A group of researchers from the Hong Kong University of Science and Technology has declared there will be no machine that can travel through time, because they have proved that nothing can faster than the speed of light.
The research team, led by Du Shengwang, said it has proved a single photon cannot travel faster than the speed of light in vacuum. The study reaffirms Einstein's theory that nothing travels faster than light, and most sadly, proves the impossibility of achieving humanity's dream of time travel as well as faster-than-light warp drive.
"Einstein claimed that the speed of light was the traffic law of the universe -- or, in simple language, nothing can travel faster than light."
"The results add to our understanding of how a single photon moves. They also confirm the upper bound on how fast information travels with light," Du said in a statement put out by the university on its Web site.
The possibility of time travel was raised 10 years ago when scientists discovered superluminal or faster-than-light propagation of optical pulses in some specific medium. However, Du and his crew said this phenomenon is only a visual effect and could not be used for transmitting any real information.
There was also hope that a single photon may be able to travel faster than the speed of light. However, there was no experimental evidence. Du and his colleagues decided to test this and measured the ultimate speed of a single photon with controllable waveforms. The results confirmed Einstein's theory.
"By showing that single photons cannot travel faster than the speed of light, our results bring a closure to the debate on the true speed of information carried by a single photon."
So at least for now, it seems time travel will never become a reality -- and will remain safely in the realm of science fiction.