Professor Du Shengwang at the Hong Kong University of Science and Technology claims proof that a single photon obeys Einstein's theory of General Relativity. Expanding on this claim, Prof. Du asserts that this proves that time travel is impossible.
In essence, the good professor's claim is that the quantum behavior of light which his team has observed also confirms the wave behavior of light. He further asserts that because a photon cannot move faster than a photon, then neither can anything else.
First, it's clear that Prof. Du is only addressing time travel to the past with this claim, as we all travel through time at 60 sec/minute, absent any particular acceleration frame.
Secondly, it's also clear that Prof. Du is overreaching in his application of this "discovery" that photons move at the speed of light.
Consider the familiar twins paradox, where one is accelerated to a significant proper fraction of the speed of light and the other remains stationary during his twin's travels. When they are reunited, the returning twin will find that he has moved into his own future - more time will have elapsed on Earth (we'll assume that's the locale) than will have for him in his ship.
Observed, however, from the opposite viewpoint, the stationary twin - in a very real sense - will have traveled to his own past, as represented by his now-younger twin.
According to Einstein, it's all one which frame of reference we choose, so there's no real reason, other than convention, to choose only the future-ward time dilation.
We believe that at Groom Lake, government physicists are currently experimenting with just this sort of reference-frame reversal scenario in order to develop a faster than light drive.
If nothing else, there is always the Warp Drive outlined at Baylor University which addresses this precise thought experiment: they force the "ship" to remain stationary while forcing space itself to flow past at ftl speeds.
Posted by Procrustes 17
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