How to pull of an art heist...or how scientists have created a time-masking cloak

In a popular comparison: an art heist takes place in a crowded museum--before your eyes and surveillance cameras. you don't see the thief, not even the actual taking of the painting. The opportunities would be staggering...and scary, but this is exactly what scientists at Cornell U are claiming to have done. Not the actual heist, but creating a time cloak that hid an event for 40 trillionths of a second.

While other invisibility cloaks created move light beams away from an object (like making an armored tank disappear or nanotubes creating a mirage), the Cornell team (backed by the Pentagon) found a way to alter how fast the light moves, changing the dimension in time, not space. By doing this, it makes it appear to the human eye or surveillance cameras (or even laser security beams) that an event isn't happening.

"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."

This 'hole in time' is created using fiber optics as light moves inside a fiber thinner than a human hair. The scientists shoot the beam of light out. With other beams, they create a time lens that splits the light into two different speed beams that create the effect of invisibility by being too fast or too slow.

In the diagram a laser beam passes through a "split-time lens" - a specially designed waveguide that bumps up the wavelength for a while then suddenly bumps it down. The signal then passes through a filter that slows down the higher-wavelength part of the signal, creating a gap in which the cloaked event takes place. A second filter works in the opposite way from the first, letting the lower wavelength catch up, and a final split-time lens brings the beam back to the original wavelength, leaving no trace of what happened during the gap. (Image and Caption via Cornell University)

"It is significant because it opens up a whole new realm to ideas involving invisibility," McCall said

Click to watch a time cloaking simulation:



If you had such technology, what would you do with it?

Time Travel-- A breakthrough in the Speed of Neutrinos

Do you remember the post I did a few weeks ago about time travel and it not being possible, because scientists had demonstrated that a photon couldn't be sped up beyond the speed of light?

Well, physicians at CERN have had a breakthrough. According to Reuters and BBC, scientists have claimed to have recorded neutrino particles going faster than the speed of light. What does this mean? It means that Albert Einstein's theory of relativity- that nothing can exceed the speed of light- could be wrong.

After thousands of experiments, no result of a particle breaking the limit had ever been documented. The last three years, however, Dr Ereditato and his colleagues have found that neutrinos may just do that.

The team had been preparing a beam of one type of muon neutrinos (neutrinos can come in a variety of different types and can change), sending them from Cern to an underground laboratory. The experiment had been to see how many show up as a different type (tau neutrinos). Instead, what they found was that the particles showed up a few billionths of a second sooner than the speed of light would over the same distance. After repeating the experiment 15,000 times, they reached the same statistical results.

If what was found is true, this could change a lot of what we know about the rules of physics. What do you think of these findings?

Time travel-- Impossible or impossible for now?

We've all watched sci-fi shows and movies with time travel where something is either sent backwards in time or forward into the future. In various shows, a person is usually the one going back and forth (usually with the aid of some kind of device). The idea is based on Einstein's general theory of relativity, suggesting that time slows down for objects moving at high speeds. it also suggests that space and time get pulled out of shape near an accelerated or rotating object.

In the 1920s and 1930s, scientists that an infinitely long cylinder spinning at speeds close to the speed of light could be used to warp space-time. Many experiments have been done, including one by Carrol Alley who synchronized two atomic clocks and put one on an airplane. The one on the plane became microseconds behind the one on ground, suggesting that perhaps time had slowed with the speed of the plane.

And in 2001, Ronald Mallet theorized that the gravitational field produced by a laser beam could be manipulated to allow time travel. Wormholes have also been theorized to perhaps allow instant travel from one point to another (whether it's to one point in time to another or one dimension to another).

However, physicists at Hong Kong have recently demonstrated that a photon cannot be accelerated beyond the speed of light, implying that time travel is impossible at least in one area. The research team, working to Einstein's special theory of relativity (that nothing can travel faster than the speed of light) showed that this is true.

What do you think? Do you think time travel is possible through other means? If you could go back in time, where would you go? Or would you go into the future?

Read the article here.