Physicists have determined an upper limit for the speed of sound
A group of researchers found that the maximum possible speed of propagation of sound waves is about 36 km / s..
Sound waves are disturbances that move energy between points in space and can move at different speeds, depending on the density of the medium of movement. For example, the approach of a train can be recognized earlier by the noise from the rail tracks than by hearing it through the air..
Scientists knew that waves couldn’t travel faster than the speed of light, but they didn’t know how fast sound could travel. Physicists from Queen Mary University of London, Cambridge University and the Vereshchagin Institute for High Pressure Physics of the Russian Academy of Sciences decided to unravel this mystery.
Since the speed of movement of sound waves depends on the constant of the fine structure and the ratio of the masses of the proton to the electron, it can move fastest in metallic hydrogen, with which it is very difficult to conduct experiments under terrestrial conditions due to the difficulty of obtaining (it is formed at a pressure of 4.18 million atmospheres). Therefore, scientists performed the most advanced quantum mechanical calculations to establish an indicator as close as possible to the theoretical fundamental limit..
The results showed about 36 km / s, which about twice the speed of sound in diamond, the hardest known material in the world.
Recall that recently researchers have also discovered a new type of substance inside neutron stars.
text: Ilya Bauer, photo: wallhere