Let's say you're torn between two worlds. You know that one is a fevered delusion that your mind has created and the other one is reality, but which is which? ... Apply this algorithm in both worlds...
So, after having seen Matrix Reloaded, and having read advice on how to live in a simulation, I find myself wondering, how might I determine whether I'm living in a simulation? Well, I figure chances are, I'm not even living in a decent simulation. In fact, I could just be hallucinating right now. So, Aaron Swartz comes to the rescue with a very reasonable empirical test I can perform. Everything seems to check out.
Problem is, though, the test is completely dependant upon me and my perceptions. First, I have to pick a really big number that's outside my ability to perform a square root on it in my head. Then, someone else performs the square root on a calculator. I then square that number by hand, and that answer should match my first, and since I couldn't possibly perform a square root that large in my head, the answer must've come from outside my head.
Except for this: If I'm hallucinating, then there's a subdivision of me controlling the perceptions of another subdivision of me. Who's to say that the me who's performing this test isn't a complete idiot, and all the math skills are in the part producing the hallucinations? Or, hell, what if for the duration of the test my hallucination producing side decides to make me blind to any numbers greater than 4?
Hmm. Well, just to be safe, I won't try the alternate "Step in front of a bus and see what happens" test. shortname=algorithm_for_reality