Lex Fridman Podcast
#472 β Terence Tao: Hardest Problems in Mathematics, Physics & the Future of AI
And often the mathematics becomes a lot cleaner when you do that.
Lex Fridman Podcast
#472 β Terence Tao: Hardest Problems in Mathematics, Physics & the Future of AI
I mean, in physics, we joke about assuming spherical cows.
Lex Fridman Podcast
#472 β Terence Tao: Hardest Problems in Mathematics, Physics & the Future of AI
You know, like real-world problems have got all kinds of real-world effects, but you can idealize, send some things to infinity, send some things to zero.
Lex Fridman Podcast
#472 β Terence Tao: Hardest Problems in Mathematics, Physics & the Future of AI
And the mathematics becomes a lot simpler to work with there.
Lex Fridman Podcast
#472 β Terence Tao: Hardest Problems in Mathematics, Physics & the Future of AI
Yeah, so there's a lot of pitfalls.
Lex Fridman Podcast
#472 β Terence Tao: Hardest Problems in Mathematics, Physics & the Future of AI
We spend a lot of time in undergraduate math classes teaching analysis, and analysis is often about how to take limits.
Lex Fridman Podcast
#472 β Terence Tao: Hardest Problems in Mathematics, Physics & the Future of AI
So for example, A plus B is always B plus A. So when you have a finite number of terms and you add them, you can swap them and there's no problem.
Lex Fridman Podcast
#472 β Terence Tao: Hardest Problems in Mathematics, Physics & the Future of AI
But when you have an infinite number of terms, they're these sort of show games you can play, where you can have a series which converges to one value, but you rearrange it, and it suddenly converges to another value.
Lex Fridman Podcast
#472 β Terence Tao: Hardest Problems in Mathematics, Physics & the Future of AI
And so you can make mistakes.
Lex Fridman Podcast
#472 β Terence Tao: Hardest Problems in Mathematics, Physics & the Future of AI
You have to know what you're doing when you allow infinity.
Lex Fridman Podcast
#472 β Terence Tao: Hardest Problems in Mathematics, Physics & the Future of AI
You have to introduce these epsilons and deltas, and there's a certain type of way of reasoning that helps you avoid mistakes.
Lex Fridman Podcast
#472 β Terence Tao: Hardest Problems in Mathematics, Physics & the Future of AI
In more recent years, people have started taking results that are true in infinite limits and what's called finitizing them.
Lex Fridman Podcast
#472 β Terence Tao: Hardest Problems in Mathematics, Physics & the Future of AI
So you know that something's true eventually, but you don't know when.
Lex Fridman Podcast
#472 β Terence Tao: Hardest Problems in Mathematics, Physics & the Future of AI
Now give me a rate.
Lex Fridman Podcast
#472 β Terence Tao: Hardest Problems in Mathematics, Physics & the Future of AI
Okay, so if I don't have an infinite number of monkeys, but a large finite number of monkeys, how long do I have to wait for Hamlet to come out?
Lex Fridman Podcast
#472 β Terence Tao: Hardest Problems in Mathematics, Physics & the Future of AI
And that's a more quantitative question.
Lex Fridman Podcast
#472 β Terence Tao: Hardest Problems in Mathematics, Physics & the Future of AI
And this is something that you can attack by purely finite methods, and you can use your finite intuition.
Lex Fridman Podcast
#472 β Terence Tao: Hardest Problems in Mathematics, Physics & the Future of AI
And in this case, it turns out to be exponential in the length of the text that you're trying to generate.
Lex Fridman Podcast
#472 β Terence Tao: Hardest Problems in Mathematics, Physics & the Future of AI
And so this is why you never see the monkeys create Hamlet.
Lex Fridman Podcast
#472 β Terence Tao: Hardest Problems in Mathematics, Physics & the Future of AI
You can maybe see them create a four-letter word,