Speed of sound from fundamental physical constants
Abstract
Two dimensionless fundamental physical constants, the fine structure constant $\alpha$ and the proton-to-electron mass ratio $\frac{m_p}{m_e}$ 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 which provides the upper bound for the speed of sound in condensed phases, $v_u$. We find that $\frac{v_u}{c}=\alpha\left(\frac{m_e}{2m_p}\right)^{\frac{1}{2}}$, 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 current understanding of how fundamental constants can impose new bounds on important physical properties.
- Publication:
-
Science Advances
- Pub Date:
- October 2020
- DOI:
- arXiv:
- arXiv:2004.04818
- Bibcode:
- 2020SciA....6.8662T
- Keywords:
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- Condensed Matter - Materials Science;
- Condensed Matter - Statistical Mechanics
- E-Print:
- Science Advances vol. 6, eabc8662 (2020)