Light is pretty fast. In fact, it's the fastest thing we know and, according to physics, nothing can travel faster than the speed of light. Cruising along at 186,000 miles per second one can see how it would be difficult to exceed this speed.
But there's a catch. That's the speed limit of light travelling in a vacuum, like in outer space, for instance. When light travels through other material, it slows down a bit. It's all relative though, for example, the speed of light in water is down to 140,000 miles per second.
But one Danish physicist, Lene Hau, has been using this fact, not to try to break the speed of light barrier, but rather to slow light down as much as possible. And in 2001 she managed to actually stop light completely.
The process through which all of this happens in fiendishly complex and involves a collection of super frozen atoms that have formed together into a superatom known as the "Bose-Einstein condensate." This peculiar atomic cluster, only found fractions of a degree above absolute zero appears to lend itself towards slowing light down very effectively.
To being with Hau managed to slow a light pulse down to 38 miles per hour, little more than the speed of a bicycle. Then, a year later, she managed to stop light altogether.
You might be wondering what possible use this kind of discovery would be, but it actually has a number of applications. The most important would be in the world of supercomputers where the relatively slow speed of electricity is becoming an inhibiting factor in the ultimate processing speed.
The next logical step would be to replace the electrical signals with light signal, except until now, there has been now wa of storing the light signals in a similar manner to the way the electrical ones are stored in a computer memory today.
Computers of the future may well glow in the dark, as the science fiction movies would have you believe.
No comments:
Post a Comment