Is it possible to slow down light

Professor Padgett added: "It might seem surprising that light can be made to travel more slowly like this, but the effect has a solid theoretical foundation and we're confident that our observations are correct. We expect that the effect will be applicable to any wave theory, so a similar slowing could well be created in sound waves, for example.

The team's paper, titled 'Spatially Structured Photons that Travel in Free Space Slower than the Speed of Light', is published in Science Express , which provides electronic publication of selected papers in advance of print in the journal Science. Materials provided by University of Glasgow. Note: Content may be edited for style and length. Science News.

Story Source: Materials provided by University of Glasgow. Journal Reference : D. Giovannini, J. Romero, V. Poto ek, G. Ferenczi, F. When the laser is abruptly switched off, a slow pulse of light is imprinted onto the atoms, essentially bringing the light to a halt by absorbing it; the imprinted shape can then be converted back into a photon.

But it's the second method that allowed the researchers to make their breakthrough. Photonic crystals are materials perforated with billions of tiny holes through which light refracts, according to Reader's Digest.

A waveguide, meanwhile, is a confining tube-like structure, which, as the name suggests, guides the waves sent inside it any kind of waves, but in this case optical waves.

But it remains to be seen whether the approach can be extended to fully stop the pulse. This research is published in Physical Review A. Ana Lopes is a Senior Editor of Physics. A 95 , It changed the photons' shape - and slowed them to less than light speed.

The photons remained travelling at the lower speed even when they returned to free space. The experiment is likely to alter how science looks at light. They have published their results in the journal Science Express. The speed of light is regarded as an absolute.

It is , miles per second in free space. Light propagates more slowly when passing through materials like water or glass but goes back to its higher velocity as soon as it returns to free space again. Two and a half years ago, the experimenters set out to see if they could slow down light just a little - and keep it moving more slowly.

In a laboratory at Glasgow university, Dr Jacquiline Romero, Dr Daniel Giovannini and colleagues built what amounts to a racetrack for photons, the individual particles of light.

Then they raced them in pairs. One photon they left in its normal state. The other photon was sent through a special mask. The mask forced the photon to change its shape and travel slower than the speed of light.