StarTalk Radio - Cosmic Queries – The 2020 Nobel Prize
Episode Date: October 26, 2020Can black holes alter light speed? Is astrophysics the Meryl Streep of the Nobel Prize in Physics? Neil deGrasse Tyson, Chuck Nice, and astrophysicist Janna Levin, PhD, answer Cosmic Queries about bla...ck holes and the 2020 Nobel Prize in Physics. NOTE: StarTalk+ Patrons can watch or listen to this entire episode commercial-free here: https://www.startalkradio.net/show/cosmic-queries-the-2020-nobel-prize/ Thanks to our Patrons Sand McUnicorn, Marcus Guerra, Loren Kimble, Mahmoud Hayat, Rupert Thomas, Elliot T Rauba, Byron J Reid, and J Ayala for supporting us this week. Photo Credit: Event Horizon Telescope, CC BY 4.0, via Wikimedia Commons Subscribe to SiriusXM Podcasts+ on Apple Podcasts to listen to new episodes ad-free and a whole week early.
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Welcome to StarTalk.
Your place in the universe where science and pop culture collide.
StarTalk begins right now.
This is StarTalk Cosmic Queries Edition.
We could not resist the Nobel Prizes in Physics related to black holes.
Chuck, we're devoting this entire Cosmic Queries to black holes
as manifested in the recently announced Nobel Prizes in physics.
And the cool thing about it is no one will ever be able to see or hear this video
because it won't be able to escape our black hole.
Oh, is that right?
I didn't know that all of our shows are in black holes.
Just this one.
Just this one.
I know a little bit about black holes, but not as much as our guest, a recurring guest,
Jana Levin.
Jana, welcome back to Star Talk.
Thank you.
It's always good to be here, wherever here is, wherever here is now.
I know, but for you, you kind of look like you're in a safe house.
I know.
I sure am.
Yeah, are you in an identity protection program or something?
I'm at Pioneer Works, which is a cultural center in Brooklyn where I'm director of sciences.
But I tell you, if the apocalypse is happening, this is where I'm coming.
We've got all the resources you need.
Wait, wait, Chuck, did you hear that? If the apocalypse was coming, that's where she'll be,
and that's where she is now. Right, exactly. And you're invited. Okay. So wait, tell me what
happens at Pioneer Works. So we, this place really started as inspiration of Dustin Yellen
and Gabriel Florence as an art center, but with a vision of just impacting culture and creating ways, really kind of breaking down boundaries, doing things in a new way.
And when I came in, we started bringing sciences in here and we've been doing a lot of pretty incredible science events, not least interviewing Sir Roger Penrose last December.
Oh my gosh. Oh my gosh.
Oh my God.
That's why he got the Nobel Prize.
That's why he got the Nobel Prize because you interviewed him.
I just like rubbed my good karma on him.
So tell me, so I know two of the three Nobel Prize winners, maybe all three.
So there's Roger Penrose, a well-known physicist from Oxford, I think,
in the UK.
We have, who else was on that list?
Andrea Ghez.
Andrea Ghez.
And is she still in the University of California?
Yeah, UCLA.
UCLA.
Yeah.
UCLA.
And we had Gensler.
Reinhard Genzel, yeah.
Reinhard Genzel.
And so these are, so they all split the Nobel Prize, all for their work in black holes.
So if you can just give us sort of the short version of each of theirs' contribution to our understanding of black holes.
Well, technically, Roger got half the prize.
Really?
Andrea and Reinhard split the other half.
So now when you say got half the prize, are we talking about the cold hard cash?
Half the money.
Wow.
They don't get a half a medal.
They all get a medal.
But when they say half, they mean half the money.
Let me tell you something.
You can keep your stinking medal.
I want you to have the money.
I want that check.
It's a super interesting prize because that's happened before that where they've divided the prize unequally amongst the three participants and you can never have more
than three winners of the Nobel Prize. So it does reflect the fact that Andrea and Reinhardt,
their work is observational and they are,
they're both responsible independently for understanding supermassive
black hole, the center of our galaxy.
So that's why they shared in the prize because they,
they both contributed to that particular aspect of the award.
Roger Penrose was just off on his own in like 1964.
He's been off on his own forever. He's been doing his own thing.
Right.
So that was all Roger.
And he is very theoretical.
So I'd say one of the most surprising things
about this award was that
people as theoretical as Roger Penrose,
for example, Stephen Hawking,
don't usually get awarded the Nobel Prize.
And so this was considered,
I think a lot of people were kind of chilled and delighted
to see Sir Roger honored in this way.
But it could be that the trend is not so much
that they don't give it to theorists,
but if they're going to give it to theorists,
in the same breath,
they're going to give it to the experimentalists
who verified what the theorists said.
Is that a fair way to characterize this?
That is a fair way to characterize it.
But there's still a long stretch between, like,
Rogers' theory and the observations.
So if you want to talk about Rogers...
Wait, as was true with the Higgs boson.
That's right.
So they gave it to Peter Higgs.
Higgs himself.
Yeah, but he'd come up with that decades ago.
Yeah.
Whereas the fresh discovery of the Higgs boson was himself. Yeah, but he'd come up with that decades ago. Yeah. Whereas the fresh
discovery of the Higgs boson was recent, in recent news, but they stapled them together,
and then they give him the award. Yeah. Yeah, that's right. I mean, Higgs's prediction was so
very specific, though. He literally predicted there would be this one particle, it would be
roughly around this mass, and it would have these particular properties. I mean, it is a pretty spot on prediction.
Whereas Roger just sort of was dreaming big dreams.
Not to put Higgs down in any way, but, you know, there was a less specificity.
And even when Einstein got the Nobel Prize, he got it for very specific things.
He did not get the Nobel Prize for general relativity, which was clearly his greatest
achievement.
He got it for more specific statements and more specific predictions.
So maybe the Nobel Committee is coming along.
Yeah, maybe it's coming along.
But Roger did do something tremendous, which was to make generic the prediction
that black holes would be the end state of the collapse of a star.
And he was able to show that essentially singularities,
which we thought were this may be an artifact of very special circumstances and wouldn't really
happen if you thought more generally about things. He was able to prove that in fact,
it was a generic prediction of general relativity that a collapsing star would create behind it an event horizon and the interior
would create a singularity essentially wow so it's right after einstein first thinks of general
relativity that schwarzschild writes to him from the russian front and discovers this thing that
we now call a black hole but it's very front in the first world war in the first world war it's
1916 and he's on the russian front and he's 1916. And he's on the Russian front.
And he's saying, you know, the war has treated me kindly enough.
And I've been able to wander through the land of your ideas.
And so here he solves this problem.
And it's very idealized.
It's a complete sphere.
It's perfectly collapsed.
He doesn't ask how or why.
He just idealizes a situation.
And he comes up with this thing that we now call a black hole. And so for decades after that, people thought, well, that's just
a silly idealized situation. It's not wrong, it's correct mathematically, but that'll never happen
in nature. What Roger Penrose does in 1964 is he uses the most ingenious methods in a paper about
three pages long. In the final paragraph of this incredibly clear, lucid, simple paper,
he proves that in fact,
it is absolutely generic prediction of general relativity that a collapsing
body would create behind it an event horizon and inside a singularity.
So he makes black holes inevitable.
He made them real.
He made them real.
He made them real. He made them real. He made them real.
Wow.
Yeah.
Yeah, so they go from this mathematical, perfect, silly, platonic idealization to an inevitable reality.
So now on the other side of that Nobel Prize coin, we have two people, independent researchers,
who are figuring out that our galaxy has a supermassive black hole in the middle.
But, of course, you can't see black holes.
So what light can you shed on their discoveries?
Ah, I see what you did there.
You see what I did there?
I see what you did there.
You punster.
You punster.
So they demonstrated the opposite characteristics as powerful scientists.
Slow and methodical. They looked at these stars
for decades, right? Two decades. And they watched these stars orbit an invisible object.
And just, they don't even need to- At the center of the galaxy.
At the center of the galaxy. It's 26,000 light years away in the direction of the constellation
Sagittarius. So we call the object that they orbit Sag A star, Sagittarius A star, only because it's in that
direction from our point of view. It's a cute little nickname. So around Sag A star, they see
some stars orbiting and they can follow their entire orbits. One of them takes about 16, 17
years. That's kind of the one that was most helpful to them.
Just to be clear, normally when we think of things orbiting other things, we think of
planets orbiting stars. Now you're talking about stars orbiting other things.
Yeah, right, exactly. So now you have a bunch of stars in the center of the galaxy, a bunch
that are orbiting this thing. Now you can't see this thing. It's definitely dark. And it's very massive.
And contrary, I think, to sort of the popular imagination about black holes, black holes aren't huge.
The whole point of black holes is that they're tiny.
So for how heavy they are, they're tiny.
So this object, they just look at the orbit and deduce, wow, that thing is 4 million times the mass of the sun.
But it's fitting in a
region much smaller than the solar system. Not 4 million times the size of the sun, right? If you
calculate how big you think it should be, it's about 17 times the width of the sun across,
but 4 million times the mass. That's crazy. Crazy. Crazy. So they go, look, it's really heavy. It's really small.
It's a supermassive black hole. Wow. Okay. Well, there you have it. And by the way,
this is our second or third hour, the astrophysics community, our second or third Nobel Prize in a
decade. Generally, they used to throw us a bone once every 10 years. Are you saying that you guys are the Meryl Streep of the Nobel Prize?
No, no, no, I'm saying.
Well, the prize is in the category of physics, just to be clear.
So we in my community, we're not living our lives wondering if we'll be considered.
Occasionally, we do something that touches on laws of physics, and then it gets, and people take a note.
We just got it for exoplanets, which is not itself a new branch of physics,
but it's a very interesting advance in our understanding of the world,
or the universe.
So I'm just saying, maybe we're done with laboratories on Earth,
and the best laboratories on the frontier of discovery are the universe itself.
Well, it's fascinating because Hubble
lobbied for astrophysics to be considered
by the physics Nobel Prize.
Oh, wait, Hubble the man.
Edwin Hubble the man.
And not the telescope.
The telescope, right, is not live.
It's not lobbying.
That'd be awesome.
It remains inanimate. Yes, it remains. It's still, to this day, not lobbying. That'd be awesome. It remains inanimate.
Yes, it remains.
It's still, to this day, not alive.
Right.
But Hubble, you know, so what did Hubble do that was so tremendous?
Today, Hubble absolutely, unquestionably would have won the Nobel Prize.
He would have won two Nobel Prizes.
Right.
For one.
In the same decade, yes.
He realizes that there are other galaxies.
You have to realize when Einstein was working in 1905 and 1915 and 1916,
he did not know that there was another galaxy besides the Milky Way.
He suspected, but he wasn't sure, right?
So Hubble observes the first external galaxies.
But just to be clear, at that time, the universe was just the stars of the night sky.
Yeah.
And how far do they extend?
Nobody knows.
Yeah.
Yeah.
Exactly.
And then the second thing, which I'm sure, I'm guessing Neil's referring to, is he then
also notices that, oh, by the way, all those galaxies are moving away from each other.
Right.
And so he deduces that the universe is expanding.
So, boom!
So he lobbied, so he, Jenny, he lobbied the Nobel committee and then what'd they say? I
guess they said no. Well, yeah, I don't know if they were like formal letters exchanged,
but there was certainly political, you know, there was internal politics and they said no for one
month. So in 1920s, they said no for another 50 years. I don't think it was until the seventies
that the Nobel prize committee considered astrophysics. Yeah. I think the first one was
maybe the discovery of pulsars.
Yeah.
And that was the 1970s on a discovery made in the 60s.
Yeah.
Yeah.
Yeah.
Cool.
Well, actually, we got to take a break now.
But Chuck, did you load up questions?
Because this is a Cosmic Queries.
I got them all loaded up and ready to go.
And there are pages of them.
People love black holes.
All right. When we come back, more with our friend jenna levin to get us through an understanding of black holes We're back.
StarTalk Cosmic Queries.
Black Hole Edition.
Actually, Chuck, we've had other Black Hole editions of Cosmic Queries,
but this time Black Hole's done one, upped and won Nobel Prizes.
In fact, it's not the first time Black Hole's have won Nobel Prizes.
And last time we did that,
we had to bring in Jan Eleven
to explain what the hell was going on
and we're doing that again today
in this second segment of Cosmic Queries.
Jana, always great to have you back in the loop.
Thank you so much.
I always love being here.
One of the times we brought you in
was because of the LIGO discovery
of colliding black holes.
And they got a Nobel Prize. So black holes,
the Nobel comedians liken them to some black holes lately.
Yeah, definitely. I think there's probably another one in the near future.
Uh-oh. Yeah, I mean, I don't want to, you know,
I don't want to, I don't know, jinx anyone. Don't jinx them, but
don't keep us in suspense either.
Well, I think we should talk about LIGO,
but I think Event Horizon Telescope,
which took that image of the black hole at the center of M87,
which is a galaxy 55 million light years away,
and they imaged as close to the event horizon
as is essentially conceivable given the realities of where we're going.
The resolution was there.
Yes, that's right.
Yeah.
So for taking that photo, the photo of a black hole.
Okay.
It's conceivable.
So it's interesting.
If you look at the Nobel Prize announcement for this prize, they say about Roger Penrose for his contribution to understanding black holes, and they explicitly
say that, but for
Angier, Gez, and Genzel, when they're
talking about the supermassive black
hole, they don't name it.
They say for their discoveries of a
compact object at the center
of the galaxy.
They won't call it a black hole.
Yo, let me just say
that's racist. Yo, that me just say that's racist.
Chuck.
That's some racist stuff I haven't heard.
Alright? That's all I'm saying.
You are crazy.
That ain't right.
If anything has a tinge of it,
Chuck is all up in it.
He's going to be calling out.
Thank you, Chuck, for calling out the racist ways.
Well,
the interesting reason why I suspect they did that is because,
so they're looking at these orbits of these stars,
right around this dark object that we know is really heavy and really
small.
And by rights,
we should call a black hole,
but it only comes,
it doesn't come near the event horizon.
It doesn't come all the way close.
So it, It doesn't come near the event horizon. It doesn't come all the way close. So I think the closest approach of the star is about a few times as close as Neptune comes to the sun.
And that's very, very close when you're talking about an object four million times the mass of the sun.
But if it's only 17 times as wide, it's not that close.
You know what I mean?
Right.
Whereas Event Horizon Telescope is seeing stuff like right on it.
Okay, so Chuck, if they gave it to the Event Horizon Telescope
and still didn't call it a black hole, then you'll have a good argument.
Then I got a case, right?
You got a case.
We'll take that to the Supreme Court.
Now we got a case.
We're going to take that.
Okay, cool.
Oh, by the way, one thing about the Event Horizon telescope image.
First of all, a zillion people participated in that,
so they probably have to give the Nobel Prize organizationally, I would bet.
That's a really interesting question.
Yeah, so it's a reminder that today,
consortia make discoveries more so than individuals.
For LIGO, they gave it to three individuals.
Because they were at it long before LIGO was even LIGO.
Exactly. They were at it for 30, 40 years before other people joined.
And so that was different.
But some people also argue that it should be given a Nobel Peace Prize
because here you have an international consortium that transcends,
you know, all these nationalities, all of these political boards,
all of these languages, all of these political boards, all of these languages,
all of these cultural differences
and come together
and then give the work freely.
And the work is free.
They don't even monetize it.
So that's an interesting argument.
It's a form of peace.
That's exactly right.
A form of peace that scientists have known
ever since the beginning
as collaborations take us international.
A quick Event Horizon photo story.
So I used the Event Horizon photo for a tweet.
Can I tell you what that tweet was?
It was, okay.
So scientists, colon.
We've imaged a black hole in a galaxy,
in the nucleus of a galaxy 55 million light years away.
That's scientific.
Public, ooh. Public.
Ooh.
Ah.
Scientists.
Humans are causing global warming.
Public.
I don't, that doesn't agree with my philosophy.
Excellent.
How did that go down?
How did that go down?
It was, you know, people, it's social media, so it goes every which way.
Every which way, Ken. But the irony wasn't lost on most people.
That's funny.
That's brilliant.
That's a brilliant tweet.
So Chuck, so give it to me.
All right, let's get to it.
Okay, so actually we're going to start with a Patreon question from my son,
because I actually am on Patreon so he gets to ask which is
can black holes tell us anything about the age of nearby stars or stars that are orbiting them?
Interesting. Am I trying it or are you trying it Neil?? I'll try, and if I miss anything, you jump in.
Yeah, because I think there's a lot of dimensions to the answer.
So a black hole as the endpoint of a star, of a dead star,
that star didn't live very long.
You know, maybe half a million years tops.
So if you see a black hole, if it's freshly made,
then the thing that made the black hole itself was not all that old.
Half a million is not long in the history of the universe.
Not at all.
So black holes are the product of very high mass stars
that have very short lives.
But once you make the black hole, it's there, right?
So you'd have to have seen the black hole get made
to then know how young it is.
But if the black hole is just hanging out,
I don't know that you can know how old it is
just by observing. Now, we know there's an upper limit to how massive a black hole can get
as the endpoint of a dying star. But if you find a black hole that's much more massive than that,
then stuff happened after that. Or some other phenomenon went on that would have kept
accumulating, kept eating. And as it eats,
it gets bigger and bigger and bigger. So I don't know that you can know precisely the age of a
black hole, but you can get a sense of how long a black hole has been in town. Yeah, I'm going to
agree with you. And I'm going to say even more so, one of the big mysteries about the supermassive
black holes that were acknowledged, although not by name, in this year's Nobel Prize,
was that they're so big.
And we definitely know those do not form
as the end state of stellar collapse.
Something had to happen to make that thing so big.
So either it formed in the early universe,
and this is something that's really odd.
The bigger the black hole,
the less dense the material you need to make it.
It's very surprising.
So you can make a really big black hole
out of the density of air under the right conditions, which really surprises people. But if you make it from
a star, it's got to be incredibly dense. So it could be that it was made in the early universe
and not from stars at all. Or it could be that it started as a smaller black hole and then went
through a bunch of collisions and got bigger and collected other black holes and just amassed and amassed
and amassed until it was a supermassive black hole at the center of the galaxy.
And that requires a lot of time and a lot of collisions.
And just to round this out, currently, none of us in my field doubt the likelihood that
every single large galaxy has a supermassive black hole in its core.
Initially, it was hypothesized,
and then we had some early Hubble data,
and then some other data,
and then it was like, you know,
this looks pretty endemic
to what it is to be a galaxy at all.
And if you have colliding galaxies that merge,
you'd expect the black holes
to ultimately merge in the middle.
So I got you on that one.
But also, it's still, I don't know,
I haven't seen the latest in this,
but when I last looked,
there was still some uncertainty about whether the black hole
nucleated the formation
of a galaxy
or whether the galaxy
had mechanisms
that funneled material
to the center
to then make the galaxy.
Because even if you have
a billion solar mass black hole,
which some galaxies do
in their center,
that is a, it's less than one-tenth of one percent of the mass of the whole galaxy. So as ferocious as that sounds,
the total galaxy wins, if you want to, if you're on a balancing sheet. Absolutely. So you might have
thought, you know, oh, even if it's true that all of these galaxies have these supermassive black holes,
they're such a small percentage in terms of the mass, they're probably not influential on the galaxy.
Who cares?
But it actually turns out that's not the case because they can blow these gigantic winds.
They could have been very active in their early history and been like quasars.
They could have sculpted the entire galaxy.
They could have regulated the size, the shape, the number of stars that form.
So they might actually have incredible agency despite their smaller fraction in terms of mass.
And is that because in the formation of the black hole that it is spewing out materials in order for
it to become what it becomes? Yeah. In the early days, it was wreaking, it was blowing out these
jets, you know, and it was just, it was like, imagine these winds.
There are black holes whose jets are so strong that they're puncturing neighboring galaxies and basically wiping out any planetary life in those galaxies.
So they have...
The galaxy's just getting into a fight, that's all.
You're not understanding the dynamics of this.
So the Nobel for exoplanets is in a fight for the Nobel of the student-assisted black hole.
But the point is you only get to see all this if there's material in the vicinity of a black hole for it to do that to.
If a black hole completely ate everything in its vicinity, then all these mechanisms shut off.
Then it's not going to see.
Right.
Wow.
God, that's so cool.
All right.
Keep it coming, Chuck.
Here we go this is liam
pendergrass also from patreon what opportunities for future research uh into black holes are
created as a result of this particular prize being awarded so is there is there anything
new that came out of this that may spur further discovery?
Let me lead something here, and then I'm going to hand off to Jana.
Because the Nobel Prize is essentially always delayed from the discovery itself,
it's not clear whether the prize itself is stimulating more research,
because the original research already did that right so the
original search was already in we already knew it was important we already and the the best kind of
prize is the one that that affirms what you already knew and in this case this we are like
janice said we knew roger penrose was brilliant we knew he had influential papers we knew the the
the supermassive black holes
in the centers of galaxies. That's a long-standing project. So that did trigger other interesting
projects. Let's look at other galaxies to see if they have supermassive black holes with the next
most powerful telescope. But Janet, do you think the act of getting a prize itself changes any of that landscape? Gosh, I think I'm with you. I don't
think the act of getting a prize does. I think it might affect generations that are just on the rise.
Like, you know, your son, Chuck, asked a question, inspired because we were talking about the Nobel
Prize. And who knows, maybe that's going to affect your son's interest in science.
I mean, for the scientists who are
practicing now, I would say no, not so
much. But it does have that effect,
I think, for the younger generation.
Excellent point, because it's black holes
are in the news now for a whole other reason.
There's a celebration
with a big fat check
associated.
Because in America, money talks.
That's what it is.
Well, I'm glad to hear you say that
because that's for his research club.
Black holes are his focus.
So I'm going to ask you to talk to him.
And by the way, kids love black holes.
I don't care.
We're totally cheating.
That is so cute.
Do to mother kids. I'll be like, my son has Neil deGrasse Tyson and Jan 11. I don't care. We're totally cheating. That is so cute. Do to mother kids.
I'll be like, my son has Neil deGrasse Tyson and Jan 11.
I don't give a damn.
Sorry, kids.
Sorry.
That's how the cookies crumble.
That's how the cookies crumble.
What can we say?
Totally.
Wait, wait.
So, but make an interesting point, Jana,
that if it's another reason to talk about something
in the context of it having been a celebrated result
rather than just a highly respected result,
that definitely adds a societal force on this.
I agree with you there entirely.
And it's interesting that a lot of these Nobel Prizes are connected.
So, for instance, the supermassive black hole at the center of the galaxy
also has littler black holes orbiting it.
And they did form from the end state
of gravitational collapse.
Now, littler might be 30, 60 times the mass of the sun.
And so LIGO, which is the experiment
that you mentioned earlier, Neil,
that got the Nobel Prize, what was it, 2016, 2017?
2017, they're detecting the collision of two black holes
that are more around 50, 60 times the mass of the sun each.
And they might be doing that near a supermassive black hole.
And so these are all connected discoveries.
And so some of the ones that LIGO is beginning to,
and I don't want to say observe, but really listen to, because LIGO doesn't take pictures.
LIGO listens to the resonance of space around these orbiting mallets.
We're starting to think that maybe those, in fact, really are coming from galactic centers.
So there could be 20,000, 40,000 black holes around the center of our own galaxy that are just smaller ones.
Wow.
Well, all I can say to that is, there goes the neighborhood.
Black holes coming in.
And they're gathering and becoming bigger.
They're going to destroy your neighborhood.
I'm letting you know this.
And they get together.
And they get bigger.
Coming in.
And they're getting bigger. So, Chuck, we just blew that whole segment on your son's question. And they get together. And they get bigger. Coming in. And they're getting bigger.
So, Chuck, we just blew that whole segment on your son's question.
I just want you to know.
Oh, well.
Totally worth it.
Okay, so when we come back, we're picking up Star Talk Cosmic Queries with Dan Eleven.
We're back.
StarTalk Cosmic Queries.
Chuck Nice with me always.
Always a pleasure.
And you're tweeting at Chuck Nice Comic.
Thank you. Yes, I am, sir. And you're tweeting at Chuck Nice Comic. Thank you.
Yes, I am, sir.
And we're talking black holes today, so of course that means Jan 11 is in the house.
And Jana, you're tweeting at what?
Jan 11.
At Jan 11.
And it's a Jana with two Ns.
We got you.
Yeah.
Yeah.
All right.
I like an extra consonant.
You know, I lose one, his one drops off.
Jan 11 has three Ns in it, just to let the record show.
That's funny.
Yeah, what is it, 40% of the letters in your name?
So this is Cosmic Queries.
So Chuck, keep coming at us with these questions.
All right.
This one is from your wife now, right?
You're the whole family.
Okay.
All right, go. That'll be fun Patreon. This one is from your wife now, right? You're the whole family. Okay. All right, go.
That'll be a fun.
So this one is from Grandma Eugenio Barrano.
This is Eugenio Barrera.
Says, hey, Chuck, Neil, Jana, how are you?
After years of following you guys on YouTube,
I finally pulled the trigger on being a Patreon,
and I'm glad I did because now I get my question right.
Excellent, excellent.
Yeah, and he says,
I was wondering if black holes have the gravitational pull to affect light,
does it also alter its speed?
So it bends light, does it slow it down when it bends it?
So interesting.
Interesting question.
Neil, what do you think?
Want to try this one?
I would just say no.
Okay, next question.
But there's a really subtle example
that I think illustrates how bizarre it is.
Okay, yeah.
Go for it.
So because the event horizon is by definition
the place at which light cannot escape,
you could ask, well, what happens to light
at the event horizon then if it can't escape?
And so you could just drop a little beam of light,
a little bundle of light, and let's call it a photon,
and it would sit there at the event horizon.
It would not move.
It's actually a completely completely not stable, unstable,
but a place where it can be. However, you can't sit there and not move. So if you're falling
across the black hole event horizon and you fall past that little piece of light, you go,
oh, it's moving at the speed of light. But nobody can say it's not because nobody could stay there with it because you'd have to be
traveling at the speed of light to stay there with it so when you fall into the van horizon
janna in wonderland janna in wonderland that is that is a rabbit black hole if i ever heard
keep going keep going well the other way to think about it is it's like a salmon swimming up the Niagara,
like swimming upstream, and the waterfall of space-time is just falling in so rapidly
that it effectively stands still.
But nobody can stand still with it.
Everybody else has gone with the waterfall.
So everyone else, if they try to measure the speed of light, is like,
oh, yeah, it's traveling at the speed of light.
It's nearly 300,000 kilometers a second.
Nobody says it's standing still.
But technically,
it's sitting right there
at the event horizon.
But it's still trying to get out.
It's still trying to get out.
It's trying like hell to get out.
Okay.
But, oh, that is so freaky.
Trying like hell to get out.
Yeah, that's freaky.
So now,
so what's the observation
outside of the black hole?
What are we seeing?
Is it just sitting there?
You just never see that photon because it never gets to you. When you say Is it just sitting there? You just don't see that photon
because it never gets to you.
When you say, what do I see?
The only way you see something
is if the light hits your eye.
Right, so you can't do it
because it's stuck there.
So you don't see it.
Oh, oh my God.
So it's dark.
So the horizon's dark.
It's a black hole.
That's crazy.
And another, just to add another point there.
Right, you will only see that photon if that photon enters your eye, right? It's a black hole. That's crazy. And another, just to add another point there. Right.
You will only see that photon if that photon enters your eye.
Right.
So, therefore, you have no ideas even there.
This was my issue with Star Trek.
Right.
They have these phasers that, no, the phasers, right, when it shoots lasers at another ship.
Okay.
Yeah.
Those are phasers.
And then they have photon torpedoes.
They have photon torpedoes.
So they're sending this in a direction towards the ship,
but the camera view is from the side.
But you see this, like...
You see it, but it's no, no.
It's sending this energy to the ship.
There's no way you would see that laser going to the ship.
Right.
There's just no way.
Unless it's sending light in your direction,
but then that wouldn't be an efficient weapon.
Or you make like a gas cloud and it scatters.
Oh, yeah, yeah, yeah.
Okay.
You can make like a fog chamber.
No, no, no.
You have to have a fog machine.
You hit the chalkboard erasers together.
Right.
All right, Chuck, give me some more.
All right. We now know me some more. All right.
We now know Jana is a cousin of Alice in Wonderland.
Yes.
Okay.
This is from Fiz...
Fizivi.
Fizivi.
Cool.
We'll go with that.
I'm going to go with it.
I'm going with that.
It says, what did Roger P Penrose do that wasn't already done by Einstein and Schwarzschild before?
A little bit of a hater here.
A little bit of a hater.
So I think, Jana, you hinted to some of that.
Yeah.
But why wasn't Einstein's solution or the Schwarzschild solution inevitable?
What is the different thing that Penrose did
to make it a natural end state?
Well, in the simplest terms,
he was able to show that generically
without assuming any special properties,
like something's a perfect sphere.
It could have been an oblong kidney-shaped eggplant thing.
Doesn't matter.
If it collapses, he was able to prove it would
inevitably form that event horizon. And within that event horizon, inevitably would be the
singularity. And one way to think about this, which I think is really profound, is he was able
to show that all paths of light, and this is technically one of the ways that he did it,
point towards the singularity. Technically,
what that means is that the singularity is in the future. We look at a black hole, we think of a
spherical thing with a center point that says point singularity in space. What Roger Penrose
showed is the singularity is not in space, it's in the future once you're inside that black hole.
And so nobody who enters the black hole can do anything but plunge into that singularity.
You can no more avoid the singularity than you can avoid the next moment in time.
Okay.
So, wow.
Like I said, Alice in Wonderland.
There it is.
Like I said.
Dad, come on.
You know, give me a second.
I'm going to go pour myself a little vodka and we're going to come back and talk about this.
We're definitely missing some mind-altering forces.
So, Jana.
We're going to have our after-party Zoom link.
So, Jana, just to, if I understand what you're saying,
if all light beams go to the singularity,
If all light beams go to the singularity, then all possible paths into your future as you fall in would go to that singularity.
Because you can't take a path that's not the path that the light takes.
That's right.
So basically what it says is if I should, it basically says if you're going slower than the speed of light, you are definitely going into that singularity. Because the only way you could not go into that singularity is if you went faster
than the speed of light. And you can't do that. Okay. Right. So the technical language would be,
just because it's sometimes poetic to hear it, it's not necessarily edifying, but it's poetic,
is that he proved that all of the future light cones pointed towards the singularity. That's what he showed.
There's one figure in this paper in 1964 where he draws it all out. I'm telling you, it's just the
most beautiful. It's all compact. It's all right there in this one picture where he just shows
that this absolutely is inevitable that the black hole singularity forms and that it is in the future of any path on the interior of the black hole. Yeah. All right. All right, Chuck, keep it coming.
Okay. All right. This is Izzy Roar. Says, hi, Neil, Chuck, Janet, it's Violetta, my mom, Izzy.
I'm 12 years old from Birmingham, Alabama, and I love all things astrophysical. Professor Gez says that the data collected, which ultimately proved the existence of Sagittarius A,
are consistent with Einstein's general theory of relativity,
while absolutely 100% not consistent with Newton's law of gravity.
And even then, she said that Einstein is right, at least for now.
My questions are, how can something, a major thing like this in the cosmos, abide by general relativity and yet not follow one of the most basic and fundamental laws of physics?
Does this mean we will need to discover a new law of gravity?
And does this mean general relativity needs to be upgraded or expanded upon?
P.S. Jenna, you are the first woman astrophysicist
I ever saw in an episode of StarTalk a few years back,
and you have inspired me so much ever since.
Thank you for rocking science so hard
for girls and kids like me all over the cosmos.
Go, Jenna!
Thank you.
Go, Jenna!
Thank you. And by Jenna. Thank you.
And by the way, none of that question impressed me like the way the question began.
Because she knew that the word data is plural.
Plural.
These data show up.
These data are.
So if you know that, you're ready for any kind of scientific career.
Well, I was so flattered and flushed that I forgot the question. Oh, but I think I got it.
It's actually... I think it's if it violates Newton's laws, how is that possible if Newton's
laws apply across the universe, but it satisfies Einstein's laws? What's going on?
So I liken it this way. Just because Newton's laws aren't all-encompassing
doesn't mean the laws are, like, wrong.
They're not dead wrong.
And I sometimes try to explain it this way.
If you thought English was the only language in the universe
and then you discovered there was this broader concept
called language,
it wouldn't make English wrong.
English is not useful.
It just has a limited range of validity.
It doesn't help you with French or Arabic
or whatever other language.
It turns out that there are extensions
that's a much bigger umbrella,
which is this concept of language, right?
So to a certain extent in its limited range of validity,
Newtonian physics is great,
works terrific. It just doesn't work everywhere all the time. It's just not big enough. It's not
that it's wrong. It's just a subset of a larger concept. So the first thing that Einstein did
when he was trying to test his own theory was exactly to make sure he, he matched,
he respected Newton,
that he respected Newtonian dynamics in its range of validity,
which would be when you're not moving very quickly,
when you're around big things like the earth,
when you're moving slowly,
like it should look like Newton said it should.
So,
so it's not as though when I drop an apple it no longer does what I used to think it
does just because of general relativity. So what you're also saying there is that
if you take Einstein's equations and put in low gravity and low speeds, they become Newton's
equations. That's right. They become very close approximations to Newton's equations. That's right. They've become very close approximations to Newton's equations.
Exactly. Okay, so they're still in the same
sandbox. The sandbox
is bigger now. Yeah.
Newton never considered
what happens if I crush the earth to a point.
Or what
happens if I was going
near this beetle.
And those were exactly
the kind of thoughts,
experiments,
the kind of fantasies
that led Einstein
to realize that,
oh, Newtonian mechanics
would slowly look different
than we presume it is.
And we would start to learn
that there are generalizations
that start to look
very different
in certain extreme circumstances.
All right, Chuck,
we only have like
a couple of minutes left.
Give me,
see if we can squeeze
two in here. And Janet, soundbite answers. Okay, go. Okay. All right,
here we go. Cameron Bishop says singularities or ringularities. I just got to know what we know
about the geometry at the center of a black hole. Yeah. What's a ringularity, Jana? Oh, in a spinning
black hole, it turns out that the singularity has a different geometry than it does in what Schwarzschild considered, which was just kind of a perfect implosion.
But I think that...
Is it a donut?
And wouldn't most black holes then be spinning black holes?
Yes, most black holes are spinning black holes.
Yeah, absolutely.
And when things collapse, just like an ice skater pulling in her arms, they tend to spin faster and faster. So we do believe that black holes are likely spinning.
But most, to be honest, most astrophysicists and theoretical physicists believe that the
singularity is where general relativity will break down, kind of connected to your previous
question. We believe that there's another theory that will make us understand
that singularities actually don't exist.
And that they're signaling,
they're telling us,
this isn't working anymore.
Like, this is breaking down.
As has been said,
the singularity is where God is dividing by zero.
Which is, that's a no-no.
No, seriously, you're now going to have a cult.
Like, you can't say stuff like that it's gonna be in q anon
come to where god divides by zero november 3rd
god is dividing by zero like another one quick another one. Quick, Chuck, give it to me. All right, very quickly.
This is Sam Axe.
Sam says this.
If you were to throw some antimatter into a black hole,
would that shrink it or make it bigger?
So a lot of people have a misconception
that antimatter has negative energy or negative mass,
but it doesn't.
There's really not, to our knowledge,
anything with negative mass.
So if you have an electron,
its antiparticle has opposite every other quantum number.
For instance, if the electron's negatively charged,
the positron's positively charged.
But they both have the same mass.
So mass and energy is what matters
when it goes into a black hole.
You might change the charge of the black hole,
but you're just going to make its mass go up.
It's going to get heavier.
Okay, so yes, antimatter is not some panacea
for undoing the universe and the damage that to get heavier. Okay. So, yeah. So antimatter is not some panacea for undoing
the universe and the damage that gravity has done.
Right.
Guys, I think we've got to call it quits there.
We're out of time. Man. Damn.
Man. That was awesome.
Always so good. It's always so good
with Jenna Levin.
I miss you guys. I hear rumors
that you're working on another book.
This is rumors. I'm just saying.
I am.
This is rumors.
Okay, when the book comes out, can we bring it back?
Yeah.
Black Hole Survival Guide.
Oh, we need that.
Well, we got to bring it back for that.
Can we bring it back?
I'd love that.
Okay, we'll talk about your book.
And we'll bring it back soon.
I think your book is coming out even just in a few weeks.
Yeah.
So, all right, Chuck, always good to have you.
Always a pleasure.
Janet, we love you here at StarTalk, and thanks for always accepting our invitations.
All right.
Always.
This has been StarTalk Cosmic Queries, the Black Hole Nobel Prize edition, of course, with Jan Eleven.
I'm Neil deGrasse Tyson.
You're a personal astrophysicist.
Keep working hard. Das ist die Platte.