Research physicists from the University of Adelaide (Australia), led by Professor Andre Luiten, have created the world's most accurate thermometer. It can measure temperature to the nearest 1 / 30th of a billionth of a degree per second.
As you know, the atoms of any substance are in constant motion and the speed of their movement is not least influenced by the ambient temperature. The thermometer is a polished crystal disk, into which two beams of red and green are introduced. Depending on the temperature of the crystal, the speed of their passage changes.
So, when the crystal is heated, the red ray lags slightly behind the green one. Further, a kind of circulation occurs, as a result of which the rays cross the disk thousands of times, creating the phenomenon of the "whispering gallery" well known in physics. Something similar, only in relation to sound, can be observed in St. Paul's Cathedral in London or among the Quiet Walls of the reservoir at Barossa. Scientists can only measure the existing difference in speed with maximum accuracy.
According to Professor A. Luiten, the developed technique will allow in the future to make ultra-precise measurements of other quantities, for example, pressure, humidity, force, which will be of great importance for scientific research in various fields.