Leave it to a bunch of physicists to get all practical on us and publish a paper definitively killing the idea of time travel – one of the great storytelling tools of science fiction. A team at Hong Kong University of Science and Technology, led by Du Shengwang, said they had proven that a single photon, or unit of light, “obeys the traffic law of the universe.”
What is the “traffic law of the universe.” According to the University website, “Einstein claimed that the speed of light was the traffic law of the universe or in simple language, nothing can travel faster than light.”
If this is true, and most reliable physicists believe that it is, this research pretty much kills the idea of time travel, warp speed, and transwarp drive. Science fiction lovers worldwide are crestfallen.
Of course there is some good news. Now I can’t go back in time, kill my grandfather and prevent myself from being born. Which is great, because I don’t have to worry about ending up in a parallel universe with a different psychological arrow of time.
Can I still leave the Earth in a spaceship, get very close to the speed of light in my ship and return to Earth in the future? Yep. But that’s not the kind of time travel the physicists in Hong Kong were trying to debunk.
Their research centered around the idea that nothing can travel faster then light. Which means you can’t get far enough ahead of a light beam (or a beam of other electromagnetic radiation) to read its information in the past. Think of it this way. “I Love Lucy” was broadcast in 1951. The television signals carrying the broadcast left the Earth’s atmosphere at 186,200 miles per second (The speed of light in a vacuum) 60 years ago. In order to see them, you would need to travel faster than they are traveling, pass them in space and then receive them on your TV. This would allow you to see into the past.
The new research says that, since you can travel faster than light, you can never pass, or even catch up to, information that has happened before you – therefore, under Einstein’s “traffic law of the universe,” time travel is not possible.
Of course, this experiment assumes that we cannot imagine or create other ways to solve the problem of time travel. As much as I am a believer in the laws of physics, I am also a hopeless techno-optimist. If faster-than-light time travel is not possible, I’d live to think that one day, we will figure it out using another method. And, no matter what physical walls we hit, I hope we don’t lose the inspiration to imagine the impossible.