Archive for July 25th, 2008

What is deep mathematics?

July 25, 2008

Note added 12/9/09: It seems that many people are looking at this post, because Derren Brown claims to have used “deep mathematics” combined with “the wisdom of crowds” to predict the lottery. All I can say is that this is obvious nonsense. Whatever method you use to predict the lottery, the drawing of the balls is a random process, so you will not improve your chances of being correct. Brown has done a clever trick — I won’t speculate about his methods, as I’m not interested enough in them — but his explanation of how he did it is not to be taken seriously.

In this post I shall discuss the proofs of two statements in real analysis, one of which is clearly deeper than the other. My aim is to shed some small light on what it is that we mean when we make that judgment. A related aim is to try to demonstrate that a computer is in principle capable of “having mathematical ideas”. To do these two things I shall attempt to explain how an automatic theorem prover might go about proving the two statements in real analysis: in one case this is quite easy and in the other quite hard but by no means impossible. In the hard case what interests me is the precise ways that it is hard, which I think say something about the notion of depth in mathematics.