Now You See It, Now You Don't: Time Cloak Created

Awesome, it may only be for a fraction of a second but it is still very cool stuff.

Foxnews
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.

‘Invisibility Cloak’ Uses Mirages to Make Objects Vanish

Once again Science Fiction becomes reality.



Wired
It happens when a big change in temperature over a small distance bends light rays so they’re sent towards the eye rather than bouncing off the surface. So if you see a pool of blue water in the middle of the desert it’s just the blue sky being redirected from the warm ground and sent directly into your eye. Your brain, being the clever little computer that it is, swaps this mad image out for something more sensible: a pool of water.

With that in mind, the researchers wanted to find a material that has an exceptional ability to conduct heat and quickly transfer it to surrounding areas to mimic the light-distorting temperature gradients of the desert. That material, they found, was sheets of carbon nanotubes.

The nanotubes — one-molecule-thick sheets of carbon wrapped up into cylindrical tube — have the density of air but the strength of steel. They’re also excellent conductors, making them an ideal material to exploit the “mirage effect.”


Through electrical stimulation, the transparent sheet of highly aligned nanotubes can be quickly heated to high temperatures. By transferring that heat to its surrounding areas, a steep temperature gradient is generated, which causes the light rays to bend away from the object concealed behind the device. Therefore, the object appears invisible.