Oh, mind you, I don't always agree that 50 million Elvis fans can't be wrong - but it would seem to me that science still covers mathematics better than philosophy - simply because philosophy is often wishy-washy, changes frequently, and is very subjective, where mathematics is pretty solid and rarely changes.
ZaayrDragon - Badly Shaved Monkey has already responded fairly definitively to this, but as a serious student of Philosophy (the academic discipline, not the fruity "here's my belief system") I should add that this is just plain untrue. First off it's untrue because mathematics changes with an interesting frequency at the higher levels, and secondly because philosophy is not in the slightest subjective (it's based around the concept of an
argument for crying out loud, that's intersubjective at the very least), and because it's about as far from wishy-washy as you can get. Also I should add that googling for the definition of Philosophy isn't really a very good method of argumentation here, if only because the question "what is philosophy?" is one of the central questions of.... philosophy. Any definition of philosophy that isn't controversial is going to be fairly strictly methodological, and that sort of definition is going to be one that mathematics tends to fall under reasonably easily.
Taffer:
I think that Mathematics is Logic defined. Maths is simply a way of representing logic, and allowing us to do very complicated logical processes without overheating our own brain.
Technically, the way of representing logic is called Formal Logic, and while it's the area of Philosophy that is the most mathematical (in fact, there's really little ground on which to divide mathematics and philosophy strictly due to this massive overlap), it's still technically a part of Philosophy and not Mathematics. (In, at the very least, in the sense that if you take Logic in a university it'll be under the purview of the Philosophy department more often than not.)
Also, under the philosophic usage of 'possible worlds' there wouldn't be one where 1 +1 didn't equal 2. 1, +, and 2 are considered rigid designators which apply to the same objects across all possible worlds, and it's logically necessary that 1+1=2. Now, there could be a possible world where in that world's version of English differed enough that the sentence spoken out loud meant something different, but thats an entirely different matter from saying that in that world 1+1 =/= 2.
(Also this is far from the same thing as a possible world in which there are more than 3 spatial dimensions - as it isn't a logically necessary truth that there are 3 spatial dimensions. (Or, at the very least, it's a fairly controversial one that requires some serious argumentation to establish.))