Of course, that assumes that there is such a proof. While both have been proven, the proofs are by no means simple. But there’s no reason to believe that “simple” proofs exist within our mathematical structure.
And, hey, as long as we’re asking the alien to prove open or difficult problems, why not ask for a polynomial time solution to an NP-complete problem?
I dunno. It’d be cool proving you were an alien, but in doing so you’d be making some serious history, it’d be the biggest news story ever, etc etc. The thing is, it’s something you could only do once. I’d be inclined not to rush it, and to spin out the time beforehand, pretending to be a human who just happens to know or do lots of amazing weird shit. All very A Connecticut Yankee in King Arthur’s Court. It would be somewhat cool.
It also reminds me of this passage from HHGTTG:
The scary thing is, I was actually in Japan a couple of weeks ago.