By altering the speed of light beams, like those used for data transmission, U.S. military-funded scientists created a hidden pocket in time that one day may be used in computer espionage.
Researchers from Cornell University in Ithaca, New York showed that it’s possible to cloak very fast events -- those lasting less than about 40 trillionths of a second. Further investigation may enable longer occurrences to be obscured as well, according to a paper published in the journal Nature.
The scientists took a stream of light and shifted it through a lens, causing some beams to travel faster and others slower. That created a so-called temporal void, where events -- in this case, a fast pulse of light -- can happen without being observed. When the stream passed through a second lens, no one watching it would know that the light pulse had taken place, the paper said.
“The cartoon version is a robber coming in, opening a safe, stealing and running out, while a closed-circuit television just sees the safe as closed,” said Martin McCall, a theoretical physicist at Imperial College London. He wasn’t a study author, though today’s research was inspired by work his team published in November 2010 online in the Journal of Optics.
The project was funded by the Defense Advanced Research Projects Agency, part of the U.S. Department of Defense responsible for developing new technology for the military.
Most computer data passes through optical fiber cables, where data is compressed as light, enabling communication to pass over long distances at high speeds, said Alexander Gaeta, an applied physicist at Cornell who led the research team. If the research can expand the time pocket from its current scale of picoseconds, or a trillionth of a second, to a nanosecond, or a billionth of a second, it may enable groups like the U.S. National Security Agency or the Central Intelligence Agency to sneak looks at computer data without being detected.
In other words, time spent computer snooping would be cloaked in a temporal void.
“When you put the word ‘cloaking’ in your title, there are a number of applications like that,” Gaeta said, referring to his paper’s title “Demonstration of temporal cloaking.”
There may be other uses, including enabling faster emergency processing of data, he said.
The bank-robbing cartoon idea, though it serves well as a nifty visual to understanding the concept, wouldn’t realistically work, said McCall.
“To cloak minutes, you’d need an apparatus that’s the size of the solar system,” he said. “This is likely to impact at the nanoscale, where it can start to work with timescales of current communication systems.”
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