The black hole is one of the most interesting ideas in physics because the rules of the universe as we understand them react differently in black holes. Yet the traditional black hole in which gravity is so heavy that not even light can escape is not the only form of this phenomena. There are subtypes of black holes, and one of those, the sonic black hole, has been created in a lab.
As the name suggests, the sonic black hole is similar to the true black hole except that instead of everything being drawn in, it is sonic waves which are trapped inside this effect. This was done by Israeli scientists in 2009 and the hope is that it will allow scientists to examine the phenomena of black holes better. More recently, a far larger experiment was done in which hundreds of thousands of atoms were slowed, rather than a few dozen.
In order to create a black hole, the scientists created the Bose-Einstein condensate. This involves cooling two clouds of rubidium cooled to as close to absolute 0 as possible with a very small gap between them. This creates a gap with very low density, and atoms flow through it faster than the speed of sound. Because the atoms are moving faster than the sound waves, the sound waves fall backwards as they try to flow out. The easiest way to explain it is like trying to swim against a strong current. Currently the scientists who did this were able to create it for eight milliseconds with the use of lasers in order to create the near absolute 0 conditions.
There are a number of reasons why this is an important experiment that scientists have been trying since the idea of a sonic black hole was first created, but one of the major ones is that it could help to prove the existence of Hawking radiation.
Hawking radiation is a radiation which is expected to be emitted from true black holes is important because it means that matter can escape from a true black hole. This is important for a number of reasons, but the primary one is that this type of radiation means that given enough time, even black holes could evaporate. Another important point is that because light and other radiation is not drawn into a sonic black hole, the ability to actually examine this is far easier than a traditional black hole.
While there may be little or no current practical value to the creation of a sonic black hole, experiments like this one can help us better understand the basic nature of the universe because the most important questions in science are not the ones we already know, and this type of experiment is the type that can lead us to answers for which no one had a question.
Sources:
http://dsc.discovery.com/news/2009/06/17/sonic-black-hole.html
http://www.physorg.com/news/2011-01-physicists-sonic-black-hole-lab.html
