‘Time Travel Impossible’ According to Hong Kong Scientist’s Study

AFP – A group of physicists from the Hong Kong University of Science and Technology research team claim they have proved that outside science fiction, time travel is impossible.

The HK research team, led by Du Shengwang, said they had proved that a single photon, or unit of light, “obeys the traffic law of the universe.”

“Einstein claimed that the speed of light was the traffic law of the universe or in simple language, nothing can travel faster than light. Professor Du’s study demonstrates that a single photon, the fundamental quanta of light, also obeys the traffic law of the universe just like classical EM (electromagnetic) waves,” the university posted on its website.

According to the research team, the possibility of time travel was raised 10 years ago when scientists discovered superluminal – faster than the speed of light – propagation of optical pulses in some specific medium. Despite the fact that it was later found to be a visual effect, some researchers continued to believe it might still be possible for a single photon to exceed light speed.

Du, however, believed Einstein was right and determined to end the debate by measuring the ultimate speed of a single photon, which till now, had never been done before.

“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,” said Du, assistant professor of physics. “Our findings will also likely have potential applications by giving scientists a better picture on the transmission of quantum information.”

The team’s study was published in the US peer-reviewed scientific journal Physical Review Letters.