We take it for granted that the past is fixed. History always happened the way we remember it happening. But how do we know for sure that that’s the case? If time travel is possible, time travelers could be zipping back and changing things around all the time. How would we even be able to tell if that was the case? We asked a number of experts on time travel — none of whom have actually traveled in time themselves. (Or if they had, they were keeping it under their hats.)
“Presumably, when a time traveler would change our past, this would also instantaneously change our memories of the past in order to render them consistent with the ‘new’ past,” says Christian Wüthrich, a professor of Philosophy and Science Studies at UCSD. …
Time travel is impossible.
We heard this a lot, from many of the experts. As Jon Thaler, a physics professor at the University Illinois at Urbana-Champaign, tells io9: “The problem is that we don’t know how to construct a theory that permits time travel. Without a theory, it is difficult to know what phenomena to look for.” SEE COMPLETE TEXT.