Scientists find upper limit for the speed of sound

Soundwave Credit: PublicDomainPictures from Pixabay

A research collaboration between the University of Cambridge, Queen Mary University of London and the Institute for High Pressure Physics in Troitsk has discovered the fastest possible speed of sound.

The result - about 36 km per second - is around twice as fast as the speed of sound in diamond, the hardest known material in the world.

Waves, such as sound or light waves, are disturbances that move energy from one place to another. Sound waves can travel through different mediums, such as air or water, and move at different speeds depending on what they’re travelling through. For example, they move through solids much faster than they would through liquids or gases, which is why you’re able to hear an approaching train much faster if you listen to the sound propagating in the rail track rather than through the air.

Einstein’s theory of special relativity sets the absolute speed limit at which a wave can travel which is the speed of light and is equal to about 300,000 km per second. However, until now it was not known whether sound waves also have an upper speed limit when travelling through solids or liquids.

The study, published in the journal Science Advances, shows that predicting the upper limit of the speed of sound is dependent on two dimensionless fundamental constants: the fine structure constant and the proton-to-electron mass ratio.

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Image: Soundwave
Credit: PublicDomainPictures from Pixabay

Reproduced courtesy of the University of Cambridge



The University of Cambridge is acknowledged as one of the world's leading higher education and research institutions. The University was instrumental in the formation of the Cambridge Network and its Vice- Chancellor, Professor Stephen Toope, is also the President of the Cambridge Network.

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