Lene Hau has already shaken scientists' beliefs about the nature of things... in 1998, Hau, for the first time in history, slowed light to 38 miles an hour, about the speed of rush-hour traffic...
Two years later, she brought light to a complete halt in a cloud of ultracold atoms... In the experiment, a light pulse was slowed to bicycle speed by beaming it into a cold cloud of atoms. The light made a "fingerprint" of itself in the atoms before the experimenters turned it off. Then Hau and her assistants guided that fingerprint into a second clump of cold atoms. And get this - the clumps were not touching and no light passed between them."The two atom clouds were separated and had never seen each other before," Hau notes. They were eight-thousandths of an inch apart, a relatively huge distance on the scale of atoms.
The experimenters then nudged the second cloud of atoms with a laser beam, and the atomic imprint was revived as a light pulse. The revived light had all the characteristics present when it entered the first cloud of atomic matter, the same shape and wavelength. The restored light exited the cloud slowly then quickly sped up to its normal 186,000 miles a second...
She is coolly confident that light-to-matter communication networks, codes, clocks, and guidance systems can be made part of daily life. If you doubt her, remember she is the person who stopped light, converted it to matter, carried it around, and transformed it back to light.
31 July 2009
Light converted into matter - and back into light!
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Are there no constants in this universe?
ReplyDeleteThere must be a time machine in there somewhere...
ReplyDeleteNo, not a time machine... but think of it... if other matter could somehow be linked to a mass of frozen Light, perhaps we have just made the first babystep into lightspeed travel?
ReplyDeleteSo are the temperatures involved colder than deep space? Almost certainly not, so it would appear to be the super cold clouds that cause the effects?
ReplyDelete@Doc Rock: Good grief. Could this mean that the speed of light in space isn't what we think it is?
ReplyDeleteNo, speed of light in space is still the same. This phenomenon relies on super cold, super dense (relatively) clouds of atoms. Space is regarded as a vacuum, and they don't kid when they use the term. Space is not necessarily cold air, it is the manifest absence of heat. Heat is particle motion. No particles, no motion, no heat. Ergo, no super dense super cold atom clouds to slow light, no alteration of the speed of light. Fascinating though are the NASA studies about the changes in passage of time. (Something postulated LONG before space travel was possible, but confirmed. Time moves more slowly in space. This too deals with speed of light constants. Very cool stuff).
ReplyDeleteClarification - by "not necessarily cold air" this means NOT cold air...there is no air in space (air referring to the distinct gaseous mixture that floats around our atmosphere). Furthermore, that time "moves more slowly" in space is explained by the fact that the speed of light is a relative constant (relative to what speed we are moving at)...not sure if I clearly or accurately related that in the previous post.
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