“OK, so, some scientists at MIT think they’ve come up with a viable model for time travel. Granted, there are other models, many of them it seems, for real-life time travel but all of them use the ideas of relativity and extremely curved/disrupted space-time. That means that under relativity, time travel should be able to happen in a place like a black hole, where space-time is just getting shredded, or in a theorized wormhole, which is a place in the universe that “breaks off” from our universe and rejoins at a different time.
"I’m hazy on exactly what their paper is getting at, but that open span of probability seems to be part of why this is possible. And something called “post-selection,” which, from what I gather, is like taking an event, a thing that happened in the world, changing it or doing something to it, and thereby “conditioning” the cause of that event. That’s a serious brain knot, I know, but it’s a thing that scientists are working out as possible. It’s part of why quantum computing is such a big deal.
"Then, for the time machine, you take that effect and combine it will quantum teleportation, which, if you’ll remember, is the instantaneous, faster-than-light communication method between two “entangled” particles. So I guess it’s more like being in two places at once, one here and one there communicating with each other in a sort of closed space-time loop. So it’s not really free-reign time travel I don’t think, or maybe not even travel back to “our” universe—but travel to a parallel “our” universe instead."