Lex Fridman Podcast
#472 β Terence Tao: Hardest Problems in Mathematics, Physics & the Future of AI
Within mathematics itself, there's also a theory and experimental component.
Lex Fridman Podcast
#472 β Terence Tao: Hardest Problems in Mathematics, Physics & the Future of AI
It's just that until very recently, theory has dominated almost completely.
Lex Fridman Podcast
#472 β Terence Tao: Hardest Problems in Mathematics, Physics & the Future of AI
99% of mathematics is theoretical mathematics, and there's a very tiny amount of experimental mathematics.
Lex Fridman Podcast
#472 β Terence Tao: Hardest Problems in Mathematics, Physics & the Future of AI
I mean, people do do it, you know, like if they want to study prime numbers or whatever, they can just generate large data sets.
Lex Fridman Podcast
#472 β Terence Tao: Hardest Problems in Mathematics, Physics & the Future of AI
So once we had the computers, we began to do it a little bit.
Lex Fridman Podcast
#472 β Terence Tao: Hardest Problems in Mathematics, Physics & the Future of AI
Although even before, well, like Gauss, for example, he discovered, he conjectured the most basic theorem in number theory, which is called the prime number theorem.
Lex Fridman Podcast
#472 β Terence Tao: Hardest Problems in Mathematics, Physics & the Future of AI
which predicts how many primes, up to a million, up to a trillion.
Lex Fridman Podcast
#472 β Terence Tao: Hardest Problems in Mathematics, Physics & the Future of AI
It's not an obvious question.
Lex Fridman Podcast
#472 β Terence Tao: Hardest Problems in Mathematics, Physics & the Future of AI
And basically what he did was that he computed, I mean, mostly by himself, but also hired human computers, people whose professional job it was to do arithmetic, to compute the first 100,000 primes or something, and made tables and made a prediction.
Lex Fridman Podcast
#472 β Terence Tao: Hardest Problems in Mathematics, Physics & the Future of AI
That was an early example of experimental mathematics.
Lex Fridman Podcast
#472 β Terence Tao: Hardest Problems in Mathematics, Physics & the Future of AI
Theoretical mathematics was just much more successful because doing complicated mathematical computations was just not feasible until very recently.
Lex Fridman Podcast
#472 β Terence Tao: Hardest Problems in Mathematics, Physics & the Future of AI
Even though we have powerful computers, only some mathematical things can be explored numerically.
Lex Fridman Podcast
#472 β Terence Tao: Hardest Problems in Mathematics, Physics & the Future of AI
There's something called the combinatorial explosion.
Lex Fridman Podcast
#472 β Terence Tao: Hardest Problems in Mathematics, Physics & the Future of AI
If you want to study, for example, Zermatt's theorem, you want to study all possible subsets of numbers 1 to 1,000.
Lex Fridman Podcast
#472 β Terence Tao: Hardest Problems in Mathematics, Physics & the Future of AI
There's only 1,000 numbers.
Lex Fridman Podcast
#472 β Terence Tao: Hardest Problems in Mathematics, Physics & the Future of AI
How bad could it be?
Lex Fridman Podcast
#472 β Terence Tao: Hardest Problems in Mathematics, Physics & the Future of AI
It turns out the number of different subsets of 1 to 1,000 is 2 to the power of 1,000.
Lex Fridman Podcast
#472 β Terence Tao: Hardest Problems in Mathematics, Physics & the Future of AI
which is way bigger than any computer can currently enumerate.
Lex Fridman Podcast
#472 β Terence Tao: Hardest Problems in Mathematics, Physics & the Future of AI
In fact, any computer ever will ever enumerate.
Lex Fridman Podcast
#472 β Terence Tao: Hardest Problems in Mathematics, Physics & the Future of AI
There are certain math problems that very quickly become just intractable to attack by direct brute force computation.