Is it possible to make a time machine ? If yes, how ? If no, why ?Report
We feel that we live in a three-dimensional space and the fourth dimension of time. We can move around in the three-dimensional space freely. But feel that we are traveling linearly in time at a constant rate in the same direction (that we call the future).
Einstein’s special theory of relativity leads to Twin’s paradox and simultaneity and such other paradoxical situations- where the relative space-times of two people can change drastically if they relatively travel at speeds comparable to the speed of light. Of course, such high speeds require huge amounts of energy. Mass also becomes heavier at high speeds.
Although very expensive, at least we know how we can travel to the FUTURE– We just have to travel in a spacecraft at high speeds comparable to that of light.
But then, what about traveling to the past?
Also, what about teleportation in the three dimensions– that is, jumping from one point to another without passing through intermediate points? Do you think we need to solve teleportation problem before we can think of solving time-travel?
Of course, travelling into the future is trivial, since everyone is doing it all the time already. You might be able to move faster in time by moving faster in space, or by living in high orbit for a while¹, but you can achieve the same effects with cryogenic stasis. Get frozen up, take a nap, thaw, wake up. Congratulations, you are now in the future.
Moving through time slower would sound like a more worthwhile thing to try, if for some reason you want to age faster than the rest of us. (Who knows, maybe you just really need to catch a deadline.)
I recall reading somewhere – I think it was in a theoretical physics popular science book, probably Michio Kaku’s Hyperspace – that it would be theoretically possible to create a time machine that takes you into the past, but you could never travel further back than the moment the machine was created.
¹ If I’m not mistaken. I always forget if being close to a heavy object makes time go faster or slower for you, so maybe it’s the other way around.