[John] Well, I used to say, and I'm still inclined to say occasionally,
that I hate it, I hate the Game of Life.
I don't really, at least I don't anymore.
The reason why I felt like that was that,
whenever my name was mentioned with respect to some mathematics,
it was always the Game of Life.
And I don't think the Game of Life is very very interesting.
I don't think it was worth all that, I've done lots of other mathematical things.
So I found the Game of Life was overshadowing much more important things and I did not like it.
Now, well, I'm getting old,
my capacity for hatred is getting less, I suppose.
And it was an achievement. I'm quite proud of it.
I just don't want to talk about it all the time.
[Brady] I'm sorry. [John] It's allright.
[Brady] I could not ask you about it. [John] That's ok.
[Brady] What is the Game of Life? This thing that you're stuck with now.
[John] Well, you'll really be able to focus on this. [Brady] Yes, I can focus on that, no problem.
[John] Have I got some coins in my pocket?
[John] Curses, I don't. Have you?
[John] In the Game of Life, you drop a handful of nuts, counters or something.
The rules are: At any given time, you've got some of these things that
are full, I call that alive,
and some of them are empty, I call that dead.
If you've got too many neighbours..
The neighbours of a cell are all the 8 things nearest to it.
If you got too many neighbours, you die.
If you got 4 or more (in other words, that's the exact definition of 'too many'),
you die of overcrowding.
Probably because there isn't enough food in that region.
But if you've only got one or no live neighbours, you die of isolation.
Now, let's look. This guy is going to die of isolation.
This guy only has one neighbour too.
They both gonna die.
But the other thing is, if you're dead at the moment, but you've got exactly 3 live neighbours,
you see, this guy has three live neighbours, at the 8 places next to it,
And so is this guy. Can you see? We've got 3 (neighbours).
So there is going to be a happy event next time.
Two things are going to be born here and here.
And these two are going to die.
I might as well eat them.
This guy is going to die.
And these things now, who are babies at the moment,
are gonna grow up there, they had the harder lessons there.
Let's go out of slow.
Next time, I'll just do it quickly.
There is going to be somebody born here, because he has three live neighbours, and somebody born here.
The condition for giving birth is that you have exactly three parents.
That seems rather unusual, but it's not really imitating the human life, so to speak.
It definitely isn't.
The places I'm pointing to now are going to be born.
And this one has four live neighbours. 1,2,3,4.
So he's going to die.
And this one only has one live neighbour, so he's going to die.
This guy dies of overcrowding, and this guy, right next door, dies of isolation.
So they're going to die.
And the places my fingers are pointing to are going to be born.
With this configuration.. This is the same shape as it was when we started two moves ago.
But it's moved a little bit.
And if you just follow it, it will keep on moving like this forevermore.
It's what we call "The Glider".
I wish I hadn't called it "The Glider", because if you look at it,
when somebody programmed the machine for you,
it looks more like an ant.
I wish I called it an ant, it just walks across the plane.
[Brady] What has been proven about the Game of Life? And since it...
[John] It's a long time ago, we've proven everything about it.
Namely, we proved that it could do arbitrarily computations,
it could build copies of itself,
which had interesting properties, could move across the plane.
It's hard to say exactly, easily to an audience that doesn't actually understand these things.
exactly how we proved those.
I'm not entirely responsible for that.
When I first told it to Martin Gardner, who wrote the mathematical games column in the Scientific America,
I advertised really, I didn't know that it would have these properties, I hoped it would.
And so, I advertised for a finite configuration which grew indefinitely.
That was the simplest testable instance of this sort of ubiquity, this universality.
And somebody at MIT build (Gosper and a few colleages of his),
came up with this thing called "The Glider Gun", which emmited a glider every 30 moves.
And we played with that, and in the end, succeded in proving this universality thing.
You know, we called it "The Game of Life", because it seemed, in a little bit ...
Well, some of the ideas we had were taken from real life.
If you have too many organisms of your type in a given region, you die of,
because there isn't enough food for you, or something.
If you've too few, well, it's nice to have a few companions.
And if you don't have the companions, you might as well die, I mean, that's it.
And so on. So the..
The basic rules are tremendous simplification of the rules of real life,
for very very simple organisms.
You have the unpredictability of real life too.
And yes, it all comes from very very simple rules.
So I think that's why people are interested.
You know, who would have thought.
Well, I thought, but typically, one doesn't think
that one can get a decent simulation of real living things in such a very simple way.