Measuring the temperature of a real-life black hole may be a near-impossible mission. Physicists have now succeeded in taking the temperature of an experimental sonic black hole produced in the lab. This experiment has also helped scientists look into the predictions of cosmologist Stephen Hawking.
Experimenting with a Lab-made Black Hole
The sonic hole used in the research traps sound rather than light. This work is helpful in proving Hawking’s prediction that black holes are not really black. The prediction expands to say that at each black hole’s edges, there is a small stream of particles bleeding out. This is said to happen at a temperature determined by the relative size of the black hole itself. The particles moving out of a true black hole make up very faint radiation, so this is difficult to observe. Physicists have, however, been able to spot traces of radiation from black holes simulated in the lab.
The sonic black hole was created using atoms of the element rubidium. These particles were chilled to the extreme to reach a state referred to as Bose-Einstein condensate, after which they were allowed to flow. In this state, the atoms prevent the escaping of sound waves. This is similar to how a black hole traps light using its gravity.
The results of the new study align with Hawking’s prediction about the temperature of a sonic black hole. The work is reported in a recent edition of Nature. The findings have been hailed by physicists, including Ulf Leonhardt from the Weizmann Institute of Science in Rehovot, Israel. He was not part of the study but points out that the experimental findings are a significant milestone for the field in an area never tested before. Previous experiments have only gone as far as demonstrating the presence of radiation but without taking the temperature of the lab black hole.