Saturday, March 29, 2008

The Void

Physicists Make Artificial Black Hole Using Optical Fiber. (Via 3QD). OK, that's interesting. Wonder what that involves...

To make their event horizon, Leonhardt and colleagues used a titanium sapphire laser and a microstructured optical fiber—one containing a hexagonal arrangement of air-filled holes that ran its length. They first transmitted an ultrashort, intense laser pulse down the optical fiber. The optical fiber is susceptible to nonlinear effects, such that when an intense pulse of light hits the fiber, it changes the physical properties of the fiber. In this case, the first pulse created a distortion that amounted to a change in the fiber’s index of refraction, which moves along with the pulse. The pulse itself was slowed by the distortion. Leonhardt and colleagues then sent a “faster” stream of infrared laser light in pursuit of the first pulse. When the faster-moving second pulse encountered the distortion, it got trapped at its edge and couldn’t break past it. This edge became the fiber’s “event horizon.”

“Light propagating in a moving medium is similar to the light propagating in curved space” such as you would find near a black hole, explains Volovik. So “it is possible to create artificial horizons.”

Following Einstein’s theory of relativity, as light approaches the event horizon, it would slow down immensely and be stretched out; time would also proceed very slowly. Scientists have worked out what this deceleration would look like, and Leonhardt and colleagues say they observed the predicted effects in their optical-fiber event horizon.

Leonhardt and his colleagues hope their artificial event horizon will let experimentalists see whether anything can escape from a black hole.

There may be a drawback (although the project below is not the same as above): Black Hole Eats Earth.
...Walter Wagner and Luis Sancho contend that scientists at the European Center for Nuclear Research, or CERN, have played down the chances that the collider could produce, among other horrors, a tiny black hole, which, they say, could eat the Earth. Or it could spit out something called a "strangelet" that would convert our planet to a shrunken dense dead lump of something called "strange matter." Their suit also says CERN has failed to provide an environmental impact statement as required under the U.S. National Environmental Policy Act.
For more, try here.
...For in fact what is man in nature? A Nothing in comparison with the Infinite, an All in comparison with the Nothing, a mean between nothing and everything. Since he is infinitely removed from comprehending the extremes, the end of things and their beginning are hopelessly hidden from him in an impenetrable secret; he is equally incapable of seeing the Nothing from which he was made, and the Infinite in which he is swallowed up. (Pascal, Pensées sect. II, 72).

1 comment:

MT said...

It's not obvious to me that a law wasn't violated when this story crossed the PR event horizon. Here's another model black hole.