still there after the explosion.

• 5:33Chuck Nice?

  Did you say every nova is a, is a binary system?

• 5:35Speaker 01

  That's correct.

• 5:36Chuck Nice?

  So is, does that mean that one star is feeding another star?

• 5:41Speaker 01

  That's exactly right. And feeding may not be exactly the right word. You might think of it as a kind of cannibalism.

• 5:50Chuck Nice?

  Ooh.

• 5:51Speaker 01

  Involuntary feeding.

• 5:52Chuck Nice?

  Oh my!

• 5:53Speaker 01

  Of one star by the other.

• 5:55Neil deGrasse Tyson?

  Wait, wait.

• 5:56Speaker 01

  And it's worse.

• 5:57Neil deGrasse Tyson?

  Wait, wait, but the, the big bulbous star that's handing over the matter.

• 6:00Speaker 01

  Right.

• 6:00Neil deGrasse Tyson?

  It was asking for it, because it was, it's, it's, it's, it's in, in-

• 6:05Chuck Nice?

  It's actually in its space.

• 6:06Neil deGrasse Tyson?

  In its space.

• 6:06Chuck Nice?

  It's in its face.

• 6:07Neil deGrasse Tyson?

  Up in its face. Up in the space.

• 6:09Chuck Nice?

  And the little star is like, "Why are you my grill, man?"

• 6:12Neil deGrasse Tyson?

  That's exactly correct.

• 6:13Speaker 01

  I'll give you that. It's also worth remembering that there's a kind of zombification going on here.

• 6:20Chuck Nice?

  Ooh.

• 6:20Speaker 01

  Because the little star is almost always what we call a compact degenerate object. Either a white dwarf, or a neutron star, or a black hole.

• 6:32Chuck Nice?

  Hi-ho. Listen, I got a gambling problem, what can I say?

• 6:37Speaker 01

  So it's not just you have some overbearing bulbous, hasn't been able to control itself star involved. But it's actually being eaten.

• 6:51Speaker 01

  By this nearby very compact.

• 6:54Neil deGrasse Tyson?

  It actually takes two to tango.

• 6:58Speaker 01

  Very much so.

• 6:58Neil deGrasse Tyson?

  Right, okay. Tell me exactly what's happening. So the secondary star, is that what it's called? The big one?

• 7:06Speaker 01

  The ma- it's sometimes called the donor, sometimes called the secondary star.

• 7:10Neil deGrasse Tyson?

  That star also has to be in a late stage of its own life to become a red giant and swell to become so large to overspill the gravity boundary.

• 7:22Speaker 01

  That happens in some cases, but it doesn't actually have to be a red giant. It can be a main sequence star, still burning hydrogen.

• 7:29Neil deGrasse Tyson?

  Just like the sun.

• 7:30Speaker 01

  Just like the sun.

• 7:31Neil deGrasse Tyson?

  Our sun, yeah.

• 7:31Speaker 01

  Identical to the sun in every way.

• 7:33Neil deGrasse Tyson?

  Oh.

• 7:34Speaker 01

  And the reason that it's starting to be accreted onto, or it's feeding the companion is just that it's so close.

• 7:42Neil deGrasse Tyson?

  Right.

• 7:42Speaker 01

  That as a little bit of it expands, just a tiny bit of expansion during its evolution, the nearby star has enough gravity to be able to immediately vacuum off.

• 7:54Neil deGrasse Tyson?

  Uh huh.

• 7:54Speaker 01

  Suck off any material that expands beyond a certain radius. So it doesn't have to be.

• 7:59Neil deGrasse Tyson?

  So close orbiting ones, it doesn't have to, okay, gotcha.

• 8:02Chuck Nice?

  Wow, so have we, have we ever taken a look at these systems and seen like planetary uh, systems around them?

• 8:14Speaker 01

  We've looked. It would be an extremely unpleasant environment.

• 8:20Chuck Nice?

  Uh huh.

• 8:20Speaker 01

  For any planetary system. Nobody has found one.

• 8:25Chuck Nice?

  Okay.

• 8:26Speaker 01

  Even if it was there, it would be extremely hard to find because there's a lot of light being given off by these guys. They're intrinsically.

• 8:35Chuck Nice?

  Gotcha.

• 8:36Speaker 01

  They have hot spots.

• 8:37Chuck Nice?

  See, I see.

• 8:38Speaker 01

  The accretion disk, the donut of material around the compact star is quite bright. It flickers like crazy and any planet would be, of course, thousands of times or hundreds of times less massive.

• 8:52Chuck Nice?

  Right.

• 8:53Speaker 01

  Than the two stars.

• 8:54Neil deGrasse Tyson?

  Well, just when you say the disk flickers, is that every time a little bit of matter hits it, you get a little bit of bright spot?

• 9:01Speaker 01

  You have stuff being sucked off the donor into a donut shaped. Accretion disk, as it's called, around the compact object. And as that stream of material bangs into the doughnut.

• 9:14Neil deGrasse Tyson?

  You got hot spots.

• 9:15Speaker 01

  It causes flickering continuously on a time scale from minutes to seconds, probably down to milliseconds.

• 9:21Neil deGrasse Tyson?

  And the doughnut is a mechanism to feed the compact object.

• 9:26Speaker 01

  That's.

• 9:27Neil deGrasse Tyson?

  So now, why doesn't it just explode as soon as stuff hits the surface?

• 9:31Speaker 01

  You need to not just get a little bit of hydrogen onto the surface, because if you put a bit of hydrogen on the surface of a white dwarf, it can just sit there. The hydrogen doesn't feel the need to explode until it reaches a certain density and temperature. And that critical density and temperature mean that in the case of a, let's talk about a white dwarf star, just for concreteness, that's what most novas are, white dwarf stars. These are guys that are about the mass of the sun, so several hundred thousand times the mass of the earth, but they're only the size of the earth. And how much hydrogen do they need to accrete in order to become explosive? Well, because they're the size of the earth, about 8,000 miles across,

• 10:16Speaker 01

  they need to accrete about a mile of hydrogen, so about a Pacific Ocean's worth of hydrogen onto their surface. At that point, the density and pressure at the bottom of the Pacific Ocean of hydrogen is about 10,000 grams per cc, so about 1,000 times denser than lead. Temperature reaches 40, 50 million degrees. At that point, the hydrogen becomes highly explosive.

• 10:43Neil deGrasse Tyson?

  Nice.

• 10:44Speaker 01

  Boom. You blow up, and you get to be about 100,000 to a million times as bright as the sun.

• 10:51Neil deGrasse Tyson?

  But I need to clarify something.

• 10:52Speaker 01

  Yep.

• 10:53Neil deGrasse Tyson?

  Hydrogen as a gas.

• 10:54Speaker 01

  Right.

• 10:55Neil deGrasse Tyson?

  Is explosive, so that's not what you meant.

• 10:58Speaker 01

  Right.

• 10:58Neil deGrasse Tyson?

  Okay, so be precise there.

• 11:00Speaker 01

  It is not the kind of explosion that you're thinking of in the earth's atmosphere where hydrogen combines chemically with oxygen.

• 11:08Chuck Nice?

  All the humanity!

• 11:12Neil deGrasse Tyson?

  From the Hindenburg.

• 11:13Speaker 01

  Yes.

• 11:16Neil deGrasse Tyson?

  The last. Sorry for going dark there, guys, sorry. That's it. The last original ever filled with hydrogen.

• 11:22Speaker 01

  We're talking something 100,000 or a million times more energetic, because we're talking nuclear reactions.

• 11:29Neil deGrasse Tyson?

  Right.

• 11:30Speaker 01

  So instead of the hydrogen combining with oxygen, we're talking about protons smashing into each other. overcoming the the the charge barrier between them

• 11:41Chuck Nice?

  right

• 11:42Speaker 01

  fusing together

• 11:43Chuck Nice?

  nice

• 11:44Speaker 01

  basically a hydrogen bomb

• 11:45Chuck Nice?

  ah yeah

• 11:46Speaker 01

  and once you do that, once you become a million times as bright as the sun, we can see you not throughout the Milky Way, not just throughout the Milky Way, not just in the Andromeda Galaxy, but I've tracked more than a hundred novas in the Virgo Cluster of Galaxies, fifty million light years away.

• 12:04Chuck Nice?

  wow

• 12:05Speaker 01

  so these become

• 12:06Chuck Nice?

  really, really bright objects yeah, so I love the idea that I've never heard it put before when you say the Pacific Ocean um, amount of hydrogen because it's also pressure, right, that you need, right?

• 12:21Speaker 01

  that's exactly right

• 12:22Chuck Nice?

  yeah, so it's like the same way as you get to the bottom of the Pacific, you you would be crushed because of the pressure, it's that same pressure that is causing this ignition.

• 12:31Speaker 01

  and the pressure, of course, is causing the density to be higher and higher. The higher and higher density pushes the protons closer and closer together.

• 12:40Neil deGrasse Tyson?

  which ordinarily don't want to get together

• 12:42Speaker 01

  right

• 12:42Neil deGrasse Tyson?

  because they have the same charge.

• 12:44Speaker 01

  science is amazing, I'm sorry, it's just so damn cool, it's just so cool, man!

• 12:51Neil deGrasse Tyson?

  let's put a pin in that, and now let's go to supernova

• 12:53Speaker 01

  yep

• 12:53Neil deGrasse Tyson?

  and then we'll go to our Q and A.

• 12:54Speaker 01

  it used to be thought that there were two kinds of supernovas.

• 12:58Neil deGrasse Tyson?

  let me guess, type one and type two.

• 13:00Speaker 01

  that's precisely right.

• 13:01Neil deGrasse Tyson?

  two types!

• 13:02Speaker 01

  and of course, it turns out that the type one supernovas are in what we call Population Two

• 13:09Neil deGrasse Tyson?

  yeah

• 13:09Speaker 01

  galaxies, and that type two supernovas, just the opposite.

• 13:13Neil deGrasse Tyson?

  one of my early books, there was a chapter titled The Confused Person's Guide to Astronomical Jargon.

• 13:19Chuck Nice?

  nice

• 13:19Neil deGrasse Tyson?

  that was the name of the chapter.

• 13:20Chuck Nice?

  and

• 13:21Neil deGrasse Tyson?

  it should be like required reading, I think.

• 13:22Chuck Nice?

  yeah, exactly, yeah.

• 13:24Speaker 01

  so now with almost a century's worth of study of these things, we know that in very, very first, very first principles, the broadest way of looking at these supernovas are that they're either what we call core collapse supernovae.

• 13:40Chuck Nice?

  okay

• 13:41Speaker 01

  that is massive stars where the inner part of the star which holds itself out against the gravity of the rest of the star

• 13:51Chuck Nice?

  mhm

• 13:52Speaker 01

  loses that pressure. Somehow that inner part of the star collapses in on itself.

• 13:59Chuck Nice?

  Okay.

• 14:00Speaker 01

  And when it does so, the whole star implodes, bounces on the inner part of the star, and then much of the star is blown away. So that's a core collapse supernova. And the other kinds are what are called single or double degenerate supernovae. And these are guys, stars that are mostly white dwarfs.

• 14:24Chuck Nice?

  Okay.

• 14:25Speaker 01

  That have also lost their source of pressure in their centers, collapse down to become probably neutron stars in most cases, releasing enough energy to blow off the outer envelope. And these two very different kinds of supernovas have very different properties in terms of what we see in their spectra, what we see in the ejecta, the stuff that's good, that gets blown off of the two stars. So we know that they're two very different things. And within the core collapse supernovae, they can be anywhere from oh, 20, 30, 40, up to 100 times the mass of the sun.

• 15:07Speaker 01

  While the other ones, the degenerate supernovas, are somewhere between about 1.4 and about three times the mass of the sun. So much lower masses.

• 15:19Chuck Nice?

  And those are the ones that also don't pay child support.

• 15:21Speaker 01

  Never.

• 15:22Chuck Nice?

  Yeah.

• 15:23Speaker 01

  But they are the ones that let us discover the dark energy.

• 15:27Chuck Nice?

  Nice. So as I'm hearing you describe this, I can't help but recall to mind, like neutron stars, because that's basically what you described, if I'm right, a neutron star, and then if it's spinning very fast, it's then a pulsar, right?

• 15:47Speaker 01

  If it's spinning very fast and has a magnetic field.

• 15:50Chuck Nice?

  Oh, okay.

• 15:51Speaker 01

  That's an extremely important part of it, which it almost certainly does.

• 15:54Neil deGrasse Tyson?

  And the magnetic field can't be aligned with the axis of rotation.

• 15:58Speaker 01

  Not perfectly. It's gotta be tipped.

• 16:00Chuck Nice?

  Okay.

• 16:00Speaker 01

  You get all of those things, you're gonna end up with a pulsar. For a while.

• 16:04Chuck Nice?

  For a while.

• 16:05Speaker 01

  Maybe a hundred million years.

• 16:08Speaker 01

  Listen, that's just a blink.

• 16:10Chuck Nice?

  That's a blink in the eye.

• 16:11Speaker 01

  To an astronomer.

• 16:11Chuck Nice?

  Wow, look at that.

• 16:12Speaker 01

  After some time, after that hundred million years or so, it's gonna go radio quiet. It's not gonna be as interesting. So for every pulsar we see wandering around out there, they're probably a hundred quiet, or listened to.

• 16:25Chuck Nice?

  Right.

• 16:25Speaker 01

  That we can hear the beep beep beep. There's probably a hundred quiet ones.

• 16:29Chuck Nice?

  Now, here's my last question, cuz I know I don't. That's not your last question. I know, it never is, but I don't wanna take up time from the people. Bro, are you about to ask a question? Yes. Where's your Patreon? Oh, come on, now? I'm asking on behalf of, let's see.

• 16:59Speaker 03

  I'm Nicholas Costella, and I'm a proud supporter of StarTalk on Patreon. This is StarTalk with Neil deGrasse Tyson.

• 17:17Chuck Nice?

  Everything you just said.

• 17:19Speaker 01

  Yep.

• 17:19Chuck Nice?

  Seems to me.

• 17:20Speaker 01

  Hmm.

• 17:21Chuck Nice?

  Like, the same things in the process of creating a black hole, except you need a lot more mass. And then what happens in the end is that we can't see into it because at some point, the gravity is so great that light can't escape. If that is the case, and this process is the same. Just bear with me.

• 17:42Speaker 01

  Yep.

• 17:42Chuck Nice?

  Why can't we study this to kinda know what's happening inside of a black hole?

• 17:50Speaker 01

  The answer is a few-parted.

• 17:54Chuck Nice?

  Okay.

• 17:55Speaker 01

  So first of all. We only know for sure of one kind of all the core collapsed supernovas because there are different kinds of flavors. Oh. So think of them as ice cream, there's chocolate, vanilla, strawberry, raspberry. Terry Garcia. So there's many, many, many different subtypes of the massive star supernovas. We know of the ones that are called Type 2 Plateau Supernovae that they have red supergiant progenitors. Okay. That is the stars that make these kinds of supernovas. Right.

• 18:35Speaker 01

  And almost certainly end up as black holes, as modest mass black holes are red supergiants.

• 18:42Neil deGrasse Tyson?

  But do you get a supernova with the black hole or not? Or does everything just get sucked in?

• 18:47Speaker 01

  Some of the stuff gets blown off.

• 18:49Neil deGrasse Tyson?

  Okay.

• 18:50Speaker 01

  We think, yet, and the reason we think that is we've seen lots of supernovas and we look at them. We've observed lots of supernovas and when you look really, really carefully, a century later, two centuries, a thousand years later, we see a supernova remnant. We see a big expanding cloud of gas, the Crab Nebula is maybe the classic example.

• 19:12Neil deGrasse Tyson?

  Can you also measure the rate at which the gas is moving away?

• 19:15Speaker 01

  We can.

• 19:15Neil deGrasse Tyson?

  And turn the clock back and say it must have started.

• 19:18Speaker 01

  For sure, absolutely. Very cool. That's how we know we're beyond the shadow of a doubt. And we know that there is a very, very bright, rapidly spinning neutron star in the center of that supernova. There is a beautiful pulsar there too. So there we have absolute proof, as much as you can prove anything ever in astrophysics, that you had an intermediate mass star, maybe 10 or 15 or 20 solar masses, that collapsed down to give you a spinning neutron star and the supernova remnant. But there may be dark supernovas too. There's a good case to be made for some stars, very, very bright luminous stars that just go.

• 20:01Speaker 01

  And disappear out of the

• 20:02Neil deGrasse Tyson?

  I've seen a video of that, I mean, I mean, animation of it.

• 20:05Speaker 01

  Yeah.

• 20:05Neil deGrasse Tyson?

  It's, it's, it's scary, actually. It's like the whole thing gets flushed down its own toilet. And there's no, you know.

• 20:12Chuck Nice?

  Like a snake eating itself.

• 20:13Neil deGrasse Tyson?

  Yeah, yeah.

• 20:14Speaker 01

  If you will, except that it's not gone.

• 20:18Chuck Nice?

  Right.

• 20:18Speaker 01

  The black hole is still there.

• 20:20Chuck Nice?

  Right.

• 20:20Speaker 01

  And if you are a highly adventurous astronaut racing through the universe and you don't have the right sensors, you're gonna go right down it, right down the throat of that snake that swallowed itself. And you're not even gonna know it. It's just gonna take you right down.

• 20:36Neil deGrasse Tyson?

  Which of these is responsible primarily for the heavy elements in the universe?

• 20:40Speaker 01

  Probably a combination of them.

• 20:42Neil deGrasse Tyson?

  Combination, okay.

• 20:43Speaker 01

  So one kind of nova that we didn't mention before are kilonovas. And the reason that they're called kilonovas is because they're about a thousand times more energetic than a nova, which is about a million times the brightness of the sun. So these are about a billion times the brightness of the sun. And a supernova, which is about a thousand times brighter than a kilonova, so you could call it a mega nova, except we call it a supernova. And then there are things that are 10 to 100 times brighter than that, and those are the hypernovas. And there's different mechanisms, different things that are going on in each case.

• 21:21Neil deGrasse Tyson?

  So, so, but you have that inventory, so we can, we can account for the, the elements in the universe.

• 21:27Speaker 01

  Yes, and we have a fair idea, just by taking spectra, breaking up the light into all its components and measuring what's coming off in supernova remnants, how much iron, how much silicon, how much nickel is being produced in different kinds of supernovas. So certainly some of the core collapse supernovas are producing certain kinds of elements. Probably the collapse of the degenerate objects is producing much of the iron in the universe. And ordinary novas are probably producing a good fraction of the nitrogen in the universe. So every time you take a breath, you're breathing in some of the excreta.

• 22:09Speaker 01

  Every breath you take is some of the excreta of a nova.

• 22:14Chuck Nice?

  Well, when you say it like that. Not so pleasant. I wasn't about to say, "Thanks, supernova." But now I'm like, "Mmm."

• 22:21Neil deGrasse Tyson?

  So what you got here?

• 22:22Chuck Nice?

  All right, here we go. Let's jump into it. This is from Diipen. Hello, Dr. Tyson, Dr. Shower, your lordship. First, we're taught that matter in neutron stars is strange. Then we say that collision of neutron stars creates heavy metals like gold and platinum. How are these normal metals created from strange matter?

• 22:49Speaker 01

  Great question. The answer is that while the matter inside a neutron star is at not just strange, but insane sorts of densities. One with 13 or 14 zeros after it, grams per cubic centimeter. So quadrillions, trillions or quadrillions of grams per cubic centimeter. Once the kilonova has exploded, maybe some of it fallen into a black hole, but some of it's been blown off. That expanding matter starts going down in density.

• 23:28Speaker 01

  And so the free neutrons inside the neutron star start combining with each other. Some of them start decaying into protons. Neutrons and protons combine to make nuclei. And that's how you get ordinary matter because you get out of the incredibly dense state inside the neutron star. You've escaped. You're free to become yourself. You're free to become gold or platinum.

• 23:54Chuck Nice?

  That's right, Dad.

• 23:58Chuck Nice?

  Oh, that's very cool, man. Great question. All right, this is Stacy Hughes. Hello, all. This is Stacy Hughes from Nebraska. I have heard somewhere that large stars are going to stop being born before other stars. If that is true, how much sooner than the last stars dying out will the last supernova be? And what types of stars will be born after the last supernova? And will we still be here when that happens? Let me take that last part for you. Don't look like it.

• 24:36Chuck Nice?

  So go ahead.

• 24:38Speaker 01

  Given the rate at which humans have been developing technologies capable of destroying all of us, I'm not sure. I'd say we have maybe a 50/50 chance.

• 24:47Chuck Nice?

  Okay.

• 24:48Speaker 01

  Okay, but if we make it through the next century or two, maybe we'll get smart enough or maybe we'll disperse away from the earth and be able to hang in there. Let me answer your question about the most massive stars. When we look out in the Milky Way galaxy, we see large clouds of gas and dust.

• 25:07Chuck Nice?

  Okay.

• 25:08Speaker 01

  Including things we call giant molecular clouds. And these are the objects that give birth to new stars. And we see the same kinds of objects in nearby galaxies and we can image them in great detail with the Hubble Space Telescope or the James Webb Space Telescope. And we see clusters of thousands of stars being born now throughout the Milky Way, throughout nearby galaxies. And there are almost always some really, really luminous, very, very massive stars in these youngest clusters, up to about 100 times the mass of the sun.

• 25:43Chuck Nice?

  Okay.

• 25:44Speaker 01

  Will this eventually stop? Well, we see galaxies where this has stopped. Because when galaxies crash into each other and merge, most of the gas, the hydrogen gas, the stuff out of which stars is born, much of it is liberated. It's blown out of those galaxies. We're left behind with an elliptical galaxy that doesn't make many stars anymore. And so at some point, it's possible, in fact likely, that every galaxy in the universe that has hydrogen in it will have lost all or most of that hydrogen. And when that happens, star formation is going to ramp down and eventually stop. Billions of years into the future. But not right now. Will we be around billions of years in the future?

• 26:27Chuck Nice?

  Yeah, come on.

• 26:28Speaker 01

  Can I tell you?

• 26:29Chuck Nice?

  Yeah, I can. I can tell you. I can tell you right now.

• 26:32Neil deGrasse Tyson?

  You know, you got the answer now.

• 26:33Chuck Nice?

  I got the answer right now, Stacy. That's a great question, though. And these gas clouds that you see, are these the same as stellar nurseries? Is that what we?

• 26:42Speaker 01

  That's exactly right.

• 26:43Chuck Nice?

  Oh, okay.

• 26:43Speaker 01

  The nearest prominent one, you can see it with the naked eye, is the Orion Nebula.

• 26:47Chuck Nice?

  Right.

• 26:48Speaker 01

  Underneath the three stars in the belt is this lovely glowing cloud.

• 26:51Neil deGrasse Tyson?

  And if you're in the southern hemisphere, they're above the belt.

• 26:54Speaker 01

  That is true.

• 26:56Speaker 01

  And there's one-

• 26:56Chuck Nice?

  So like us to hit below the belt.

• 26:59Speaker 01

  And there's one O star, one of those massive stars that's doing all the ionization, all the excitation. It is the guy that is responsible mostly for the central part of the Orion Nebula, looking like it is. If it weren't there, it'd be a much less interesting thing to look at.

• 27:17Chuck Nice?

  Wow. That is super cool, man. All right. This is Christopher Pfeffers, and Christopher says, "Hello, Dr. Shara. Dr. Tyson, Lord Nice, Chris Pfeffers here from Charleston, Indiana. Dr. Shara, you've spent decades studying exploding stars and binary systems, some of the most extreme objects in the universe. For people who might think space is just empty and still, can you walk us through what happens in a closed binary system, where one of the stars steals matter from another, eventually causing a supernova, a nova, or a... or even a supernova? What does that cosmic drama look like?

• 28:01Chuck Nice?

  And should everyday people even care about these distant events? Do they help us understand our own sun? Or even where the elements that make up life on Earth come from? Thank you for your work, sir." There it is.

• 28:17Speaker 01

  Well, first of all, it's my pleasure. I appreciate the pat on the back, sort of, the verbal pat on the back.

• 28:23Chuck Nice?

  Right.

• 28:23Speaker 01

  I do it- The reason I I've spent decades doing this is because I love it. Astronomy in some sense is my hobby. Uh, the fact that someone's willing to pay me to do it and to teach.

• 28:34Neil deGrasse Tyson?

  That's the old adage. Take your hobby, make it a career.

• 28:36Speaker 01

  It's.

• 28:37Neil deGrasse Tyson?

  And you'll never, was it?

• 28:39Chuck Nice?

  Right, well, yes, you'll you'll never be something.

• 28:42Neil deGrasse Tyson?

  No, you'll never work a day in your life.

• 28:43Chuck Nice?

  You'll never work a day in your life, that's it.

• 28:44Speaker 01

  And it's been a joy and in some sense I haven't worked a day in my life because it's always been fun. It's always been great.

• 28:49Chuck Nice?

  That's pretty cool.

• 28:50Speaker 01

  I get to work with lots of bright, young people doing their masters and PhDs and work with them all the time. So it's a glorious way to spend one's life. Okay, let's zoom in on one of these systems, one of these binary systems. And I'm going to pick a particular system.

• 29:06Chuck Nice?

  Okay.

• 29:07Speaker 01

  That you're going to be able to see with your naked eye.

• 29:10Chuck Nice?

  Oh.

• 29:11Speaker 01

  Next year or the year after.

• 29:13Chuck Nice?

  Okay.

• 29:14Speaker 01

  Okay.

• 29:14Chuck Nice?

  All right. Relatively short period of time.

• 29:17Neil deGrasse Tyson?

  I bet he's talking about T corona borealis.

• 29:19Speaker 01

  And Neil has just thrown a bone in his eye.

• 29:22Neil deGrasse Tyson?

  Don't tell anybody.

• 29:23Speaker 01

  Exactly right.

• 29:25Neil deGrasse Tyson?

  And when he says it, just act.

• 29:26Chuck Nice?

  I will act surprised.

• 29:27Neil deGrasse Tyson?

  Act surprised, okay. Yeah, so.

• 29:29Chuck Nice?

  What is it?

• 29:31Speaker 01

  So there is a star called T corona borealis. Woo, surprise. Uh, that is going to get brighter than the North Star, brighter than Polaris.

• 29:40Chuck Nice?

  Wow.

• 29:40Speaker 01

  Uh, either tonight or tomorrow night or sometime in the next year or two.

• 29:44Neil deGrasse Tyson?

  Could just, I have to, I have to jump in here.

• 29:46Chuck Nice?

  Okay.

• 29:46Neil deGrasse Tyson?

  Um, so I I don't want to cast shade on how bright it's going to get, but Polaris ain't that bright.

• 29:54Chuck Nice?

  Okay.

• 29:55Neil deGrasse Tyson?

  Our North Star.

• 29:56Chuck Nice?

  Which I've heard you say this.

• 29:58Neil deGrasse Tyson?

  Even nine out of 10 people, you say, what's the brightest star? They'll say North Star. It is not in the top 10, it's not in the top 20.

• 30:03Chuck Nice?

  All right.

• 30:04Neil deGrasse Tyson?

  It's not in the top 30.

• 30:05Chuck Nice?

  Yes.

• 30:05Neil deGrasse Tyson?

  It's not even in the top 40.

• 30:06Chuck Nice?

  Yes.

• 30:07Neil deGrasse Tyson?

  Okay, so I did put that out there right now. And what the Corbor, what is that reference?

• 30:12Speaker 01

  Corona borealis.

• 30:14Chuck Nice?

  Mm hmm.

• 30:15Speaker 01

  Latin for a northern crown. And it is a constellation, a little grouping of stars that looks like a semicircle.

• 30:25Speaker 01

  A crown, okay.

• 30:26Chuck Nice?

  Gotcha.

• 30:27Neil deGrasse Tyson?

  That's a tiara would be that.

• 30:29Speaker 01

  That's a better term.

• 30:30Neil deGrasse Tyson?

  It would be, wouldn't it?

• 30:31Chuck Nice?

  Exactly.

• 30:32Speaker 01

  Much better.

• 30:33Neil deGrasse Tyson?

  So is there a crown in the southern hemisphere?

• 30:35Speaker 01

  There is Corona Australis.

• 30:36Neil deGrasse Tyson?

  Okay, good. So that's why you specify the Borealis.

• 30:39Speaker 01

  That is correct.

• 30:39Neil deGrasse Tyson?

  Yeah, okay. So pick it up from there.

• 30:41Speaker 01

  We saw this star last erupt about 79 years ago. And then 80 years before that, we saw it erupt as a nova. And each time it became about second magnitude. And one of my colleagues, Brad Schaefer, has made a pretty good case for it having erupted 80 years before that. And then he even points out some possible evidence for an eruption in the 1200s. So this is a star, this is a recurrent nova.

• 31:11Neil deGrasse Tyson?

  Wait, nobody was looking up in the 1200s? They were just trying to not, whatever.

• 31:15Speaker 01

  Not starve to death?

• 31:16Neil deGrasse Tyson?

  Get eaten by dragons or not starve to death.

• 31:18Speaker 01

  Or die of the bubonic plague? No, no, no, there were people who actually did notice changing stars, things that were wild. And of course, there were no electric lights in those days.

• 31:31Chuck Nice?

  Yeah, a lot more stars to look at.

• 31:33Speaker 01

  There were.

• 31:33Neil deGrasse Tyson?

  Actually, sorry, it was the 14th century, which was the only century where the population of the world was lower at the end than it was at the beginning. From bubonic plague and all of this.

• 31:43Speaker 01

  Black death will do it every time.

• 31:47Chuck Nice?

  That's why I can't stand that they called it the black death.

• 31:51Chuck Nice?

  Of course, the most deadly of deaths has to be the black death. No, go ahead. I'm being silly, go ahead.

• 31:59Speaker 01

  No worries. So this star, this massive white dwarf is cannibalizing its companion, which is a, in this case, a red giant star.

• 32:10Neil deGrasse Tyson?

  Authentic red giant.

• 32:10Speaker 01

  This is an authentic red giant.

• 32:12Neil deGrasse Tyson?

  Can you see both stars when you look at them? Or are they too far away?

• 32:15Speaker 01

  You can see neither. It is roughly 13th magnitude in quiescence. So if you look with a terrific pair of binoculars, you still can't see it. You need at least, if you want to see it with your naked eye or with your eye, you need at least, say, an eight or a 10 inch telescope to be able to see it at all.

• 32:34Neil deGrasse Tyson?

  Really good backyard telescope would catch this.

• 32:36Speaker 01

  We'll see it when it's in quiescence. And it's going to jump in brightness approximately 100,000 fold.

• 32:45Speaker 01

  Uh, to reach roughly the brightness, a little bit brighter probably than Polaris for a few hours. Uh, and then it'll fade away and then on a time scale of um, a week or two. You won't see it again. Uh, and you won't see it again for another 80 years.

• 33:00Neil deGrasse Tyson?

  So when I was in the Pacific Northwest, I took a photo of your star. And I don't know if I got to show it to you. Uh, did I? Did I ever show it to you?

• 33:07Speaker 01

  I think you might.

• 33:08Neil deGrasse Tyson?

  Cause you know, there was a chance it could have blown up while I was looking at it.

• 33:11Speaker 01

  Exactly.

• 33:11Neil deGrasse Tyson?

  And then I'd be the first.

• 33:13Speaker 01

  To have seen it.

• 33:13Neil deGrasse Tyson?

  I'd have been the first out of the box on that one.

• 33:16Speaker 01

  Yep. Everyone wants to be the one to see it. Starting on its rise.

• 33:21Neil deGrasse Tyson?

  Of course.

• 33:22Speaker 01

  And so people have little charts. And okay, there's T Corona Borealis.

• 33:26Neil deGrasse Tyson?

  So somebody's watching this thing every night.

• 33:28Speaker 01

  Of course. Someone is watching it basically every minute.

• 33:31Neil deGrasse Tyson?

  24 hours a day.

• 33:32Speaker 01

  24/7.

• 33:33Neil deGrasse Tyson?

  Because half the world is dark at any given time. A- a- and we got people everywhere.

• 33:38Speaker 01

  Of course you do. There are tens of thousands of so-called amateur astronomers who are every bit as professional as professional astronomers.

• 33:46Neil deGrasse Tyson?

  In that community.

• 33:47Speaker 01

  Go ahead.

• 33:48Neil deGrasse Tyson?

  It is a badge of honor to say, I am an amateur astronomer. If you say that, you can ask them any question about the night sky and they'll have an answer.

• 33:56Speaker 01

  They know.

• 33:57Neil deGrasse Tyson?

  Even some of my colleagues wouldn't know. Because we, they know the night sky. They're out there every night.

• 34:02Speaker 01

  Hmm.

• 34:03Neil deGrasse Tyson?

  As I was when I was, you know, had my backyard telescope. See, my rooftop, right? There's no backyard in the Bronx.

• 34:09Speaker 01

  Right.

• 34:10Neil deGrasse Tyson?

  I was hauled to the roof.

• 34:11Speaker 01

  So the thing for me that is most exciting about T Corona Borealis is that as a recurrent nova, it was predicted and, and there were only 10 recurrent novae known in the whole Milky Way.

• 34:25Neil deGrasse Tyson?

  Okay.

• 34:26Speaker 01

  Uh, about a decade ago. It was predicted that boom, you blow off a shell of matter. Then 80 years later, boom, you blow off another shell, another, another, another. The stuff doesn't all come off at the same speed. Some of it comes off at high speed, some at a lower speed. So what that means is when the next shell goes off.

• 34:49Neil deGrasse Tyson?

  Someone's gonna overcome, it's gonna, the fast stuff is gonna overtake the slow stuff.

• 34:53Speaker 01

  Bingo. So you're gonna have shells colliding with each other.

• 34:56Neil deGrasse Tyson?

  When shells collide.

• 34:57Speaker 01

  Shells colliding, Jerry.

• 34:59Chuck Nice?

  No, that's amazing.

• 35:00Speaker 01

  And so it's gonna be a traffic pileup.

• 35:03Chuck Nice?

  Right.

• 35:04Speaker 01

  It's like, you know, one car running into another. And if that's right, that hasn't just been happening for 80 or 160 or 240 or 320 years. It's been going on for thousands or tens of thousands of years, which means you've got hundreds or thousands of shells piled up on top of each other. That means you should have a super shell.

• 35:28Chuck Nice?

  Right.

• 35:28Speaker 01

  A super remnant surrounding T. corona borealis.

• 35:33Neil deGrasse Tyson?

  Where it's, where the fastest stuff is plowed onto itself.

• 35:37Chuck Nice?

  Right.

• 35:37Neil deGrasse Tyson?

  Bulldoze its way through.

• 35:39Speaker 01

  But that's not all. Wait, wait, there's more because as that shell builds up in mass, it's also acting like a snowplow, plowing up all the stuff in the interstellar medium in front of it.

• 35:53Neil deGrasse Tyson?

  The stuff that's there anyway as bystanders.

• 35:56Speaker 01

  Is gonna get mowed over and is going to be incorporated into that super shell. So there should be a super duper shell around it, and we've just found it. Oh, he buried the lead. You heard it here. What? So we've been using a gorgeous new, not expensive telescope. Oh. The kind of telescope that so-called amateurs use refracting telescopes. Six of them bolted together in parallel, and we stared at T. corona borealis for about 100 hours.

• 36:34Neil deGrasse Tyson?

  They're not in darkness for 100 hours, just wanna make that clear.

• 36:36Chuck Nice?

  Oh, okay.

• 36:37Neil deGrasse Tyson?

  They get the dark stuff tonight.

• 36:39Chuck Nice?

  Right.

• 36:40Neil deGrasse Tyson?

  They close the hatch and then tomorrow night, pick it up again.

• 36:42Chuck Nice?

  We're back at it.

• 36:43Neil deGrasse Tyson?

  Okay, back at it. Okay, go.

• 36:44Speaker 01

  And so we actually have thousands of images taken over more than 100 nights of T. corona borealis, and we add up all those images. And we took pictures through filters that only transmit the light from hydrogen, only transmit the light that comes from nitrogen ions, sulfur ions, and so on. And we found.

• 37:07Speaker 01

  A super shell surrounding T. corona borealis that's about three times the diameter of the full moon.

• 37:12Neil deGrasse Tyson?

  That's fabulous.

• 37:13Speaker 01

  So it is a degree and a half on the sky. And you might then think, well, when T. corona borealis goes off, it's going to be like a flashbulb going off in the room, in a room full of little mirrors. It's going to be like Christmas lights going off as this flash of light propagates outwards.

• 37:34Neil deGrasse Tyson?

  Echoes off the material. The super shell.

• 37:38Speaker 01

  One would hope that that would be true.

• 37:40Neil deGrasse Tyson?

  That's amazing.

• 37:41Speaker 01

  It's probably not.

• 37:42Neil deGrasse Tyson?

  Oh, no!

• 37:43Speaker 01

  So the downer is we published in a paper that just came out a couple of months ago saying, there's not going to be fluorescence.

• 37:51Neil deGrasse Tyson?

  Okay.

• 37:52Speaker 01

  So the atoms themselves are not going to light up because they're too far apart and there aren't enough of them, it's not going to be bright enough to detect. Now, maybe, just maybe, if there was dust, little grains of silicon and carbon and other, what we call refractory elements, high-temperature stuff, little grains that were tossed out in the last Nova eruption, the one 80 years ago, those might reflect enough light for us to see as a light echo. And you know that a day or two or three after this goes off, the Hubble Space Telescope is going to get pointed at it, the James Webb Space Telescope.

• 38:32Neil deGrasse Tyson?

  Yeah, we're very good about that. Something happens, everybody. Comes together. We are the most come-together. Shares information. We are the most come-together. We're always about a collabo. Always, especially since not every telescope will observe it in the same way. Yeah. So you get different kinds of data coming together. I always say, the only people to collaborate more than rappers are astrophysicists. So, Mike, on my iPhone, I controlled a digital telescope when I was in the Pacific Northwest, didn't even leave the comforts of the living room when I did this. See, he's, he's, he's old school. He's like, what? You didn't like ascend the mountain?

• 39:08Chuck Nice?

  You did not suffer for that image?

• 39:11Speaker 01

  I've been up in the prime focus cage of telescopes for nights at a time.

• 39:17Neil deGrasse Tyson?

  Tell me about on your rocking chair.

• 39:19Speaker 01

  Exactly.

• 39:20Neil deGrasse Tyson?

  So this image, I, I found it, but it was behind a tr- a very modeled tree. And so, uh, the digital telescope tracks it. And but so the tree ends up blurred as it's tracking the, the actual object. So it looks, it's a very undistinguished dot on my, on my picture.

• 39:36Speaker 01

  Had you caught it near its maximum, you would basically have saturated the image.

• 39:41Neil deGrasse Tyson?

  Yeah.

• 39:41Speaker 01

  All of the image would be just one bright point of light.

• 39:45Chuck Nice?

  Wow.

• 39:45Neil deGrasse Tyson?

  But there's no saturation anymore because this knows what it's doing. It takes 10 second images.

• 39:49Speaker 01

  Yes.

• 39:50Neil deGrasse Tyson?

  And then stacks them.

• 39:51Speaker 01

  Right.

• 39:51Neil deGrasse Tyson?

  Yeah, the old days, you, you expose it.

• 39:53Chuck Nice?

  Overexposed.

• 39:53Neil deGrasse Tyson?

  It would get overexposed.

• 39:55Chuck Nice?

  Yeah. Now you don't have that problem because you're getting all separate images.

• 39:59Neil deGrasse Tyson?

  Separate, then you stack them and add them and you get it. Keep going.

• 40:02Chuck Nice?

  All right, let's keep going. Man, this is really cool stuff.

• 40:27Chuck Nice?

  This is Joel Bradley and Joel says, greeting Dr. Tyson, Dr. Shower, Lord Nice. Joel here from Guilang, Australia, and I have a question regarding our favorite pre-supernova star, Betelgeuse. Whilst I understand that life of a star is extremely long from our perspective, how is the timeframe for Betelgeuse going to supernova between now and 100,000 years? Is there any sign that will warn us of it happening in our lifetime? Or will we just look up one night and go, oh, wow, look at that?

• 41:01Neil deGrasse Tyson?

  There it was, there it was. What's the life expectancy of Betelgeuse from birth to death?

• 41:07Speaker 01

  Something like a, uh, well, the star itself.

• 41:10Neil deGrasse Tyson?

  Yes.

• 41:10Speaker 01

  If you consider the main sequence lifetime. Probably a few million years.

• 41:15Neil deGrasse Tyson?

  Got it. Okay.

• 41:16Speaker 01

  Okay, so it was hydrogen burning for a good fraction of its lifetime, maybe a million years, maybe two, three million years.

• 41:21Neil deGrasse Tyson?

  When it's astrophysicist speaking, he means hydrogen fusion. Right, of course.

• 41:25Speaker 01

  So Betelgeuse was initially as a very massive star fusing hydrogen into helium. Then it left the main sequence, ascended the red, and then the red supergiant branches.

• 41:35Neil deGrasse Tyson?

  Ran out of hydrogen in the core.

• 41:37Speaker 01

  Hydrogen, needed to do something else, needed a new source of energy, otherwise it was gonna collapse. The core got dense enough and hot enough for helium to start fusing into carbon.

• 41:48Neil deGrasse Tyson?

  And helium has two protons in its nucleus. Now you gotta get two protons, next to two protons, you gotta be hotter than whatever you were for hydrogen. Look at that.

• 41:56Speaker 01

  Typically, you've gotta be in the hundred million degree range instead of the twenty million degree range in order for that to happen. So it is really hot down there in the core of Betelgeuse. Betelgeuse has only got, probably in the best case, a hundred thousand years to go. But it might be tomorrow.

• 42:14Neil deGrasse Tyson?

  Okay, that's a really bad prediction.

• 42:18Neil deGrasse Tyson?

  Can you do better, can you do better than that?

• 42:20Speaker 01

  Fifty years ago, the prediction would have been, we don't know why it's a red supergiant. So we, so we have gotten a lot better. Yes, we would love to do better, and the answer is if you.

• 42:32Neil deGrasse Tyson?

  We should, we should appreciate how far we've come, even in our ignorance.

• 42:36Speaker 01

  If you give me enough money, I will build a detector that will tell you several days in advance when it's gonna go off.

• 42:42Neil deGrasse Tyson?

  Nice.

• 42:42Speaker 01

  And what is that detector going to be? Well, it's gonna be the biggest, baddest neutrino detector that's ever been, been built on Earth. Right now, we've been super clever, we, meaning physicists collectively, not me, have built enormous detectors using cubic miles of seawater or, or ice. The Ice Cube detector, for example.

• 43:06Neil deGrasse Tyson?

  In Antarctica.

• 43:07Speaker 01

  In Antarctica, and a gorgeous detector right near Sicily, a huge underwater detector.

• 43:13Neil deGrasse Tyson?

  And the rapper Ice Cube goes down there and performs for the scientists.

• 43:19Speaker 01

  But if we could build a detector that was, say, oh, a thousand times the volume, so instead of a mile by a mile by a mile, we'd love to build something that was ten miles by ten miles by, by a, by a few miles at least. Um, we'd have a thousand times the sensitivity. Now, why do I care about neutrinos? Well. As the star is right near the end of its lifetime and just about to flash off, it's not just gonna

• 43:46Neil deGrasse Tyson?

  Do you see the light?

• 43:47Speaker 01

  Do you see the light? Yeah. It's gonna burn the carbon into magnesium, the magnesium into heavier elements, all the way up to iron. And you're gonna get a great flux of neutrinos coming out of the core of the star in the last few hours, maybe days

• 44:05Neil deGrasse Tyson?

  Wow, okay.

• 44:06Speaker 01

  Of the life of the star, certainly in the last couple of minutes. And then during the implosion, you're gonna get another blast of neutrinos. So these will come out of the star before anything else.

• 44:19Neil deGrasse Tyson?

  Okay, but they're not going the speed of light.

• 44:22Speaker 01

  They're not.

• 44:23Neil deGrasse Tyson?

  So, what, it, so...

• 44:25Speaker 01

  Doesn't matter. And the reason it doesn't matter is that Betelgeuse isn't that far away. We're talking hundreds of light years, we're not talking millions or billions of light years away. And as a result, the difference between the speed of the neutrinos

• 44:40Neil deGrasse Tyson?

  Which is very fast.

• 44:41Speaker 01

  Which is very, ninety-nine point nine, many nines, the percent the speed of light. The difference in speed between the neutrinos

• 44:50Neil deGrasse Tyson?

  Right.

• 44:50Speaker 01

  And the gravitational radiation

• 44:53Neil deGrasse Tyson?

  Okay.

• 44:53Speaker 01

  That will be emitted

• 44:54Neil deGrasse Tyson?

  And that's going the speed of light.

• 44:56Speaker 01

  That is moving exactly at the speed of light.

• 44:58Neil deGrasse Tyson?

  And we have something that could detect that, if it happens.

• 45:00Speaker 01

  We have several detectors, at least three up and operating now that are gonna detect those gravitational waves.

• 45:07Neil deGrasse Tyson?

  Are they all collectively LIGO, or is it just the American ones called LIGO?

• 45:11Speaker 01

  The, they're collectively called the LIGO, LIGO, and each one of them has its own name. There, for example, the Italian one is referred to as Virgo. But the LIGO, if you will, the LIGO assembly

• 45:25Neil deGrasse Tyson?

  Right.

• 45:25Speaker 01

  Uh, is, is the three telescopes.

• 45:27Neil deGrasse Tyson?

  We get the gravitational waves

• 45:29Speaker 01

  Right.

• 45:30Neil deGrasse Tyson?

  And they will come at the same speed as the explosive light, I presume.

• 45:35Speaker 01

  They, they're gonna precede the light.

• 45:37Neil deGrasse Tyson?

  Oh, because you have the collapse.

• 45:38Speaker 01

  You have the collapse, and then you gotta expand again to get big enough to have a photosphere, a radiating surface, big enough. So it's gonna be tens of minutes to tens of hours before you see it in the optical.

• 45:52Neil deGrasse Tyson?

  This is gonna be amazing. We'll see them right, one right after another, each of these, the sequence of events.

• 45:58Speaker 01

  So we're gonna see the gravitational radiation and the neutrinos arriving almost simultaneously. We may get lucky and see a few of the early neutrinos coming a few seconds or minutes early. That would be just in the last gasps of, oh, I'm, I'm just, I'm finished my carbon burning. I'm gonna do my magnesium burning. That didn't help me. I'm gonna do my, my silicon burn. That helped me even less. I'm gonna do my iron burning. So you get more and more frantic.

• 46:28Neil deGrasse Tyson?

  I've never seen you imitate a star before.

• 46:30Speaker 01

  That was it. That was it.

• 46:31Chuck Nice?

  That was a dying star right there.

• 46:33Speaker 01

  And so.

• 46:34Neil deGrasse Tyson?

  Because what he's doing is, the star's trying to not die.

• 46:37Chuck Nice?

  Right.

• 46:38Neil deGrasse Tyson?

  And so it's finding every possible.

• 46:39Chuck Nice?

  Finding everything it can do to burn.

• 46:41Neil deGrasse Tyson?

  And if it can't, if there's not enough, it's gonna collapse on there.

• 46:44Speaker 01

  And so maybe in that last minute, we'll start seeing a neutrino here, another one, another one, another one, and then tens of thousands of them arriving. And that's gonna be the harbinger. That's gonna tell us supernova's coming. Supernova's coming from there, that direction. If we have all three detectors.

• 47:04Neil deGrasse Tyson?

  You could triangulate back on it.

• 47:06Speaker 01

  We can triangulate to about plus or minus a degree.

• 47:08Neil deGrasse Tyson?

  Okay.

• 47:09Speaker 01

  You know, a little bit more than the area of the full moon on the sky.

• 47:12Neil deGrasse Tyson?

  Yeah, but how many supernova progenitors are in the area of a full moon on the sky?

• 47:16Speaker 01

  We typically get, you know, I mean, in a, in a square degree, we've got millions and millions of stars. You don't know which one it is, but if you triangulate back to that one square degree where Betelgeuse is.

• 47:30Neil deGrasse Tyson?

  And Betelgeuse is in the middle of the thing.

• 47:32Chuck Nice?

  Right.

• 47:32Neil deGrasse Tyson?

  That's pretty much.

• 47:33Speaker 01

  You go whoop, whoop, whoop, whoop. Turn on your alarms.

• 47:36Neil deGrasse Tyson?

  So how bright, how bright will Betelgeuse get? Cause it's already bright. It's like, what is it? It's, it's, it's zeroth magnitude. What is it?

• 47:43Speaker 01

  Maybe minus.

• 47:44Neil deGrasse Tyson?

  Minus one, maybe.

• 47:45Speaker 01

  Something like that. It's certainly one of the, you know, 15, 20 brightest stars in the sky.

• 47:49Neil deGrasse Tyson?

  Way brighter than the North Star.

• 47:50Chuck Nice?

  Once again.

• 47:51Speaker 01

  Right. So right now, currently, it's maybe a million times, yes, the luminosity of the sun.

• 47:58Chuck Nice?

  Okay.

• 47:58Speaker 01

  But it's going to go to at least 10 billion times. It's gonna get at least 10,000 times brighter.

• 48:04Chuck Nice?

  Wow.

• 48:05Neil deGrasse Tyson?

  Wow. So then 15 magnitude. That'd be visible in daytime.

• 48:08Speaker 01

  It's, oh, it's, it's certainly gonna be a daytime thing.

• 48:10Neil deGrasse Tyson?

  It's gonna compete with the full moon for brightness.

• 48:12Chuck Nice?

  That's great.

• 48:14Neil deGrasse Tyson?

  Oh my gosh.

• 48:15Chuck Nice?

  Well, Joel, there you have it, my friend. If you have a neutrino detector,

• 48:22Chuck Nice?

  you will know exactly when this is going down.

• 48:24Neil deGrasse Tyson?

  You'll know first.

• 48:25Chuck Nice?

  If you get the neutrinos and you get the gravitational waves at the same time, just know, Elizabeth, I'm coming to join you, honey. Betelgeuse is about to kick the bucket and you can watch it. So, that's super cool.

• 48:37Speaker 01

  One good piece of news, I mean, you're headed in absolutely the right direction. I don't want you scaring anyone, though.

• 48:44Chuck Nice?

  Okay.

• 48:44Speaker 01

  You don't need to go down to your basement or your sub-basement. Because even though there are gonna be lots of high-energy neutrinos coming and whacking you, none of them's gonna hurt you.

• 48:56Chuck Nice?

  Right.

• 48:56Speaker 01

  There aren't gonna be enough gamma rays to fry our ozone layer.

• 49:00Chuck Nice?

  Or make you the Hulk.

• 49:02Speaker 01

  Or make you the Hulk, or give you a sunburn. So, don't worry about that kind of stuff. It's just gonna be something ultra-cool that you can walk out and see something that really nobody has seen since the 1600s. We had two supernovas almost back to back.

• 49:18Neil deGrasse Tyson?

  Was that, how bright was Kepler's supernova?

• 49:20Speaker 01

  It was also the same kind of brightness, maybe not quite as bright as that.

• 49:25Neil deGrasse Tyson?

  In the daytime?

• 49:26Speaker 01

  It was seen in the daytime probably for a month or two, but I gotta go check that.

• 49:32Chuck Nice?

  So, let me ask you both this, then. The most famous star in the night sky and also reportedly shone during the day, the star of Bethlehem. Do we have any real record of what that was?

• 49:47Neil deGrasse Tyson?

  Go on, ask the Jewish man about the star of Bethlehem. Go ahead.

• 49:52Speaker 01

  So, my forefathers did not draw a diagram or a map of where it was.

• 49:59Chuck Nice?

  Ah-ha.

• 49:59Speaker 01

  In fact, this only appears in the New Testament.

• 50:03Chuck Nice?

  Right.

• 50:04Speaker 01

  As a star in the east.

• 50:07Chuck Nice?

  Star in the east.

• 50:08Speaker 01

  You know, that's a little vague.

• 50:11Neil deGrasse Tyson?

  You think?

• 50:11Chuck Nice?

  A little too vague, huh?

• 50:13Speaker 01

  A little.

• 50:13Chuck Nice?

  Yeah, gotcha.

• 50:14Speaker 01

  And so, what can we do that is maybe better? Well, we can go back to the people.

• 50:23Neil deGrasse Tyson?

  That's all, that's the best info available.

• 50:26Speaker 01

  Well, we can try and cross-correlate it because while the astronomers in the ancient holy land were not quite up to the task, there were three sets of astronomers who were up to the task and really were doing their jobs on a night-by-night basis. And these are the imperial astrologers of China, Japan, and Korea.

• 50:52Neil deGrasse Tyson?

  Okay.

• 50:53Speaker 01

  Who were looking at the sky every night as harbingers, either for good or bad.

• 50:58Neil deGrasse Tyson?

  Yeah.

• 50:58Speaker 01

  Good or evil.

• 51:00Neil deGrasse Tyson?

  Yeah.

• 51:00Speaker 01

  Because clearly, the gods were up there.

• 51:04Neil deGrasse Tyson?

  Right.

• 51:04Speaker 01

  And the emperor was a demi-god.

• 51:07Neil deGrasse Tyson?

  Right.

• 51:07Speaker 01

  So whatever was happening to the gods was affecting the emperor. So we'd better watch out really carefully and write down what was going on. And so, from about 300 B.C., but certainly from 0 B.C. onwards, there are pretty good nightly records in all three kingdoms. And the star of 1054, the, what's today, the Crab Supernova is?

• 51:34Neil deGrasse Tyson?

  The Crab Nebula?

• 51:35Speaker 01

  The Crab Nebula is detailed, in great detail, wonderful detail, in all three kingdoms' records.

• 51:44Neil deGrasse Tyson?

  Wow.

• 51:44Speaker 01

  So we know all about it.

• 51:46Neil deGrasse Tyson?

  So we know that it took place.

• 51:47Speaker 01

  Took place.

• 51:48Neil deGrasse Tyson?

  On July 4th, AD 1054. And astrophysicists, to this day, celebrate with fireworks. You see it, launching fireworks, that's what, that's what's going down.

• 52:00Chuck Nice?

  That's so funny.

• 52:01Speaker 01

  So you'd like to look for a-

• 52:04Neil deGrasse Tyson?

  So they would have had records, for sure.

• 52:06Speaker 01

  If there had been a really bright supernova.

• 52:09Neil deGrasse Tyson?

  Uh huh.

• 52:10Speaker 01

  Or a really bright nova.

• 52:12Neil deGrasse Tyson?

  Bright anything, yeah, sure.

• 52:13Speaker 01

  A bright nova, a nova that's only, say, 100 light-years away. And there are stars that are capable of becoming novas only 100 light-years away. That is an easy star that can become brighter than Venus. So, not quite a middle-of-the-day, scary-you-have-to-death brightness, but still pretty bright.

• 52:32Neil deGrasse Tyson?

  Pretty bright.

• 52:33Speaker 01

  So, you gotta go look really carefully at the Chinese, Japanese, and Korean records from, say, minus 10 to plus 10.

• 52:43Neil deGrasse Tyson?

  Yeah.

• 52:44Speaker 01

  Um, you know, AD, and there is no good candidate.

• 52:48Neil deGrasse Tyson?

  And there's no good candidate. Okay.

• 52:49Speaker 01

  Yeah.

• 52:49Neil deGrasse Tyson?

  Wow. And by the way, Planetariums, historically, always had a Christmas show of the star of Bethlehem. And was it a planetary alignment? Was it Venus? Was it this? Was it that? And but it really wasn't any of those, right?

• 53:01Chuck Nice?

  And that's kind of a disappointing ending to a planetary show.

• 53:04Neil deGrasse Tyson?

  And but we would we got so sick of the show. I mean, it was just not there was no science in it.

• 53:09Chuck Nice?

  Yeah.

• 53:09Neil deGrasse Tyson?

  And so in the in the in the parlance of planetary, you know what we call it?

• 53:13Chuck Nice?

  The war on Christmas?

• 53:14Neil deGrasse Tyson?

  No.

• 53:18Neil deGrasse Tyson?

  No, it was tradition. People come to see that and they go to the Rockettes.

• 53:21Chuck Nice?

  Right.

• 53:21Neil deGrasse Tyson?

  And that was that would be the holiday thing.

• 53:23Chuck Nice?

  That makes sense.

• 53:24Neil deGrasse Tyson?

  No, but it became the SOB show.

• 53:27Speaker 01

  SOB standing for?

• 53:29Neil deGrasse Tyson?

  Star Bethlehem.

• 53:31Chuck Nice?

  There you go.

• 53:33Speaker 01

  So we now have the technology. Astronomers now have the technology to once and once and for all answer the question.

• 53:40Chuck Nice?

  Okay.

• 53:41Speaker 01

  And I'm going to tell you how you heard it here first.

• 53:43Chuck Nice?

  Oh, right.

• 53:45Speaker 01

  Using the kind of telescope I described, the one that found the super shell.

• 53:49Neil deGrasse Tyson?

  What question are we answering now?

• 53:50Speaker 01

  Was there a star?

• 53:51Chuck Nice?

  Star Bethlehem.

• 53:52Speaker 01

  Was there a transient? Was there a bright nova or supernova?

• 53:56Chuck Nice?

  Right.

• 53:57Speaker 01

  Within, say, 10 years of zero AD.

• 54:00Neil deGrasse Tyson?

  Yes.

• 54:01Speaker 01

  And we can actually answer that question now quite definitively. And within five to 10 years, certainly within 10 years, we're going to be able to give you that answer quite definitively.

• 54:10Neil deGrasse Tyson?

  Because you could.

• 54:11Chuck Nice?

  Because you are looking right now.

• 54:13Neil deGrasse Tyson?

  Because you're going to be if it was something that exploded, you'd be able to see the remnant that's 2,000 years old.

• 54:18Speaker 01

  And we're going to be able to track the expansion.

• 54:22Chuck Nice?

  Yes.

• 54:22Speaker 01

  And then track the expansion backwards.

• 54:25Chuck Nice?

  Right.

• 54:26Speaker 01

  To see when it's went off.

• 54:28Chuck Nice?

  You will know for a fact.

• 54:29Neil deGrasse Tyson?

  Oh, my gosh.

• 54:30Chuck Nice?

  And see, this is the cool thing about astrophysics, because it comes with receipts. You know what I mean? You cannot bullshit. This is Cicero Artifon. What a cool name, Cicero.

• 54:42Neil deGrasse Tyson?

  We've had Cicero before.

• 54:43Chuck Nice?

  Yeah, we've had him before.

• 54:44Neil deGrasse Tyson?

  This is more than a Cicero out there, but I doubt it.

• 54:46Chuck Nice?

  There ain't no two Cicero Artifons, that's for sure. Hi, Dr. Tyson, Dr. Shower Lord Nice, Cicero Artifon here from the cold lands of Toronto, Canada. Brrr. We use these incredibly bright supernovae as standard candles to figure out how far away galaxies are.

• 55:04Chuck Nice?

  Galaxies are, but it feels a bit counterintuitive, doesn't it? How can something so incredibly distant and that happened so long ago? Act as a reliable measuring tape for the cosmos? What's the ingenious method that allows us to use these far off stellar explosions? To gauge such immense distances?

• 55:29Speaker 01

  That's a terrific question. These are the so-called type one A supernovae.

• 55:35Neil deGrasse Tyson?

  You weren't happy with just two types of supernova, were you?

• 55:37Speaker 01

  We had to subtype and subtype. The type one A's are the magical supernovae that give us astronomers a yardstick. We want to know how far away something is. So that we don't just see how bright it is, but how energetic it is. We can turn brightness into energy, into physical units.

• 55:59Chuck Nice?

  Right.

• 56:00Speaker 01

  And the type one A's are something that we call standard candles. Or equivalently, standard hundred watt light bulbs. They're not-

• 56:14Neil deGrasse Tyson?

  Candles were quite honored that we use them in this reference.

• 56:16Speaker 01

  Yes, they did, and they-

• 56:18Neil deGrasse Tyson?

  It's very classical.

• 56:19Chuck Nice?

  Yeah, since they really suck as a light source, they should be honored, but go ahead.

• 56:22Speaker 01

  Well, the standard candle was made out of whale blubber.

• 56:27Chuck Nice?

  Whale blubber actually-

• 56:28Speaker 01

  A certain size-

• 56:29Neil deGrasse Tyson?

  The oil lamps, yeah.

• 56:31Chuck Nice?

  I take it back then, because, believe it or not, those actually burn pretty evenly in-

• 56:35Neil deGrasse Tyson?

  Well, if you have a big enough wick, yeah, but go ahead.

• 56:37Speaker 01

  That was the point. The beautiful thing about type one A supernovas is not that they are really all exactly the same intrinsic luminosity. But because we're able to measure the distances to some galaxies with other tools that we believe in very firmly.

• 56:56Speaker 01

  Especially the Cepheid variable stars and now the so-called tip of the red giant branch stars. We have a few hundred galaxies whose distances we know with great accuracy.

• 57:08Neil deGrasse Tyson?

  Nearby.

• 57:09Speaker 01

  Nearby.

• 57:10Neil deGrasse Tyson?

  Mm-hmm.

• 57:10Speaker 01

  Out to perhaps fifty million light years.

• 57:13Neil deGrasse Tyson?

  Yeah, that's nearby.

• 57:14Chuck Nice?

  Okay.

• 57:15Neil deGrasse Tyson?

  Fifty million light years.

• 57:16Speaker 01

  Our backyard.

• 57:17Chuck Nice?

  Let's go there tomorrow.

• 57:17Speaker 01

  Our backyard. And we see type 1A supernovas going off there and we can measure their light curves, their brightness as a function of time, very precisely. And then we put them on the same graph and we see that the brighter ones also last longer.

• 57:35Neil deGrasse Tyson?

  Mm-hmm.

• 57:36Speaker 01

  But when we collapse them down to the same width, in other words if we just shrink them digitally, both in brightness and in width, they all lie right on top of each other. So they are standardizable candles. Standardizable hundred watt light bulbs.

• 58:00Chuck Nice?

  That makes that great.

• 58:01Speaker 01

  So the thing we can measure easily is how long they take to fade.

• 58:05Chuck Nice?

  Yeah.

• 58:05Speaker 01

  And then we use that how long they take to fade information to crunch down

• 58:11Chuck Nice?

  Right.

• 58:11Speaker 01

  the light curve onto the standard light curve. And then we can look at supernovas that are ten or twenty times further away than the furthest Cepheid. And that's how we can step way outside our backyard.

• 58:25Neil deGrasse Tyson?

  So it relies on the nearby calibration, basically, to trust what the extrapolation is gonna be.

• 58:30Speaker 01

  And then you get far enough out to say, "Good grief. We thought the Hubble constant meant that the universe was always expanding at the same rate. Everything is cool."

• 58:43Chuck Nice?

  Right.

• 58:44Speaker 01

  It ain't so.

• 58:45Chuck Nice?

  Right.

• 58:45Speaker 01

  We have a change. We have an acceleration in the expansion of the universe. Where did that come from? Who ordered it?

• 58:54Chuck Nice?

  Yeah.

• 58:54Speaker 01

  The so-called dark energy?

• 58:56Chuck Nice?

  Right.

• 58:57Speaker 01

  We have no idea what it is, why it's there, et cetera, et cetera, but it seems to be there. And that's because of the type 1A supernova.

• 59:04Chuck Nice?

  Right, because you know, because of your standardizable uh um uh candle system.

• 59:11Speaker 01

  Yep.

• 59:12Chuck Nice?

  That it works all the way out to here. It's just that when you got to that point.

• 59:16Speaker 01

  Yep.

• 59:17Chuck Nice?

  Beyond that, that's when things change. Well, something had to change because everything else going, coming from this point forward to us still works.

• 59:27Speaker 01

  Everything still works. The physics is fine.

• 59:30Chuck Nice?

  Works, but it allows us to implicate the universe and not the standard. Standard, that's the point. Yeah, that's amazing.

• 59:37Speaker 01

  And to add, answer the second part of the question, um, why does the, how did the universe figure out to do something like this? It turns out to be these wonderful white dwarfs. These collapsed objects actually have a maximum possible mass.

• 59:53Chuck Nice?

  Right.

• 59:54Speaker 01

  They can't get more than about 1.4 times the mass of the sun. If they do, then the gravitational forces within cannot be resisted by any pressure force without. And so there is a magic number.

• 1:00:10Chuck Nice?

  They actually calibrate themselves for you.

• 1:00:13Speaker 01

  There you go.

• 1:00:13Chuck Nice?

  That's amazing. Oh, my God. Science is so crazy.

• 1:00:17Neil deGrasse Tyson?

  No, no, think about it, because if the white dwarf would blow it, blow up at different masses.

• 1:00:24Chuck Nice?

  Right.

• 1:00:24Neil deGrasse Tyson?

  You don't know.

• 1:00:25Chuck Nice?

  You don't know what you're looking at.

• 1:00:26Neil deGrasse Tyson?

  Everybody's blowing up at the same mass.

• 1:00:28Speaker 01

  It's just a little more complicated than that, but here's the one caveat.

• 1:00:33Chuck Nice?

  I was proud for a second.

• 1:00:34Speaker 01

  Because, because you can have two white dwarfs, a binary white dwarf merge.

• 1:00:40Chuck Nice?

  Oh.

• 1:00:41Speaker 01

  And then you can be anywhere between 1.4 and 2.8 times the mass.

• 1:00:46Chuck Nice?

  Gotcha.

• 1:00:47Neil deGrasse Tyson?

  So that's. That will still count as a 1A supernova.

• 1:00:49Speaker 01

  That'll still count as a 1A, and that's why you have brighter ones and fainter ones and shorter decay times and longer decay times. Cause you have the little guys at the 1.4 and the bright, bright guys at 2.8.

• 1:01:04Neil deGrasse Tyson?

  Okay.

• 1:01:04Speaker 01

  Okay, and we've learned how to calibrate for that.

• 1:01:08Chuck Nice?

  Okay.

• 1:01:08Speaker 01

  Little extra complication.

• 1:01:10Neil deGrasse Tyson?

  Like since I've been in graduate school, I don't think we knew that back to in my day.

• 1:01:14Speaker 01

  Nope.

• 1:01:15Neil deGrasse Tyson?

  Right.

• 1:01:15Speaker 01

  Nope.

• 1:01:15Neil deGrasse Tyson?

  Now, so my little contribution to this.

• 1:01:18Chuck Nice?

  Go ahead. Go ahead.

• 1:01:19Neil deGrasse Tyson?

  I am. Last author on a paper. Okay.

• 1:01:24Speaker 01

  Last but not least.

• 1:01:25Neil deGrasse Tyson?

  Last author on a paper. The first author was Brian Schmidt. Okay. Okay. Uh.

• 1:01:31Speaker 01

  Nobel Prize winner.

• 1:01:32Neil deGrasse Tyson?

  Nobel Prize winner for discover, co-discovering the dark energy. Mm-hmm. With supernova type one A's. I'm on one of his supernova papers where, very proud of this. Uh, it is a supernova whose light curve does not fit the light curve of other supernova that it's supposed to, until you invoke the expanding universe time dilation on its light curve. There you go. And then, when you de, then when you mathematically remove the time dilation of the light curve, it falls right back on, on cue. Super cool. So you, you get its distance and its speed with, which is receding?

• 1:02:14Neil deGrasse Tyson?

  And that, that rate stretches out the light curve. Mm-hmm. And so it was the first paper to demonstrate that. And now it's a routine correction that you make. So. So the, so let me just see if I got this right. The stretching of space. Yes. Is really what makes the difference. Yes, and the stretch of space also stretches the time, the, the timeframe. That's correct. That's, wow, you're smart, man. Well, no, no. No, there's fifteen other authors on it.

• 1:02:44Speaker 01

  Okay. They were all brave.

• 1:02:45Neil deGrasse Tyson?

  Yeah.

• 1:02:46Speaker 01

  Because the first time you publish something wildly different from what anyone else has ever seen, there's always this little nagging voice in the back of your mind, did I screw up somewhere?

• 1:02:57Neil deGrasse Tyson?

  They're all there, weren't you?

• 1:02:59Speaker 01

  Am I gonna be a laughing stock?

• 1:03:01Neil deGrasse Tyson?

  Is this interesting result, resulted in me screwing up? Right. Right, right, because if it matched other results, you all couldn't have screwed up in the same way. Right. Right, right. So just to, to be clear about the timing. So if you're, if you are receding. Right. And you're sending one pulse per second, let's say, but you're receding, the next pulse will not get to you after a second. It's a little longer. Exactly. Because you're now farther than when you had sent the first pulse. Right. And so that, in a timed light curve, will stretch out the light curve. That's all. No. And so this got corrected for, and there was. I mean, you say it like it's nothing, but I mean, that's pretty elegant to be, to, if you think about it. It was. And he went on, he got a bunch of these and got the Nobel Prize, and that was it.

• 1:03:44Speaker 01

  Deservedly so.

• 1:03:45Neil deGrasse Tyson?

  I, I didn't get an invitation to the Nobel Prize. Oh, wow. Listen, it's in the mail.

• 1:03:52Neil deGrasse Tyson?

  Michael, I think we have to quit it there.

• 1:03:54Chuck Nice?

  Wow, that was great, man.

• 1:03:55Neil deGrasse Tyson?

  I mean, you, you, you're such a good talker. We didn't get to as many questions as we might have.

• 1:03:59Speaker 01

  Sorry about that.

• 1:04:00Neil deGrasse Tyson?

  But they were good questions.

• 1:04:01Chuck Nice?

  Yeah, they were great questions and great, great answers. And I learned a lot, so. Well, this is, this is, I, I don't, oh, I can, I can, I can actually, uh, tonight, uh, when I take my edible, I can think about all of this. I can think about all of this and really just like marinate.

• 1:04:19Speaker 01

  Just before you do, though, I want you to check whether T-Cor Borer has exploded.

• 1:04:24Chuck Nice?

  I'll do that first.

• 1:04:25Neil deGrasse Tyson?

  You can look out your window.

• 1:04:26Chuck Nice?

  First I'll check my neutrino detector.

• 1:04:29Speaker 01

  Otherwise you may see three or four T-Cor Bores when you look out the window.

• 1:04:34Neil deGrasse Tyson?

  All right, uh, thanks, friend and colleague, Michael Shara.

• 1:04:38Speaker 01

  Great pleasure, thank you.

• 1:04:39Neil deGrasse Tyson?

  Chuck, good to have you, man.

• 1:04:40Chuck Nice?

  Always a pleasure.

• 1:04:41Neil deGrasse Tyson?

  All right, this has been yet another episode of StarTalk Cosmic Queries, the Exploding Stars Edition, oh yeah. Neil deGrasse Tyson, bidding you as always to keep looking up.