|
Light barrier broken by German physicists |
|
|
|
|
Written by Staff Writer
|
|
Sep 07, 2007 at 07:29 PM |
Scientists claim to have broken the ultimate speed record - by making photons travel faster than light. Exceeding the speed of light, 186,000 miles per second, is supposed to be completely impossible.
According to Einstein's special theory of relativity, it would take an infinite amount of energy to accelerate an object through the light barrier. Travelling faster than light also turns back time with bizarre consequences.
An astronaut moving beyond light speed would theoretically arrive at his destination before leaving. But two German physicists now claim to have forced light to overcome its own speed limit using the strange phenomenon known as quantum tunnelling.
|  |
The research, published in the new Scientist magazine, involved an experiment in which microwave photons, energetic packets of light, appeared to travel "instantaneously" between two prisms forming the halves of a cube placed a metre apart.
When the prisms were placed together, photons fired at one edge passed straight through them, as expected....
After they were moved apart, most of the photons reflected off the first prism they encountered and were picked up by a detector.
But a few photons appeared to "tunnel" through the gap separating them as if the prisms were still held together.
Although these photons had travelled a longer distance, they arrived at their detector at exactly the same time as the reflected photons.
In effect, they seemed to have travelled faster than light.
Quantum tunnelling is a well known phenomenon that occurs as a direct result of the strange uncertainty which pervades nature at very small scales.
It allows sub-atomic particles to break apparently unbreakable barriers.
Tunnelling is also involved in radioactivity and nuclear fusion.
Without it, the Sun could not shine, and some scientists believe the universe itself only came into existence because of tunnelling.
|
|
Last Updated ( Sep 09, 2007 at 12:19 PM )
|
Blog