Is the Speed of Light Variable?

"186,000 miles per second: It's not just a good idea... it's the law!"

So goes the old nerdy joke reinforcing what has been drilled into generations of Physics 101 students: the speed of light, as Einstein showed, is constant and absolute, never faster or slower.

Or maybe not. A team of scientists at France's Ecole Polytechnique Federale de Lausanne (EPFL) claims to be able to manipulate the speed of light, speeding it up and slowing it down.

Previously, light speed has been manipulated under highly controlled conditions, using exotic gases and environments. The EPFL experiment, however, used ordinary fiber optics to affect specific portions of the light signal (exploiting a bit of "wiggle room" in Einstein's laws).

The team's success opens up a host of possibilities for controlling signals on a fiber optic cable, allowing standard fiber optics to carry even more data. The benefits of this research could also be applied to microwaves for next-generation wireless communications.

Related research at Princeton has shown that light can be trapped and bent at sharp angles, using quasicrystals made from polymer rods. Such manipulation can lead to more efficient fiber optic junctions.

Source: Ron Piquepaille's Tech Trends, Phys.Org