That's just fantastic.

When I was younger,

although not quite so young that I should really not have known better,

I sent one of the most harsh messages I've ever sent in my life.

I'm going to share it with you now.

I'm not proud of it, but here it is:

“I've blocked you everywhere else,

“and now I'm going to block you here too.

“My only regret is that I can't block you in real life.”

Past me was a dick.

I couldn't block them in real life, right?

Because they were still in the same social circles,

They were still going to get invited to the same events,

still going to be part of the same things,

and it's going to be awkward,

particularly after I send a message like that.

And some folks would say that I should just get used to it,

that I should just be at the peace with the fact that some people are just jerks,

and some personalities clash, but I thought,

what if instead: we use technology to fix that.

So my proposal for you tonight is: blocking in real life.

Which has been done in science fiction, right?

This is from Black Mirror.

But the trouble with science fiction blocking

is that they have to make it work on camera,

and that means inevitably it's a messy fuzz of pixels or something like that,

and that's not useful, that's not helpful.

Because a messy block of pixels can still see you,

and you can still see it,

and it can still punch you in the face.

So that's not great.

But we do have an algorithm for this that will already work,

and Photoshop has it, it's called content-aware fill,

and it's the…

“Woo!” from a Photoshop user there!

Although given this audience,

possibly the man who created the feature, we don't know.

I was actually originally in that photograph.

There I am, that's the original.

But nowadays it's trivial to just find an object,

paint it out, and there you go.

And if you didn't have those two identical bushes

right there in the middle,

you might not even spot that I was never there in the first place.

Now, Facebook already has facial recognition for people, right?

So in theory, you get a photo… here's one of me and some friends.

You get a photo,

you could highlight the person,

and you could paint them…

Yes, well it doesn't…

It does go a little bit Cronenberg sometimes.

But in the next few decades we're going to figure out how to make

much, much deeper connections into the brain.

We're already starting to see some things like this.

We've been using deep brain stimulation for Parkinson's patients since 2006,

that's when that paper was from,

and spoiler, or as they insist on calling it here,

“abstract”…

Abstract: it works.

And we've already got people controlling robot arms with brain implants,

and exoskeletons with EEG caps.

Okay, so no-one is actually working on a neural lace yet…

No, of course Elon Musk is working on a neural lace,

because Elon Musk is working on everything that Iain M Banks ever wrote about.

So let's say that it works.

Let's say that in the next few decades,

over the rest of the century,

we get something that starts to make deeper and deeper connections into the brain.

And to start off with it's going to help

an increasingly-aging population to deal with senescence,

but eventually it will trickle out to the rest of us.

And I'm willing to bet that humanity won't regress into virtual worlds,

because virtual worlds are good for gimmicky games, but they're not real.

There's no real human interaction there.

And sure, the uncanny valley has pretty much been solved, right?

That is Johnny Depp playing young Johnny Depp in the latest Pirates movie.

But you can't have that for human interaction.

I'm willing to bet there's the same uncanny valley effect for talking to someone.

You can't simulate a human without simulating something that's very close to human,

and that would be unethical, even if it was possible.

But you could hijack the vision centre.

You could use all those same little tips and tricks

that the brain has been using for, well, millions of years of evolution,

to just quietly make you not notice things.

If you walked here like this,

and quietly routed yourself around an obstacle without even seeing it,

you're already using those tricks.

And yes, I have footnotes.

You could just tell your vision centre to quietly remove things, or add things in.

You could teleport to a remote office by saying to your implant,

or whatever it is, you want to go there.

It'd paint your vision with that,

and it would paint you into the vision of the people there.

But if you can do that,

then you can start to remove things as well.

Those implants could use the sort of hacks that we've talked about

to quietly remove objects, and people, and anything.

To start off with, this would just be used on annoyances.

It'd be used on the baby that's crying on the plane,

it'd be used on the jerk who keeps leering at you at the bus stop every day.

But eventually it'd start to roll out and roll out,

you'd be able to block someone.

You won't appear in their perceptions,

and they won't appear in yours.

And sure, there are going to be people out there without implants,

but increasingly, as it becomes more and more normalised,

like smartphones are today,

they're going to find themselves in a kind of a twilight zone

where a lot of people are ignoring them.

The same way that people get better customer service by tweeting someone

than they do by calling on a landline.

And okay, there are people who are going to try and get around this, right?

There are going to be moments of human ingenuity that…

It was really expensive to get that photo made, by the way,

just the skywriting costs alone.

But in general, people would be okay with this,

because no-one here could tell me the last person who unfriended them on Facebook,

not with certainty.

Because you can't remember everyone you're friends with,

and you don't check every day, and it doesn't notify you,

and it's not particularly offensive when it happens.

They're just not appearing anymore,

you've just forgotten about them.

So once we're happy with that,

the technology can start getting better, and better, and better.

It can start blocking objects and concepts and ideas,

and it can start to just automatically work out the things

that your brain flinches away from and automatically start to block them.

And people will start sharing block lists, right?

It won't be monolithic,

it won't be brought in from on high,

but you will just tend to block the same things your friends block,

because if you don't, you keep noticing the elephant in the room,

and you keep being the awkward one at the dinner party

who keeps talking about things that people don't understand.

Or alternatively your friend is,

and will you please shut up about that, Dave,

we don't know what you mean!

Literally, we don't know what you mean.

People, shops, homes, offices, entire cities just quietly erased.

Imagine crowds of people just sliding past each other on the street,

just by unspoken, unknown, mutual consensus, just removing each other.

I mean, China Miéville talked about this in his book 'The City & the City', right?

But those two cities were divided by tradition, and etiquette,

and occasional violent retribution,

and tourists just had to fit in – there'd be none of that.

Instead of going to war,

feuding nations could just block each other.

And their citizens' implants would be legally mandated

to just quietly edit the other country out.

Maybe it gets to the point where you don't know the other world exists

until you're an adult.

Maybe children are just kept from it,

because you don't want to talk to those people.

Until then it's just a rumour,

it's just bumps in the night and explanations for ghost stories.

And then you get to being 18, or 21, or whatever,

and you have a look in the other world to see what it's like,

and it's terrible.

Never ever want to go back there.

They'll say there are people who've blocked everyone,

and we'll never know for sure.

But I could look out at a full house like this

and not know if my eyes are gliding over the people from another world.

Maybe there's someone else on stage and I'm just walking and talking around them,

because that's what my implant lets me do.

Which means there is one little question left over:

what happens when you edit out the idea of implants from people who have implants?

Because there are going to be people who hate the idea.

Maybe they were fitted with them from birth.

Maybe they were given them for work and have to have them, but they hate the idea

that the thing that is heading through their eyes into their brain isn't reality.

And how would that be any different from me being on this stage right now

telling a story and you immediately dismissing this as science fiction?

Ignore that itch behind your ear, it's probably nothing.

My name's Tom Scott, have a good night.

MATT PARKER: All right!

There's your camera...

Tom Scott, ladies and gentlemen!

My goodness.