(Newswire.net — January 23, 2015) — Glasgow, UK – How do you slow the speed of light? Easy, just put it through different materials, like water for example. When light passes through dense environments, the photons slow down. However, here is the light speed constancy thing. At the moment the photon leaves dense area, it speeds up to the famous 186,282 miles per second measured in free space. That is why we say the speed of light is a constant number. Well, until now.
Scientists from the Glasgow and Heriot-Watt universities – members of the Scottish Universities Physics Alliance – managed to slow the photon down below the speed of the light. They published the details and the results of the experiment in the journal Science Express.
Reportedly, they sent photons – individual particles of light – through a special mask, which changed the photons’ shape – and slowed them to less than light speed. They also used a control photon that travels the same distance as a reference point. When the unchanged reference photon enters the meter long track it travels at the constant speed of light. Data showed that the photon which left the mask and changed form, actually remained at a slower speed hitting the target later.
The photon was not significantly slower, just a few millionths of a second. However, it showed that it had not just been slowed by the mask, but had continued to travel at less than light speed even after it had returned to free space.
So what does it mean? Basically, it means that science will now look at the light in an altered way.
“It’s really, really interesting,” said Dr Daniel Giovannini from the University of Glasgow. “It’s just one of those big, fundamental questions you may want to ask yourself at some point in the pub one night,” he said referring to the moments when you question the fundamentals of existence, consciousness or a time travel.
Questioned on the origin of the idea by BBC Scotland’s science correspondent Kenneth Macdonald, Dr Giovannini said it’s been a satisfying intellectual and experimental challenge.
“It mostly comes from a question we asked ourselves two and a half years ago. We just kept working on it.” he said.
Researchers using large aperture lenses to accurately measure very short distances may be forced to take a second look for tardy photons, but the good news is that we are not in for any nasty surprises on shorter distances, BBC reported.
Although Dr Giovannini concedes the physics is more fundamental than applied right now, he believes that practical, everyday uses for the discovery are possible.