Stopping light in its track

Feb 14, 2008 10:31 GMT  ·  By

Black holes are some of the most mysterious objects in the whole universe. Except a handful of properties, almost nothing is known about what lies beyond their event horizon, whether it's a wormhole, a ultra-dense singularity or some other structure we have no knowledge about. And here is the worst part of the problem, we may never peer beyond the event horizon of a black hole to see what lies inside it. I mean one may observe what the inside of a black hole looks like, but it would probably be the last thing he ever sees!

A UK team of physicists claim to have recently succeeded to simulate the properties inside the event horizon in laboratory conditions, with the help of a special optical laser system. The experiment relies on the principle that light of different wavelengths travels at different speeds through a fiber optic.

Thus, by sending a low speed laser pulse through a optical fiber, followed by another fast traveling laser signal, the optical properties of the optical fiber system will be distorted so severely, that the second laser signal traveling at high speeds through the fiber would actually reduce its speed as it encounters the first fired signal. While trying to surpass the speed of the first signal, the fast laser pulse would actually be captured by the slow moving signal, replicating the properties of a black hole's event horizon.

This way physicists are able to study the effects on light both out and inside the event horizon of a black hole, something impossible until now through astronomical observations. Following the publication of the study, astrophysicist rushed to calculate the frequency shift which takes place as the light approaches the event horizon of a black hole, and, not surprisingly, the calculations match the results of the laser experiment conducted at the University of St. Andrews.

Although it is said that nothing can escape the gravitational pull of a black hole, during the 1970s, British physicist Stephen Hawking calculated that, in fact, black holes should radiate particles through the event horizon, through a process widely known as Hawking radiation. Given enough time, a black hole would evaporate out of existence. However, observing this specific radiation coming from a black hole is close to impossible, considering the amount of radiation noise through the universe.

By using the laser system method, UK physicists calculate that their artificial event horizon could radiate photons while heated to about 1000 degrees Celsius.