Quantum Quandary: StarTalk Live! With Brian Greene & Janna Levin

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Coming up on StarTalk, we have Star Talk live at the Beacon Theater, New York City.

We're celebrating the 100th anniversary decade of the discovery of quantum physics.

Not only that, the 1920s was when we discovered that the Milky Way galaxy was not alone in the universe, and that the universe itself was expanding.

So, we brought out the big guns for that one.

We've got Jan Eleven and Brian Green, two cosmologists with whom you are most familiar, and a very special comedic guest, Hassan Minaj.

So, join me and Chuck Nice as we host that evening.

Coming up,

welcome to Star Talk,

your place in the universe where science and pop culture collide.

Star Talk begins right now.

So before we begin, I just want to, I didn't know this until today, that the two of you are actually current collaborators on some research.

Could you just highlight what that is?

What are you doing?

I mean, Brian and I have been working together for years.

Mostly, we've been thinking about extraspatial dimensions

and different cosmological implications, implications for theoretical physics, you know, hiding some dark energy in some extra dimensions.

As one does.

As one does, yes.

You're thinking about higher dimensions.

Yes.

Because

the three plus time dimensions are not enough for you.

Well, you know, even Einstein, when he started working, wondered why three.

I mean, it's a curious question.

Once you start...

Well, it's a magic number.

Yeah.

Is it your your favorite number?

Wait, wait, those are schoolhouse rock people right there.

They count the three.

They got it right away.

Okay, but how many dimensions are there, really?

We don't know, but certain theories tell us that it could be much more than the ones that meet the eye.

So it could be as many as 10 or 11.

Oh, like gender.

But you.

I said it, and now I'm getting arrested.

All right, but to just make up other dimensions,

it sounds like you're pulling it out of your ass.

I mean, I'm sorry.

Yeah,

it's all.

You didn't deny that immediately.

Worry about this.

Partly it is, but it was also deep mathematical reasons that lead us to these ideas.

Yeah, and you know, we figure if nature can try some experiments, she will.

So every every possibility might actually happen.

Okay.

So we're just exploring.

All right.

How much weed do you guys smoke?

All right.

So.

Complete silence.

The microscope and telescope were invented 400 years ago.

And like I said, they take us to the grandest visions of our understanding of our place in the universe and the tiniest visions that also give us an understanding of our place in the universe.

And so

those first steps were magnified at the dawn of the 20th century, especially through the 1920s.

And so

let's start out with the large and we'll end with the small.

Okay?

So let's go back to the roaring 20th.

Let's just do that.

And here's something that it's hard to even believe, that just 105 years ago, we didn't know if there were other galaxies.

We just thought all the stars in the night sky,

the Milky Way, was the entire universe.

We weren't given reason to think anything else.

There were these fuzzy things in the sky.

Okay, they're just fuzz.

We call them nebulae, which is Latin.

For fuzz.

Yes, thank you.

So you just thought it was just space lint.

Yeah.

Yeah.

Yeah.

And, But some fuzz lint, space, not even messing in.

Nebulae, some nebulae were spiral-shaped, and others were irregular.

And the irregular ones were found in the plane of the galaxy, whereas the spiral ones were in every direction you looked.

Interesting.

So that was odd.

It was the first.

thing.

Well, maybe we can unpack this and figure out what's going on.

So there was a famous debate, took place in 1920,

hosted by the National Academy of Sciences

between

Heber D.

Curtis, yes.

Unfortunate name.

He had that name.

And Harlow Shapley, soon to become the director of the Harvard College Observatory.

And Heber Curtis was director of the Allegheny Observatory.

Two very different.

Yeah, I'm going to say one of those sounds more expensive.

All right.

So they debated whether these spiral things were other galaxies

with a term coined by Immanuel Kant in the 1700s, who thought about this, philosopher.

Yes, Chuck?

Brian did it to me, man.

What does Brian do to you?

Because he knows I can't hear the name Immanuel Kant without

being 12 years old.

I'm so sorry.

Okay.

So he's a philosopher, deep thinking philosopher.

He looked up and he saw these spiral objects and he thought of them as possible island universes.

Oh, that's pretty cool.

An island universe.

That's beautiful.

That is.

But we didn't have evidence to say that, to support it, but it was a deep idea.

at the time.

So there they are.

They debated this.

But based on what evidence?

Just hot taken?

They're scientists.

Okay.

All right.

Which means...

Sometimes we have rose-colored glasses towards the past.

Yes, I get it.

I get it.

So here's how it works.

Two scientists argue

there's a pact implicitly signed before they even begin, which is either

you're right and she's wrong,

you're right and he's wrong, or you're both wrong.

They know this going into the conversation.

It's nerd thunderdog.

So two scientists enter.

Two scientists leave, but one's a little embarrassed.

Pay-per-view, Saturday nights.

Yeah.

So

here's.

This is their Tyson Jake Paul real kind of throwdown.

So let's go to the Harvard fellow.

Yeah.

Because you can always tell a Harvard man, but you can't tell him much.

Oh, got it.

So they were insufferable back then as well.

Got it.

Were they also like, I went to school in Boston.

Fuck you.

Just say it.

Just say it.

So

say it, you know?

I don't know.

All right.

So back to the

Let's Merch.

Shapley.

was heavily invested in the entire night sky being part of the being the whole universe and the Milky Way.

And he had evidence at the time from a fellow astronomer who had looked at the spiral nebulae and claimed that he found them having moved on the sky.

Now, if you're really, really far away, that's essentially impossible to measure.

But if you're close up and you're moving, you can see that movement.

Okay?

Things that are close to you.

So the example here is, if I see a plane moving across the sky, and then I see a bird moving at the same angle, I don't conclude that the bird is going 600 miles an hour.

The bird is much closer.

So at much lower speeds, I can see it cross my field of view.

So

because it's closer.

That evidence suggested that the spiral nebulae were nearby, and he He bet on that horse, but it was the wrong horse.

He was doing what a good scientist will do.

He took the data, put his confidence in the data.

It was later shown that the data he was basing his argument on was false.

It could not be verified by the work of other scientists.

In fact, no, the spiral nebulae had no motion across the sky.

And so Shapley was just wrong.

Later, we would later show that he's wrong.

And

what puts the nail in the coffin?

1923.

Edwin Hubble.

Oh, the man.

Hubble was a person before he was a telescope.

Yeah.

I thought he was born a telescope.

Born a telescope?

Yeah, just like when you're a kid, you're like, of course,

there was ninja turtles and they were birthed.

Yeah, there it is.

There it is.

So he had an idea.

based on evidence and it turned out to be wrong because the evidence was flawed.

So there's some lessons lessons there.

And if one scientist has one bit of evidence, you don't alert the authorities yet until there's confirming other experiments to do so.

That is what the peer review is all about.

That's the peer review is all about.

And by the way, for anybody who wants to know, scientists are haters.

Okay?

That is what they do.

You come up with something, and somebody goes, I call bullshit, and then it's on.

And it's just on.

Wait, wait, so Neil, so Neil, peer review to us non-scientists is basically it's scientific group chat where you present

your

take or information.

And the 17 other friends that are in the group chat get to be like, bullshit.

Oh, shit.

And Sapley had a green bubble in the chat.

Oh, goddamn.

God damn,

what a horrible life to live.

He was the one green.

He was the one green.

Surrounded by blues.

Yeah, and if you have an idea and it's shown to be wrong,

then it's just wrong.

In fact, Einstein, after his relativity, which we'll get into in a couple of minutes,

that was hard to accept by people, right?

It was hard.

It was very counterintuitive.

Someone came up with a work saying 100 against Einstein.

100 against Einstein.

And then he's rumored to say what after that.

Well, see, I just learned this anecdote, but he's rumored to have said, why 100?

If I'm wrong, one would have been enough.

Wow.

Yeah.

It's pretty great.

Yeah.

And believe me, I've been married for 27 years.

That is right.

Stop.

Okay, so here's what happened.

So Edwin Hubble is curious about these spiral nebulae.

And he finds a star in them that matches a kind of star that's not in a nebulae, that's just sort of nearer by than that star.

It's a very specific kind of variable star named after the very first of its kind, Cepheid variable.

The first of its kind was found in the constellation Cepheus.

And so that's how we categorize types of variable stars.

The first one in a constellation, all the others, no matter where you find them, are that variety.

Found a Cepheid variable there.

And what was spe tell us what's special about the Cepheid variables?

Well, they have a very predictable property where their luminosity, how bright they shine, is related to a sort of oscillation.

And so you can tell that you're looking at precisely one of those.

It's very easily identifiable.

If you get the luminosity out of it, then you can say, I can see the period vary.

Right.

Based on that period, I know how bright it should be.

How bright it should be.

So it's as though you knew your light bulb.

Right?

Yeah.

You can tell if you have a very bright light bulb far away or a very dim light bulb up close.

Right, how can you distinguish the two?

And how do you distinguish the two if you know nothing about the light bulb?

But if you know everything about your light bulb, you know exactly what it is, then you can say, oh, I know this light bulb, and so I know exactly how far away it is.

So he says this star is of this particular luminosity, and the only way it can be that dim

is if it is far outside our galaxy.

I just recently saw the actual plate, and it's really stunning.

He crosses out.

The photographic plate.

Yes, the photographic plate where he makes this detection.

He wrote NOV, I think,

for Nova originally.

He thought it was a different kind of object.

And then he crosses it out and writes V-A-R, exclamation point for a variable star.

So it's a real epiphany that he realizes.

He knows what he's seen.

And right at that moment, he understands it's far away.

So Emmanuel can

turn out to be right.

These were, in fact, island universes.

And Hubble wrote to Shapley

on this.

And I had to look this one up.

Shapley, what's the quote here?

He said,

he said, here is the letter that destroyed my universe.

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This is Star Talk with Neil Degras Tyson.

It's important to know what he actually meant by that because Hubble himself never was convinced that these were actually other galaxies.

He proved that there was something beyond the outskirts of our galaxy.

We knew our galaxy about 100,000 light years across.

His analysis showed this to be 900,000 light years.

We now update it to 2 million light years.

But Hubble was so conservative that he was unwilling to then say this is an island universe.

This is a galaxy in its own right.

What an idiot.

Wait, what's the difference, just from a space real estate standpoint?

What's the difference between an island universe and a galaxy?

What are we talking about?

They're poetically identical.

They're the same.

They're the same.

Poetically identical.

Got it.

Yeah.

Okay.

Yeah, because if our galaxy is our

universe and it's another galaxy, then you get to call that a universe.

Except, once we see the full breadth of it all, we got to reallocate how we use the word universe.

Because it's uni-verse.

one

in one verse right

but we're in we're in the we're in the the multiverse spider-man we're in the

we'll get to that

okay yeah yeah yeah we'll get to that all right minus the spider-man but we'll

you didn't like the second one

i thought it was great so so jana how did we're reeling from the fact that we are not the universe we're just a part of a universe.

And then a few years later, Hubble

discovers that these spiral nebulae

are

in motion,

body and soul.

So what's going on there?

Yeah, so once he's starting to be able to use these Cepheid variables and these standard candles to get a strong sense of how far away things are,

he can start to do that kind of mapping out the local environment,

what we have right nearby, and then also galaxies further away, these little smudges on the sky.

And he begins to catalog not only that there are other galaxies around us at great distances, but they also seem to be receding away from us largely, predominantly.

Yeah, and so he makes a plot.

He makes a plot.

So this is very strange.

I mean, you're looking at all of these enormous galaxies.

So a galaxy is a collection of hundreds of billions of stars, and they're pretty localized, and maybe they're spirals and blobs, and they're very far away.

And they're also also moving away from us in every direction, which is very peculiar.

So he makes this plot.

It's completely freaky, but it gets freakier because the further away they are, the faster they're expanding away from us.

And they're calculating this all without computers.

Well,

people were called computers back then.

Sure.

If you look at old dictionaries,

look at the word computer, a person who makes computers.

The person who computes.

Yeah, so.

Well, wait,

and there's a room full of computers.

And yes, but they're doing it without the machines.

There's a room full of computers at Harvard at the time.

Yes, so he actually uses the work of one of the Harvard computers, which was a woman named Henrietta Levitt.

And she was part of a group of women who worked at the Harvard Observatory that were called Pickering's.

And she talked like this.

Well, they were called Pickering's Harem because Charles Pickering at one point was so frustrated with his male computers that he fired them all.

And he said, my maid could do a better job.

And he hired his maid, who was Wilhelmina Fleming, and she did a great job.

And she hired all these other women, and one of whom was Henrietta Levitt, and she made 30 cents an hour.

Go ahead.

Are we applauding her or her pay?

That was weird.

30 cents an hour.

She should be making iPhones.

Okay, so

I said it.

I said it.

All right.

So, but mixed in here, we've got simultaneous things going on.

Einstein's general theory of relativity is already at the races.

Okay, so that came in in 1915.

15.

Okay, that gave us a mechanism to understand what the whole universe could be doing.

Just catch us up on that.

Well, Einstein writes down his equations in 1915, and initially he applies them to things like the motion of the Earth around the Sun and terrestrial and nearby motion, local things.

But then some other

very creative thinkers, one in particular was a Belgian priest named Georges Lemaitre.

He

decides to apply the mathematics not to something in the universe, but to the entirety of the universe and find from the equations that the universe should be expanding over time.

It should be spreading.

Bro, just to be clear, he was able to do that not based on his training as a priest.

He was a priest physicist.

He was a priest-physicist, but no doubt his interest in applying these ideas to the entirety of the universe was not distinct from his focus on the big questions of existence.

So they weren't that separate, although he, in his own mind, was very clear.

He said there are two ways to have deep insight about the world.

There's mathematics and there's salvation.

And he said, let me follow both.

And that's what he did.

But not intermingled.

He was very clear not to there was a line in the sand.

Absolutely.

Yeah.

I'll let you guys figure out the pronunciation.

So he takes the equations.

We have an expanding universe.

But he, so Lematre before, before Hubble

predicts an expanding universe.

Yes.

Using Einstein's equations.

Yes.

So Einstein could have made the prediction and he didn't.

Yeah.

In fact, in 1917, Einstein actually got there first.

And when he applied the equations to the entirety of space, he was very disturbed that he couldn't get a universe that met his own philosophical prejudice.

Which was.

That the universe is fixed, eternal, static, and unchanging.

Why would anybody think the universe could be anything other than that?

Well, I mean, there is this book called Genesis, which seems to suggest a beginning.

Okay.

So there are some people who think perhaps that that vision is not correct.

But Einstein and many others at the time very firmly believed that the universe could not change on the largest of scales.

And that's just a philosophical bias.

Totally.

And in fact, he changes.

Wait, wait, wait, wait.

How could he get away with that if all the galaxies have gravity?

And if they all feel each other's gravity, they would all collapse down into one point.

Yeah, so this was an argument that Isaac Newton actually gave hundreds of years earlier.

But if the universe is infinitely big, and if the galaxies are spread across an infinity of space then there is no center for them to collapse toward yeah so you can envision a static universe now if it's infinite if it's infinite if and only infinite but even more than that einstein then in his own general relativity recognized basically the issue that you're raising in a finite universe and he said let me introduce a repulsive push to counter the attractive pull of gravity.

Anti-gravity.

An anti-gravity force field called the cosmological constant.

So he introduces this into the math in 1917.

It was not in the 1915 equations.

He introduces it just to have a static universe that will allow him to breathe easy.

And to fulfill his philosophical bias.

Then Lematra says

we can have an expanding universe.

And so how did Einstein react to that?

Einstein learns of this from Lemaitre in 1927.

And he says to Lemaitre, your calculations calculations are correct, but your physics is abominable.

Oh, those fighting words.

They were fighting words.

Wait, by which he was saying, you can't trust that every mathematical calculation tells you something real about reality.

Some math should be in math textbooks, and it's interesting, but it's nothing more than a mathematical curiosity.

And he says, Lemaitre, your idea of an expanding universe, that's a mathematical curiosity.

It's not real.

Okay, so then

1929, Hubble discovers an expanding universe.

Now what?

What happens next?

Well, so it's interesting because the way I originally described it is kind of confusing.

You might think it makes it seem like we're at the center of this expansion and everything's receding away from us.

But the way the Hubble law is specifically, it's much more like the space between every galaxy is actually stretching.

So from their point of view, if you were on one of those other galaxies, it would also look like everything's receding away from them.

Right, everything's receding away from them.

And if you imagine that it's not the galaxies literally moving on space-time, but actually the distance between the galaxies that's stretching, then something further away is actually moving away from you faster.

There's more space stretching.

And this was really closer to Lemaitre's description.

Not even closer.

It simply wasn't static.

So just so I'm clear, at that time, they believed there's only one galaxy in approximately 1925.

Just so I'm following.

I feel like I'm in a Chris Nolan.

No, no, no, no.

Watching Tenet.

Let me just pause real quick.

No, no, up until 1923, 24.

One galaxy.

One galaxy.

It was

It was one universe.

One universe.

Copy.

Yes.

Here we are, 2025, from what I understand.

Yes.

Now there's

how many universes are we in now?

But are you talking island universes or are you talking universe universes?

I'm talking about the whole universe.

Oh, good God.

There's one universe that we know about filled with a hundred billion galaxies, each of which has on the order of a hundred billion stars.

There are theoretical ideas that Neil is suggesting we might get to tomorrow

that speak to the possibility there might be other universes.

So the answer is we don't know for sure, but the data seems to suggest that there's one universe.

Well, we were talking about this backstage.

If

the delta is that big between those two numbers, which is one and you just basically said a gajillion,

how do we know that

what we're living in right now, the data that we know right now, isn't going to be wildly off.

And 50 years from now or 100 years from now, they'll be like, look at those dumb dumbs in 2024.

We hope that that's what will happen.

That's what we live for.

We live to be wrong.

Stupid.

I don't know.

We live to be wrong.

We're scientists.

Oh, God.

We live to be wrong.

We're scientists.

Got it.

Okay.

Well, so let's follow through this reasoning.

We discover an expanding universe.

If we're expanding, that means we're bigger today than we were yesterday.

And bigger yesterday than we were the day before.

So

logically, where does that take us?

Bigger.

No, no, going back in time.

Oh, I'm sorry.

So, yeah.

So,

if you're already disturbed about the lack of permanence to the universe, then this very quickly leads you to have even greater existential dread because if you run the movie backwards, then everything was once closer together.

And if you keep running the movie backwards, it gets to a point which seems quite catastrophic, where these galaxies are literally on top of each other.

And eventually, you're kind of imagining something that's so dense that you have to start thinking of it as hot and

soupy and and and chaotic and

then what?

What did Lemaitre call this?

Yeah, so Lemaitre basically said, look, if the math is saying that the universe is expanding today and if then Hubble's data shows that the universe is expanding today, just wind the cosmic film in reverse.

You run the film backwards and things get closer and closer together and there suggests that there's a point in the distant past when everything was on top of everything else and he calls this the primeval atom this is the beginning according to his description okay and i happen to know there was an astronomer active at the time very brilliant guy named fred hoyle who was not into a universe that would be changing yeah he knew the universe was expanding he couldn't reason that away he accepted that yeah he accepted that but if you're expanding but you're always the same that must mean matter is being spontaneously created in the void to create new galaxies so that statistically the universe always looks the same.

Yeah.

You know, but here's the thing.

If the universe is expanding, that in itself is a change.

So why would you not accept a changing universe?

Because he wanted to always look the same for all of time, for all eternity, in the past and in the future.

Again, it's a philosophical bias.

But I think the idea of the beginning was particularly disturbing.

The idea, so this primeval Adam that La Maitre.

Because it's disturbing to scientists, but not for religious people, where God made the universe.

They're perfectly happy with the beginning.

Look, Pope Pius XII, perhaps the nerdiest pope in history who loved science.

Wait, wait, why do you know this?

I don't know.

He took Lemaitre's work and he said, there is the scientific evidence for Genesis.

That's what he said.

And when Lemaitre heard this, he threw a fit.

Belgian priest Lemaitre.

The Pope is talking to him.

Not directly, but yes, when he catches wind, that this is what the Pope is saying.

And one of his students who was in the class that Lemaitre had to teach that afternoon after learning said that Lemaitre, who normally was very quiet and mild-mannered, he came in and ranted for 45 minutes because his whole point was, I am not blending my religious life and my scientific life.

And here the Pope is taking my scientific work and he's turning it into religion.

But notice he said all that to a student and not the Pope.

You don't want to know the Galileo situation.

Exactly.

Yeah, so I have a tamer version of that quote.

It's, as far as I see, such a theory of the primeval Adam remains entirely outside any metaphysical or religious question.

Yeah, that's after I had a couple drinks and chill.

Okay, so then it got called the Big Bang by

Fred Hoyle.

By Fred Hoyle.

Yeah, so Fred Hoyle was in a 1948 BBC radio interview.

Why do you know this level of detail about this?

And so he is describing his own approach, which as you mentioned, is a steady-state approach where matter is created spontaneously and fills in the gaps in space.

And so they ask him about this other approach, not his.

And he says, oh, that theory in which all matter must be created in one big bang.

And that's where the idea of big bang theory comes from.

Now,

people have interpreted that as a derogatory description.

His own way of recounting the story is he was simply trying to draw a distinction between a theory in which, in his steady state, only a little bit of matter is created here and there across space versus this other theory.

Like one hydrogen atom per century per cubic light year.

I mean, there's some small rate.

Not quite that small.

So it is one atom per century per Olympic-sized swimming pool.

Oh, okay.

I thought it was a bigger combat.

And that's all that you need.

And so it's kind of an amazing...

In the whole universe, yeah, yeah.

Yeah, because what's more believable that one little atom forms in a cubic, you know, in a swimming pool-sized arena of space per century, or that there's this moment where everything is created all at once.

Frame it that way, his theory sounds perhaps a little bit more believable.

Less crazy.

Yeah.

Yeah.

So what do we have to assume if there is a Big Bang?

So we've got to assume that the expansion has been uniform the whole time not necessarily no it doesn't have to be uniform yeah it can change over time but that's been always expanding it's always expanding okay yeah and unless there's extra dimensions those might all right well

it could expand differently enough brian and i had to talk about this later

well yeah you can squeeze into the other dimensions there could have been chaotic mixing of the expansion and contraction but overall the overall volume of the universe was expanding.

But the way you get this is looking at the rate at which the universe is expanding.

Yes.

And that is a slope on a graph.

And Hubble first derived that.

And

there's a slope.

He called it the letter C, which is for constant.

But since then, we swap that out with a capital H for Hubble.

And we call it the Hubble constant.

Very famous Hubble constant.

So it's constant over space.

I mean, it's not important to space.

It's fairly over time.

It's really the Hubble parameter, we should call it, because it does change in time.

It could have been faster in the early universe, faster in the future.

All right, so Hubble,

he had the wrong, turned out, the Cepheid variable he used,

he didn't know at the time, there were two varieties of Cepheid variables, the one that's near us and the one that you can see from far distance, far away.

And he presumed they were the same.

No reason to think otherwise.

So he got the wrong distance, the wrong expansion rate of the universe.

So Cepheid is like diabetes.

It's type 1 and type 2.

Yes, there's a type 1 and type 2.

Exactly, I think.

Maybe not exactly.

I'm not sure.

Yes, there's literally type 1 Cepheid and type 2 Cepheid, and you got to use apples and apples when you're doing this exercise.

So he got an age of the universe of 2 billion years.

We would later refine these numbers.

When I was in graduate school many moons ago, the uncertainty, in the Hubble constant was a factor of two.

There was a 10...

So with the Hubble constant, you run the film backwards, ask how much time at this expansion rate, looking backwards, when do we get to time zero?

That makes sense.

Yeah, just when is everybody in the same place at the same time?

That's a perfectly sensible question.

And we got two numbers.

There are two camps.

Okay.

A 10-billion-year camp and a 20-billion-year camp.

A whole factor of two.

And everyone is fighting for their,

and we know they both can't be right.

And so

we need better data.

One of the goals.

Wait, is it being off by 10 billion quite a bit?

That's a lot.

Again,

Canadian, and I only took physics one

in undergrad.

I did not advance.

I don't want the smoke, but I am saying being off by 10 billion is a lot.

Here's the thing.

Like if you go out to dinner and we split it, and I'm off

by

that big of a delta, if I'm 50, 50, if I'm yeah, if I'm a hundred percent off, yes,

yes, aren't you like you lose your science

little thing?

No, so you know what I mean?

Like, here's the thing disbarred,

yeah, here's the thing, but you know, you just get to talk your shit.

Here's the thing, you are off by 10 billion.

You get to talk your shit still.

Here's the thing: like my dad in the living room when he's giving his opinions about politics.

He just gets to run his mouth continuously.

I got this.

Go ahead.

This is a me and my dad thing, but I'm just a little mad that

a capital S scientist was this off.

Okay.

Go ahead.

And I have a second question.

The universe is vast.

Yes.

In time.

Yeah.

And in space.

Sure.

It is

vast

in every metric we've ever established for it.

There are things that are vast in size,

in temperature, in speed,

in gravity.

And so if I'm off by a factor of two,

between 10 billion and 20 billion,

I could have been off by a factor of 10, by a factor of 1,000, by a factor of a million.

We were quite happy.

We were in the same sandbox having that conversation.

So it's kind of like being Jeff Bezos.

You know, if I'm off by 10 billion, eh, not so bad.

So,

so.

Can I also ask you the second philosophical question, which is, which is, no, no, no, this is, this is for real.

When you were like, it's either 10 billion or 20 billion.

And I was asking you this backstage, which was, if, when the number is that big, is it almost like the United States has debt?

Where they're like, the deficit is at 28 trillion.

And you're like, what does it even matter now?

Yeah, but it's at a gajillion million.

Like, what does it matter?

Why does the number?

Because I feel like a freshman in college.

It's going to matter an awful lot.

I would say that actually 10 billion is actually quite good.

10 to 20 is very much in the ballpark.

You should run the Federal Reserve.

No, you should.

You should.

At this stage, you know,

that's a good way to think about it.

You could have been off by a trillion.

Well, but the future is going to be much, much longer than the past.

So it's not as though the universe kind of will expire within another 10 billion years, like we're confined to this number.

The future could be just a huge number.

We could be living in a time where it's not 10 billion.

But can I just give you perhaps one, these are all very, very good answers, but perhaps one other way of looking at it.

You're saying it was a bad question.

Bad question.

Your great answer is bad question.

We don't care whether it's 10 billion or 20 billion.

The number doesn't matter.

What does matter is?

That's the most American answer, by the way.

That's the most American answer.

Here.

The truth is we don't care, but we want our theories to work.

We want our theories to make predictions that match with observations.

That's the only thing that matters to us.

The actual answer that comes out, whether it's 10 billion or 50 billion people.

Or 42.

Like you're saying, it just doesn't matter.

But we need to have a consistent description so that we have evidence that we know what we're doing because evidence matters.

And both sides could not be right.

Right.

And so when the Hubble telescope was launched, Okay, I'm just getting out of graduate school.

It is launched.

The number one goal set for that telescope was to resolve that discrepancy.

The telescope's named after the guy who gave us the Hubble constant in the first place.

Within two or three years, we nailed it.

And the Hubble constant, its value would give us an age of the universe at about 14 billion years, which is comfortably between those two extremes.

And that's science working at its best.

It was, there's a limit to how much we can keep beating each other over the head.

Let's get more data.

Let's build a telescope that'll solve this.

And in fact, today, there is a similar argument happening.

It's not between 20 billion and 10 billion, which as you say is a factor of two or 100% difference.

Now we're down to the 5% difference.

We understand things that well that we have two groups that are 5% apart describing a number of years,

billions of years into the past, and that's the precision with which we can do it.

Within 5%,

they'll kill each other.

So again, we don't care the exact number.

We care that we can describe it with that level of precision when we're talking about events that happened billions of years ago.

That's the mind-bending.

And here's the issue.

When it was 10 and 20 billion, you always have to report your uncertainties for a number in science.

And those uncertainties had a little bit of overlap.

in the middle and it landed where you expected it to land.

Now that we have two other warring factions on the value of the Hubble constant, those two numbers are within 5% of each other, but the uncertainties are tight.

So the uncertainties don't overlap.

And if you look at, go Google search on Hubble tension, and that's what will come up.

Adam Reese is coming to Pioneerworks in October.

I just planted an ad.

Adam Reese, who's a Nobel Prize, one of the Nobel Prize winners who discovered that the universe is not just expanding, the expansion is getting ever faster, it's accelerating, who is part of this Hubble tension debate?

We'll be speaking at Pioneer X on the Hubble Tension.

I dropped a commercial.

Without waxing philosophical, I just don't want to miss this point that we're not actually saying, which is what makes science so incredibly great is exactly what you all just demonstrated.

It is this pursuit of the truth based upon the best available information at the time.

So it's okay if it's wrong.

Because when it's right, we're going to get there.

Yes.

You got it.

All right, so

we're turning the clock back

and

we get to the Big Bang.

And,

but now the universe, large-scale universe described by general relativity, is now small.

It is so small,

the equations go back, the universe is the size of an atom.

Does quantum physics apply to the entire universe or only to atoms?

Where are you on that, both of you?

Well, at this point, we feel we have to invoke quantum mechanics to understand what was happening in the Big Bang.

The energy scales are so dramatic

that we're really probing quantum physics.

High energies, you're really looking somewhat surprisingly at small scales.

So

we are still trying to grapple with what the Big Bang is telling us about the potential to understand not just general relativity, but a kind of quantum variant of that, if there is such a thing.

Yeah, so I got general relativity and I got quantum physics.

Do they make nice in the sandbox?

It's a deep.

and difficult question and one that I and many others have spent their lives trying to answer and we do not fully have the answer yet.

Let me restate that.

Yeah.

That you and others have spent your lives failing to answer.

Yes.

Okay.

I agree.

That's a question.

But I think

that's okay.

Did you hear that?

Ah, take that.

Okay, you got a fan over here.

All right, go.

No, it's exactly the case.

So when you take Einstein's equations of the general theory of relativity and you try to invoke quantum mechanics within the same calculations, which as you eloquently noted, you'd have to do.

If you're talking about the whole universe when it's incredibly small, you need Einstein's general theory of relativity.

It's the whole universe, after all.

But you also need quantum physics because it is so small, and that's the theory that describes the small things.

And when you try to simply put the equations together, you get one answer out from almost any calculation, which is infinity.

And that might sound, oh, that's interesting, a big, deep, mystical number.

No, it's nonsense.

Infinity is nature's way of grabbing us by the lapel and slapping us around and saying, you're doing something wrong.

You've got to figure this out.

So I've heard another one that's

affinity is where God divides by zero.

Yes.

Stephen Hawking.

Yes.

Yeah.

Oh, Stephen Hawking said that.

Well, at least that's what he's attributed to me.

Okay.

Okay.

So, but

you say they don't make nice in the sandbox.

Yeah.

So there's a limit.

What's this Plank length?

What's going on there?

Well,

the Planck length is the scale at which.

Right, named after who?

After Max Planck, the

I love how you say Max.

I don't know.

What do you think of Max Planck?

I say Max Planck.

I don't think.

Max Planck.

Well,

a hundred years ago in the early discoveries of quantum mechanics was

thinking about whether the universe was discrete or if it really was a continuum.

And if I looked, for instance, at the air in this room, if I look closer and closer, do I find out it's actually made of individual molecules moving around and it's not actually a continuum and same with water and

was thinking about these things so in other words water is not infinitely divisible you get to a molecule at some point eventually you get to an individual quanta a little particulate a discrete bundle

and in thinking about this there was sort of a fundamental scale that that we would say is when we can definitely no longer think in a way where we're ignoring this quantum scale, where we're forced, as Brian's describing, beyond that, we're definitely going to strike an infinity.

But by the Planck length, we're in trouble.

We really should be

trying to understand the theory of gravity at a quantum level.

Maybe that means that space-time is coming in little individual bundles.

I don't even know how to think about that.

I'm just thinking about correlations between little tiny.

Space-time is coming?

Yeah,

that was a wild sentence.

That was very Game of Thrones.

Space-time is coming.

Well, I mean, if it came from the Big Bang, I mean, was it the moment that space and time was, in fact, created?

And are we thinking about things of a continuum of space-time itself?

Brian, how big is that smallest unit?

The Planck knife is 10 to the minus 33 centimeters.

And again, I know the question will be, well, you know, how do you think about something that's so small?

What does it matter?

It's 10 to the minus 33 or 10 to the minus 31.

And again, I don't care about the exact value, but that's where the mathematics takes us.

And just to get a feel for that, if you were to take an atom and

take a tree.

Take a tree and expand it to be the size of the observable universe.

A tree.

Yes.

Then the Planck scale, that 10 to the minus 33 centimeters, would expand roughly to the size of an atom.

So the Planck scale is to an atom as a tree is to the universe.

That's how tiny the distance we're talking about here.

And why?

I'm going to channel.

And so you measured this.

You measure this with a ruler.

What do you mean?

I know.

I'm going to channel himself.

Can I channel you right now?

You can channel me.

I'm not going to even pretend like I understand what's happening.

I'm going to be 100% honest.

There's like 3,500 people here, and I'm like, don't act like you know.

No.

I'm going to channel.

You lost me at space-time is coming.

And by the way, you came in quite hot, Brian, and you're like, I know what you're thinking.

And that's not what I was thinking.

I was thinking, I think it's really incredible.

Let's just have a quick little tangent here.

I think it's really incredible.

It is almost 9 p.m.

And this many people went on ticketmaster.com,

paid fees, you way back there,

up there.

Yes.

Way up there.

Yeah.

You guys paid tickets to learn about space nebula.

It was very heartening.

So that's what I was thinking about, Brian.

It's actually like, you know, when people say this country's going to shit and math and science is at an all-time low, I'm like, you know what?

It's the math and science lovers.

I've got a speaking theater.

On a.

You know.

Of all things, you could be doing at 9 p.m.

Just.

So, so I'm channeling.

Hustan here.

Sure.

Why do you have any confidence at all that you know what's happening on a scale that small?

We don't.

We don't.

Oh, okay.

That's the end.

That's the end.

Oh, Chuck, come back.

You guys.

We don't know anything.

We're going to be off by a whole lot.

Good night.

Take care.

Thank you, beacon.

So

let me see if I can unpack this.

Yeah.

We're going to figure it out right now.

Okay.

Sure.

Is it true that every prediction we've ever made with quantum physics, when we've been able to test it, has come true?

Absolutely.

Okay.

Is it true that general relativity, we already know what its boundaries are because they're calculations you cannot make because of this infinity problem?

Absolutely.

Therefore, if one of those is going to succumb to the other, it sounds like Einstein has to

bow down to the quantum.

He's going to have to

bend the knee to the quantum.

He's going to bend the knee to the quantum.

So either quantum will absorb Einstein, or there's a higher level understanding that'll absorb them both.

I would say that's true.

But also, quantum isn't in competition.

We have theories of matter for instance nuclear forces that we understand they can be quantized right theory of electromagnetism can be quantized.

So there are laws of physics and quantum mechanics is a regime in which we're understanding the highest energy attributes of those laws of physics.

Now gravity

Einstein's general relativity has replaced the theory of gravity with this theory of space-time, this theory of geometry.

Replaces Newton's theory, right?

Replaces Newton's theory of gravity, but it is one of those forces.

It should sit with the matter forces and have a classical regime, meaning a regime in which we don't have to worry about quantum mechanics, things look smooth, we understand general relativity works beautifully.

The regime sounds very political.

It does.

It does.

Dictator.

Totally does.

Dictator.

It sounds very, very USSR.

It sounds very

good.

But then when we go to the early universe, like the Big Bang or in the cores of black holes, where things start to get very extreme, we want to be able to quantize

that law of gravity.

As we have quantized other systems, it's not going to replace gravity.

Exactly.

It's not going to replace gravity.

We want to quantize gravity.

And that seemed like a perfectly reasonable request.

Okay, so Einstein's equations are not quantized.

They require a continuum.

So how do you quantize gravity?

Good.

So Jana's describing the history is very insightful and useful.

So we had an equation for electricity and magnetism that came from Maxwell.

We were able to blend that with quantum mechanics, giving us quantum electrodynamics.

It works.

We had equations describing the strong and weak nuclear forces.

We were able to embed quantum mechanics into those theories.

Works wonderfully well.

When we try to play exactly the same game with Einstein's theory of gravity, general relativity, and try to put quantum mechanics in there to quantize it, it just doesn't work.

So what does that mean?

It means you're not smart enough to...

Well, it's an interesting thing.

It could be that we're not smart enough.

And I'm full well willing to take that as the ultimate answer.

But there's a lot of evidence, if you allow me to come right up till today for just a moment.

I know you wanted to go to the next one.

This is the centennial, but go on.

Yeah, so there is evidence today that Einstein's general relativity, the reason why you can't quantize it, The reason why you can't put quantum mechanics into it, it already seems to have quantum mechanics embedded in a deep and subtle way that Einstein himself didn't recognize.

Oh, please do tell my, because my edible just kicked in and this is fascinating.

I mean what you're saying right now is revolutionary because what you're saying is you can't put something into something.

That's it.

We just don't know where it is inside of that thing.

But once we find it in there, we're going to be like, yo, that's where it is.

And be like, I told you not to put it in there.

It was already in there.

Okay, Chuck.

I'm amazing.

Chuck just blew a gasket.

We gotta.

No, that is like, that's like, that's simple.

It's elegant.

It's profound.

It's amazing.

I agree.

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All right, so let me let's back up back to the Roaring 20s.

And I just want to go down the list of completely freaky things that quantum physics prescribed that defied anybody's common sense and which is why it's still freaky.

In fact, what's that quote from, was it Feynman about quantum physics?

What did he say?

Yeah, there are a few, but if you think about quantum mechanics without getting dizzy, you haven't understood a single thing about it.

Oh, and I understand it very well.

Okay,

so 1923,

the wave-particle duality is proposed.

Yeah.

So that's kind of freaky.

That particles are also waves.

Yeah, it was Prince Louis De Bruis who basically.

He was a prince.

He was a prince, yeah.

And so he said, look, in 1905, Einstein showed us that light, which we had thought of as a wave, actually needs to be described as a particle, so-called photoelectric effect.

That's how we went to the phone.

1905, 1905.

1905.

And then in 1923, in his Ph.D.

thesis, Louis Du Broy says, let me do the reverse.

Electrons, we always think about them as particles.

Maybe they need to be thought of as waves.

Wow.

And that is a key moment in the world.

Wasn't his Ph.D.,

that was a prince who did that?

A prince.

A prince?

I don't believe it.

I know current monarchy.

Not that intelligent.

Let's be honest.

Harry or William,

you're not cooking this up.

There's too much incest.

I mean, you know this, you understand science for you to be operating at that level.

So not buying it.

You cheated off someone's paper, not buying it.

So his PhD thesis, if I remember correctly, was like 12 pages long or something.

Very short.

Very short.

Yeah.

And he got a Nobel Prize for a 12-year-old.

So he got a Nobel Page Prize.

And he got a Nobel Prize for a 12-page PhD.

A PhD paper.

Yeah.

Okay, let me just say, that's the smartest dude ever.

Well, that's how you know he was royalty.

He turned in a 12-page PhD.

12-page paper and he took it.

They're like, Dr.

Prince.

And he's no, thank you.

Double-spaced 12-page PhD paper.

With tighter margins.

You entitled pieces of shit.

A couple of years later.

Neil, you just...

I'm sorry, Neil.

I

shouldn't have spoken ill of the monarchs there.

No, no, that's this.

I got nothing.

This is America.

We fought a war to get away from monarchs.

Not for long.

Just give it time.

Okay.

So

then Schrodinger came around.

Oh, we have a Schrodinger fan up there.

That was the cat.

That was the cat.

That was the cat.

Cat.

So, what does Schrodinger do for us?

Well, Schrodinger begins to think more abstractly about what's real and what's not real.

So, we're used to thinking of particles.

You've already described de Broglie and the electron.

We think of these little fundamental particles almost like billiard balls acting out their lives, and they have some concrete existence.

Schrodinger starts to say, well, this wave-particle duality, that's pretty profound, but maybe the only thing that's real is this thing called the the wave function, which is the probability for the particle to be in a certain state, to be in a certain location, to be moving with a certain speed.

But the particle itself, in some sense, isn't real anymore.

If you look for it, sometimes you'll find it in a concrete location.

But what is really determined by equations, by the laws of physics, is the wave function, which is this probabilistic description.

And the wave function occupies physical space, doesn't it?

Yeah, the wave function occupies physical space.

Only for a single particle.

So it's a kind of important subtlety.

For one particle, you can think about this wave function as filling space.

If there are two particles, it lives in six-dimensional space.

If there are three particles, it's in nine-dimensional space.

So you really can't think of it in these ordinary terms.

Oh, I am high.

Okay.

So

if the particle can be anywhere here and I have some barrier here,

it could show up on the other side of the barrier.

Right, but it doesn't actually travel through.

So, let's say your barrier is a concrete wall.

There's some small probability that you would find the particle.

The wave function would describe the probability of finding the particle in this region of space, but it doesn't actually, like a billiard ball, travel through the cement wall.

Okay,

this might be the THC talking, but the way you guys are talking,

there just might just be one particle.

Like, there aren't a bunch of particles.

It's just one particle.

I told you he blew a gasket.

Well,

but Richard Feynman had the idea that maybe there was one particle that circled around through time and cycled back over and over again, giving what appear to be many particles now, but there's only a single particle through this temporal cycle.

So you're right on target.

Moving forward and backwards through time.

Oh my God.

Okay, give me.

All

show up on the other side of the barrier, then that you guys came up with a word for that, and it's tunneling.

Quantum tunneling.

It can quantum tunnel through the barrier,

but that's the point of shortage.

You're saying what's real is just this probabilistic likelihood of finding the particle.

The particle itself, in some sense, does not have concrete existence anymore.

It challenges the whole nature of reality.

No, but concretely, there is a probability that we could calculate for the likelihood of you tunneling through the stage and being underneath the floor.

And it's a non-zero probability.

It's kind of small, so it's unlikely to happen, but that's what quantum mechanics tells us.

But the smaller I get, the more likely it will happen.

Exactly.

It can happen in the laboratory.

Yeah, okay.

So just for context here.

Wow.

We were trying to understand how the sun made energy.

And we did the calculation.

Once we determined the sun is mostly hydrogen and it's hottest in the center.

We said it must be undergoing fusion.

And so, but you run the math, to undergo fusion, a proton, the nucleus of a hydrogen atom, has to merge with another proton, the nucleus of another hydrogen atom.

Protons have the same charge.

And electrostatically, like charges, repel.

So they have to be moving fast enough

so that before they have a chance to repel, they stick together and form a new nucleus.

Okay.

We calculated what temperature that was necessary, because high temperatures give you higher speeds.

We calculated that temperature, and it was 100 million degrees, and there was no way the center of the Sun was going to give us 100 million degrees, because you can calculate through sensible laws of thermodynamics what that should be, and we were scratching our heads.

And then quantum physics comes around, and then you invent this spooky, magical thing called tunneling.

And we discover in our calculations that that at a mere 10 million degrees see these this matters 10 million hundred million

at a mere 10 million degrees they would otherwise not hit but some of them tunnel through and connect tunneling makes the sun's energy production even possible

and I was like

Because it's not just something that particle physicists worry about in their laboratory.

I have to worry about it as an astrophysicist.

Why are you worried about this?

It's okay.

Okay.

Thank you.

Thank you.

The sun's going to sun.

Neil Robbins.

Let them.

Let the sun.

Let the sun do that.

Thank you.

It's okay.

Okay.

Thank you, Neil.

Don't blow it.

Take out.

That's very

clear.

Okay, so tunneling.

There's a lot of tunneling.

So now what about the Heisenberg uncertainty principle?

That seems like the biggest thing of them all.

Talk me through that real fast.

Yeah, I would say, so That's the real moment when the old ways of looking at the world are shown they have to be jettisoned.

Because the old way of looking at the world, what is reality?

Reality is stuff that's at a location moving with a certain speed.

That's the way we describe the world.

And Heisenberg with the armature of quantum mechanics says you can't actually do that.

You can't specify the location and the speed simultaneously of any object.

You can't do it according to the quantum equation.

So the very language of reality that we used to use.

No longer applies.

Why can't you measure both at the same time?

Well, if you have a particle described as a wave, right, and you want that particle to have a definite location, that wave has to be highly spiked so that you can say, ah, almost 100% likelihood it's at this location.

But when you see how the notion of velocity comes into quantum mechanics, it has to do with the wavelength of the wave.

And so if you want something to have a definite speed, it has to have a definite wavelength.

That's not spiky.

So to have definite location, you need spike.

To have definite speed, you need wave.

Those are different shapes.

And you can't have them at the same time.

You can't have them at the same time.

Can I try an analogy nowhere near as precise as what Brian just said, but sometimes I like this musical analogy.

If you play a chord,

which is a whole bunch of notes together, you can play chords, but you can't simultaneously be playing a single note.

So the chord is like a superposition of the notes.

And how this relates is that when you're in a precise location, what Brian's describing as a sharp spike, you're sort of in a superposition of velocities or momenta.

So

it's like the location is the note,

the velocities are the chords, or vice versa.

If I know the velocity exactly and I'm playing chords, I'm no longer playing individual.

I can't isolate a single individual note.

I'm in a superposition of notes.

So how does all this connect to the, what they call the observer effect, where you, I want to measure the particle right there, I got to look at it, so I shine light on it, and the light sends it somewhere else.

Yeah.

So I can't actually ever know what the particle is doing.

Right.

And so there's two things in there.

One is, as you're saying, to look is to interact.

And when you interact, say by bouncing a photon off a particle, you affect the particle.

Because I need the photon to take the picture.

That's right.

So that's one key point that emerges from these ideas.

But the other point.

So we can never know anything.

No, no.

No, no, this is.

We don't hide on that.

Don't hype on that.

That's the crazy thing.

Y'all went on this crazy.

Hello, please.

I'm sorry.

I'm sorry.

I got it.

I got it.

That is just not right.

Okay.

Quantum mechanics tells us that the things that you thought you could know are not the things that you can know.

But with quantum mechanics, we've made predictions of the anomalous magnetic moment of the electron to 14 decimal places using a theoretical calculation, and we've measured it, and it agrees decimal by decimal by decimal on all of those numbers.

And that's why we love these numbers.

They show us that we understand what we're doing.

Okay, Brian just blew a gasket.

So you can know without knowing, is what you're saying.

We can know.

Let me just say this, Brian.

The type of energy you're bringing.

All right, right, right.

Oh, man, you are built for CNN.

This type of panel smoke.

Oh, fantastic.

Yeah.

All right.

So this should so be in one of those Street Fighter squares.

The decimal to the decimal to the.

Yeah.

Oh, it's great.

This is great.

This is good stuff.

This is good television.

So, so.

Go ahead, Neil.

So this observer effect

has been widely misapplied by people thinking my consciousness is affecting the measurement.

Look, there is a big mystery at the heart of quantum mechanics.

Even with our capacity to make calculations that agree with observations to the level of precision that I just emphasized, perhaps with unnecessary theatricality,

there is a question that we don't know how to answer, which is what you're asking.

When you observe, you seem to be able to coax one result, one answer, even though the quantum description embodies many possibilities.

We don't understand how that happens.

Is this the many world hypothesis?

That's one answer.

But the Schrodinger equation is so beautiful, and it does not actually include in it a way to understand how measurements are made.

Yes, that's the key point.

And so if you really take the Schrodinger equation very seriously, it simply says there are all of these possibilities and they're all heavy.

But we don't have a theory of measurement.

to get us through

where we are in the physics.

Just, you know, there are proposals.

People have put down down mathematical equations that do answer this question.

What is the many-worlds hypothesis?

The many-worlds hypothesis is: if you have a description of a quantum system like a particle, and the quantum wave says 30% chance here, 20% chance here, 50% chance over here, when you measure it, you don't get only one result.

There's one of you that finds it over here.

There's another one of you that finds it over here.

And there's a third one of you that finds it over here.

But these are all in different universes.

Oh, it's recognized.

So you just invented multiple universes to explain something you can't otherwise explain.

The math invented it.

Thank you, Chuck.

Wait, wait, wait.

That's really important.

So this guy named Hugh Everett, 1957 in Princeton, he studies the math, the very equation that Janet made reference to, the Schrödinger equation.

He says to himself, let me take the math completely seriously and see where it takes me.

And the math takes you, when you look at the paper, it's direct to this possibility of there being multiple universes.

It's not made up.

It really emerges directly from an analysis of the equations.

And the equations make predictions that are confirmed.

So you say, maybe I should take this math fully seriously, and that's where it takes you.

So

the passion with which Brian is describing this is like me explaining why I have glitter on my face when I come home because I was at an arts and crafts fair.

All right, we're going to have to land this plane soon.

Just briefly,

I know you spent your career doing this, but just in 30 seconds, explain string theory.

Oh, my God.

20 seconds.

Does life have meaning?

Go!

I only need 10.

No.

Look, the old picture was that the fundamental constituents of matter were little dot-like particles.

The string idea is that maybe they're little extended filaments.

And why do we introduce this idea?

When you introduce this idea, quantum mechanics and general relativity do play well in the sandbox.

Wow.

Okay.

And that was less than 30 seconds.

Whoa.

All right.

Okay.

So what's in the future?

So I know astrophysically, we don't know anything about dark matter.

We don't know anything about dark energy.

We shouldn't even name them because we don't know enough about them to even name them.

And they should be called invisible.

You should be called Fred and Wilma.

With no bias.

So or faster than the light.

Time travel, time travel, faster than the light travel, before the Big Bang.

Is what you're working on or your peeps, does it address any of this?

Will quantum mechanics take us to all the places we need?

Yeah, I mean, there's zero evidence that quantum mechanics has any cracks whatsoever.

It's the only theory that we've written down in the history of the world.

It's the most successful theory.

The most successful theory.

Ever.

And so we intend to...

Which gives you confidence to believe crazy stuff that it predicts.

Exactly.

And so we're pressing on.

And ultimately, we think putting general relativity and quantum mechanics either because they're already born together or because they're blended together will be the key to answering these questions.

We're not there yet, but that's exactly where we're headed.

And why do you need these extra dimensions?

Well, Brian was describing string theory, which may or may not be true, but string theory actually requires extra dimensions for it to make sense, for the mathematics to allow gravity and matter and quantum mechanics to play nice together.

But even without string theory, the idea that there are extra spatial dimensions is just kind of a natural extension when you start to think about space and time.

And you start to take seriously Einstein's ideas.

So now we're in the predicament where maybe those extra dimensions are harboring the dark energy.

Maybe there's some explanation for the dark matter having to do with the extra dimensions.

So now we can start to think of the extra dimensions as a dark sector that are harboring really the resolutions.

Like we're observing them already.

We just don't have the direct connection to be certain.

So they're invisible in plain sight.

Is that what you're saying?

Yeah, I mean, they're not literally visible, but maybe dark energy is a consequence of quantum energies, which is what paper Brian and I wrote many years ago.

Dark

dark energy, which is driving the universe to expand ever faster, which is something we observe.

It is also driving my administration.

I've got to land this plane,

go on, go on.

Oh, well, just that we might be observing through something like dark energy indirect evidence of extra dimensions.

We can't literally see into them, we can't point to them, we can't move around in them yet, but we are living with the consequences of the data.

So, these could be manifestations of these higher-order phenomena in the universe.

Which is part of the motivation for thinking about them.

Perfect sense.

Thank you, Chuck.

Just wanted to put a button on that.

Quote from Einstein in his denial of quantum physics, in spite of him contributing so mightily to the field.

You described the probabilistic nature, especially from Schrodinger's equation, and Einstein said, God does not play dice with the universe.

And Niels Bohr retorted, Einstein stopped telling God what to do.

You know, you don't know if God needs to make some money real quick.

You don't know that.

With the dice?

Yeah, you know, I can see him down.

Papa needs a new universe.

I like how back in the day scientists threw shit at each other very poetically.

The way they kind of shit posted was very, the use of

good vocabulary to work with.

Great, vivid language.

They still do it the same today.

The way I'm going to land this plane is offer you a cosmic perspective, something that I'm prone to do when we are exposed to this much information.

When I think of the 1920s,

as a scientist, it may be the most consequential decade ever in the history of science, based on how it influenced our thought,

the trajectory of our research.

that would follow.

But I want to make a slightly different point.

Before the 1920s,

what are scientists doing?

Well, they're doing science-y things, right?

In a lab, there's a chemical or there's a particular, there's a material or a- Erlenmeyer flask.

Yeah, flask, thank you.

Yes, you flesh out the picture of your lab.

Okay.

Suppose it was the 1920s and you had a friend, relative,

or you were a politician and you heard that someone is working on the structure of atoms and molecules.

You'll say, why does that matter to anyone?

I'm a carpenter.

I just care that my wood atoms cut or that they can be shined or polished or painted.

Why does that matter to me?

I'm making cars in an assembly line.

Why does it matter to anybody?

You're taking your brilliant intellect and applying it to something that nobody cares about except your cadre

of people.

But they will tell you, well, it's the foundations of matter.

And they'll tell you, I don't care.

You're using up

national resources to do this.

Well.

What has happened

every time

we research the frontier of science

in basically every frontier of science,

whatever it looks like when you're doing it, it's easy to say that'll never apply to anything.

I don't know.

Why are you doing that?

You wait a little while, they're clever engineers, clever other scientists, they see problems in the world and they see a possible solution.

Do you realize today

there is no creation, storage, and retrieval

of digital information without an exploitation of the quantum.

The IT revolution that is responsible for nearly half the GDP of the world at some level

was birthed in that decade at a time when people are just exploring the edge of our understanding of the world.

Yeah, it would take 50 years longer than what is typical for an R ⁇ D project to show up as a household product.

But all I can tell you is if you know anyone who says, we're doing too much science, or this science is not relevant to me, or I don't know why you're doing this, that doesn't sound like it makes sense.

What you're doing is you're cutting out at the kneecaps.

the legs of a future waves of discovery that could transform civilization.

Not only take us to where we might want to go, but possibly solve problems that we might have created for ourselves.

So

there is nothing more short-sighted in this world than anybody running up and saying we should do less science.

Because every one of us in this room has been touched by it.

And there's no greater greater demonstration of that than the science that unfolded in that decade, the 1920s.

That's the quantum side of it.

In the astrophysics side, that births our understanding of the beginning of the universe and how the sun makes us energy.

We would then learn how the stars manufacture elements in their core.

We would learn, take a few more decades, exploiting the quantum, applying to other realms of science.

We would would learn

that the very ingredients of our bodies,

the carbon, the oxygen, the nitrogen, the iron, are traceable to stars that underwent thermonuclear fusion following all the rules of quantum physics.

And those stars exploded, scattered that enrichment across the galaxy.

creating the environment, the chemical ingredients to make star systems with planets, and on some of those planets,

life.

So that that era

not only gave us our IT revolution, it gave us an awareness of ourselves that borders on the spiritual.

And it's the fact that not only are we alive in this universe,

because of our ingredients are traceable to stars, the universe is alive within us.

And that is a cosmic perspective.

This has been Dark Talk

live from the Beekman Theater.

This is like our fifth time at the Beacon Theater, fifth or sixth time, and you guys have been a marvelous audience for us.

We love you all.

And.

Oh, no, thank you.

And I, but more than loving you all, we love the support you give for science because there is no future of civilization without it.

We might as well just move back to the cave.

So, as always, Neil deGrasse Tyson here, thanking our panel.

We've got Chuck Nice,

Brian Green.

Chan 11.

Hassan Minaj.

Neil deGrasse Tyson.

You're a personal astrophysicist as always bidding you to

keep looking.

Eight of you knew this, okay?

I'm going to do it one more time.

Come on.

All right, here we go.

What's the tagline?

Let me just do it.

Okay.

Neil Neil deGrasse Tyson, your personal astrophysicist.

Bidding you too?

Keep looking up.

Keep looking up.

Here we go.

Remember it's, he's going to go, he has a da-da-da-da.

And remember, those eight people, they cared.

You guys all paid money, recipe, currency, a real number that we know, Brian.

We know exactly how much you paid to those sharks at Ticketmaster.

F them.

Now,

he's going to go, Neil de Gras has it,

keep.

And you go, looking up.

Here we go.

Neil deGrasse Tyson, your personal astrophysicist, astrophysicist, bidding you all to keep

up.

All right.

Yes.