Start digging at all deeply into the problem of consciousness and philosophy of mind, and you’ll quickly encounter arguments of radical solipsism, the view that it is impossible to prove the existence of anything other than your own conscious experience, and certainly not any external reality. Though most philosophers don’t take this claim very seriously, there has yet to be made a convincing argument against it.

Eric Schwitzgebel has just posted an interesting argument suggesting that there may be ways to experimentally disprove radical solipsism, using nothing more than your own mathematical ability and a copy of Excel. It’s certainly preliminary work, but fascinating nonetheless.