Timeline for Fastest Speed of Sound
Current License: CC BY-SA 4.0
5 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Oct 22 at 13:42 | comment | added | Quillo | Unfortunately, this paper is plain wrong since any ultrarelativistic gas already exceeds this limit by far. The only rigorous limit known to date is that sound (and any signal) must be subliminal. In fact, in neutron star studies it is only required that the speed of sound is less than "c", see e.g. the discussion in section 4.1 of arxiv.org/abs/2410.08008 ("Frozen and equilibrated f and p modes of cold neutron stars: nuclear metamodel predictions", 2024). | |
| Oct 17, 2020 at 23:43 | comment | added | Anders Sandberg | Note that the equation refers to hydrogen; for nuclear matter the relevant mass-ratio would be something involving quark masses, and the fine structure constant replaced by the strong nuclear force counterpart. It is not a general answer to the question, despite the nice paper. | |
| Oct 17, 2020 at 17:54 | comment | added | Thomas | It's an amusing paper, but it's not rigorous (just dimensional analysis), and it only applies to solids for which the speed of sound is determined by the bulk modulus, and the scale for the bulk modulus is set by a typical chemical bonding energy. Certainly not relevant to relativistic fluids, such as neutron matter or the quark gluon plasma. | |
| Oct 15, 2020 at 17:24 | comment | added | AccidentalTaylorExpansion | It is so satisfying that 4 years later the answer to this question changed because of new science. | |
| Oct 15, 2020 at 17:19 | history | answered | user121330 | CC BY-SA 4.0 |