Stories
Slash Boxes
Comments

SoylentNews is people

Scientists Find Upper Limit for the Speed of Sound

posted by Fnord666 on Sunday October 11 2020, @01:03AM   Printer-friendly
from the not-breaking-news dept.

upstart writes in with an IRC submission for nutherguy:

Scientists find upper limit for the speed of sound:

A research collaboration between Queen Mary University of London, the University of Cambridge 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.

[...] 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.

Journal Reference:
K. Trachenko, B. Monserrat, C. J. Pickard, et al. Speed of sound from fundamental physical constants [open], Science Advances (DOI: 10.1126/sciadv.abc8662)

Original Submission

 
This discussion has been archived. No new comments can be posted.
Scientists Find Upper Limit for the Speed of Sound | Log In/Create an Account | Top | 12 comments | Search Discussion
Display Options Threshold/Breakthrough Mark All as Read Mark All as Unread
The Fine Print: The following comments are owned by whoever posted them. We are not responsible for them in any way.
(1)

  • (Score: 2) by Gaaark on Sunday October 11 2020, @02:04AM (2 children)

    by Gaaark (41) Subscriber Badge on Sunday October 11 2020, @02:04AM (#1063099) Journal

    Can you hear me now?

    --
    --- Please remind me if I haven't been civil to you: I'm channeling MDC. ---Gaaark 2.0 ---

    • (Score: 0) by Anonymous Coward on Sunday October 11 2020, @02:11AM (1 child)

      by Anonymous Coward on Sunday October 11 2020, @02:11AM (#1063102)

      That string in your tin can telephone isn't going to break any speed-of-sound records.
      But the intelligibility might be better than some 5G connections...

      • (Score: 2) by c0lo on Sunday October 11 2020, @02:26AM

        by c0lo (156) on Sunday October 11 2020, @02:26AM (#1063103) Journal

        But the intelligibility might be better than some 5G connections...

        See, toldchya, you should'ave used Huawei strings. (grin)

        --
        https://www.youtube.com/watch?v=aoFiw2jMy-0

  • (Score: 3, Interesting) by sonamchauhan on Sunday October 11 2020, @02:30AM

    by sonamchauhan (6546) on Sunday October 11 2020, @02:30AM (#1063104)

    Just wondering: the researchers determined the ultimate limit based on some pretty fundamental constants.

    The speed of sound is related to elasticity and hardness. Is this relationship linear?

    Does that mean the hardest materials that can be created will be roughly twice the hardness of diamond?

  • (Score: 1, Interesting) by Anonymous Coward on Sunday October 11 2020, @02:33AM

    by Anonymous Coward on Sunday October 11 2020, @02:33AM (#1063105)

    I’ve been admiring the date all day
    10102020
    But SoylentNews has already jumped to tomorrow’s date :(
    Going faster than the speed of light perhaps?

  • (Score: 2) by Immerman on Sunday October 11 2020, @02:34AM (5 children)

    by Immerman (3985) on Sunday October 11 2020, @02:34AM (#1063106)

    I can only wonder what the proton-to-electron ratio has to do with the speed of sound in neutronium.

    As I recall the speed of sound typically increases with density, and if you're talking "the fastest speed theoretically possible" neutronium would be an obvious contender, wouldn't it?

    Or perhaps they're just talking the fastest speed of sound theoretically possible through atomic matter - which is perhaps more relevant to our daily lives, but if you're going to limit your analysis to one of the least-common forms of matter in the universe, it seems like you should stay away from making absolute claims without qualifiers.

    • (Score: 0) by Anonymous Coward on Sunday October 11 2020, @02:50AM (2 children)

      by Anonymous Coward on Sunday October 11 2020, @02:50AM (#1063112)

      This was calculated for metallic hydrogen.

      We have calculated the speed of sound in atomic hydrogen for the I41/amd structure, which is currently the best candidate structure for solid atomic metallic hydrogen.

      The paper abstract:

      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.

      • (Score: 0) by Anonymous Coward on Sunday October 11 2020, @03:02AM (1 child)

        by Anonymous Coward on Sunday October 11 2020, @03:02AM (#1063115)

        Gee, that equation looked fishy (where did "12" come from). Turns out it was maligned by conversion to text -- go to tfl for the actual equation, where the "12" is seen to be an expression raised to the 1/2 power (square root).

        • (Score: 0) by Anonymous Coward on Sunday October 11 2020, @03:13PM

          by Anonymous Coward on Sunday October 11 2020, @03:13PM (#1063253)

          Thank you, you are correct. I copy/pasted then removed the citation superscripts, but I didn't do anything for the equation.

    • (Score: 3, Interesting) by c0lo on Sunday October 11 2020, @07:53AM

      by c0lo (156) on Sunday October 11 2020, @07:53AM (#1063156) Journal

      As I recall the speed of sound typically increases with density

      Nope, everything being the same (i.e. the hardness) the larger the density, the slugish the sound.
      From FTA

      The longitudinal speed of sound is v=(M/ρ)1/2, where M=K+4/3G, K is the bulk modulus, G is the shear modulus, and ρ is the density.

      ---

      and if you're talking "the fastest speed theoretically possible" neutronium would be an obvious contender, wouldn't it?

      I may, but not necessarily. It depends on the hardness of neutronium.
      Unfortunately, TFA deals with EM mediated bonding forces.

      --
      https://www.youtube.com/watch?v=aoFiw2jMy-0

    • (Score: 2) by c0lo on Sunday October 11 2020, @08:04AM

      by c0lo (156) on Sunday October 11 2020, @08:04AM (#1063159) Journal

      The speed of sound drops with the atomic mass in elemental solids [sciencemag.org]

      --
      https://www.youtube.com/watch?v=aoFiw2jMy-0

  • (Score: 2) by c0lo on Sunday October 11 2020, @07:28AM

    by c0lo (156) on Sunday October 11 2020, @07:28AM (#1063152) Journal

    If a tree falls on a neutron star, does it makes a sound?

    --
    https://www.youtube.com/watch?v=aoFiw2jMy-0
(1)