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Summary:
Alexander Gaeta, Cornell professor of applied and engineering sciences, and colleagues have made a small scale of a temporal cloak which transports information by a beam of light. They created a time lens, very similar to the way glass lenses focus light, which can control signals in time. They used a technique called four-wave mixing in which two beams of light, a signal and a pump, are combined together through an optical fiber. When they are combined, they change the wavelength of the signal being sent. To create the time gap, the researchers controlled the signals wavelengths to go up while they bumped down the pumps wavelengths. The beam then travels through another very long stretch of the fiber. While this occurs the light passing through is slowed down. How slow the light travels is related to the wavelength. During the gap researchers found a beam of light at a higher wavelength causes a flaw in the light coming through to the other end. Afterwards, the higher wavelength will catch up to the slower, closing the gap. Next, another four-wave mixer pulls both parts back and shapes them into their original form. This shows evidence that no gap ever existed and their is no evidence to show its existence.
Critique:
This is a very interesting finding. What if one day we will all be able to travel back in time?
Impact:
I think that this discovery in science will help scientists better understand the concept of time.
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