A Filipina physicist from the University of the Philippines and her colleagues at the University of Glasgow have discovered how to slow down light travel to less than the speed of light without actually touching it.
Dr. Jacqueline Romero, who finished both her undergraduate and graduate studies in Physics at the UP and is currently on a post doctoral fellowship in Scotland, is part of a team of scientists who have finally proven by experiment that light particles can be slowed down in a near- vacuum.
The speed of light at 186,282 miles per second in free space has been regarded as an absolute.
In common refraction, this speed has been observed to slow down and change direction when passing through glass or water and going back to its higher velocity as soon as it returns to free space.
But Romero’s team has shown that the speed of light can remain slowed down even after returning to free space, and that it can do so without interacting with glass or water.
The results been published in the Science Express journal in the paper “Spatially structured photons that travel in free space slower than the speed of light” by collaborators from the Scottish Universities Physics Alliance which include fellow physicists Daniel Giovannini, Václav Potocek, Gergely Ferenczi, Fiona Speirits, Stephen M. Barnett, Daniele Faccio, and Miles J. Padgett.
Their experiment had the team placing individual particles of light called photons on a racetrack with one photon left in its normal state, and the other sent through a special mask. The mask changed the photon’s shape, slowing them to less than the speed of light. The photon continued to travel at the lower speed at 0.001% slower than the (normal) speed of light even after being released to free space.
The experiment is considered ground-breaking and will likely change how science views light henceforth.
The implications may range from a review of the accurate measure if very short distances using large aperture lenses, to the use of light to make extremely precise measurements in determining how far the Moon is from Earth.
While there are no immediate practical applications for this scientific feat, the results of the experiment has reignited talk of the possibility of teleportation and suspending sunlight in thin air.
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