scipaBreaking the rules of relativity
May 12th 2006 13:08
When Einstein proposed his theory of special relativity in 1905, he suggested that the speed of light, c, is a fundamental constant of nature. According to his work, the speed of light is always constant regardless of the speed of the observer and no information can be transmitted faster than the speed of light in a vacuum.
Einstein’s theory has come under fire over the years, as light has been made to move faster and slower than the prescribed c under experimental circumstances – using lasers, evanescent waves or quantum mechanics. Now, physicists at the University of Rochester, New York, have stumbled upon what they call “light’s most exotic trick yet” – moving backwards, and at a speed greater than c!
Backward motion is achieved with a pulsed laser in a length of optical fibre. The May 11 University of Rochester media release explains: “As the pulse enters the material, a second pulse appears on the far end of the fiber and flows backward. The reversed pulse not only propagates backward, but it releases a forward pulse out the far end of the fiber. In this way, the pulse that enters the front of the fiber appears out the end almost instantly, apparently traveling faster than the regular speed of light. To use the TV analogy again—it's as if you walked by the shop window, saw your image stepping toward you from the opposite edge of the TV screen, and that TV image of you created a clone at that far edge, walking in the same direction as you, several paces ahead.”
The key to this apparent violation of the rules of relativity lies in the second postulate of special relativity that states that no information can be transmitted faster than c. Here light appears to travel so quickly backwards because the original information has been split and sent in different directions.
What a very elaborate illusion…
Einstein’s theory has come under fire over the years, as light has been made to move faster and slower than the prescribed c under experimental circumstances – using lasers, evanescent waves or quantum mechanics. Now, physicists at the University of Rochester, New York, have stumbled upon what they call “light’s most exotic trick yet” – moving backwards, and at a speed greater than c!
Backward motion is achieved with a pulsed laser in a length of optical fibre. The May 11 University of Rochester media release explains: “As the pulse enters the material, a second pulse appears on the far end of the fiber and flows backward. The reversed pulse not only propagates backward, but it releases a forward pulse out the far end of the fiber. In this way, the pulse that enters the front of the fiber appears out the end almost instantly, apparently traveling faster than the regular speed of light. To use the TV analogy again—it's as if you walked by the shop window, saw your image stepping toward you from the opposite edge of the TV screen, and that TV image of you created a clone at that far edge, walking in the same direction as you, several paces ahead.”
The key to this apparent violation of the rules of relativity lies in the second postulate of special relativity that states that no information can be transmitted faster than c. Here light appears to travel so quickly backwards because the original information has been split and sent in different directions.
What a very elaborate illusion…
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Comment by liz
hope you like today's post on UFOs a little better