What can science prove?

[Frank]

You might say I can't conclusively say that because I can't even be sure I exist. But I am sure I exist

Doesn't matter how sure you are. You have no proof beyond "reasonable", "allowable", "mainstream" assumptions. In the every day, colloquial sense of "proof", sure, everything you're saying is correct. But in it's strictest sense, no. It is in that strict, perhaps overly pedantic sense that my argument presides. You can prove things to a level of absolute certainty to people, yet still not have it proven as a certainty itself.

I'm with the philosophers on this one. I believe that's where the philosophy of science lies.

If some philosophers would like to think there's a transcendent definition of certainty that's fine by me (and I might not necessarily disagree, depending on context), but it still doesn't preclude what I'm trying to say. It's a matter of context. For instance, if I qualify a statement (by saying "assuming I exist and the laws of nature remain unchanged") then I can make conclusive statements.