Wednesday, August 22, 2007

Flash Facts: Quantum Tunneling

Has the speed of light been broken? A pair of German physicists claim to have done just that, reports the Scotsman. Using a process known as quantum tunneling, Dr. Gunter Nimtz and Dr. Alfons Stahlhofen of the University of Koblenz say they have accelerated microwave photons past the speed of light in defiance of Einstein's special theory of relativity, which states that an infinite amount of energy would be needed to accelerate any object beyond the speed of light. "In an experiment, 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." Aephraim Steinberg, a quantum optics expert at the University of Toronto, isn't buying it, however. At New Scientist, Steinberg offers an explanation for the quantum tunneling effect, leaving Einsten's theory and the speed of light intact.

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