[MUSIC]

So over the past 50 years or so, computing

power has doubled every 18 months.

And when you add that up,

it’s really pretty amazing.

The smartphone that I have in my pocket is

more powerful than a super computer from

1970.

So an actual question is where

does this ultimately lead?

Do we run into some limits,

does this stop?

Certainly there have been some signs

lately of running into limits.

Clock speeds, the number of computational

operations per second that computers can

do, actually stopped increasing

about ten years ago.

And the features sizes it seems hard

to shrink them much further,because

you can’t really make them out of

things that are smaller than an atom.

So what happens next?

[MUSIC]

You could try to find

some kind of shortcuts,

the big example of that

is quantum computing.

Prior to quantum computing no one

really ever found any shortcuts.

The number of steps you needed to solve

a problem was not exactly the same, but

it was about the same.

Quantum computing just

totally blows that up.

I once calculated that if you took all the

silicon in Earth’s crust and converted it

into conventional computer chips, and

ran it through the age of the observable

universe the biggest number you could

factor would be about 5,000 bits.

And if you wanted to factor a 5,000 bit

number on a quantum computer that’d only

take you about two and a half hours,

if it was running at the same speed.

So it’s really a very dramatic thing.

And besides factoring numbers,

quantum computers can also be used for

certain other things like

simulating chemical reactions.

Which might help for example in designing

new catalysts to generate cheaper energy,

or to design new medical drugs.

But our question is are quantum

computers the end of the road?

The natural next place to

look is quantum field theory.

Quantum field theory is the physics

describing things where quantum mechanics

and special relativity are both important.

So quantum mechanics is important when

you’re describing small things like

particles.

And special relativity is important

when you’re describing fastings,

things that are moving close

to the speed of light.

So in collaboration with Heathly and

John Prescol, I’ve studied this question,

and what we found was that

conventional quantum computers can

emulate quantum field computers.

Anything that could happen

with quantum field theory,

you could simulate using

conventional quantum computers.

So this doesn’t provide a new,

dramatic advantage in the way

that quantum did over classical.

>>So what now?

>>Well, there is another aspect of modern

physics that you could consider as well,

namely, general relativity.

So this is Einstein’s theory of spacetime,

his theory of gravity as being

a curvature to spacetime.

And at present, it’s not really well

understood how to reconcile quantum

mechanics with general relativity.

A sufficiently small black hole would

be a place in the universe where

quantum mechanical effects and

general relativistic effects

would both be important.

So if you had a black hole where general

relativity and quantum mechanics both come

into play, could we use that as

some kind of hyper computer?

Does that give us something beyond

what even quantum computers might do?

[MUSIC]

In recent work with Ning Bao and

Adam Bouland,

I’ve started to investigate these models,

just kind of looking at them one by one.

And saying,

what would be the computational

implications of these models?

And in a lot of models, what you have to

do to get general relativity and quantum

mechanics to fit together, is you have to

modify quantum mechanics a little bit.

And oftentimes,

when you modify the of quantum mechanics

all kind of crazy stuff happens.

You start to have signals being able

to be transmitted faster than light.

And if a signal is transmitted faster than

light from a certain reference frame,

a certain perspective, it’s actually

being transmitted backwards in time,

which can lead to all

kinds of crazy paradoxes.

And a second thing that can happen, is you

get kind of insane computational power.

So why think about these things now?

We don’t quite have

the quantum computers ready yet

to simulate quantum field theories.

And as far as building

computers out of black holes,

that’s very far from

anything we can do today.

And so today we can look at imaginary

computers of the far future,

what powers will they have?

And we hope that by thinking about this

we can not only push the limits of

computation, but we can push the limits

in terms of our knowledge of physics.

[MUSIC]

## RELATED VIDEOS

If you lost money in the stock market, please watch this. // Lost money in stocks Lost money trading

## If you lost money in the stock market, please watch this. // Lost money in stocks Lost money trading

## By Elbert Gonzales

March 6, 20200Bitcoin’s price a distraction from its transformative technology?

## Bitcoin’s price a distraction from its transformative technology?

## By Elbert Gonzales

March 6, 20200What is the Bitcoin price going to be after the halvening?

## What is the Bitcoin price going to be after the halvening?

## By Elbert Gonzales

March 6, 20200