- Hey Einstein fans, you're about to watch
a special edition of StarTalk just for you,
all about Einstein.
This is StarTalk.
I'm your host, Neil deGrasse Tyson,
your personal astrophysicist.
I got Chuck Nice, cohost.
I got Janna Levin, old time friend, colleague, physicist,
expert on the universe in all the ways that matter.
Especially for this conversation,
'cause we're celebrating the life and times
of Albert Einstein.
So, Albert Einstein was born in Germany
on March 14th, 1879.
And Chuck, you know what day that is?
- 1879, March 14th?
- [Neil] March 14th, any year.
- In any year?
- [Neil] Yeah, what day of the year is March 14th?
- I believe it's the day that precedes the Ides of March.
What is March 14th?
I really don't know.
- Before the Ides of March, there's Pi Day.
- Oh, my God, yes. - Yes.
- Okay, I didn't know it was actually March 14th,
but of course, that makes sense, 3.14.
- 3.14, yeah, you get pi out of March 14th,
when written in the American way,
where we put the month before the day of the month.
- Right. - Yeah.
- Exactly. - So 3.14, that's Pi Day.
Then you get really geeky,
and then add 1:59.
3.1415, 1:59 and 26 seconds.
Then you get a full on Pi Moment.
- Can I just suggest that that's probably
the access code to every physics department in the world?
- That's pretty funny.
That's the one, two, three, four of physics departments?
- If you walk up to a sealed theoretical physics department,
- And you'll get it.
Oh, my God, it worked.
- And tomorrow, the missiles got launched,
all because of Janna.
- Yeah, I shouldn't reveal these things.
- So let's talk about this.
Janna, what is the annus mirabilis,
and why do we even say that in Latin?
Why can't we just say it in English?
His Miracle Year.
- I don't know, why do we say it in Latin?
And that's a different question.
We'll just talk about the Miracle Year, first.
- It's America, Jack.
- So, 1905? - Yeah, 1905.
- 1905. - How old is he?
- 25. - Yeah, yeah.
- So, Einstein was a clerk in a patent office,
and he couldn't get a job in a physics department.
His father was desperately writing
to famous theoretical physicists,
saying, my son's really committed.
- Like any dad. - And he couldn't get hired.
One of his professors called him a lazy dog.
And here he is, in this patent office in Berne, Switzerland,
and he has a drawer at his desk that he calls
the Physics Department.
And in this drawer he has these scientific papers
he's working on in between finessing other people's patents
to make them better. - Wow.
- And in that year, he has this extraordinary year,
where he publishes a series of three papers
that absolutely transform modern physics.
One of them is on the Special Theory of Relativity,
one of them is on Brownian motion,
which refers to the atomic aspect of air and molecules.
Like, if you see a little piece of lint,
you notice that it takes a zig-zaggy pattern,
that's because it's all these little atoms hanging on to it.
And the photoelectric effect, which is staggering,
because it probes the wave-particle duality of light,
that sometimes light acts like a wave,
and sometimes it acts like a particle.
- He, by this time, was 26. - Yeah.
- Chuck, how old are you? - And unemployed.
- Verify? - I'm 22.
- There's still time. - So, I got time.
- Okay, you got time.
Thank you for verifying that.
So, you called it an annus mirabilis.
- [Janna] Why do we say it in Latin?
Because it was all in German.
- Did that get him a job?
- He became, he did become,
to the credit of the scientific community,
even though this outsider was publishing these papers,
it was very swiftly accepted,
the significance of all these papers.
And that should also be a lesson
to those many people who send me their theories,
that when they're transparently correct,
they are grabbed at with glee.
- All the most amazing, mind-blowing,
earth-shaking scientific research
was published in legitimate journals, accepted by peers.
So as they say, to be a genius is to be misunderstood.
- To be misunderstood is not to be a genius.
- Oh, that's nice. - Yeah, that makes sense.
- So you can't come to me and say,
I have an idea, but the establishment is not,
they're gonna reject it.
- [Janna] Therefore it's brilliant.
- Therefore, right.
- They don't get this, man.
They just don't understand.
- I'm starting a Facebook page for everyone to evaluate,
so you don't have to come to us.
Amongst themselves, talk amongst yourselves.
- [Neil] Talk amongst yourselves.
- Now we have Twitter for that.
- Now, he didn't call it Special Theory of Relativity.
Who called it Special?
- That's interesting.
I actually don't know, specifically, the history.
- Why do we have you on this show?
- Because I can explain Relativity.
- Does someone out there know why?
- I mean, the General Theory obviously came later,
when he included the curvature of space-time.
But I don't know who actually coined it Special.
It was just the Theory of Relativity at the time.
- Right, because the paper was on
the electrodynamics of moving bodies.
That's the name of that paper,
of the Special Relativity paper.
- Grabbing title.
But the amazing thing. - Page-turner.
So that was, wait, 1905, then a General Theory
comes out when?
- So, that's 10 years,
and he basically pulled that out of the ether.
- It's probably published in 1916,
but it's 10 or 11 years of struggling with the mathematics
to elevate what we now call the Special Theory
to the General Theory. - Working alone.
- Yeah, he was being influenced by people like Grossmann,
who was a mathematician.
Hilbert was very influential.
So Einstein wrote down several wrong theories along the way,
and there's actually a kind of adorable story
when he was thinking about something
like gravitational waves,
where he kept changing his mind, in print.
He would write papers, say they're real.
- You used the word adorable for a physics story.
- Let the record, adorable for a physics story.
- Let the record catch that.
Pause for a moment.
- And right after this, believe me,
we're gonna get to some very darling theories.
- With cheeks you just wanna pinch.
All right, go on. - He writes a paper saying
gravitational waves are not real.
Then he writes a paper saying they are.
Then he writes another paper several years later,
saying that they're not.
And between acceptance of his paper and publication,
he sneaks in a draft of a manuscript
that says that they are.
And one of his colleagues says, Einstein.
You have to be really careful,
your famous name is gonna be on these papers.
And he just laughs.
He says, my name is on plenty of wrong papers.
You do not need to worry about that.
So it takes him a long time.
I mean, there's decades of him
figuring out gravitational waves,
and the General Theory was 11 years,
and he needed help from other people.
He wrote down several wrong theories.
- Ha, no. - What's hard to hear
is he needed help.
Deadbeat. - Einstein, you dumbass.
- 10 years, damn.
- Is that actually something that is,
did that do anything to?
- In retrospect, that is short order.
Look at String Theory, where we're decades deep.
- Still in it, for decades after decades after decades.
- It might be hundreds of years.
- And that's dozens of leaders in the field.
- [Janna] Really brilliant people.
- And we have one guy, Einstein.
- By himself. - Basically, yeah.
I didn't mean to take away Janna's point,
that there are others trying to push things along.
- They're nudging him along.
- Right, right. - They're nudging him along
because he's actually putting something out there
to be nudged. - Good point, good point.
- It was really interesting
that it was really him on the, I mean, largely,
there were other physicists.
But him largely on the physics side,
and the mathematicians pulling him up.
Because he was not actually
the most sophisticated mathematical thinker.
Another one of my Einstein quotes, it says,
"You think you have a lot of difficulty with mathematics?
"You should see my difficulties with mathematics."
So, he was a very intuitive thinker,
and he really, originally, rejected the idea
that you had to do all of this differential calculus,
and this really elaborate mathematics.
He thought, that's ridiculous, it's totally overkill.
- Pure thought should be able to--
- You could just think it through,
and it would be like algebra.
And he did that with the Special Theory.
It was stunning,
but he could not do that with the General Theory.
He had to step it up to be differential calculus
and curved manifolds, no mean feat.
- Wow. - Yeah.
But it's pretty.
It's not only adorable, it's pretty.
- What grade did you get in that class, Chuck?
- I was gonna say that what I kinda go with
is that you don't need that.
- You say, I will never need that in my life.
- I will never need that in my life.
Like I actually use that.
- So, he does this, and then in 1921,
he wins the Nobel Prize.
So, but he did so many things,
what did he win it for?
- Well, he didn't win it for Relativity.
- That ain't right. - Wow.
- Which is really interesting.
- That's pretty crazy.
- Yeah, was it the photoelectric effect?
I think technically, it was the photoelectric.
Contributions to quantum, I don't remember the phrasing.
Do you have the phrasing?
- I might, in my notes here. - It was something like
contributions to quantum.
Like, often they're phrased in a way that...
- Give you latitude.
- Moves you from a specific, right.
But it was not for Relativity,
and that is clearly his greatest accomplishment.
- Wow, so it's kind of like if,
when an actor never wins an Oscar,
and then they're just like,
all right, we're just gonna give you a Lifetime Achievement.
- He won it in '21, which is quite early, in a way.
I mean, it was pretty soon after he proposed,
it's not staggeringly late after he proposed
this revolution of quantum thinking.
And the interesting thing is
that he never really accepted quantum mechanics, right?
So he initiates this revolution.
- What is up with Einstein?
- I just keep insulting Einstein.
- But wait a minute, is that his brilliance,
the fact that he was so self-contradicting?
He just, no, I can't, it couldn't be,
it just couldn't be that.
- I think there's something to that,
which is his refusal to accept something
that he didn't actually understand.
- That's a good point.
Plus, you gotta remember the era he came from.
In the 19th century, into the 20th century,
this was the towering achievement of classical physics,
where the world, the universe, was deterministic.
If you tell me where to stand,
and I measure the motions and the momentum,
I will predict all future of this universe.
That was a certain posture the community of physicists has.
Up comes quantum physics,
is it a wave, is it a particle,
is that some percent of the time?
And what was his famous quote,
he was trying to tell God what to do?
What was it?
- "God doesn't play dice", was that the one?
- [Neil and Chuck] God doesn't play dice.
- Well, telling God not to throw dice.
- Oh, he tells God not to throw dice?
- I think so.
I think as quoted by Niels Bohr, or somebody,
"God doesn't play dice with the universe."
- No, He plays roulette, instead.
He plays craps table.
- He plays craps, you know?
- Then what does Stephen Hawking say later?
"God not only plays dice,
"but He sometimes throws the die where you can't see them."
- Yeah, there ya go.
- Sounds to me like God's a grifter.
- And then, Einstein said something else,
at another point about God, and then,
I think it was Niels Bohr, said,
"Einstein, stop telling God what to do."
Just got pissed off.
So, tell me if you agree with this, Janna.
So, this is my measure of why I think General Relativity
is a crowning achievement of the human mind,
greater than almost anything else.
Special Relativity, from 1905,
I think there were enough people on the tail of that,
on the trail of that, that if Einstein were not around,
Special Relativity would have been figured out
within a few years of that date.
Maybe by 1910.
Whereas General Relativity is so different
from how anybody was thinking,
it might have gone another 50 years.
And so this, for me, makes General Relativity
a greater singular achievement than Special.
- I do think that you're right,
it would have been many decades before it was discovered,
if it had not been discovered by Einstein,
General Relativity, and that is intriguing.
- That's how I know you badass among your colleagues.
- I also think it would have looked totally different.
So Einstein gave us all of this,
the General Theory of Relativity is a theory
of curved space-time,
and we follow the natural curves in space.
And all of this elegance of geometry.
But none of it is necessary.
There's a whole bunch of extra degrees of freedom,
in thinking about geometry, that are not at all required.
And I think what would have happened,
is that somebody like Richard Feynman,
who was a particle physicist,
who was thinking about interactions of particles,
would have discovered General Relativity,
but would never have hung
all of this space-time language on it.
It would have just been masses
exchanging gravitons. - Would have had
a different facade.
- Yeah, it would've looked totally different.
- And a completely different frame
of reference. - And completely
different machinery, yeah.
- Everything would have been,
wow, that's incredible.
- Yeah, I really think it would've been like,
oh, particles exchange light,
and that's electromagnetism.
This would've been, particles exchange gravitons,
and that's the Theory of Gravity.
- Gotcha, yeah.
So, was Einstein more of a poetic thinker
when it came to these things?
I mean, where do you get this kind of expanse,
and elegance, that you can attach
to what you're talking about?
- I mean, I don't want to presume to know,
but you do have a sense that here is a very visual thinker,
and very intuitive.
And so all the space-time machinery,
there might be excesses to it
that are not formally required,
but create such powerful imagery and tools,
that in that particular example, which is often rare,
it's kind of the contrary of Occam's razor,
where the extra machinery actually leads
to better, clearer intuition,
than the total, leanest abstraction
of just particles exchanging gravitons.
- That's beautiful, right there.
- Yeah, you should write a book or something.
- Yeah, yeah.
Book in there somewhere, isn't there?
- Somewhere, man.
- So Janna, your book The Black Hole Blues,
it explored LIGO.
Not so much LIGO, but the quest to measure gravity wave.
- And what effort that would take.
Could you describe to me what's going on
when two black holes collide?
And how they're gonna give us a gravity wave?
What I think of as gravity waves all the time.
- Yeah, so in principle, they do give us gravity waves.
- Are we giving off
gravity waves now?
- Yeah, right now, Chuck and I.
- Okay, right.
- It's just pretty modest. - Right.
- If you think about how weak gravity is,
the entire Earth is pulling on me,
and with my little arms, I can resist.
- [Neil] You can lift stuff away from the Earth.
- Yeah, whereas if it was charged,
if it was that much charge pulling on me, I'd be liquified.
So, gravity is incredibly weak.
It takes an entire planet, - I'm gonna say thank God.
- To even make it hard for me to walk.
- That's a good thing, then.
- You know the quick calculation you can do?
Back when we had a Space Shuttle
that would launch people into space.
If you took all the electrons
out of one cubic centimeter of the nose cone,
just remove the electrons,
and put them at the base of the launch pad,
the shuttle wouldn't be able to launch.
- Wait a minute.
- Because the electrons would be--
- Just the electrons.
- In one cubic centimeter. - One cubic centimeter.
- At the base of the launch pad.
They would be pulling on the leftover extra protons
that are at the top,
they would be attracting one another.
- Right. - You would not be able
to launch the, right.
- Oh, wow. - One cubic centimeter.
- One cubic centimeter. - Right.
- So the difference between the gravitational attraction
between an electron and a positron,
and their electromagnetic attraction,
is something like a trillion trillion trillions.
So, it's that much stronger, the electrical attraction,
than the gravitational attraction.
- The gravitational pull.
- It's weak.
So, gravitational waves are incredibly weak,
so what you need in order to have any aspiration,
even Einstein didn't think this would be possible,
because he didn't think anything in the universe
could possibly bring space-time
out enough. - It's pre-black hole.
- Pre-black hole.
So, you need something like
the tremendous radical concentration of mass and energy
in a black hole.
Not only that, but you need them to be
in the final throes of their orbits together.
So, it's like mallets on a drum,
when they get closer and closer,
they're getting louder and louder.
And it's like this crescendo.
So when LIGO made its first detection,
it was the last one fifth of a second
of the orbits of two black holes,
each one about 30 times the mass of the Sun,
a couple hundred kilometers across.
They're going very nearly the speed of light,
and they're executing a few orbits
in the final one fifth of a second, and boom.
It's finally loud enough,
that even though it's traveling
for 1.3 billion years across the cosmos,
by the time it hits the Earth,
if you think about the time it left,
that just multi-celled organisms
were differentiating on the Earth.
- Yes, they were. - You know,
and then there's this race.
They're building LIGO, you know, in the final hundred years.
And then boom, when it hits, it's just barely loud enough.
- And all the while, that wave is heading towards Earth.
- That's right.
But it could have been the previous several billion years,
it's been ringing the Earth,
but there was nothing there capable of detecting it.
- Now, is there any way that we could have missed it?
- Yeah, many ways.
So that actual night that the first detection was made,
was supposed to be the first science run
of the advanced instruments.
It was in September 2015.
And they decided they weren't ready, yet.
So they canceled the science run.
And instead they were there, it's Sunday night,
Monday morning, in the middle of the night,
hammering on the instrument, trying to mess with it,
just as tests.
They're literally driving trucks along the access roads,
slamming on the brakes to see if it screws
with the instrument.
And then in the middle of the night, they get exhausted,
they put their tools down, they go home.
The same thing happens in Washington State,
this was in Louisiana.
And within the span of an hour,
this thing that's been traveling 1.3 billion years
smacks the instrument.
- Doesn't that tell you that this is happening
more frequently than we think?
- Way more frequently, because everyone told me,
with the exception of Kip Thorne,
that black holes would be years on.
That we would detect all kinds of things first
that we predict existed,
but black holes were far off in our future.
And they were not only the
first thing detected-- - The first thing.
- It was beautiful black hole signature,
but it was the first four things we detected,
were all black hole collisions.
- Wow, look at that.
- Black holes all the time.
- All black holes, all the time.
- So, what's the future of this?
- Well, a wonderful thing happened not too long ago,
they made an announcement that they detected
the first neutron stars colliding.
So neutron stars are dead stars
that aren't quite big enough to become black holes.
They're under two times the mass of the Sun,
and they're dense dead stars.
They're often highly magnetized.
But the interesting thing, see, black holes are empty.
They're just darkness, empty space.
There's nothing there.
So when they collide, it's in darkness.
The black hole collision-- - Just to be clear,
when we say that a black hole has a certain size,
that's not a physically occupied volume.
Describe the size of a black hole.
- The size of a black hole is really just
the extent of the shadow it casts on the sky.
- By convention, that's what we use.
- Yes, by convention, it's the region beyond which
light cannot escape.
And so it is literally just the shadow cast on the sky,
if you were to-- - Three-dimensional shadow.
- Yeah. - Okay.
- Did you know you can have a three-dimensional shadow?
- Yeah, you should call it black ball, not black hole.
- What could go wrong?
The French already objected to black hole.
- Did they? - Yeah.
Trou noir, it's offensive in French, apparently.
- What do they call it?
- A black hole.
They gave in, you know?
- They gave in.
- Couldn't resist forever.
So, that's the fascinating thing about a hole.
When we think of a hole,
we think of a circle in a horizontal surface
that you go through in a plane.
Whereas this is a hole in three-dimensional space
you can fall into from any direction.
- And walking into the shadow should be as harmless
as walking into the shadow of a tree.
Nothing's there, you wouldn't notice anything.
You'd cross right over.
There's no dense material there,
there's just nothing there.
So when black holes collide, it's truly a dark event.
Which, even though this, the first collision
was the most powerful event ever detected
since the Big Bang,
none of it came out as light.
None of it.
- So can I ask you this?
- If it did, it would be the brightest thing
in the night- and day-time sky.
- It would have outshone all the stars
in the observable universe, combined.
- So, okay.
If we don't see what's colliding,
what is colliding?
- Space-time itself.
So the black holes blob together.
- And the shadow distorts. - Hold on for a second.
Wait, just hold on.
Ah, my head!
- A bout of existential angst. - Oh, God!
Ah, space-time itself!
- Space-time colliding, yes.
- Then, this blobby thing,
it sheds off all its imperfections,
and it settles down to be one bigger black hole.
So there's a black hole out there, as far as we know,
a little bigger than 60 times the mass of the Sun,
that's just wandering the cosmos aimlessly,
completely dark and completely quiet.
- I'm just a hole. - But the fantastic thing
is they settle down. - Yes, I'm only a hole.
- Don't get in my way.
- That's amazing!
- Yeah, you see it, I mean you hear it,
in the recording that LIGO makes.
You hear it ring down.
You hear it settle down to a final black hole.
- So, tell me how 1.3 billion light years away,
we can know it's two black holes,
one 28 times the mass of the Sun, one 36,
what is getting modeled there, to give us that confidence?
- There's an old-fashioned mathematical problem,
can you hear the shape of a drum?
And it's very similar.
If I bang a drum-- - That's beautiful.
- Yeah. - That's beautiful.
- I think that'll be the title of my memoirs.
- Can you hear the shape of a drum?
- Can you hear the shape of the drum?
- We all recognize sounds.
Our phones go off, and we're like, that's my ringtone.
So, it's kind of similar.
We have a prediction for how the mallets, the black holes,
bang on the drum of space time, creating a sound.
And it's a very specific prediction,
it's not a whole range of possibilities.
We can literally hear, if I played for you our predictions,
the difference between black holes
that were extremely disparate in size.
It sounds different.
If the black holes were on wildly eccentric orbits,
it sounds different.
So, you can reconstruct the motion, size, behavior, spins,
of the mallets. - With high confidence.
- With some things, less confidence than others.
So, like, the spin of the black holes is hard to determine.
They're both probably spinning.
Some things with less confidence.
But that they were two black holes,
with a pretty good degree of confidence.
- And with the masses that they were ascribed.
- Right, with the masses they were ascribed.
So you can tell how big they are, too,
because you can hear the orbits, again,
just like how you can hear mallets on a drum.
And even knowing-- - But that's a weaker signal,
- Well, it is, but it's .7 times the speed of light,
and you can tell when it's done one full orbit,
and that tells you how big the system is.
And that means you've got these two black holes
summing to a little more than 60 times the mass of the Sun,
in a region only of a couple hundred kilometers across.
And so how are you gonna do that?
- Yeah, there's only one way.
- So, are there any black holes tiny enough
that they spin and collide,
and create the sound of a triangle?
- Well, it is fantastic that black holes
that are just a few times to 10 times the mass of the Sun,
something in that range,
actually ring space-time in the human auditory range.
- What? - Yeah.
LIGO is an instrument--
- You told me that once, and I said,
what are you talking about?
There's no sound in space. - LIGO is an instrument
sensitive to the range of the piano.
So, it's true, there's no sound in space,
because there's no air.
And anyone who sees somebody screaming outside a space ship
is gonna write complaints on Twitter
that they don't know what they're talking about.
But if you were near enough those two black holes,
really near enough, your ear could technically ring
in response to the gravitational waves.
- What you're saying is,
your eardrum that is normally set into vibration
by vibrating air molecules,
in this case would be set to vibrate
by vibrating fabric of space-time.
- Yeah, it would pluck it like a string.
- Yeah, like a harp string. - Yeah.
- Ooh. - Wow.
- That's weird. - That is weird.
- I don't even wanna...
- That's really wild, I like it.
- If you heard that, like, get out.
Like imagine, you would see nothing.
- Oh no, if you heard that,
it's too late. - You would see nothing,
but you would hear.
Too bad it doesn't, actually,
maybe that's what it says when you hear it.
- It's a warning sign. - Instead of a boom,
it's just like a ha, ha, ha,
- So what would, hold my eardrums aside,
what would my body feel if a wave went across my body?
- So, presumably, right now,
there are black holes colliding all over the universe.
We're being squeezed and stretched,
but again, it's so weak, that we don't even notice.
- If it's strong, will I say, "Ooh, I felt that"?
Or, if it's reshaping the fabric of space and time,
and I occupy that coordinate,
wouldn't I just shake with it, and I wouldn't even know?
- Yeah, probably most of these--
- Get that, Chuck, what I was just saying?
If I draw a stick man on a rubber sheet,
and I bend the rubber sheet, the stick man goes with it.
- Without even knowing that he's being bent.
- This is just how I'm doing it.
- The difference with the stick man,
is that we're bound together.
So, for instance, your head is harder to squeeze and stretch
than your eardrums.
- Speak for yourself.
- If you were there, your ear would start resonating
more willingly than your head would.
So, the fact that we're bound means we're resisting
to some extent.
So the whole Earth, when the wave passes,
doesn't really notice it.
It's just so atomically bound to itself.
- It would just be so funner if, in fact, we did.
- Yeah, I think it's gonna be more like,
for these long waves,
it's gonna be more like bobbing on an ocean.
You know, just kind of what the mirrors
in the LIGO instrument do.
When the wave passes, they bob on the wave.
It's not that the mirror itself
is being squeezed and stretched,
it's that it's starting to swing.
- And that's what you're looking for.
You're looking for the motion of the mirror.
- This opened a whole new way of observing the universe.
Any way to bring LIGO to bear on the Big Bang itself?
- Definitely gravitational wave experiments,
but probably not LIGO.
LIGO can put limits on the Big Bang.
So the Big Bang might've actually made a bang.
When the universe was created,
gravitational waves probably really cacophonous.
It probably sounded like noise.
But, it's outside of really the range
LIGO's optimally designed to detect.
It's much more likely that a space-based instrument
like LISA, the Laser Interferometer Space Antenna,
if it ever launches, that LISA would be able to detect
the sound of the bang.
- It would be a cacophony.
- Yeah, noise.
Just like (whooshing).
So you asked me, how do you know it's black holes?
Those two things sound really different.
- Different, yeah. - Wow.
- Black holes sound like (ascending trill).
- That was good.
Let me hear that again?
- I don't know if I can do it again.
- It's a black hole. - It's called a chirp.
- Black hole colliding. - Black hole colliding.
- Those are two black holes colliding.
Much less, I don't know, macho, than most people expect.
It has this sort of sweet little chirp.
- Has anyone thought about how you get
a 30 solar mass black hole?
- That's a really excellent question.
So not only was the first--
- I don't know how you make one of those.
- Right, and not only did they detect
the first gravitational waves,
but they actually started probing new astronomy.
We had no idea there were black holes that big.
The projections were for much smaller ones.
And now we know there's one 60 solar masses,
so maybe there are hundred,
or hundred and fifty. - Maybe there's some
that are bigger than that.
- Right, so did those already collide with other black holes
to get that big?
Or were they formed by direct collapse?
Did they skip the death star state?
We don't really know.
So that's, already people are working on--
- Yeah, because normally,
if you wanna learn about black holes
in your astrophysics class,
what did you get in your astrophysics?
- My astrophysics...
- He's taking it with me next semester.
- Okay, excellent.
- No, I got an incomplete.
I got an I, I got an I in astrophysics.
- So, you learn that one way to get a black hole
is the end point of a high-mass star.
But, high-mass stars are 20, 30, 40, 50 solar mass,
but they lose a lot of mass en route.
So by the time it's done,
you don't really have 30, 40, 50, 60--
- Solar mass.
And so, but now we know for a fact that we do have one,
because we've watched them collide.
- LIGO picked them up.
- There are some people that think they're pure dark matter.
That they don't form from stellar collapse,
that they're not the death state of a star.
That they're an example of dark matter.
- I'll tell you this,
just as a vote for science here,
any time we have a new instrument
that takes us into a parameter space
where we have not previously looked,
you discover stuff that nobody ordered.
- [Chuck] Right.
- Now, a well-designed experiment
is thought up to test for something
that you have an idea about, right?
So, we think we will detect colliding black holes.
You do it, and oh my gosh, it's a kind of black hole
we never even thought was there.
Good science is that which shows that maybe
you were on the right track to begin with,
but then opens up whole new places
that you never even knew.
So now the next generation LIGO,
you're gonna know how to...
how to be better at what it is for the new stuff.
- And they'll discover 60 solar mass black holes
that will collide, and say, damn, look out.
Watch where you going.
- It wouldn't be the 60s,
because the 60s would be more powerful than the 30s.
- Oh, right.
- It would detect lower mass black holes,
or the 30 mass black holes farther away.
- Father away. - Right?
- Also, what about something
we've never even thought of before?
And when you think of the time
Galileo first pointed the telescope at the sky,
he's looking at Saturn, and he's looking at the Sun.
He's not thinking quasars and black holes,
those things aren't even conceivable to him.
And what we all really hope, secretly,
is that we're gonna discover stuff in gravitational waves
that we couldn't possibly see in light.
After all, 95% of the universe is completely dark.
- Right. - Right, exactly.
So, maybe there's something out there
that we have not even thought of,
and that is what everyone hopes for, to be honest.
- Have to think about that.
- [Chuck] It's very cool, man.
- [Janna] Some crazy noise.
- Yeah, 'cause the stuff we had no idea even existed,
so we opened up new windows of observation
onto the universe.
Stuff that only talks to us in ultraviolet,
or in infrared.
Until we had ultraviolet or infrared telescope,
it was not there.
The birth call of the universe itself.
- The cosmic microwave background, is microwaves.
- That was a non-thing-- - You gotta see them, now.
- Until we had microwave detectors.
Nobody even talking about the early universe,
until you could do that.
- Now, thanks to them, we have Hot Pockets.
- So, can you give us just some final reflections
on Einstein's life, so that if we wanna think,
if we wanna live,
you know how a religious person would say,
I wanna live the way Jesus lived?
And so, in the geek world, you say,
I wanna live the way Einstein lived.
Is there anything that you can tell us?
- I really admired, above all else,
Einstein's independence of mind and spirit.
So, when everyone else was saying,
oh, there's something wrong with this supposition
that speed of light is a constant.
That just makes no sense whatsoever.
- Still doesn't really make sense.
- It's really challenging.
But Einstein accepts,
and this is something that's often misunderstood
in the idea of relativity.
He accepts the rigidity of the constraint.
That's what he does.
And then around that constraint,
he sees where he's free to move, and it's very limited.
But from this tight constraint, he makes this,
it's like squeezing a balloon in one direction,
and it blows out in the other direction.
It leads to things that were so much more magnificent
than just allowing the speed of light to not be a constant.
- You know, it's interesting that you say that.
I just thought of this now.
The worst thing you can tell an engineer is,
build this, and there are no constraints,
and spend as much as you want.
- It's like, oh, my gosh, I don't know what to do.
But if you say, it's gotta be 30 kilos in mass,
and it's gotta use this much power,
and it's gotta fly in this way,
and it's gotta be made of theses materials, go.
Then, that's where the creativity--
- Absolutely. - And so, for example,
how do you get a telescope
bigger than the width of your rocket into orbit?
How do you do that?
And people say, oh, okay, you just tell the engineers.
They invent a telescope that-- - Unfurls.
- [Neil and Janna] Unfurls.
- Who would've ordered that? - I didn't think of that.
- Who would've thought of that?
- Necessity is the mother of invention.
- You think of it because I didn't let you
do something else.
I loved your reference to Einstein in that context.
It didn't constrain him, it liberated him.
- That's right, exactly. - So, I wanna ask you
something, 'cause you just sparked a question--
- Make it quick, 'cause we're running out of time.
- Out of time.
Okay, so you said about Einstein,
and light being a constant.
So, when LIGO detected the pulsar,
the neutron star-- - Oh, the neutron stars.
- The neutron star.
When they detected that,
did they make the detection and see the light
at the same time, since light is a constant?
- This is why everyone was incredibly excited.
It might be, at the end of the day,
the most highly studied astronomical event in history.
Basically, some huge fraction
of the entire international astronomical community
turned telescopes, satellites, all kinds of instruments,
in the direction of the collision.
- We do that. - Yeah.
It was a network. - We good about that.
- We good that way. - Just imagine.
- Yo, I got your back. - We got your back.
It's a very important thing.
I'm in the middle of my own research program,
then, in the old days, it would've been a telegram,
now it's that, oh, my gosh, there's an event over here,
and I have my detector,
which is different from your detector.
Now we have 9,200 different kinds of detectors
getting different aspects--
- Of that one event. - One event.
- Yeah. - And you look at this part,
and I look at that part,
and I look at this wavelength,
and you look at that wavelength.
And you put that all together, all eyes, all hands on deck.
All telescopes, check it out.
- It was really remarkable.
So LIGO caught about a minute in the recording,
but all of these telescopes combined caught a month.
- And it kept spiking in different wavelengths.
It would go in the infrared, in the gamma ray,
in the x ray.
And so all these different instruments had their time.
- Yeah, so that's how we roll.
International collaboration. - Got each other's back.
All right, guys, we gotta shut it down, here.
But, Chuck, always nice to have ya.
- Always a pleasure.
- Janna, even more nice to have you.
We'll find some excuses to talk about Einstein
and the universe just to get you back.
- Love it. - All right.
You've been watching, and possibly only listening,
I'm your host, Neil deGrasse Tyson,
your personal astrophysicist.
And as always, I bid you to keep looking up.