by Terrence Aym
January 10, 2012
A team of Pentagon, DARPA-funded physicists at Cornell University made magic happen in their lab: they created a gap in perceived time that cloaks objects and events.
One day such technology may permit soldiers and intelligence agents to carry out secret operations completely undetected. Some even envision a veritable stealth army of temporally-cloaked agents operating behind enemy lines—or infiltrating enemy installations—invisible from the outside perceived time flow.
The breakthrough research headed by Moti Fridman of Cornell—results published in the journal Nature ["Demonstration of temporal cloaking"]—pushes the proverbial envelope of recent experiments manipulating time and space to achieve heightened levels of covertness.
According to the editors of Nature, the success of the experiment is “a significant step towards full spatio-temporal cloaking.”
How to manipulate the spatio-temporal environment
According to the paper appearing in Nature, the scientists tweaked time and space through the clever manipulation of light in fiber optic cables. They achieved the masking of an event for a tiny fraction of a second.
Although admittedly the gap in perceived time is small, the research may open the door towards the achievement of longer events culminating with spatio-temporal cloaking devices that can be used by humans to cloak actions, machinery, even air and spacecraft.
The method the scientists used to create the cloak takes advantage of the intrinsic nature of light.
Although most have been taught that light travels at a uniform speed of 186,000 miles per second, that’s not quite true. Different frequencies of light travel at slightly different speeds. The team subtly manipulated the normal light flow for the barest fraction of time enabling an event to occur without light emitting from it. Such manipulation results in an object or event effectively becoming invisible—as if a hole were punched in the time stream.
Green meets red — and ever the twain shall meet
The ingenious manipulation of time allows using its properties to cloak things, perhaps much bigger things in the future.
Wired.com describes the actual method: “The entire experiment occurred inside a fiber optics cable. Researchers passed a beam of green light down the cable, and had it move through a lens that split the light into two frequencies, one moving slowly and the other faster. As that was happening, they shot a red laser through the beams. Since the laser “shooting” occurred during a teeny-tiny time gap, it was imperceptible.”
The technique also has major implications for sending encrypted messages. When light can be segmented, redirected and “gapped,” secret messages can be impossible to decode, or even detect.
“Our results represent a significant step towards obtaining a complete spatio-temporal cloaking device,” the study claims.