I understand that forward time travel in a sense is possible when traveling at high speeds preferably near the speed of light. I understand time dilation and how it works. Then I read on how backwards time travel could be possible, and that is where it did not make much sense to me. Im not questioning, if these theories are correct, if it is possible, i know with our technology that it is not. My question is how it would be possible just in theory. I read on cosmic strings and how they can achieve backwards time travel, they can make a gap in spacetime to travel across, then i read if you go back across you're going back in time? that doesn't make sense to me. I also heard that if you were able to stay stationary and if you could rotate the universe while you were stationary you could go backwards in time. That also doesn't make sense to me. maybe im not understanding spacetime fully. can someone clarify spacetime and those thoeries to me.
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Time travel itself doesn't make much sense to me. What appears to be possible on paper in complex math calculations and formulas isn't always the reality.
For instance, time stops at the speed of light - so, in theory, if a man could travel at the speed of light, he could transverse the entire universe in no time - despite the universe's enormous, incomprehensible size.
Time travel into the future is not only possible but we, you and I, do it every time we hop on an airplane and travel somewhere. True the future is only microseconds from the past, but it is the future when we hop off a plane and check the wall clock in the terminal.
On the other hand, travel into the past is impossible, even by worm holes that tear and J-walk across the fabric of the space-time continuum. And this is the time travel theory I believe you are talking about. But Stephen Hawking, who knows a little bit about time travel, says using worm holes will not work because of positive feedback.
Positive feedback is that effect that causes an amplifier to screech when a mike gets too close to it. In the case of the worm hole, the positive feedback is of the radiant energy of the here and now, which feeds through the hole into the there and then, and then comes back to the here and now to form a loop of radiant energy. As a closed loop, the cycle repeats itself building up in energy each time until the worm hole almost instantaneously explodes and destroys itself, and everything and everyone inside it. [See source.]
It is much more of a phenomena of the concept of time fundamentally breaking down at the quantum level that enables quantum reverse time travel.
You cannot really guarantee reverse time travel in any experiment.