So, you have already given us so many crazy ideas out there.

I think a couple of decades ago,

you made the case that we might all be living in a simulation,

or perhaps probably were.

More recently,

you've painted the most vivid examples of how artificial general intelligence

could go horribly wrong.

And now this year,

you're about to publish

a paper that presents something called the vulnerable world hypothesis.

And our job this evening is to give the illustrated guide to that.

So let's do that.

What is that hypothesis?

Nick Bostrom: It's trying to think about

a sort of structural feature of the current human condition.

You like the urn metaphor,

so I'm going to use that to explain it.

So picture a big urn filled with balls

representing ideas, methods, possible technologies.

You can think of the history of human creativity

as the process of reaching into this urn and pulling out one ball after another,

and the net effect so far has been hugely beneficial, right?

We've extracted a great many white balls,

some various shades of gray, mixed blessings.

We haven't so far pulled out the black ball --

a technology that invariably destroys the civilization that discovers it.

So the paper tries to think about what could such a black ball be.

CA: So you define that ball

as one that would inevitably bring about civilizational destruction.

NB: Unless we exit what I call the semi-anarchic default condition.

But sort of, by default.

CA: So, you make the case compelling

by showing some sort of counterexamples

where you believe that so far we've actually got lucky,

that we might have pulled out that death ball

without even knowing it.

So there's this quote, what's this quote?

NB: Well, I guess it's just meant to illustrate

the difficulty of foreseeing

what basic discoveries will lead to.

We just don't have that capability.

Because we have become quite good at pulling out balls,

but we don't really have the ability to put the ball back into the urn, right.

We can invent, but we can't un-invent.

So our strategy, such as it is,

is to hope that there is no black ball in the urn.

CA: So once it's out, it's out, and you can't put it back in,

and you think we've been lucky.

So talk through a couple of these examples.

You talk about different types of vulnerability.

NB: So the easiest type to understand

is a technology that just makes it very easy

to cause massive amounts of destruction.

Synthetic biology might be a fecund source of that kind of black ball,

but many other possible things we could --

think of geoengineering, really great, right?

We could combat global warming,

but you don't want it to get too easy either,

you don't want any random person and his grandmother

to have the ability to radically alter the earth's climate.

Or maybe lethal autonomous drones,

massed-produced, mosquito-sized killer bot swarms.

Nanotechnology, artificial general intelligence.

CA: You argue in the paper

that it's a matter of luck that when we discovered

that nuclear power could create a bomb,

it might have been the case

that you could have created a bomb

with much easier resources, accessible to anyone.

NB: Yeah, so think back to the 1930s

where for the first time we make some breakthroughs in nuclear physics,

some genius figures out that it's possible to create a nuclear chain reaction

and then realizes that this could lead to the bomb.

And we do some more work,

it turns out that what you require to make a nuclear bomb

is highly enriched uranium or plutonium,

which are very difficult materials to get.

You need ultracentrifuges,

you need reactors, like, massive amounts of energy.

But suppose it had turned out instead

there had been an easy way to unlock the energy of the atom.

That maybe by baking sand in the microwave oven

or something like that

you could have created a nuclear detonation.

So we know that that's physically impossible.

But before you did the relevant physics

how could you have known how it would turn out?

CA: Although, couldn't you argue

that for life to evolve on Earth

that implied sort of stable environment,

that if it was possible to create massive nuclear reactions relatively easy,

the Earth would never have been stable,

that we wouldn't be here at all.

NB: Yeah, unless there were something that is easy to do on purpose

but that wouldn't happen by random chance.

So, like things we can easily do,

we can stack 10 blocks on top of one another,

but in nature, you're not going to find, like, a stack of 10 blocks.

CA: OK, so this is probably the one

that many of us worry about most,

and yes, synthetic biology is perhaps the quickest route

that we can foresee in our near future to get us here.

NB: Yeah, and so think about what that would have meant

if, say, anybody by working in their kitchen for an afternoon

could destroy a city.

It's hard to see how modern civilization as we know it

could have survived that.

Because in any population of a million people,

there will always be some who would, for whatever reason,

choose to use that destructive power.

So if that apocalyptic residual

would choose to destroy a city, or worse,

then cities would get destroyed.

CA: So here's another type of vulnerability.

Talk about this.

NB: Yeah, so in addition to these kind of obvious types of black balls

that would just make it possible to blow up a lot of things,

other types would act by creating bad incentives

for humans to do things that are harmful.

So, the Type-2a, we might call it that,

is to think about some technology that incentivizes great powers

to use their massive amounts of force to create destruction.

So, nuclear weapons were actually very close to this, right?

What we did, we spent over 10 trillion dollars

to build 70,000 nuclear warheads

and put them on hair-trigger alert.

And there were several times during the Cold War

we almost blew each other up.

It's not because a lot of people felt this would be a great idea,

let's all spend 10 trillion dollars to blow ourselves up,

but the incentives were such that we were finding ourselves --

this could have been worse.

Imagine if there had been a safe first strike.

Then it might have been very tricky,

in a crisis situation,

to refrain from launching all their nuclear missiles.

If nothing else, because you would fear that the other side might do it.

CA: Right, mutual assured destruction

kept the Cold War relatively stable,

without that, we might not be here now.

NB: It could have been more unstable than it was.

And there could be other properties of technology.

It could have been harder to have arms treaties,

if instead of nuclear weapons

there had been some smaller thing or something less distinctive.

CA: And as well as bad incentives for powerful actors,

you also worry about bad incentives for all of us, in Type-2b here.

NB: Yeah, so, here we might take the case of global warming.

There are a lot of little conveniences

that cause each one of us to do things

that individually have no significant effect, right?

But if billions of people do it,

cumulatively, it has a damaging effect.

Now, global warming could have been a lot worse than it is.

So we have the climate sensitivity parameter, right.

It's a parameter that says how much warmer does it get

if you emit a certain amount of greenhouse gases.

But, suppose that it had been the case

that with the amount of greenhouse gases we emitted,

instead of the temperature rising by, say,

between three and 4.5 degrees by 2100,

suppose it had been 15 degrees or 20 degrees.

Like, then we might have been in a very bad situation.

Or suppose that renewable energy had just been a lot harder to do.

Or that there had been more fossil fuels in the ground.

CA: Couldn't you argue that if in that case of --

if what we are doing today

had resulted in 10 degrees difference in the time period that we could see,

actually humanity would have got off its ass and done something about it.

We're stupid, but we're not maybe that stupid.

Or maybe we are.

NB: I wouldn't bet