Research ArticlePHYSICS

Speed of sound from fundamental physical constants

See allHide authors and affiliations

Science Advances  09 Oct 2020:
Vol. 6, no. 41, eabc8662
DOI: 10.1126/sciadv.abc8662


Two dimensionless fundamental physical constants, the fine structure constant α and the proton-to-electron mass ratio mpme, are attributed a particular importance from the point of view of nuclear synthesis, formation of heavy elements, planets, and life-supporting structures. Here, we show that a combination of these two constants results in a new dimensionless constant that provides the upper bound for the speed of sound in condensed phases, vu. We find that vuc=α(me2mp)12, where c is the speed of light in vacuum. We support this result by a large set of experimental data and first-principles computations for atomic hydrogen. Our result expands the current understanding of how fundamental constants can impose new bounds on important physical properties.

This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial license, which permits use, distribution, and reproduction in any medium, so long as the resultant use is not for commercial advantage and provided the original work is properly cited.

View Full Text

Stay Connected to Science Advances