StarTalk Radio - Running Out of Matter with Michelle Thaller

Episode Date: July 21, 2026

Could spacetime curve in the opposite direction and produce a repulsive field instead of gravity? Neil deGrasse Tyson and comic co-host Chuck Nice tackle fan questions about photons, heat death, gravitational waves, neutron stars and more with astrophysicist Michelle Thaller. NOTE: StarTalk+ Patrons can listen to this entire episode commercial-free. Thanks to our Patrons Richard Asante, Zan Barrage, Nekoda, Charles O'Neal, Fred FredericM, Douglas Torrance, Barbara Ziola, Nightangelj91, Leslie Woodward, Bryan Jones, Lori Tchen, Walter Lockhart, Paul Walker, Brian Kemp, ismael valdés, Pasquale Perrotta, Xavier LaVigne, nova 🧚🏼‍♀️, Everett Corniel, Ron Herman, Ox, Emile Rougeau, Tony Scaringi, Ceedubya, Michael Bohonek, RS, Jeong Lee, YourCousinRicky, Jesse Wassner, Brett, Agustin Cabanas, James Pack, Dave Baxter, Clarence wirley, Sketchy McDoodles, Chris W, clayton clarkson, David Furth, charles price, Robbie Wells, Gilbert Garcia, Pitbull6098, Ashtyn2022, Kate eftink, Charles Sterner, Liz Dub, Rin Dragon, Liviu N. Spiroiu, Elle Belle, John DiNonno, Researcher Siks, Socal, James Adamson, B Mikhail, Dom Tedeschi, Estella Linthicum, Zionic God, Aye Koe, and Robert Galan for supporting us this week. Subscribe to SiriusXM Podcasts+ to listen to new episodes of StarTalk Radio ad-free and a whole week early.Start a free trial now on Apple Podcasts or by visiting siriusxm.com/podcastsplus. Hosted by Simplecast, an AdsWizz company. See pcm.adswizz.com for information about our collection and use of personal data for advertising.

Chuck, we finally got Michelle Fowler on StarTalk, a friend, a colleague, and science educator. We love these folk. Oh, yeah. She's fun. She's got the energy that we all want and seek of someone who's enthusiastic about the moving frontier of the universe. The energy of a neutron star in the compact form of an astrophysicist.

Ooh. That came out of the show. I got that from the show we just did. That's the highest. compliment I've ever heard anyone get who's an astrophysicist coming right up on StarTalk. Welcome to StarTalk. Your place in the universe where science and pop culture collide. StarTalk begins right now.

This is StarTalk. Neil of Grass Tyson, you're a personal astrophysicist. Got with me, Chuck Nice. How you doing, man? What's up, Neil? All right. We do a cosmic queries. Yes, we are. With an old friend and colleague, Michelle Thaler.

Michelle, welcome to StarTalk. It is wonderful to be here. Great, great to be talking to you guys. Yeah, so you're not only a fellow astrophysicist, you're a fellow science communicator, and we love that species of scientists. You are recently a NASA-Ga-Guard Space Flight Center, but the last time you weren't recently of it, you were of it.

So how recently have you no longer been part of them? Yeah, retired in October. I think it was October 2024. Okay. Yeah, so been retired for a couple of years, been doing speaking. I've been doing a lot of lecturing with Smithsonian journeys. That's been a lot of fun. I know that, yes, yes.

Yeah, just having fun being a freelance astrophysicist. There you go. Nice. Whoa. Astrophysicist. at large. We got a personal astrophysicist and a freelance astrophysicists. We can talk about whatever you want.

I'm not working for anybody. So total... I'm not working for anybody. I like that. But let me just finish up with your CV here. You were research scientists with the Spitzer Space Telescope, one of the big, what do they call them, the Grand... Great Observatories, yes.

Great observatories. And that one was a band of the spectrum that Hubble did not cover. So that was infrared, right, that spits their telescope? Could you straighten us out here? Locally, we have the Goddard Institute for Space Studies who lost their lease with Columbia, as it was removed by the White House, but that has the word Goddard in it.

And then we have the Goddard Space Flight Center in Maryland. They're both NASA. Could you just help us distinguish the two? Well, yes. So the Goddard Institute for Space Studies has for a long, long time, been the center for NASA, basically earth science, climate science. Yes.

And so, you know, that was the thing. So they had a very close link to Columbia University. Columbia University leased this building to them. Famously, it's the building that if you remember Seinfeld, you know, the sitcom Seinfeld, it's the cafe. That's that building. Yeah, that's right. The diner's in that building. Yeah.

It just says restaurants on the front. Yeah, absolutely. It's the greatest name for any eatery ever. It's a restaurant. Yeah. Yeah. So, I mean, absolute heroes. of mine work there. I mean, these are the people that are doing, you know, they're there in the middle

of Antarctica, ground-truthing measurements from satellites. They're making sure we understand what's going on with, you know, the atmosphere and the oceans and all of that. You could say it, Michelle, you could say, they're doing God's work. God's work. Goders work. God's work. God's work. God's work. Absolutely. No, true heroes of mine. And, yeah, it's been rough. It's been a a rough couple of years for them. Yeah, in fact, at the museum, we have a few refugees that have taken pitch tent within our facility. Because we're just down the street a couple of miles from Gis, Goddard Institute for Space Studies. But they're homeless at this point.

They're still all paid as scientists, but they're homeless. But it has the name Goddard in it, yet so did the Space Flight Center. So now we go to Maryland and what happens there? Well, yeah, so Maryland, right, so this is this giant base. At the moment, it's still NASA's largest base in terms of people that go there. I think they're down a little bit. But when I was there, there were about 10,000 people

that worked there every day. And that's pretty incredible. I mean, it's, I mean, one statistic they had is that if Goddard were to leave NASA, then Goddard would become the world's second largest space program. I mean,

I mean, Goddard itself is bigger than the other space programs, you know, around the world. And again, so Goddard builds, builds satellites that, or telescopes that get launched.

Well, yeah. Well, so, I mean, the Hubble Space Telescope was built largely at Goddard, the observatory. part of the James Webb Space Telescope. We build the Goz satellites, the weather satellites. I mean, yeah, I mean, there's four huge science divisions. You've got Earth science, which is the biggest one, and then heliophysics study the sun, the space weather action center, you know, all the stuff the sun's thrown at us. And then you've got, you know, the planetary stuff and the

astrophysics stuff. It's the world's largest science base that we know of. Yeah, for now. Please, please keep it that way. Yes. Chuck. Yeah. Yeah. Michelle, tell me what are the consequences of the budget cuts we've read about to NASA overall and to Goddard specifically where you once worked? It's been a couple years of, I mean, I really feel for all of these people, all of my

former friends, and so many of them have left. I mean, I've seen some of our absolute best scientists. And not only that, our best engineers, one of my best friends who's just an incredible kick-ass systems engineer, as she got scooped up by Switzerland. And I mean, the scientists are going overseas. With NASA and Goddard in general, it's been this real seesaw. Is there going to be a huge cut? Or, well, then Congress kind of restores the funding, so maybe not.

Oh, no, no, we're going to do the huge cut. Oh, well, well, maybe not. So, I mean, it's this time of terrible uncertainty. And, I mean, aside from, you know, programs being on the canceling block and losing scientists, the other big thing I've been seeing that's been heartbreaking is, you know, the best young people, the best scientists. So NASA was required to get rid of all of their, all the people that were hired in the last three years, right? All the people that were still on probation.

You know, I mean, this may be the person you wanted to get, the leader, you know, right out of graduate school. They're going to be the leader for the future. If they were there less than three years, you can still legally fire them. And so those people are gone. And you have a lot of the best scientists now going, well, why should I work for NASA? Why should I work for any kind of government agency? Because they can just up and cancel my job, you know, at a moment's notice. And just to be clear, when you use the word probation, you don't mean they did something bad and they're under observation.

This is just the starter period of time over which you could be removed for no cause at all just because you're not vested in the government system yet. Is that a fair way to characterize that? That's right. I mean, everybody sort of has a trial period when you're hired as a government scientist, you know, equivalent to sort of like getting tenure at a university. You know, you're there sort of for a while where it's legally, you know, easy to say, oh, well, that wasn't the right fit. You know, maybe you should go somewhere else. But then when they make you permanent, that's harder to do. And so, so, yeah, by probationary, that doesn't mean that any, nothing was wrong.

These are the best people in the world. If you do something wrong, they put you on double secret probation. Yes, that's right. So, Michelle, this sounds like when we, I think I might be a little older than you, but same sort of generation where we're, we're, in graduate school and we as a nation are the beneficiaries of the smartest people in other countries coming to the United States for opportunity to express their talents and their brilliance. And it's bad for their home country, good for America. Right.

And now I have colleagues, as do you, who are getting the phone call from Europe. We got a lab for you in Germany. We got a lab for you in Paris. and here's money and it's funded and it's stable, come on down. And so now the world is cherry-picking us. They weren't sending us their best, their brightest. They weren't.

Yeah, but now we're sending our best and brightest out. Yeah, yeah. So where does this land, do you think? Are we going to recover from this? Well, I mean, one of the physics journals, I remember had a full-page ad from the country of Denmark saying, you know, come to a place where facts still matter, right? Damn.

I mean, oh, yeah. Yeah, no, other countries are on it. Oh, that's a burn. Yeah, I mean, Europe is a beneficiary, Canada, and China. I mean, China as well. I have a lot of colleagues that got offers that's like, we'll bring your whole lab over, all your graduate students, like you said, funding. It's so unnecessary.

I mean, the thing that has been so tragic about this is that science research in the United States is a low-budget item. Oh my God. You know, we do not spend a lot of money on this already. I mean, the thing that I was so proud of, I mean, you know, I worked for sort of the science part of NASA. You know, we're doing all the Earth science, the Mars Rovers, you know, the web telescope. But 110 active missions any given time. Each of those missions employs thousands of people, in some cases tens of thousands of people across the country, across the world.

They do it all for under $6 billion a year. Wow. I mean, that's a nothing burger when it comes to a budget. I mean, we get so much innovation. You know, you can demonstrate. We've had economists do studies that you get two, three times that the economic advancement of money put into science research. Just to be clear, that's the $6 billion out of the $30 billion that is NASA's annual budget. And you're referring to just the science, which is not putting people in orbit.

That's not the space station. That is not launching astronauts. That is science. Putting people in orbit, of course, has to be more expensive because you need to be a lot more careful when there's when there are human lives on stake. Yeah, they want to come back usually. They want to come back. The lovers don't need to come back. People, you got to bring them back, you know. What you can do for the cheap? I mean, some of the missions that blow me away, you know, I mean, basic physics, how to neutron stars work nicer. That's actually on the space station. But it's a small thing. Just a couple hundred million dollars. I mean, these little budget items, you know, James Webb of course. course, is a bigger one, but that was over like 20 years and employed, again, tens of thousands of people. These are tremendously great value for the money. Did you say it was 30 billion? That's all

we spend? 30 billion? The total. Yeah, it's around there, plus or minus for NASA in a year. So 30 billion is less than four tenths of one percent of your tax dollar. And I do the experiment. You take a full dollar and just cut into it, just a single dollar bill cut into it four tenths of 1% of its width, and it doesn't even reach the paint, the ink of the bill. Okay, you can remove that and the bill is still there. A, B, what I wanted is to create a new budgeting system where agencies get the money people think they're getting. Because the visibility of NASA is so huge compared to their actual budget.

No one would guess off the top that they're getting. getting four-tenths of 1%. They would say 5%. I've heard some people say 10%. And I say, that's the budget we should give. I like that. Give them the visibility budget. Yeah. Yeah. And by the way, everybody loves NASA. Still, it's one of the few government agencies where people believe in the institution of the agency and they also trust it. And it's respected around the world. It's respected around the world. You know, that and what was formerly the NIH, which is now the SAD, as in just sad. That doesn't even stand for anything.

It's just sad. I mean, NIH is a whole other story. I mean, honestly, that's even more worth saving than NASA. I mean, as much as I'm a huge NASA and space fan, I mean, do not mess with the NIH. Good Lord. I mean, we need to keep that research going. The cancer research, the Alzheimer's research.

I mean, again, Center for Disease Control, things like that. Oh, my God, do we need those? So, yeah, and remember, I mean, for $30 billion, you're still talking about the whole budget of NASA, and the human space program is the big chunk of that. All the Earth science, all the climate science, all the weather satellites, you know, all the monitoring the sun, all the exploring the universe.

And all the space telescopes are in the science. All the space telescopes, yeah. So, I mean, it's nothing. I mean, I don't know if this is true, but I remember one economist saying that they'd shown that the Pentagon, the military, across all over the world, had spent more money on air conditioning in a year.

than that budget. Oh my God. So I'm not absolutely sure that's true. But, but, you know, it's on that level. I mean, we're not even a fighter jet, basically. Looks like America has stepped in a pile of doge crap. Yeah.

Doge do-doo. This is Ken, the nerdneck Zabera from Michigan, and I support StarTalk on Patreon. This is StarTalk Radio with Neil deGrasse Tyson. So let's pivot now. to our questions. So Michelle, we've solicited questions from our fan base, well, from our Patreon supporters, and they know who you are, they know your expertise, and these are targeted for you.

And to the extent that we overlap in expertise, I'm happy to put in my two cents, but we're really here to see what you've got to say in response to these questions. Chuck has them all. I haven't seen any of them. And so, Chuck, what do you have for us? All right. So inquiring minds, one to know. This is Ross Graves, who says, Hello, I admire and I respect you all, Dr. Tyson, Dr. Thaler. Lord Nice, this is Ross from California. When a photon is absorbed and reamitted or reflected,

is the journey through spacetime physically continuous, or does that interaction create an entirely new quantum history for the outgoing light in the sense that the light experience is no time of its own, if reflected, did it hit a surface and restart its experience as a reflection? Dude, that's a matrix like crap. He just, that's amazing. That is an amazing question. I love it.

I love it. Did it take on a new identity as a reflected photon? That's what that comes down to. So, Michelle, what do you have to say about that? Okay, all right, all right. So I'm going to say, I'm going to start out saying, this is something that is a question of mine. So, I mean, well done.

Because I mean, this is actually something that I wish I understood better. I only recently came to a better understanding because of some great podcasts, actually. It was a podcast Veritasium that Derek Mueller does. That finally I could understand why the speed of light is different speeds. When you go through the vacuum of space, it's the fastest anything can go, the speed of light, when it passes through air or water or glass. You see that classic bend, right? When you look through water, you see light like bend, and that's because the speed changes.

And it was only his podcast that finally got me to understand, you know, light is an electromagnetic field. And when it's in the presence of other electromagnetic fields, when you're not in a vacuum, there's other atoms and molecules around, the electromagnetic field basically becomes a combination of those two fields. And he did this great podcast about that. The question about whether a photon is reflected becomes a different photon is fascinating. So let's break it up. Let's go back to the beginning. I mean, this is one of the craziest, and it's true. You know, the idea that when you're traveling at the speed of light, I mean, photons obviously don't have any consciousness. They're not able to observe this. But a photon has no idea that space and time exist. When you're traveling at the speed of light, time goes to a zero. You don't experience the passage of time. And, you know, when you think about you're frozen in a moment of time, you can go any distance in the universe instantaneously to your perspective. So a photon doesn't really experience the universe as ever having expanded. You know, we're still a point, a thing, you know, almost a singularity to a

photon. It does not experience space and time. What the hell does that mean? I mean, how do you wrap your head around that? When, I mean, the light that's, you know, bouncing off my lamp from my face right now doesn't agree with me that space and time exist. Now, help me unpack this, Neil, because I don't have a great answer. I would like a better answer. Let me restate what you said, but I don't have a deeper understanding just for having restated it. It's the photon has to know that the universe expands because it gets redshifted.

Right? So the photon you detect has a different energy than the photon that was emitted. So even though the photon does not experience space time, we measure a different photon, a different energy for that photon. Some of that energy got shared with the expansion of the universe. So that's something I can't claim to fully understand how it doesn't exist in time at all, yet it changed its wavelength before it arrived on location with you. Now, let me ask you, I didn't see that episode with Veritasium, but it was also a recent understanding of mine as well, that when photon moves through a medium, it is moving at the speed of light between atoms of the transparent medium, but it interacts with each atom and continues forward, and that interaction creates a time delay. So the photon is never actually ever going slower than the speed of light. It just got waylaid en route through the transparent medium.

Now, is that consistent with what you got out of the Veritasium episode? So wait, wait, Neil, let me just, because, well, Jesus. So I'm trying to, I'm trying to. Take a cleansing breath, Chuck. Yes. Take a cleansing breath. Okay. I'm trying to get.

this as a metaphor because that's how I'd see and understand this. So in the vacuum of space, that would be like taking a pool ball and shooting it straight across the table into the pocket. And it's going at that speed. But then when you put it through a medium, that would be like having the same speed, but banking it off of three banks and then going into the pocket. So your speed doesn't change, but the fact that you had to bank it three times is what slowed you down. However, however, what you're describing does happen to light, but that's when light scatters. Okay. So that's a different phenomenon. It keeps in the same direction at all times. Ah, gotcha, got you, got you, got to, got you. That's the difference between a transparent medium,

a translucent medium, and just something that completely scatters the light. So, Michelle, are we an agreement that we're talking about a new photon as it goes through a newly shaped photon after it interacted with these other fields? Is that a fair way that you think of... The way the podcast did it, and this was the first time I ever sort of thought, oh, okay, I get this. You know, we were sort of talking about photons as particles here, like little billiard balls and stuff, but of course, remember famously, they're electromagnetic waves, right?

I mean, they're not just little balls. And so what the podcast did is it showed that there's electromagnetic wave, there's a photon going in, and there's other atoms around. And basically the electromagnetic wave starts those other atoms kind of vibrating along with it. But there's a delay. There's a lag to kind of get those other fields, those other electric fields vibrating as the photon goes by. And the resulting speed is actually a combination. It's actually a way of resolving those two different vibrational modes.

So the photon is like to the other, you know, atoms like, bro, you're bringing me down. Yeah, I can slow him down. Bro, you're a drag on me, man. I can't, I got to, come on. I'm serious. Like, get off me. And then... Let me get the hell out of this medium.

Yeah, because once he exits the medium, it's back at the speed of light. The speed of the wave that we measure is a combination of the speed of the photon in a vacuum, but then also the speed of the variations of the, basically the, the oscillations of everything around it. Those two combine into the measures of the photon that we see. That's fascinating. So the, so the, so the, the, the, of the, of the, of the, of the, of the, of the question about, I mean, it's the same thing, Neil, absolutely. When you talk about how a photon

changes, even as it goes through a vacuum, it loses energy. It's a very similar question that if a photon is reflected, is it a different photon? I mean, it can certainly be a different energy, right? I mean, when a photon is reflected, you usually lose some energy in the reflection. So, I mean, I mean, there's all sorts of things. Photons absolutely can change. Just to be clear, Chuck, if the photon hits a surface and reflects, some of its energy, is imparted as momentum to that surface. And that's why solar sales work at all. It has to be. Yeah. Yeah.

So, yeah, there's an energy change there. So I'm voting for a completely different photon here. What do you think, Michelle? Yeah. Like I said, Ross Graves is a name that's familiar to me. So, yes, I thank you for this fabulous question. And I have to say, I do not have an extremely clear answer. I'm not ashamed of that. This is one I've wondered myself.

Okay, so let's vote. That's right, yeah, yeah. I'm voting that the photon that came out, it's a new quantum state that is carrying the mission forward after it had its delay from the medium through which it passed or the medium off of which it reflected. Now, I'm going with that. Okay. I'm going with, I wish I had the same properties and there was a reflection, Chuck. And real Chuck. And I could tell all the people I owe money, you need to go talk to reflection, Chuck.

That's not me anymore. That's not me anymore, buddy. No, that's a great question. Okay. What else you have, Chuck? All right, here we go. This is Jow Costa. And Jow Costa says, good tidings.

Dr. Tyson, Dr. Thaler, Lord, nice deep breath now, Chuck. Jal Costa here. Greetings from Portugal. All right. Portugal. Yes, he says, if matter isn't being created, only transformed,

will there come a day when the universe runs out of matter to create new astral bodies? If so, how will we be able to notice such a situation developing? Will the creation start to become rarer, smaller,

or deficient, as in less frequent, less energetic, or less stable? Thank you. And please keep making our necks hurt. Oh, I like it. Look up making that hurt.

Oh, no, I see. I see what he did there. He's saying, you got him looking up so much. You gave him a neckache, Neil. Okay, you can lay down and look up, and then you're just looking straight ahead. That's true. The geometry works out there, shall.

Yeah, yeah. Well, it sounds to me like somebody is just describing what's called the heat death of the universe, and the answer is yes. The answer is that the universe is slowing down in the sense that it's not so much that matter can't be destroyed. It can. It can be converted into energy, right? Matter and energy are two sides of the same coin. That famous equation, you know, hopefully the only one you ever have to deal with in life,

you know, unless you want to be a scientist, is energy equals mass times the speed of light squared. Good old Albert Einstein. E.E.C. squared. That's most people's first equation they learn in elementary school, even before you know what it means. It's a very elementary school equation. Yeah. So, I mean, so you can destroy math. you can make it into energy, and you can make energy into matter. That's what we do in particle accelerators. We get things going with such high energy. When things collide, there's so much energy around, it actually creates new matter.

That's how you find new types of particles. So energy and matter are equivalent. And so there is, but absolutely what's happening is that in the early universe, there were things that were much higher temperature, much higher energy. Stars, for example, are an example of something that's a very low entropy. Stars create very high energy radiation. And, you know, over time, yes, I mean, every time you basically generate, you know, heat, I mean, if sunlight comes down, it's a high energy photon, hits the earth, warms things up,

what's released, the heat is a lower energy type of light. You've lost energy. You've made from a high energy particle of light. Now it's a lower energy type of light. And so eventually the universe, all of the photons that were high energy are going to hit things, get absorbed by things, make things warm, get re-emitted, and they're going to lose energy over time. And so, yes, the universe is running down. And eventually we're going to get to a point where there's nothing left but very low energy photons. You know, photons that are so low energy,

they're probably not even detectable. And then it's sort of anybody's guess as to, you know, does time and space exist anymore when there's really, everything is just the same temperature. A very, very low temperature is the only thing that the universe has. So it's a misnomer to call it a heat death if it's actually a cold death. It gets cooler and cooler. Yeah, yeah. So it's the heat that's dying. Yeah.

It's the heat that's like, oh, go out of me. Yeah. Just go out without me. Plus the expanding universe also drops, is dropping the temperature with it. Right. Absolutely. You've got a photon going through expanding space and think about, you know, draw a squiggly line on a piece of elastic and pull the elastic.

And that that wavelength drops down. You lose energy. I mean, it's really kind of as simple as that. Wait, just to be precise, the wavelength gets longer. The wavelength gets longer. That's right, yes. And that's the lower energy wavelength. Lower energy.

So it drops down. The wavelength gets longer, the frequency drops. Right. And if I may, what Michelle just described is exactly how the warming of the planet happens. High energy comes in, pierces our atmosphere, becomes lower energy and a longer wavelength, which is trapped by greenhouse gases. And that's how we heat up, because as everybody has learned from Neil, the atmosphere isn't hot, the ground gets hot, and radiates heat back into the atmosphere. And that is the cycle that creates a warming of the planet. Just so that you guys know that it's real.

Okay? It's real. And send $5 to Judge Sennett campaign. By the way, just to be precise, there is a layer of the atmosphere that does absorb light directly from the sun. And that's the thermosphere where the ultraviolet gets absorbed and by the ozone. And so that there is a layer that is hotter. But we're not experiencing that layer down here. Oh, yeah, that's cool.

Yeah. The hottest part of the troposphere is right above Earth's surface. Right above Earth's surface. Okay. Nice. Yeah. Right. And what's the part?

See, now this is where the explainers are all swirling in my head. What is the part where the excitation of the molecules is such that it's, we say it's cold, but it's actually hotter? Chuck, could it be that there's upper layers of the atmosphere where the particles themselves are high energy, but there isn't many of them so that you don't feel that temperature that you otherwise would. So the concept of temperature

kind of loses practical meaning there. Right. Okay, I said it like a... Could be what you're thinking about. Yeah, that's exactly what I was thinking about, but I said it like a dumb two-year-old. Like Michelle, if I flew you through the sun's

corona, which is five million degrees, would you feel that, given how low density the particles are that have such high temperature. We are really, really lucky the answer is no, because, I mean, the corona is one thing, but also let's remember, I mean, we actually, our whole solar system is in this hot bubble of gas in the Milky Way galaxy. Maybe there was a star that exploded here billions of years ago, but the temperature of the gas

we're going through is in the millions of degrees in our galaxy. The thing is, the gas between the stars is so thin. It's like, okay, there goes, there goes a proton, zip, you know, there goes an electrical, drawn Zup, you know, I mean, there's so few particles that it doesn't really impart any heat to you. I mean, yes, the average speed of these high energy particles is equivalent to being, you know, millions of degree gas. And just like Neil said, so the sun's corona is this extended atmosphere of a very hot gas. We have a spacecraft. NASA has a spacecraft called the Parker Solar Probe that is orbiting well within this solar corona right now. You better believe it would not be

a live returning data if it really felt like 500 degrees. Yeah. So the, the, the analogy we used to use use is when you think about, you know, everybody who's like done some baking, you get your oven up to 500 degrees. That's some serious baking if you're baking at 500 degrees. It's pizza. We're going for pizza ovens here. Yeah. Yeah. You're a pizza. You're a pizza shop on the corner of Lennox Avenue, 125th Street. Yeah. If you have a 500 degree oven, okay. So if you, if you open the oven and you just stick your hand in, your hand is, is not actually feeling like it's 500 degrees all of a sudden. If you were to touch like a metal part of the oven, if you were to touch the rack, then you'd burn your hand. Because, I mean, all of a sudden

now you have a denser object. You've got the metal. Yeah. A little bit of a thing about the Parker Solar Probe. It's another another incredible person, Eugene Parker, and he was the person that discovered this wind of high energy particles from the sun, the solar wind. The solar wind. Yeah, a fabulous launch. I'm glad somebody told me that a Delta Heavy looks like it explodes on the pad before the rocket comes up. I was at that launch was amazing. The whole idea, the surface of the sun is only about, you know, say roughly like 10,000 degrees Fahrenheit. But as soon as you get off the surface, the gas becomes millions of degrees hot. I mean, this was a big mystery. And how does the sun do that? I mean, normally if you've got a hot campfire, you know, the farther where you walk,

the cooler it seems, why does the temperature go up? And the Parker Solar Probe has really helped answer that. There's all of these complicated accelerations due to magnetic fields around the sun. The particles pick up speed. There are shocks in there. So, I mean, we're figuring out how the sun works. It's not something we know until we go there near the sun, fly around in this corona and see what's going on. And look at that. You're getting all of that for a lousy $6 billion dollars. Okay. What the hell is wrong with you people? Okay, Chuck, that's his daily, I got to blow a gasket once a day. It's worth it. It's worth blowing a gasket over.

If memory serves, the Parker Solar Probe set a speed record. Oh, yeah. It goes over 400,000 miles an hour. Oh, holy, get the, yeah. I keep having to look that up because I don't believe it. And then I look it up again. You don't believe it. Because it gets pulled in by the sun's gravity.

That's right. And there it is 400,000 miles an hour. Wow. Amazing. All right. Well, let's move on. I have a few more questions. Let's try to fit in a bunch more.

So let's tighten up the answers and see how many we can fit in. Let's just do the questions and then we just have to have Michelle back to ask more. That's all, you know. I'm always here. That's right. Yeah, we're not going anywhere. I mean, you know, why these people, they're just like, you didn't get to my question. What?

What, you think, you got information we don't? We're getting canceled? What do you know? What do you know that we don't know? You know, we can do this again. I'm always up for questions. All right, here we go. This is Tristan Breaker, who says,

Good evening, Dr. Tyson, Dr. Thaler, Lord Nice. Tristian here from Utah. Considering gravity is caused by the curvature of space time, hypothetically, could gravitational waves from two separate sources intersect forming a constructive interference pattern combining their amplitudes? If so, could this create regions and space? where the curvature of spacetime is great enough to produce a gravitational field as though a celestial body were present, even though nothing is there.

Additionally, wouldn't the crest of the waves create an inverse gravitational field? Could space time curve in the opposite direction imagining the common fabric of gravity demonstration, for instance, producing a repulsive field rather than an attractive one? my heartfelt thanks to you for bringing awareness to the wonders of the universe. Well, Tristan, all I could say is, first of all I need some of that weed, you smoking. Because, man, that is some serious stuff. Maybe check with our producers. Maybe for questions like that, we should create a little certificate that we send back out to them.

For questions that are above and beyond the call of duty. We've had two so far in this show. It's a deep thought question. That's a deep thought question. Michelle, are you up on gravitational waves? What's the latest thing? Oh, I love gravitational waves. Are you kidding?

I was a postdoc at Caltech. I better love gravitational waves. So, oh my God. Let me just say how impressed I am with gravitational wave detection. Because this is something, when I was a postdoc at Caltech, it was a big deal, the LIGO project, the laser interferometric gravitational wave observatory.

It was something that Caltech was involved in. And I honestly, I talk about my skeptical nature, I was like, they're never going to detect these bastards. I mean, this is really, so LIGO at the time, there were two facilities. There are now more. You've got a laser that's about about two miles long. And another one going out in a 90 degree angle. There we go.

In a corner. So two miles each direction. And those lasers, you know, are. are supposed to be exactly the same length. Imagine trying to calibrate that, you know. And so the lasers are going back and forth, bouncing around. And then if a gravitational wave comes by, a gravitational wave is literally a wave in space and time. And so space contracts in one direction.

And all of a sudden the two lasers are no longer the same length. They're different because space contracted. And so the person with the question is absolutely right. That's what gravitational waves do. The thing that makes it mind-blowing that we detected these things, is they're tiny, luckily, for us. I mean, they're a thousand times smaller than a proton. And to give you a sense of that, I mean, not that the human brain can even get that,

and the human brain's not going to get the next one either, but it's the equivalent of measuring from us to the nearest star, Alpha Centauri, about four light years. Light year is about six trillion miles. Damn. You're going on 24 trillion miles. That would be the equivalent of the distance between us and the nearest star. varying by the thickness of a human hair.

Wow. They're trying to measure that. Holy! Are you allowed to swear on this podcast? I'll do it for you. Holy shit. I could go more than that, probably. I could swear I'll do it.

You know, I did not think they'd be able to do this. And in fact, Michelle, you know, the Nobel Prize, which was ultimately given to the project, for me, I view that as not only a prize for the scientific result, but for the engineering that enabled it. Oh, my gosh. Yeah. With that measurement being so infinitesimally small, how do they know that somebody didn't just bump the table?

Absolutely. So, I mean, so this is the thing, right? I mean, please on the table. Right. Exactly. So somebody bumped on table in the next state, right? I sneezed in Australia. Yeah, I know.

So there's, I mean, there's all of these, you know, there's all this noise in the detector, right? The detector, like you said, there's all kinds of noise going on in the detector. And then this, I was just making sure I had my, my dates and everything. So this would have been in September of 2015. And just to clarify, when a scientist uses the word noise, they're not necessarily and almost hardly ever are talking about sound. Yeah, they're not in the lap going, Shut your ass up. Who knows?

Maybe that's what the detector was saying. Cut down the noise. No, we're talking about sources of interference to the signal you're trying to measure, no matter what those sources are. Right, so go on, Michelle. There's all kinds of little variations. I mean, the lasers are under vacuum,

but, you know, there's all kinds of things happening. So in September of 2015, you know, there's all kinds of noise. there's all kinds of variation, but then all of a sudden, one of the detectors goes, wamba, wumba, boom, just like that. And then at the speed of light

between one detector, which was in Louisiana and the other one was in Oregon, the same pattern, wumba, wumba, boom, boom, goes off. And it was absolutely unquestionable. It was the same pattern,

the same frequency, at the speed of light, gravitational waves travel, the speed of light from one detector, and people were like, Nobel Prize. Yeah, that's fantastic. Oh, my God.

But, I mean, Let me just say, because I want to say, what that event was. There were two black holes, 1.4 billion light years away. This event happened 1.4 billion years ago. The black holes were both on the order. In another galaxy. In another galaxy. Yeah, I was way out of our galaxy.

Far away, by the way. Yeah, far far away. Yes. Thank you, Chuck. Those two black holes are both about. It's far far away. It's far away. Yeah, yeah.

1.4 billion light years, don't need to worry about it. Yeah, yeah, that's right. You know, there were two black holes that were roughly 30 times the mass of the sun apiece. We caught them in only the last two seconds, point two, two tenths of a second of them spiraling together and merging into a bigger black hole. And in that point two seconds, they accelerated from 30% of the speed of light to 60% the speed of light. Black holes 30 times the mass of the sun. And about two times the mass of the sun was converted into pure energy. Wow. In 0.2 seconds.

This is an unbelievable thing. It's real. That is a monster proportions that the human brain can't go any. I have no idea what that is. And it happened and we measured it. Michelle, wasn't that the most energetic event in the universe in that moment? I think it had to be. It was more energy than every star in every galaxy in the observable universe. Wow.

Yeah. Yeah. In that 0.2 seconds, right. In that 0.2 seconds. Jeez, Louise. So tell us about, so if this happens with some frequency, no pun intended there, then two waves that do intersect, what can we say about them? Do they magnify any kind of gravitational disturbance in the space time?

What can we say about what is happening? Because when you drop two pebbles in a pond, you see interference patterns with the peak gets higher and the valleys get lower. So it's exaggerates. What's there? Can we? Presumably we can expect just that same thing, can't we? Yeah, I think the answer is yes, but it's at a tiny, tiny, tiny scale. And also, I mean, this was a fantastic energetic event that the gravitational wave detector was able to detect this event.

But there's also a background of gravitational waves, binary stars going around each other. kinds of things. I'm actually making tiny little gravitational waves right now. So, you know, the, it's, again, we, we come to this idea of noise. Wait, you were making gravitational waves because you were lifting your hands up and down. A mass is moving. There's something moving. There's mass moving around. That's right. It's really, really small. It's not that you have special powers. You're just moving your body. Just to be clear. Exactly. Yeah. That'd be a great superpower, you know, making gravitational waves. But anyway, yeah, so the answer I think is yes.

But I don't think there's going to be any organized effect of that. Because there's just, I mean, think about, you know, waves on a giant lake, a giant ocean. There's ripples going every which way. And yes, they are interfering. When they add together or, you know, they can, you know, I think all that's happening. But I don't think that has any measurable effect on what's going on in the universe. It's tiny. So in Tristan's question, it,

was, would it be able to perhaps give the appearance of a celestial body being there when none is there because of the curvature of space time itself? And you're saying that that's not going to happen. Okay. No. Cool. The energetics are too small. So just to be clear, it gave off more energy than all stars combined in the universe

over those 0.2 seconds. But then that energy in the form of gravitational waves moved how many billions of miles to reach us? 1.4 billion light gears. 1.4 billion light. So it's been diluted over that distance to the low energies that were ultimately detected in LIGO. Right?

I mean, just think of the volume. Because anybody at this distance in any direction from those colliding black holes could make this measure. Yeah, yeah. So that energy is expanding through the entire universe

and we're just catching our one little piece of it. What was that event like? I mean, because if you feel, close to that event. I mean, I mean, I mean, I mean, that must have ripped apart any matter, you know, within quite a, quite a large distance. I mean, I'm sure we could, you know, have somebody do the math on that. So, I mean, it's, it's, it's, so no, I don't think there would be, it can't make it seem like there's a star there. This is not a solution for dark matter. Sorry. It's not. Okay. All right.

This is, uh, Rachel Ambrose, who says, Rachel here from Texas. I love Michelle's big think interview. It was the first. time I heard someone articulate the profound weirdness of reality in a way that completely resonated with how I have always felt but could never adequately explain. And I just appreciated that so much. Thank you, Michelle. My question is about neutron stars. I am confused why the high-energy fast radio bursts, the FRBs, come to us in the form of low-energy radio frequencies rather than x-rays or gamma rays. What mechanism causes such a high-energy event to manifest as radio light?

Ooh. So this has built in the knowledge that radio waves are lower energy light than x-rays or gamma rays. And if it's a high-energy phenomenon, why is it wasting itself with radio waves? So, Michelle, you answer that one, Michelle. Yeah, yeah. Okay, so yeah, I at least know a little bit about that. I mean, as I said, I mean, one of the missions I absolutely adore is called Niser, the Neutron Star Interior Composition Explorer.

It's on the space station. It's a Goddard Run mission. Fantastic. It's about the size of a washing machine. Again, not an expensive mission. And it's able to actually get x-rays in this case, x-rays from neutron stars, and it times the arrival of the x-rays so precisely we can make a map of what the surface of a neutron star is like. They're tiny.

stars are only about 20 miles across. They usually have about twice the mass of the sun packed into 20 miles. These are extreme things and they're real. I mean, we study many of these. And they're so incredible. When you do a map of these and they often are rotating very fast, you actually get this strange effect on the side of the map because light is bending around. There's so much mass, the curvature of space and time is so extreme.

two solar masses packed into 20 miles that you actually can see behind a neutron star as well as in front, the light curves around it. And so, I mean, what an incredible real monster. So what you're saying is it has many properties that we would find with black holes in its distortion of the fabric of space and time in their vicinity.

The neutron star group at Goddard said that neutron stars are far more interesting than black holes because with black holes, you have this dark event horizon that nothing ever comes out of. You don't know what's going on in there. With neutron stars, you got the freaking thing right in front of you. It's still here with us. And you can study something that has such extreme conditions,

that there's no laboratory on Earth. We can even study what matters like under these conditions. It's amazing. Wow. But yeah, okay, so going back to why it's radio waves, neutron stars definitely do admit high-energy radiation. They're actually the source of what we think are gamma-ray bursts, dangerous blasts of high-energy radiation.

We're using an X-ray telescope to observe these things. The surface of a neutron star is very hot. It definitely does generate these high-energy things. The way you get radio waves is something, Neil, I'm sure it's a favorite of yours too. It's a lovely thing called synchrotron radiation. And would you like to go ahead and talk about synchrotron radiation? How could you not? As I understood it.

No, as I understand it, the neutron star has to be magnetic, has to have a magnetic field. That's right. And as it rotates, it can accelerate electrons that are ambient in the environment. And you can accelerate electrons off of magnetic field that will radiate radio waves. Yes. We call it synchrotron radiation. I think I accounted for that correctly. Is that correct?

Yeah. I mean, the one thing that's perhaps, you know, something to mention about synchrotron radiation. I mean, so you've got a couple things going on. I mean, you also have, you know, electrons are charged particles. they respond to a magnetic field. They can actually be accelerated. Neutron stars have jets. We see those as well.

Also, when you get, synchrotron radiation happens largely when electrons spirals around a magnetic field. Just by the act of spinning around, that's a form of acceleration. That's what it was. And that generates. It creates its own frequency, spiral frequency that is the radio wave. So what's fun about the neutron star, just to summarize that, is different processes within the environment of a neutron star give you different bands of light that are different telescopes can participate in, which is kind of fun.

And then you can compare notes across different wavelengths of light. This is why astronomers just aren't greedy. It's like, oh, we need a radio telescope and an infrared telescope and an x-ray telescope and a visible light telescope. But you're absolutely true. You see totally different things in these different wavelengths of light. And so as high energy and dramatic objects, neutron stars are, you better believe they are. There was one in, God, was it, was it 2007?

There was an event that actually blew off a measurable amount of our atmosphere. And the whole magnetic field of the earth was ringing like a bell for a while. Now you're telling us this? Wow, look this up. This is all real. And we traced it back to a neutron star that we think is about 50,000 light years away. The neutron star had a little bit of a bad day. The crust we think shifted by about a centimeter.

And that gave off so much energy. that 50,000 light years away, it blew off a bunch of our atmosphere. Oh, my. These are intense things. Michelle, I'm going to be honest. I could have lived without that information. Yeah, I know. It keeps up in night, doesn't it?

I mean, he cares about asteroids, right? I mean, killer asteroids. No, I mean, these blasts of high-energy radiation from neutron stars, some people think that may limit the age of civilizations in the galaxy. Eventually, we all get hit by one. Wow, another great question. Thank you, Rachel. All right.

This is Brett, and Brett says, hi, Dr. Tyson, Dr. Thaler, Lord Nice. Tuning in from Dublin, Ireland. My question is, what unlikely possibility or possibilities do you hope are true? Oh. Ooh. That's father for good thought. It is. An unlikely possibility that you're like, oh man, that'd be so great if that were true.

Yeah. So, boy, that can go in so many different directions. Because I mean, I've got, I mean, what a great question, Brett. Look at you. I can lead all. I got one for you, Michelle. Okay, I got one too. You go ahead.

I think I got it. I think it's unlikely that we'll find anything other than microbial life on Mars if we find life at all, but we would be really cool if we found sort of macroscopic crawly things living in the subsurface of Mars. I think that's unlikely, but that would be really cool if creatures crawl out from home. Would you still be satisfied if those macroscopic crawly things were fossilized in some way, but they're no longer there? No, no. We're talking about unlikely things that we want to happen. Let the thing crawl out and ride one of the rovers like a, like a, like a, Like a, you know.

I got to say. Right. You know, like, like, what do you call those horse, those, those, those, those, Bucking Broncos. Yeah, Bucking Bronco. I want to come out and ride one of our, ride one of our, uh, rovers. Our rovers. So, I mean, unlikely, but it would be really cool if it was true.

So now your turn, Michelle. Well, I mean, I mean, so I was just riffing on that. I mean, do you think it might be more likely to find macroscopic life on the moons of Jupiter and Saturn in the oceans? You know, Europa and Saladus? We're talking about, unlike. Likely things that we want to happen. Oh, you think that's a likely thing. Okay, all right, I got it.

Yeah, yeah. Unlikely things. Yeah, there could be like little brine shrimp and stuff. Yeah. What of my big excitements right now with the Web Telescope is it's looking so far away that we're looking back to a time roughly, like, let's say, about 300 million years after the Big Bang. And we're actually seeing the very first stars form. And they're absolutely different. I mean, we haven't actually found one of these first stars yet.

I really want to find a first-generation star. We're going to be looking back to a time, just like I said, a couple hundred million years after the Big Bang when stars started to form. Web can now see that far back. We have that power. And we're starting to see these pseudo stars that are formed around black holes. They're about a million times the mass of the sun, relatively small. You know, I mean, these things may become the seeds of the big black holes

that are in the centers of all galaxies, we're starting to see that forming now. And my question, I mean, I was a stellar astrophysicist. I was a stellar astrophysicist. I studied stars, that was my thing. Outstanding in your field. Not outstanding, but that's why I studied. And I would love to see what one of the first generation stars looks like.

Because my guess is it's going to look totally different, that the universe was more dense back then. There was more dark matter prevalent. I mean, dark matter has gravity. That's going to get sucked into the formation of a star, just blue gravity too. What was that first generation of stars like? My guess is they're going to be huge, many, many times the mass of the sun, many, many, many times bigger than the most massive stars we have today. And I'm wondering if they're going to work really differently because there's more dark matter in them.

Okay. What were the, what were the, I want to see that first generation of stars. And just to be clear, James Webb was specifically designed in tune. for that exercise to see the beginnings of the formation of matter in the early universe. So you're betting on the right horse there, I think. Yeah, we're doing it. I mean, these things, never let astronomers name anything. These things are called little red dots.

Ha, ha, yeah. They're massive pseudo stars around a giant black hole at the beginning of the universe from calling little red dots. Because they look like little red dots. They're so far away. Yeah. That's one of my favorites. Chuck, time for like two more questions.

All right, here we go. But only if Michelle is efficient in her answers. I promise to be efficient. You're on notice. You don't have to promise anything, Michelle. It's going to do what you want. This is Alyssa Feldhouse who says, hello, Fowler the Great.

This is Alyssa Feldhouse, tuning in from Hendersonville, Tennessee, as such a prominent female figure in the science world, what message can you give all the little girls out there that will one day stand on our shoulders? Me and my girls love how the universe works, and thank you for keeping science cool. Ooh. Oh, I always think myself as so nerdy.

I never think about cool. Okay, so a message I always have. The nerdy is the new cool. Nerdy is the new cool, absolutely. Yeah. A message I already have is you're already the right type of person to be a scientist. Math and physics did not come quickly to me. I didn't get particularly good grades in school in math and physics. It took me some time. I just loved it so much. You know, paying attention to your own curiosity and not being discouraged when maybe you don't get something very, very quickly. You're already enough. You're already there. For so long, I wondered, you know, do I have what it takes to be an astrophysicist?

I love this, but maybe I just don't have the magic thing, the right stuff. And science doesn't work that way. If you want to study it, you can study it. It's like learning a language. You know, it takes a while to become fluent in a different language. You don't really go up to a young person and say, you could never learn Spanish, you know, even if you tried. You know, no, no. I mean, science is a beautiful thing to study.

It takes time. And anyone can learn it if they're interested in it and have that, you know, that passion. more than any innate ability and talent to get all of this very quickly. So, you know, I spent way too much time thinking maybe I'm not the right personality. I'm not smart enough. And it's a cultural, you know, bullshit that science requires a certain type of brilliant, different person. So, you know, you're enough. And, you know, you're going to be the best scientist from your perspective, right?

I mean, we're all, people have different science talents. Some people are better at the math. Some people see the larger concepts. Some people are really good at communicating it. These are all really important steps, and you can find that, that part that you fit into. So you don't have to be anything other than just the way you are. Wow. Look at that.

I love it. And if I can add, not having ever been female, but being a black man in the world, there are resonant challenges that we face entering a world that, role models are not there. So I would just add that there are always people who will learn something faster than you will. And the school system tends to reward that and call those people smart and they might get a higher grade. But in the end, that's not what matters. What matters is your motivation to ultimately learn what you need to learn.

If it takes you longer to learn it, longer than the time before you're tested on it, It takes you a little longer. So what? Took you a little longer. If you get there and your ambition takes you and your interest, then ultimately that's what will dominate who and what you are as a participant on the research frontier. Not how quickly you learn a problem set on an exam in high school or in college. So ambition is something that tests hardly ever test for.

And that's what you need. And that's what you need confidence in. Yeah. And just being able to stick to something. thing. Yeah. I'm just having the grit. I mean, when I got to college, I got placed in remedial math.

I mean, I came from a public school system that didn't have a whole lot of math. And, you know, I, I just, I knew I could not get space out of my head. I was so fascinated by it. And I am so glad I stuck in when I was thinking, geez, I just don't have the talent for this. And that became the driver, your source of energy to pursue it. Yes. And I like your language analogy, because. No one will ever say, or you're not smart enough to learn Spanish.

No one will ever say that. They just say, are you committed enough to learn Spanish? Right. And you learn a little bit today and a little bit next week and next month. And eventually you wake up and you're just talking fluent Spanish, you know, and everyone can learn it. And I think that's also true with math as a language of the universe. Yes.

Well, let me add, Alyssa, that as a product of Philadelphia Public Schools, there's always comedy. All right. So Chuck, we only actually had time for that one last question, but that was a really good one to end this episode on. So Michelle, thank you for being a guest on StarTalk. Hey, I'm always here. Where are you based right now?

right now I'm in Milwaukee, Wisconsin. Whoa. Is that where you're based? Yes, yes. Cool, cool. Okay. Well, we will make sure to find you again because you're a delight to share in our answers here and to get your perspectives on the state of science in America and in the universe. All right. Chuck, always good to have you, man.

Always a pleasure. These are fan favorites, these cosmic queries. And we delight in the questions. that we receive and keep them coming. But you have to be a member of the Patreon community first. Yes, but it's only $5. That's it. $5 a month.

And I got to tell you, that's less than what the budget of NASA is. All right. I'm Neil deGrasse Tyson. You're a personal astrophysmal. as a sister. As always, I bid me you to keep looking up.