Henry Stone
Chrono Cadet
The problem that I never see anyone addressing is what the exact nature of time travel is (for the self-proclaimed traveller, at least). The idea of "okay, you go back in time and check X out, then return" is nice and all, but what if time travel is not a neat little tool that you can just do? Terminator-style TT would not let the traveller jump around like that. And anything that can be predicted with pinpoint accuracy is likely possible to deduce through other means (predicting weather phenomena or seismic activity, even sports statistics or market fluctuations. Some people do that for a living. Some are even good at it!). Not only that, but if the interviewer can ask the traveller *anything*, that requires the traveller to have brought knowledge of *literally everything* along! Even if you just go back a day, that's a big piece of mental luggage....I personally doubt that a universal test is even possible. It would take a close study at the traveller's claims of how TT work to design a test, and it would require something other than a "gotcha" mentality, since it would have to be fitted to the means that could rationally be expected from the traveller. And you would have to account for the idea that even a true, honest-to-Vishnu time traveller might still be a complete nut, who believes the Moon is made of goat's cheese and whales are soulless killers from the planet Nebiru.How would you be able to prove a time traveler is real? I'm trying to come up with a fool proof method and falling short.
In short, we'd need a true science of *dealing* with time travel, even long before the science of actual TT comes around...