Now you see it, now you don't: Time cloak created

[DreamsInDigital]

http://web.charter.net/api/hangar.php/c21hcnRjcm9wOjMwMDoyNzQsc21hcnRyZXNpemU6MzAwOjI3NDox/http://newsimages.charter.net/ap_photos//8336420a-9d78-4843-849d-ab5bf6516237.jpeg
WASHINGTON (AP) — It's one thing to make an object invisible, like Harry Potter's mythical cloak. But scientists have made an entire event impossible to see. They have invented a time masker.

Think of it as an art heist that takes place before your eyes and surveillance cameras. You don't see the thief strolling into the museum, taking the painting down or walking away, but he did. It's not just that the thief is invisible — his whole activity is.

What scientists at Cornell University did was on a much smaller scale, both in terms of events and time. It happened so quickly that it's not even a blink of an eye. Their time cloak lasts an incredibly tiny fraction of a fraction of a second. They hid an event for 40 trillionths of a second, according to a study appearing in Thursday's edition of the journal Nature.

We see events happening as light from them reaches our eyes. Usually it's a continuous flow of light. In the new research, however, scientists were able to interrupt that flow for just an instant.

Other newly created invisibility cloaks fashioned by scientists move the light beams away in the traditional three dimensions. The Cornell team alters not where the light flows but how fast it moves, changing in the dimension of time, not space.

They tinkered with the speed of beams of light in a way that would make it appear to surveillance cameras or laser security beams that an event, such as an art heist, isn't happening.

Another way to think of it is as if scientists edited or erased a split second of history. It's as if you are watching a movie with a scene inserted that you don't see or notice. It's there in the movie, but it's not something you saw, said study co-author Moti Fridman, a physics researcher at Cornell.

The scientists created a lens of not just light, but time. Their method splits light, speeding up one part of light and slowing down another. It creates a gap and that gap is where an event is masked.

"You kind of create a hole in time where an event takes place," said study co-author Alexander Gaeta, director of Cornell's School of Applied and Engineering Physics. "You just don't know that anything ever happened."

More here- Story Continues Here. (http://www.charter.net/news/read.php?rip_id=%3CD9S29UE00%40news.ap.org%3E&ps=1011&page=2)

[bennycog]

The NSM news article ! :) I was nearly going to start a thread.. You can't imagine how far ahead they actually are? Well yes Avalonia can :) They only release the news when they think they dont need to keep it secret anymore.. More chess at hand?..

http://news.ninemsn.com.au/world/8398571/Physicists-time-cloak-stops-the-clock

Pentagon-supported physicists say they have devised a "time cloak" that briefly makes an event undetectable.

The laboratory device manipulates the flow of light in such a way that for the merest fraction of a second an event cannot be seen, according to a paper published in the science journal Nature.

It adds to experimental work in creating next-generation camouflage - a so-called invisibility cloak in which specific colours cannot be perceived by the human eye.

"Our results represent a significant step towards obtaining a complete spatio-temporal cloaking device," says the study, headed by Moti Fridman of Cornell University in New York.

The breakthrough exploits the fact that frequencies of light move at fractionally different speeds.

The so-called temporal cloak starts with a beam of green light that is passed down a fibre-optic cable.

The beam goes through a two-way lens that splits it into two frequencies - blueish light that travels relatively fast, and reddish light that is slower.

The tiny difference in speed is then accentuated by placing a transparent obstacle in front of the two beams.

Eventually a time gap opens up between the red and blue beams as they travel through the optical fibre.

The gap is tiny - just 50 picoseconds, or 50 millionths of a millionth of a second.

But it is just long enough to squeeze in a pulse of laser at a different frequency from the light passing through the system.

The red and blue light are then given the reverse treatment.

They go through another obstacle, which this time speeds up the red and slows down the blue, and come to a reverse lens that reconstitutes them as a single green light.

But the 40-picosecond burst of laser is not part of the flow of photons, and thus cannot be detected.

In a commentary, optical engineers Robert Boyd and Zhimin Shi of New York's University of Rochester, likened the experiment to a level crossing on a busy road.

When a train comes, the cars are stopped, and this causes a gap in the traffic.

When the train has passed, the stopped cars speed up until they catch up with the traffic in front of them. To the observer, the flow seems quite normal, and there is no evidence that a train has crossed the intersection.

After proving that the "cloak" is possible, the next step for the researchers is to expand the time gap by orders of magnitude, firstly to microseconds and then to milliseconds, said Boyd and Shi.

The time cloak has a potential use in boosting security in fibre-optic communications because it breaks up optical signals, lets them travel at different speeds and then reassembles them, which makes data hard to intercept.

Last year, scientists reported a step forward in so-called metamaterials that act as a cloaking of space, as opposed to time.

Metamaterials are novel compounds whose surface interacts with light at specific frequencies thanks to a tiny, nano-level structure. As a result, light flows around the object - rather like water that bends around a rock in a stream - as opposed to being absorbed by it.

Fridman's work was part-supported by the Defense Advanced Research Project Agency, or DARPA, a Pentagon unit that develops futuristic technology that can have a military use. Its achievements include DARPANet, a predecessor of the internet.