In the beginning was the code | Juergen Schmidhuber | TEDxUHasselt

This talk was given at a TEDx event using the TED conference format but independently organized by a local community. Learn more at http://ted.com/tedx

The Universe seems incredibly complex. But could its rules be dead simple? Juergen Schmidhuber's fascinating story will convince you that this Universe and your own life are just by-products of a very simple and fast program computing all logically possible universes.

Juergen Schmidhuber is Director of the Swiss Artificial Intelligence Lab IDSIA (since 1995), Professor of Artificial Intelligence at the University of Lugano, Switzerland (since 2009), and Professor of SUPSI (since 2003).

He helped to transform IDSIA into one of the world's top ten AI labs (the smallest!), according to the ranking of Business Week Magazine. His group pioneered the field of mathematically optimal universal AI and universal problem solvers. The algorithms developed in his lab won seven first prizes in international pattern recognition competitions, as well as several best paper awards.

Three prisoners were sentenced to death;

one of them is French,

one of them is German,

and one of them is Belgian.

"What is your last wish?"
they asked the French guy.

He says, "A bottle
of exquisite French wine."

"What is your last wish?",
they asked the German guy.

He says, "I want to give a speech."

"What is your last wish?",
they asked the Belgian guy.

He says, "I want to get shot
before the German starts his speech."

(Laughter)

(Applause)

Unfortunately for you guys,
it is too late now.

(Laughter)

My speech will be about the simplest way
of explaining the Universe.

The Universe is following strange rules:

Einstein's general relativity,
Planck's quantum physics.

But it may be even stranger
than you think,

and the Universe may be
even simpler than you think.

Many scientists are now taking seriously
the possibility that all of reality

is being computed
by a short computer program,

as first suggested in 1967 by Konrad Zuse.

The same Konrad Zuse who in 1935,

or from 1935 until 1941,

built the first working general-purpose
program-controlled computer.

The idea is that every electron
behaves the same way,

because all electrons are essentially
using and reusing the same piece of code,

the same sub-program again and again.

To make this plausible,
consider a video game

with a realistic
three-dimensional simulation.

The program that defines
the rule of this game

is a series of zeroes and ones
in your computer.

If you look at this program,
you don't see what it does.

You have to run it to experience it.

It is true that reality still has
much better resolution than video games.

But soon, you will see
no difference no more,

because simulations are getting better

by a factor of 1,000
per decade and Swiss franc.

But in any case, in a few decades,
we will have a factor of a billion.

This means that soon we will be able

to simulate very convincingly
heavens and hells.

And soon, it would seem
very plausible indeed

that all of reality
maybe also is just a simulation.

To a man with a hammer,
everything looks like a nail.

To a man with a computer,
everything looks like a computation.

Skeptics might say,
"What about quantum physics

and Heisenberg's uncertainty principle,
and Bell's inequality?"

Don't these things show

that the Universe cannot be computed

by a simple deterministic
computer program?

And the short answers, "Not at all."

For example, Bell himself knew well
that a deterministically-computed universe

with deterministically computed
observers like ourselves

is totally compatible
with all existing physical observations.

There is no physical evidence
against this possibility.

Before I came here,

I thought this is going to be
just another TEDx talk,

and there won't be much of an audience,

but you are actually
a large audience by my standards.

The other day, I gave a talk, and there
was just a single person in the audience

(Laughter)

- a young lady.

I said, "Young lady,
it's very embarrassing,

but apparently today,
I am going to give this talk just to you."

And she said, "OK, but please hurry.
I got to clean up here."

(Laughter)

(Applause)

In the 1980s, when my brother
was a teenager in Munich,

he told me and everybody else whom he met

that the Universe
or the quantum multiverse

is the sum of all mathematics.

He was younger than me
- my brother is still younger than I am -

and he also was smarter than me

and he went on to become
a theoretical physicist,

first in Munich, then at Caltech,
at Princeton, at CERN,

and he lived in Bern,
next door to where Einstein lived.

Not at the same time.

The sum of all mathematics.

For a while, I didn't fully understand
what that means,

but then, in 1996,

I was able to formulate this idea
through a computation,

pointing out that one can generalize
Everett's multiverse theory,

pointing out that there is
a very short program,

a short and fast program
that not only computes this Universe...

If it is computable,

but there's no evidence
against this possibility...

Not only this universe but also all
other logically possible universes,

including those
with different physical laws;

for example, universes
where there's anti-gravity.

In fact, there is
a fastest, most efficient,

mathematically optimal way
of computing all possible universes,

all logically possible
computable universes;

an optimal way
that is better than any other.

I wrote it down for you.

It has only 10 lines of code.

It fits on this little piece of paper.

Ten lines of code:

the optimal way of simulating or computing
every logically possible universe.

It works like this:

You essentially, systematically enumerate
all possible programs through a program,

and then you allocate run-time
to all of these programs in an optimal way

that makes sure
that each possible universe's history

is being computed
as quickly as if it were computed

by this universe's fastest program,
which we usually do not know in advance.

Faster, say, for a constant factor
which does not depend

on the size
of the universe's history so far.

The universe itself may be infinite.

Any self-respecting
God-like great programmer

should use this optimal method

to create and become the master
of all logically possible universes.

You should not use the sub-optimal method.

That's the one that you should use.

Suppose he does that.

Then, after some time,

many of the universes that are being
computed by this optimal way

will contain a copy of you,

and of you,

as you are looking at me
with incredible eyes.

You yourself could even
become a great programmer

by just taking this piece of code,

programming it on your own computer
and simulating all possible universes.

Given the properties
of the optimal method,

it is now easy to see
that, at a given point in time,

most of the copies of yourself,

of the universes that contain
a copy of your life,

will be due to one of the fastest
and shortest programs

that is compatible with your existence.

This simple insight allows us
to make predictions about the future.

There are many possible futures
of your life so far.

Which one is going to happen?

Answer: most likely one of the few
regular, non-random futures

that can be computed
by a fast and short program.

Because randomness, random stuff,
where everything suddenly dissolves

into arbitrariness is fundamentally harder
to compute than regular stuff

even by the optimal method.

This means that beta decay,
the decay of neutrons,

which is widely believed to be random,
cannot really be random.

It has to be pseudo-random,
just like the decimal expansion of pi,

which looks random, but isn't,

because it can be computed
by a short program.

A consequence of the optimal method
of computing everything

is also that quantum computation
is not going to work well.

And the reason is because it's consuming
so much traditional computation power.

I made this prediction
12 years ago, and since then,

there has not been any progress
in practical quantum computing.

So quantum computers are sexy,
but essentially, they are dead.

What about free will?

Free will is overrated.

In my lab, at the Swiss Artificial
Intelligence Lab, IDSIA,

we often program simulated worlds

inhabited by simulated agents,
driven by simulated artificial brains

containing simulated
artificial neural networks.

In the beginning,
these guys are very dumb,

and over time, they become smarter;

through pseudo-random trial and error,
they figure out how to solve problems

that they were not able to solve
in advance, in the beginning.

They have no idea

that every single thought
of their little artificial brains

and the little artificial neural networks

in their brains

is totally deterministically
computed by a program

that does not have any random aspects.

Nevertheless, computer science,

and the whole line of reasoning
I now try to outline within 15 minutes,

is now offering
formal mathematical answers

to all questions
of philosophy and theology.

For example, one of the consequences
of this computational theology

is that your own life
must be very important

in the grand scheme of things.

You may think
that your life is insignificant

because you are so small,
and the Universe is so big.

However, given the optimal way
of computing everything

and given the probability distribution
induced by this optimal way,

probably, it's very hard
to edit your life out of this history,

of the current history of this Universe,

because the program
that computes this Universe

or one that is very much like it,

but without you and without your life,
with all its ups and downs,

it's probably much longer, and therefore,
much slower than the original program,

which does contain your life,
which is totally interconnected

with everything else that is happening
in this computable world,

if it is computable indeed.

So your life, from this perspective,
is not insignificant.

It is an indispensable part
of the grand scheme of things.

This is compatible with religions
that claim all is one

and everything is connected to everything.

May this thought lift you up
in times of frustration.

I wish to thank the organizers
for doing a great job,

and for the check,

which I am going to spend
on the education of my kids.

I wish to thank my mom, and my dad,
and the great programmer,

without whom all of this
would not have been possible.

I wish to thank my kids, without whom
all of this would not have been necessary.

(Laughter)

And I wish to thank you,
my lovely audience, for your patience.

(Applause)