Physicists Cast Doubts on Time Travel

My time travel dreams have been shattered. Physicists just proved that I cannot jump into Doc's DeLorean, accelerate to 88 miles per hour, and activate the flux capacitor to travel through time. (The flux capacitor is "what makes time travel possible," according to Dr. Emmett "Doc" Brown in Back to the Future.)

Despite previous speculation to the contrary, single photons cannot travel faster than the speed of light. Physicists at the Hong Kong University of Science determined this when they achieved the previously impossible by measuring an optical precursor. Optical precursors are the waves that precede photons in a material. Trying to picture photons on their correct scale is hard (leaving aside the even more complicated fact that photons don't actually have a defined, single size). Feel free to join me in imagining the optical precursor as the wind you feel rocking your car at the passing of a semi truck.

Theoretical debates raised the possibility of time travel 10 years ago, when scientists discovered superliminal (faster than light) propegation of optical pulses in some specific medium. Though this was later found to be an opitcal effect, researchers still speculated that a single photon might exceed light speed. The Lead physicist on the project, Shengwang Du, was determined to end the debate. His team managed to separate the optical precursor from the rest of the photon wave packet, prooving that Albert Einstein was right when he theorized that nothing in the universe can travel faster than the speed of light.

Not that I personally have the brain power to question Einstein. My brain doesn't work that way. Maybe that's good. It helps the suspension of disbelief required while watching Back to the Future, so that I can at least re-visit the fun to be had in the first and third movies in the trilogy.

Where does that leave the time travel in my book? Time travel by other means has not been entirely ruled out. I'm sticking with my wormhole theory. Imagination still needs the occasional reason to roam.