Scientists are believed to have long known that the speed of light can be slowed slightly as it travels through materials such as water or glass. But can the speed of light be slowed down? Scientists have discovered a way out of it. DailyMail reports:
However, it has generally been thought impossible for particles of light, known as photons, to be slowed as they travel through free space, unimpeded by interactions with any materials. But now in new research, scientists have managed to slow photons in free space for the first time – suggesting the speed of light is even more complex than we imagined.
The research was outlined in a paper published in Science Express today. Researchers from the University of Glasgow and Heriot-Watt University described how they have managed to slow photons in free space. They demonstrated that applying a ‘mask’ to an optical beam, which changed the shape of photons, can reduce their speed.
The team compare a beam of light, containing many photons, to a team of cyclists who share the work by taking it in turns to cycle at the front. Although the group travels along the road as a unit, the speed of individual cyclists can vary as they swap position.