Kip Thorne: Black Holes, Aliens, Wormholes & Gravitational Waves [INTERVIEW]

that if wormholes can be made, they have

to be made artificially by a very

advanced civilization. We are studying,

we're observing highly disturbed black

holes that are oscillating like that.

>> Kip Thorne is the theoretical physicist,

Nobel laurate for the first detection of

gravitational waves, a pioneer of black

hole and wormhole theory, and the

scientific mind who guided the

Oscar-winning film Interstellar.

>> The astronaut would see just blackness

in the sky overhead. You would see

basically a ring inside which you have

the universe above, outside of which you

have blackness. The astronaut would get

squashed by that gravitational pull.

>> Few rivalries in science captured the

public imagination like the legendary

bets between Kip Thorne and Steven

Hawking.

>> Steven and I had a bet of whether that

really was a black hole. He bet it was

not. In the end, I won the bet. It won

all of my bets with Hawking. In 2017,

Kip Thorne won the Nobel Prize in

physics for his pivotal role in

detecting gravitational waves with LIGO.

>> I looked at it and I thought these this

is too good a signal to be true. Similar

to Galileo was the beginning of

gravitational wave astronomy.

>> He served as executive producer and

science adviser on the Oscar-winning

film Interstellar.

>> And I initiated this movie Interstellar.

We got Chris to join as the director. I

told him you you have to abandon the

laws of physics because it's just too

boring. The physics is there, but I

would bet 1% maximum of the audience

even notices that.

[Music]

>> Mr. Professor, it's a great honor having

you here. Uh before we start there on

the shelf is a it stand proof of

something special probably this is the

proof of your bed with Stephen Hawking

>> uh on my shelf I

>> I will read it.

>> Yeah. Whereas Keip torn likes to leave

dangerously and believes that the evil

aliens will be able to reach air and

invite it by means of the intergalactic

Einstein rose bridge. And whereas Steven

Hing believes that Keip is crazy and

that no evil aliens will be able to use

a wormhole to travel to Earth. If Turn

wins, Hoking will award him a unique

trophy. If Hoking wins, Tor will award

him a t-shirt that say I'm an idiot.

What was the result of that bet?

>> That bet was a hoax. One of my students

created that bet. It was never s any

such bet between me and Stephen Hawking.

It was to a total hoax created by one of

my students. Has no reality. I I think

Stephen has probably never seen it, but

I I don't know.

>> Do you remember any bets with Hulking?

>> Well, I had many bets with Hawking. I

won all of my bets with Hawking.

>> Which uh bets with Ho with Hulking stuck

in your mind the most?

>> Well, I think the fa most famous one was

the bet over whether Signis X1 was a

black hole. Signis X1 was way back in

the early 1970s.

Astronomers discovered X-rays coming

from star

which seemed to be in orbit around

something very dark. And uh it had been

already argued by Zeldovich and Novakov

in uh Russia that that would be a

possible way to discover black holes

that you would have gases pulled off of

the star onto the black hole and as it

flows onto the black hole it gets heated

up by friction and emits X-rays. this

was what was seen. And so

Stephen and I had a bet of whether that

really was a black hole or not. And uh

and he bet it was not

he said because that was an insurance

policy. If it was then obviously it

would be a great coup for him because he

really was the foremost person who had

worked on and developed the theory of

black holes. And so at least he would

have some consolation if uh it was uh if

it failed to be a black hole. In the

end, I won the bet. And uh

>> I I remember also your bet about

so-called naked black hole. What naked

black hole mean?

>> Naked singularity. Naked singularity.

>> Naked singularity. Right.

>> Yeah. So in general relativity there is

the possibility

of a region where space and time are so

greatly warped

that the laws of physics as we know them

fail. General relativity's laws fail due

to quantum effects and some new set of

physical laws control that region

and th those are believed to be the laws

of quantum gravity which are not yet

well understood.

But such a region is called a

singularity where the laws where the

curvature or the warping of space and

time is enormously large formally

mathematically infinitely large warping.

And a naked singularity is one that can

be seen from the outside. You would be

able to go in and look in and see what's

going on in the vicinity of that

singularity. There was a lot of evidence

and a speculation by Roger Penrose and a

lot of evidence that it was correct that

there are no naked singularities in the

universe. That bet I that was a bet just

with Stephen Hawking between Stephen

Hawking and me and I argued that

naked singularities

can be formed and he argued that they

cannot be formed. And uh in fact uh

there and I guess John Presco and I were

on the same side against talking on

this. And uh in fact it was uh

discovered through computer simulations

and then very formal mathematical proof

by Demetrius Christulu that uh that in

fact you can form naked singularities.

But it appears in order to do it you

have to very finely tune

the implosion that creates the

singularity. If you perturb it ever so

slightly then the singularity doesn't

form. In the real universe, there are

always perturbations.

So although a very advanced civilization

might be able to carefully tune

an implosion to make a naked singularity

in the real universe.

If you don't have an advanced

civilization

controlling it, then such singularities

wouldn't form. That's the bottom line as

we best understand it today. But anyway,

Hawking lost the bet because there was,

as I say, initially a a computer

simulation by Matthew Choptu

and then a formal mathematical proof by

Demetrius Christulu that yes, you can

make a naked singularity if you are a

very advanced civilization and you do it

just right.

Do you think that um you know um

gravitational waves or

cosmic micro background help us answer

the question if naked singularity really

exists?

>> I don't know. I doubt it. I doubt it.

But what I think the question that can

can be answered is the details of the

singularity and the birth of our

universe. That's a different kind of

singularity.

And uh there I expect that it is true

that gravitational waves produced in the

birth of the universe will carry

information about the birth of the

universe. That we one day will be able

to see the waves and extract that

information and learn thereby about the

singularity of the birth of the

universe. and learn about the

laws of quantum gravity that control the

birth of the universe. The thing that

makes it possible for this to happen is

that

we think that in the very early universe

the universe was uh expanded expans

exponentially rapidly exceedingly

rapidly and

the expanding space in those early

moments

was able to take whatever came off of

the big bang, whatever gravitational

waves came off of the big bang and

amplify them so they become strong

enough for us to see. They just just

they swallow energy from the expansion

of the universe. In 2017, you received a

Nobel Prize for observing gravitational

waves uh using LIGO. What LIGO is? LICO

is a

set of detectors we call them or

intererometers

uh that uh observe gravitational waves

coming in from the distant universe.

LIGO has created a new way of doing

astronomy.

We call it gravitational wave astronomy.

And the point is this that according to

the laws of physics there are only two

types of waves

that can be created in the distant

universe travel across the universe

bringing us information about what's

very far away. Electromagnetic waves

which includes light x-rays gamma rays

radio waves infrared and so forth. So

electromagnetic waves and gravitational

waves. It's the only other type of wave.

Gravitational wave is very different

from electromagnetic wave. It is

according to the laws of physics, it

travels at the same speed as the

electromagnetic waves, but instead of

pushing electric charges back and forth,

it stretches and squeezes everything

that it passes through. And so you see

the gravitational wave through this

stretching and squeezing. And we

understood this very well back in uh the

1960s

uh when Ray Weiss and I both started

thinking about gravitational waves and

their detection. Uh and uh it was an

issue of finding a design for a

gravitational wave detector that had a

real possibility of success.

uh Ry Weiss came up with that design uh

including a lot of details that uh

explained how to control the various

kinds of noise you would have to uh deal

with. came up with that design in 1972.

And then I joined together with him and

we and in the end

more than a thousand other physicists

joined in on this project and we worked

until from then until the 19 until 2015

and finally saw the gravitational waves

with this detector that he had invented.

Do you remember the moment when you

observe gravitational wave for the first

time?

>> I remember when I was informed of this.

the it was the the detectors in an

automated computer system that made the

first observation and it the automated

computer system uh collected the data

and organized them in a way that

uh we could see uh what the waves looked

like and we could directly see that this

was probably waves from a coll two black

holes colliding and I woke up that

morning there was an email from a young

colleague of mine saying, "Go look at a

certain internal website for our

project. We may have discovered

gravitational waves."

>> What did you do for

>> I looked at it and I thought these this

is too good a signal to be true that it

was probably injected as part of testing

the system. So I emailed my the young

friend back and said, "I think this is a

blind injection." They would they would

They would

move. They would apply electrical forces

to the mirrors in this logo detector

that move were moved by gravity waves,

but they would move them with electrical

forces and then look to see whether they

saw in the data analysis whether they

saw that motion. And uh so I said it's a

blind injection that the experimenters

put in. He said, "No, I'm on the

committee of three people who do client

injections." We didn't do it. And we

weren't doing it because we were not yet

in search mode. The team was tuning up

very advanced detectors

uh in preparation for starting a search.

But the search was still several days

away. It wasn't wasn't supposed to start

yet. The signal came in while the way

detectors were being tuned. So it wasn't

a blind injection. When he told me that,

I still was very cautious and I said,

"Well, let's wait until

the best experts on the team have

analyzed all of the auxiliary, the extra

noise channels where you can see all

kinds of noise and understand the noise.

Let's wait until we completely

understand the noise that was going on

at the time of the detection. Then I'll

believe it." how it changed our

understanding of the universe.

>> It uh was the opening up of this second

way of seeing of exploring the universe.

It was the beginning of uh was the

beginning of gravitational wave

astronomy. It was similar to Galileo

building a small optical telescope and

pointing at at Jupiter and saying

Jupiter's four largest moons and thereby

starting instrument-based

electromagnetic astronomy. It was

basically what similar to what Galileo

did. When you look at the huge changes

in our understanding of the universe

that followed from the technology that

Galileo was the first to use for

exploring the universe with telescopes,

uh you can appreciate that now that you

have this other way of observing rev the

universe

uh that sees aspects of the universe

that can never be seen with ordinary

telescope.

that that's going to have a huge impact

on our understanding of the universe

over the coming decades and centuries.

So how does it change things? It changed

it by suddenly making it possible for us

to begin the process of exploring the

universe in this new way.

>> Can this cosmic way reveal

what was before the big bang? It may be

that by observing the gravitational

waves from the big bang that that will

give us information about what came

before the big bang. I don't know. Uh we

have never until now had

a tool

a way to observe the big bang

because all other forms of radiation

they're all they're electromagnetic.

It's whether it's light or x-rays or

radio waves or gamma rays doesn't

matter. They cannot travel through the

very hot and very dense matter of the

early universe. So with electromagnetic

waves, you cannot see what was going on

in the universe earlier than when the

universe was about 200,000 years old.

And so that first 200,000 years we don't

have direct uh observations of

um you have get some indirect

information by looking at the uh

abundances of elements that were formed

in the early universe. Uh these are

relic fossils and so there are fossils

like this that can give us indirect

universe information but even that only

goes back to when the universe was about

a minute old. and not back earlier than

that. The only way to actually observe

back to the earliest seconds of the

universe and fractions of a second all

the way back is gravitational waves

because they're the only thing that

penetrates so so effectively through

that hot dense matter that it can uh

bring us the information from the birth

of the universe. So that's our big hope

for understanding the birth of our

universe and uh the birth of our

universe we do believe is controlled by

the laws of quantum gravity

which we do not understand well there's

some understanding

and myo but my hope is that uh when we

see the gravitational waves from the

birth of the universe they're called

primordial gravitational waves when we

see them they will have information that

helps us to understand the birth the

birth of the universe and the uh and the

laws of quantum gravity that controlled

the birth and perhaps then we will have

the tools to begin to understand what

came before the big bang.

>> In your opinion

was the big bang the true begging of of

everything?

>> I don't know.

I don't have

>> nobody knows but

you know uh what do you feel

>> I

so I have I am a very observationally

grounded theoretical physicist

I I don't have strong views on issues

that are uh far from our current ability

to uh to get the answers. Uh and so I

have no

>> I'm I'm open to the poss to to various

possibilities.

>> Maybe your gravitational waves let us

find a proof existence something before.

Well, they they they may turn out to be

the tool that breaks that breaks through

the breakthrough tool that enables us to

get the answers. But uh that is not we

don't yet have we have not yet seen

those primordial gravitational waves and

so I'm just waiting. Is any question

about the black hole that keep you awake

at night?

>> No, I don't get kept awake at night by

anything.

But uh the the question that is of

greatest interest to me is the question

we've talked about not about black holes

but the question about the birth of the

universe and the gravitational waves

from the birth of the universe.

>> If you could find just only one question

about the universe,

it would be the question about the

beginning of everything.

>> Yes, that's the most important one.

Hypothetically

when astronaut would stop exactly above

the horizon of even but didn't fall

inside her what would see

the

if the astronaut stops directly by the

horizon the astronaut

is feeling

a gravitational pull that is enormous

ously large, the astronaut would get

squashed by that gravitational pole. He

wouldn't survive very long. Now, if you

ask what the astronaut would see, the

astronaut would see just blackness below

below himself and the sky overhead.

I would see basically a ring uh inside

which you have the universe above and uh

outside of which you have blackness

which is the blackness of the black hole

below him.

>> Uh what astronaut would see if an

insider

toetically of course

>> uh you see the answer in the movie

Interstellar.

>> Yeah. uh Cooper in the movie

Interstellar near the end he goes inside

the black hole gargantua

and he says as he's crossing the horizon

he says I'm I'm crossing the event

horizon he says that and the camera then

points up and for just a very short time

a about one second or a fraction of a

second you see the sky overhead and the

entire universe is inside a circle and

it's all black around but he sees uh the

the whole external universe and the

light coming in from it inside a circle

above him.

>> Why did the ring in the black hole wrap

around it and glow in the interstellar

movie? Well, all all the glowing that

you see was uh from the uh light emitted

by the hot disc that is in orbit around

the black hole. We call it the accretion

disc. It's a gas that uh is been torn

off of a star that was torn apart as it

came close to the black hole. And that

disc forms a it the disc is rather like

the rings of Saturn.

But it glows brightly. It's at the in

the movie interstellar. It is at about

the same temperature as the sun is at.

And it's shining brightly like the sun

does. And uh then due to what's called

gravitational lens effect, the uh

bending of light rays in by the

gravitational pole of the black hole.

the uh the disc is distorted so that it

be looks so that when Cooper goes inside

the black hole it looks like a ring

above himself

and smaller

>> it'll get smaller and smaller but the

our external universe is inside the ring

when he's inside the black hole when

he's outside the black hole

the black hole appears to be in inside

the ring. Does the new data uh from

gravitational waves detector suggest you

what we should change in that black hole

vis vision

>> from interstellar you know

>> no what the new data from gravitational

wave detectors does is it is telling us

about how black holes behave when they

collide

and about the

the dynamical

warping of space and time. The storm, I

like to call it, the storm in the shape

of space, the storm in the rate of flow

of time that is produced when the black

holes collide. So, it's a very much more

interesting

behavior than you see in the movie

Interstellar. But Interstellar is

dealing with a quiescent black hole, a

black hole that is quiet. It's not

disturbed.

And so in with with our gravitational

wave detectors, we're we are studying

we're observing highly disturbed black

holes that are

that are oscillating like that and in

wild sorts of ways

it's much more interesting.

>> Yeah. My question is if do we know more

uh how you know black hole looked like

We know a lot about how black holes look

when they are disturbed.

>> Okay,

>> that's we know far more. But we know

that from the computer simulations

of black hole collisions

where the predictions are verified by

the gravitational wave observations.

So the gravitational wave observations

they see the waves that are produced by

these oscillations of the black black

holes as they collide. Uh but the

details of

the of the dynamical distortions the

details of these storms in the fabric of

space and time. We see the details in

uh pharma computer simulations and then

simply verify that those predicted

details are right by seeing the

gravitational waves.

Can we use modern physics,

gravitational waves to create receive

receipt? Sorry. Um, for a small little

black hole in the lab.

In order to produce gravitational waves

that are strong enough for us to see,

you have to have a mass that is very

big.

And now small black holes can't have

that kind of a mass. If if you had a

small black hole in the laboratory, it

would just fall in the earth's

gravitational field and go into the

earth and and if it was moving slowly

enough, it would just oscillate back and

forth through the interior of the earth.

It's not going to sit in the lab.

There's no way to hold it in the lab. uh

and its motions are slow enough that

it's not going to produce gravitational

waves in the frequency bands of our

gravity wave detectors. The probability

that there is any black hole of of that

size in in there is uh is extremely

small

>> but theoretically that was it could be

possible theoretically.

So, I've not thought about this in a

long time, but I think it's all I can

say is ex it's extremely unlikely, but

it's so many decades since I've thought

about this particular issue that I I

shouldn't comment beyond that. I leave

it to my younger colleagues who've been

thinking about it more recently. I

haven't thought about it in a long long

time. A few weeks ago, I talked to

Polish physicist Nicodon Papuvski about

his controversial

desis that black hole lead to another

universe.

Don't you think that such controversial

desis expose physics to the charge of

being unfalsifiable?

>> Uh,

no I don't. Um the uh

there are portions of the universe that

we cannot observe

uh with in our epic and uh with any

technology that we might have.

But we do know now enough about the laws

of physics.

Uh and we have the possibility for

better and better and better tests of

the laws of physics. And we have and we

have that and we have the ability

through computer simulations to come to

a firm understanding of what those laws

of physics predict.

uh and uh the and so we can get answers

as to what is predicted. If we chose to,

we could go inside a black hole and see

what happens to us. Of course, we can't

publish our results. We can't send them

back out.

But nevertheless,

the fact that uh in that in you it would

be possible for me to to learn what's

going on in there by going inside the

black hole. the fact that we are getting

such a good understanding of the laws of

physics that we can begin to make firm

predictions. I would call that ver

verifiability.

If if uh that's not verifiability then

then it's impossible to verify things.

Yes, I would agree. it. But uh I find

that very satisfying if we understand

the laws of physics well enough to make

a firm uh prediction and those laws of

physics as we understand them are

capable of explaining everything that we

observe that we do observe.

>> What is the white hole? A white hole is

a a conjectured

uh object that uh instead of being

formed by stuff that falls into it as a

black hole is, it is a place that begins

with a singularity, a naked singularity

that explodes and

matter comes out. So it's sort of like a

black hole. uh being born by a collapse

of a star with time reversed. So you

begin with a naked singularity and the

uh naked singularity spews matter out.

It can be thought of as a piece of the

big bang singularity at the beginning of

the universe that didn't go bang when it

was supposed to. It didn't go bang when

the rest of the universe went bang and

it remained as a singularity for some

time and only later exploded.

>> I think that the question is if the

white hole is a necessary partner of

black hole in the multiverse scenario.

We don't know. But what we do know is

that uh and this was proved by a

post-doal student of mine many years ago

that uh

we do know that

if you have a white hole

and you have matter in the universe in

the vicinity, it will fall onto the

white hole and convert the white hole

into a black hole. It will build a black

hole around the white hole. So if when

the white hole goes bang, the stuff it

spews out can't get into our universe

because there's a black hole horizon

around it. Doug Erdley was who's now a

professor at the University of

California, Santa Barbara, he proved

this in a very elegant and rather simple

mathematical way with Einstein's laws of

general relativity. If we can do

something

to study wormhole

today, if we can do something, if we

have any tools to uh to answer for some

questions about wormholes or that's only

the theoretical war,

>> it's theoretical work because we don't

have the technology to be able to try to

make them. We don't know whether they

can be made. We do know that our

technology is far far too puny to too

weak uh to be able to make them if they

can be made.

>> Today it is only fiction.

>> So it's well

I wouldn't call it only fiction.

It is it is something that is beyond our

technological capabilities. That doesn't

make it fiction. I mean traveling uh to

Alpha Centauri is beyond our

technical capabilities but I have no

doubt that Alpha Centauri is still

there.

Mystery of black matter. Do we know

more? Can we use also gravitational

waves to

get more information about the mystery?

probably one of the biggest in the

modern cosmology.

>> I don't know whether gravitational waves

will give us any information about it or

not. The this dark matter itself

well it doesn't matter what it it

whatever it is made from it is capable

of producing gravitational waves.

But uh and so there is some hope that

you may see gravitational waves from

objects made from dark matter and there

are various speculations about this

possibility.

uh but we do not have any uh I think any

uh reliable understanding of uh

>> black matter

>> of dark matter and of how it might

produce

how it produces gravitational waves if

my guess is it probably does not produce

gravitational waves that are strong

enough for us to see but that's just a

guess

>> maybe dark matter doesn't exist

>> well There is something exists that

is producing gravity and that that and

so

dark matter is a name we give to

whatever may be the source of whatever

is the source of the gravity we observe.

You see uh its effects through uh the uh

gravitational interactions of galaxies

and clusters of galaxies through the

motions of stars around

galaxies.

you see uh that there is something there

that is pulling gravitationally

that uh we don't see any light coming

from it and uh and so we call it dark

matter and uh and and our colleagues

search hard to try to figure out what it

is, try to see it. But uh uh it uh

it something surely exists there that is

producing this gravitational pull.

>> There is a lot of controversial

hypothesis

in the cosmology. I think today

is it the proof that

we are

living in the era of the biggest crisis

of the cosmology?

>> No.

>> Why?

>> We have so many questions

uh and not so many answers. I think

>> well I think we have gotten a lot of

answers. If you compare our

understanding of cosmology in 1930 with

what we have now, we have learned an

enormous amount about the universe. We

have learned about the existence of the

cosmic microwave background and it has

become an powerful tool for learning

about the early universe.

Uh we have observations

uh of

that and of the evolution of

very young galaxies and their growth

in the early parts of the universe which

tell us ever so much about how the

universe came to be as it is. Yes, we

have huge numbers of questions, but that

inevitably happens when you start to get

answers. That means that you're in a

domain where you then can ask more and

more questions. And so I I don't agree.

I don't think we're in a crisis. I think

we're in a very exciting phase where we

will find further answers to the new

questions that are opened up by the new

observations.

But I wouldn't call it a crisis. I I

know there are many people who do. Did

any

new physics effects appear during

interstellar production that nobody

expected?

>> Uh no, but uh what we did do is uh the

computer programs that were devised by

Oliver James at

Dne, the double negative visual effects

team. uh they became very powerful tools

for studying new physics. So the new

Visics didn't show up in the movies

in the movie Interstellar, but once the

these computer codes had been uh

conceived and and developed, they

enabled us to then see details of uh

this gravitational lensing, details of

formation of images, distortion of

images, uh merging of images, breaking

images apart, that occur around a black

hole. As a camera moves around the black

hole, you're you see really quite

startling kinds of behaviors of images.

And we got really some marvelous

simulations that show precisely how

light behaves and then were able to

verify

theory associated with that called the

theory of costics.

Uh is it true that uh working on

interstellar you set Christopher Nolan

to conditions no violations of the

physics law and any speculations should

be fully compliance with science. Uh I

proposed that is a that this should be

our the guiding rules and he agreed to

them as so long as that they did not get

in the way of making a good movie. And

uh so of course I was a little worried

that he would violate them in order to

make a good movie. He was worried that I

would play a role of a policeman telling

him what he could do and what he

couldn't do. But within a with after

about an hour or two of conversation, it

became clear that we were going to work

together very effectively and we would

it would not be difficult to reach

agreement on things. So there was did

come one point where I told him you you

have to abandon the laws of physics

in uh when you depict uh the trip

through a through the black through the

wormhole uh because it's just too

boring. And so and so we talked about in

what way would he abandon the strict

predictions? Uh and so that's the one

place in where uh I told him yes I I

propose that you abandon our guidelines.

Uh in all other cases we found ways to

make a great movie a very interesting

movie which stayed within those

guidelines. And probably you spent two

weeks trying to enforce him uh to throw

our idea faster than line fly.

>> Yeah. Yeah. Well, but we reached

agreement. No, the issue was I didn't

spend two weeks trying to enforce him.

He he had learned by then that I should

go do a real calculation to be

absolutely sure.

But in this particular case, I told him

I didn't have to do a real calculation.

And so, but He gave me a week. I think

it was one week but uh to uh think about

it uh further and then we had a further

discussion and so he he agreed that we

would not use faster than light travel.

Which wildf

idea could make it to the screen today

under our actual knowledge about the

reality uh about physics how the

universe works? Well, I think there are

a variety of things. There really a huge

number of amazing phenomena that we see

in the universe and uh

and

of course there are a lot of things that

do make it to the screen.

uh but uh I think uh issues in the birth

of the universe, issues in uh the uh

collisions of black holes which have not

made it to the Hollywood screen yet,

they almost certainly will.

>> Maybe you should do this.

>> Yeah, I have other things. Maybe 20

years from now after I finish the other

projects I'm working on.

>> By the way, why decided to cooperate

with Nolan? I I watched

well so

Linda Oops and I initiated this movie

Interstellar

and uh she uh uh brought Christopher

Nolan on board to do the to direct the

movie. So he decided to cooperate with

us uh on a movie that we had already

started. Um uh but uh he he was

the very best choice we could possibly

have had to do this movie with. He

brought so much of his own to the movie

that went well beyond what Lyndon and I

had conceived.

We we conceived the movie. Uh then

Stephen Spielberg oversaw it in the

early creative phase. the screen initial

screenwriting phase and she and

Linda and Stephen brought Christopher

Nolan's brother Jonathan Nolan on board

to write the screenplay and we went

through three drafts of the screenplay

with Jonathan Nolan and then Spielberg

dropped out and and uh we got Chris to

join in as the director and uh Chris was

just fabulous on this film.

Uh Spielberg said to us that we got the

right direction for this movie and we

really did. Stephen had done science

fiction movies before. His heart was not

in this movie the way that Nolan's heart

was in this movie. He he was not just

totally consumed by it the way Nolan

was. And no Nolan uh

just made a fabulous movie. I mean it's

I just in this last week there is New

York Times has uh uh done and ident

identified

the 10 best movies I've forgotten of how

over how many years and interstellar is

one of them

>> which simplification of the physics

>> you mean in in instellar yeah

>> yeah I I didn't worry about any

simplification of physics. Um the

the physics is all there but much of it

is hidden and you have to dig very deep

to see it.

So let me give you an example

to get in this film to get down to get

to Miller's planet which is the water

planet that is very close to the horizon

of the black hole gargantua

that is the

to get there the only way to get there

is to do gravitational slingshot

around a small black hole. Uh there's no

other way to slow down enough as you

approach the planet is the only way to

do is by gravity. In the movie, uh,

Stefan

Null and I discussed, well, how do we

dis how do we handle the slingshot

issue?

And, uh, we agreed that, uh, one way,

one thing is to get the idea of this

gravitational slingshot into the movie

very early on. And so you see a

gravitational slingshot is used to get

the uh Cooper and the Endurance

spacecraft to the vicinity of Jupiter

doing slingshot. I've forgotten. I think

it's around Mercury around Venus or

around Mars. I don't remember which one.

So the idea of the slingshot is in the

movie early on. And then when they get

to uh the vicinity of Gargantua,

the

Ramaly who's a physicist who's on this

trip along with Cooper Romy makes a

remark about we will do a we can do a

slingshot around that neutron star

in order to get to Miller's planet.

Now, in reality, you need to do a

slingshot around a black hole to get to

Miller's planet. The neutron star won't

quite do it, but Christopher Nolan

didn't want to confuse the audience by

having an extra black hole there at that

point because the black hole was just a

very new thing in the film at that

moment. And so, we agreed he would use a

slingshot around a neutron star. But in

there, there is the idea. Romy makes it

very clear, using a slingshot uh

basically to slow down uh as you near

the planet. Uh the physics is there, but

I would bet 1% maximum of the audience

even notices that.

But that's the character of of

Christopher Nolan's films. They're

filled with uh just a great richness of

ideas that have all been put there very

carefully so that if you go to see the

film five times, you some learn

something new still on the fifth time or

the sixth time or the seventh time.

>> Do you know how many days passed since

the premiere of Interstellar on Miller's

planet?

>> I know.

Till now

>> until now it's a little over one day.

>> One day and 31 minutes.

>> Okay. Yeah. Yeah.

>> Uh I have very interesting question to

you. Um the water planet Miller has big

tsunami waves.

>> Could the black holes gravity really

create such a high walls of water? So

it's not being created by the gravity of

the it's a very indirect process.

So the uh issue is that um

the

the planet is close enough to the to the

black hole gargantua and the black hole

gargantua has just the right mass to

deform the planet somewhat sort of. So

it's sort of like this.

>> It's not round.

>> And then the pull of the gravitational

the gravitational pull of of gargantua

on the planet

causes the planet to want to be face

the gargantua.

It's elongated

pointing toward gargantua.

But uh in terms of planetary time, it's

not been very long. Maybe only a few

months since uh the planet

got into the vicinity of our gargantua.

So it's not yet pointing directly there.

It's swinging back and forth and slowly

slowing down. So it's like a pendulum

swinging and the swing of the pendulum

dies out due to friction.

The planet is swinging back and forth

like this under the gravitational pull

of Gargantua. And as it swings, the

water sloshes on the planet and it forms

these waves.

>> It's amazing that you remember any

single detiles of of the production.

Well, the well these details are

fundamental physics and it's the

fundamental physics that underlies the

movie and this was all done very

carefully so that the numbers all work

out. The other thing that about this is

that the swinging period which you can

calculate that you choose the mass of

gargantua such that that the planet is

mildly deformed

but then the swinging period turns out

to be about an hour and that's the

interval between the waves on the

planet. You see two waves and they're

separated by about one hour. uh in the

in the in the plot of interstellar I I

think the time difference it's an

enormous um is there a realistic mission

scenario

in which astronauts would return to

earth decades younger than they peers

>> well I mean this if you had adequate

technology

yeah

this could be a realistic thing. But we

don't have anything like the technology

that would be required. Nor do we have

any black holes with the required mass.

You have to have a a black hole uh with

a mass that is big enough that they

don't get torn apart when they're that

close to the black hole that the

astronauts don't get torn apart. Is it

true that when Carl Sean was writing a

novel contact he repeatedly asked you

for an idea of realistic cosmic tunnel?

Uh

the what he asked me for was this that

he said he had in his novel he had his

heroine Elanor Arowway is the name of

the hero her heroine in in the movie and

in the novel had

Elanor Aoway

go through a black hole to get to the

vicinity of the star of Vega. And I told

him that you can't do that. You can't go

through a black hole and get come out

the other side.

And so I suggested to him he should use

a wormhole. And uh so that's really I

think the first use of a wormhole in

science fiction films um as far as I'm

aware. Um but it was as a substitute for

black hole which is what he was

originally using. Do you believe that

there somewhere can exist passenger

that travel using wormhole?

>> I I am fairly sure that if wormholes can

be made, they have to be made

artificially by a very advanced

civilization.

They don't occur naturally in in the

universe. Um, and so then it's a

question of whether or not there are

very advanced civilizations with the

adequate technology to make them. I

don't know whether that's true or not.

But we also don't know whether the laws

of physics even permit wormholes that

it's a an interesting physics question

that there's been a lot of work done on

it, but there's been no firm answer.

Could you really send a message from

inside a black hole like Cooper did

taught his daughter's watch?

So

let me begin answering that by saying

that uh

early in my discussions about this movie

with Christopher Nolan. He told me he

wanted to have an ending for the movie

that was very mysterious.

uh even more mysterious than the ending

of the movie 2001 a space odyssey

Stanley Kubri's great film

and uh so he does the it's very hard to

understand the ending of the movie uh

and later on is when I decided I would

write a book about the movie he we

agreed that I would explain it in the

book but that's the only place you'll

ever understand the ending of the movie

So he's not as sending a message from

inside a black hole. What happens is

when he falls into the black hole as he

gets very close to the g quote gentle

singularity it's called that by Ramaly

uh he is caught up by captured by a

spacecraft

called the tesseract

which travels in the fifth dimension.

So it's a four D has a spacecraft with

four space dimensions

and the it has the four three space

dimensions of our universe plus the

fifth dimension of the the fourth space

dimension of the bulk

and uh he's carried by that spacecraft

into the bulk into the higher dimension

into the fifth dimension it's called in

the movie and carried back to earth and

although the distance back to Earth in

our universe is billions of light years.

The distance back to Earth in the

in the bulk is far less. It's uh less

than the distance between the Earth and

the Sun. He's able to get back in a in

just a a few minutes. And then the

spacecraft docks beside his daughter's

bedroom

in the fifth dimension. and all of the

action that you see in the last part of

of the interstellar movie right

>> in the last part of the movie everything

is happening he's right there by his

daughter's bedroom and sending signals

to his daughter f

>> firstly I thought that this is the

metaphor of the hypothesis of infinity

is copies of us you know and later I

understood uh the division uh could a

wormhole near Saturn from naturally in

space?

>> No, we don't. We're almost certain that

wormholes cannot form naturally in space

ever.

If if they exist, they have to be made

by a very advanced civilization.

>> Which moment from interstellar

production do you remember the most?

one single moment.

I would say the moment where uh Cooper

plunges into the black hole and and I

where you see him plunge into the black

hole, go through the horizon, turn

around and look back and see the

universe above him. I mean, this is how

the computer simulations show what he

would see. Can you actually see that

there?

>> You discovered a new star kind of stars

with Polish scientists, right?

>> Yes. Well, yes.

>> Could you tell me something more?

>> So, the Polish scientist was Anna

Jetkov.

Uh, she was a student of Bogdan

Pachinsky who was one of the really

great astrophysicists of the 20th

century. And uh so I

I was I had been working primarily in

relativity theory up to and I wanted to

work on some more realistic

astrophysical project and I met Anna I

think at a conference in Cambridge,

England and uh

she I think Bdan had probably suggested

this problem to her and of

us having could you have a star uh that

has a at the at its center it has a

neutron star in the interior. So there's

a core of the star that's a neutron star

that has densities like an atomic

nucleus has a size of a few kilometers.

Then it's surrounded by an envelope that

is really big

and the

and what would such a star look like?

How could such a star form?

It was basically called a star a a a

star with a neutron star core in it. And

so

she invited me to work with her on that

project because I knew relativity very

deeply and relativity was in involved in

this case because the neutron star had

such strong gravity and she knew a lot

of astrophysics and what she had learned

from Dan from Bugdan and so we combined

forces with her knowledge of

astrophysics and my knowledge of

relativity. So I taught her relativity.

She taught me astrophysics and and we

analyzed the problem and

>> combined

>> combi com combined and we figured out

what such a star should look like. These

are now called thorn zetcov objects

after my name and hers and

>> thorn jetkov objects right or tz.

>> Yeah.

>> And uh people are searching for them.

There are candidate TZOs

but no firm discovery of one.

What are you doing now? Tell me

something about your actual study.

>> Well, so I

am 85 years old and 16 years ago I made

a decision to uh

to resign from my professorship and

start a new career. So I made the

gradual transition into the new career.

The point was that that for I'd been a

conventional professor for nearly 50

years and I thought for my next 50 years

I wanted to do other things. Uh and so I

made this gradual transition to uh where

my career much of my career is

collaboration with people in the arts

uh and uh working on projects that

basically uh communicate ideas deep

ideas about science through the arts. By

the arts I mean film, so interstellar

uh painting. I have a book of my poetry

and paintings by Leah Hower and the

superb young painter uh about the warped

side of our universe. Uh and we

basically have tried to invent a new way

to communicate the essence of ideas

about warp spaceime to non-scientists.

The new method, the new tool is tightly

integrated, tightly coupled paintings

and verse or poetry. Uh, and so that's

another project. I've done several

multimedia concerts with the composer H

Zimmer and the visual effects team at

Double Negative at DAG. uh uh where uh

we

the visual effects team, Paul Franklin

and Oliver James and colleagues have

edited uh videos that are made by

astrophysicists

about the universe to fit Han Zimmer's

music. And we do a concert where the

orchestra plays Hans Simmer's music.

Videos from astrophysicists

uh made much more beautiful and uh and

edited to fit the music go across the

screen. Uh and then we stop after our

prologue and we talk about the music,

about the science that you're seeing on

the screen, about the uh making of the

uh the uh videos.

uh and then go on. So done that kind of

a project. I'm thinking of writing a

novel uh and uh so I'm basically

enjoying myself doing those but actually

for the last few years most of my time

has been going into uh uh writing a

history of the LIGO project this

gravitational wave project.

Do arts inspired you stronger, deeper

than physics?

>> No. Uh but they inspire me greatly. Uh

and the combination I find to be very

powerful and and a a wonderful

opportunity to be creative to in in

different ways. And uh so and I find my

collaboration with uh artists

uh artists said broadly artists

including filmmakers, musicians,

painters and so forth. I find those

collaborations to be very interesting,

very fulfilling because the they are so

creating themselves and they can ask

questions of me uh that uh make me think

uh deeply about things I wouldn't have

thought about otherwise.

>> Have you ever asked yourself why

science? Why you are scientists? Uh no,

I'm a scientist because very early on I

discovered that uh science has enormous

power

uh for

uh explaining the universe and power for

underlying technology that makes the

world better. It is far more powerful in

these ways than any other any other

approach than religion for example. Uh

and uh

and working with it and having the

beauty of new understandings of the

universe, the beauty of new technologies

by uh people associated with me

basically pioneered quantum technology,

quantum sensing, things that are a big

deal now in in private companies

that I mean it's just fun. It's a huge

amount of fun and it really has has an

impact and so how would I why would I do

anything else?

>> You said to use technology to make the

world better.

How do you look at AI development today?

>> AI development is very very early on and

there are lots of worries about it.

doesn't look like

>> and and there's lots of worries about it

and there and it is a very powerful tool

to make the world better but there are

lots of worries that may make the world

worse and uh

we just have to see we have to move

carefully and so I think but but if you

ask me what do I believe about its

dangers I say I don't know because I

haven't studied it deeply enough and I I

don't uh comment on things unless I have

studied them deeply enough to have what

I regard as a somewhat reliable opinion.

>> My last one question to you is

do you have any advice

for under all your experience to our

young viewers? Well, one single advice

that I

have, it just deals with how you choose

what to do in life.

Uh what to do for a profession, how to

spend your time. And it's advice that I

got from my grandfather when I was four

years old. He put it in simple terms for

a small child. He said, "If you find a

job when you grow up that is like play,

you'll be a big success in life.

And I came to understand that what he

was really saying was that the things

that are really worth doing are very

difficult. They require that you work

very hard uh in order to have success.

And uh in order to work very hard, you

have to enjoy what you're doing.

uh and uh that then becomes an

additional benefit because if you enjoy

what you're doing then it helps make

life worth living

and so I rather strongly believe that a

young person

as they mature as they go through

university if that's the direction they

choose as they

move into some particular profession or

they choose what to do within some prof

particular profession. Watch for things

that will be fun

and worthwhile.

Uh and but factor in the enjoyment part

of it.

That's very important to our success.

>> And my last one question, I promise. Um,

what was the keep turn

the most difficult decision in your

career?

>> I don't think in the end that any of the

decisions were terribly difficult,

but they weren't terribly difficult

because I studied uh the pros and the

cons uh very carefully. uh and then it

became fairly obvious what I wanted to

do. But one decision that initially was

very difficult was whether to pursue

detection of gravitational waves

is I knew it was going to take decades

and uh and I knew it was so hard that it

might be impossible to succeed

but I had to become convinced that you

had a reasonable possibility of success.

And once I was convinced of that, then

the fact that the payoff would be so

enormous

sway the decision. But it was it took me

several years to make the decision

because it took me several years to

become convinced that that we had a

serious possibility of success.

>> Thank you for your time. Thank you.