A black hole: physicists hope to mimic this peculiar cosmic phenomenon in the lab.
Miniature physics phenomena could show hidden shades of space.
An event horizon is dawning in laboratories. Using frozen light, physicists hope to mimic this peculiar cosmic phenomenon and glimpse something like the belches of a black hole.
At the event horizon - the rim of a voracious black hole - dimensions as we know them disappear. To an observer on a spaceship, light and time appear to stand still. A floating spaceman would seem to slow and stop.
On the horizon
Black holes are formed when ancient stars collapse under their own gravity. They pack vast mass into a pinpoint of space. Their intense gravity sucks in anything that passes too close, including light; they even distort time.
As light waves hit the event horizon, they are thought to split into pairs of particles called ’quanta’; one falls into the black hole and one escapes as Hawking radiation. "A pile-up occurs," says Melia. Many light waves produce streams of quanta heading forwards and backwards.
Leonhardt’s idea is to copy this barrier, using the recent demonstration that certain materials can halt light2,3,4. Shining a laser beam into cold matter manipulates the rate that its constituent atoms absorb and re-emit waves of a second beam, causing this second beam to slow or stop.
The point where light stands still is analogous to an event horizon, says Leonhardt: quanta will be emitted. The simulation is a ’naked horizon’: a membranous event horizon without the black hole beyond.
HELEN PEARSON | © Nature News Service
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