<p>I've been participating in many discussions online about the classic thought experiment on pressing a button a light year away with a light year long rod.  The solution boils down to the speed of sound in the material the rod is made of (if we ignore the problem of material strength and monstrous inertia of said rod).  It got me thinking about the speed of sound in denser materials and I read up on the speed of sound in neutronium which was calculated as</p>
<p><span class="math-container">$$\frac{c}{\sqrt{3}}$$</span></p>
<p>in <a href="https://physics.stackexchange.com/a/54786/83380">this answer to <em>Is the speed of sound almost as high as the speed of light in neutron stars?</em></a>.</p>
<p><strong>Knowing this and the nuclear forces holding neutronium together, is it possible to calculate the loudest sound possible in this medium in decibels?</strong>  Would adding more energy beyond this decibel limit end up creating additional nucleons due to the immense binding energy of nucleons in the same way that pulling apart quarks takes enough energy to create new quarks?</p>

CC BY-SA 4.0
2023-01-20T17:17:03.903Z
Is there a connection between loudness and speed? I think the Q would be better asked on Physics SE.
ProfRob
CC BY-SA 4.0
2023-01-20T18:36:34.940Z
I'm not sure that many non astrophysicists concern themselves overly much with neutronium, though it does ties in with QCD, it was my understanding that those with a background in such and able to answer such a question would be more likely to answer here.
Aaron Hathaway
CC BY-SA 4.0
2023-01-20T19:35:26.020Z
Well, "neutronium" is a science fiction term and doesn't exist in nature. Neutrons cannot exist in isolation without protons and electrons.
ProfRob
CC BY-SA 4.0
2023-01-20T21:04:20.150Z
@ProfRob what are you on about?  Are you not familiar with neutron radioactive sources, they emit free neutrons.  The crushing gravity of supernova remnants, should that not collapse beyond the Schwarzschild limit is great enough overcome the electron degeneracy pressure and force electrons into protons converting them into neutrons.  Neutron stars are made of neutronium for this reason.  I have to question why you're commenting on a thread about neutron stars without knowing this.  Your history seems to indicate otherwise?  Granted my education ended with a BS in astrophysics.
Aaron Hathaway
CC BY-SA 4.0
2023-01-20T21:15:01.420Z
@ProfRob my apologies, I reviewed your profile.  You are correct that science does not use the term neutronium rather neutron degenerate matter.  Your statement about free neutrons doesn't make sense to me, am I missing something?  I've done the nuclear labs with neutron sources, and done the diagrams for decay many times back in my college days.

To answer your question about the relation between loudness and speed, there is a correlation between the maximum energy of a kinetic wave within a medium and the strength of the binding forces that hold the material together.
Aaron Hathaway
CC BY-SA 4.0
2023-01-20T21:17:15.837Z
@ProfRob In air that pressure wave reaches a maximum depending on the air pressure otherwise you're left with a vacuum and no longer dealing with sound but instead a shockwave.  In a liquid you end up with cavitation.  In solids a shock wave occurs as well which rearranges the material of the solid and transforms the crystal structure.  In neutron degenerate matter you have the strong nuclear force rather than the electromagnetic force dictating the maximum speed and consequently energy of the kinetic energy wave.
Aaron Hathaway
<neutron-star><sound>
There is a decibel limit to sound based on the medium, what is the decibel limit in neutronium?
Aaron Hathaway
# There is a decibel limit to sound based on the medium, what is the decibel limit in neutronium?

(Asked by: username_0 on 2023-01-19)

I've been participating in many discussions online about the classic thought experiment on pressing a button a light year away with a light year long rod. The solution boils down to the speed of sound in the material the rod is made of (if we ignore the problem of material strength and monstrous inertia of said rod). It got me thinking about the speed of sound in denser materials and I read up on the speed of sound in neutronium which was calculated as

$$\frac{c}{\sqrt{3}}$$

in [this answer to *Is the speed of sound almost as high as the speed of light in neutron stars?*](https://physics.stackexchange.com/a/54786/83380).

**Knowing this and the nuclear forces holding neutronium together, is it possible to calculate the loudest sound possible in this medium in decibels?** Would adding more energy beyond this decibel limit end up creating additional nucleons due to the immense binding energy of nucleons in the same way that pulling apart quarks takes enough energy to create new quarks?

**Tags:** neutron-star, sound
> **Comments:**
> **username_1**: Is there a connection between loudness and speed? I think the Q would be better asked on Physics SE.  
> **username_0**: I'm not sure that many non astrophysicists concern themselves overly much with neutronium, though it does ties in with QCD, it was my understanding that those with a background in such and able to answer such a question would be more likely to answer here.  
> **username_1**: Well, "neutronium" is a science fiction term and doesn't exist in nature. Neutrons cannot exist in isolation without protons and electrons.  
> **username_0**: @ProfRob what are you on about?  Are you not familiar with neutron radioactive sources, they emit free neutrons.  The crushing gravity of supernova remnants, should that not collapse beyond the Schwarzschild limit is great enough overcome the electron degeneracy pressure and force electrons into protons converting them into neutrons.  Neutron stars are made of neutronium for this reason.  I have to question why you're commenting on a thread about neutron stars without knowing this.  Your history seems to indicate otherwise?  Granted my education ended with a BS in astrophysics.  
> **username_0**: @ProfRob my apologies, I reviewed your profile.  You are correct that science does not use the term neutronium rather neutron degenerate matter.  Your statement about free neutrons doesn't make sense to me, am I missing something?  I've done the nuclear labs with neutron sources, and done the diagrams for decay many times back in my college days.  To answer your question about the relation between loudness and speed, there is a correlation between the maximum energy of a kinetic wave within a medium and the strength of the binding forces that hold the material together.  
> **username_0**: @ProfRob In air that pressure wave reaches a maximum depending on the air pressure otherwise you're left with a vacuum and no longer dealing with sound but instead a shockwave.  In a liquid you end up with cavitation.  In solids a shock wave occurs as well which rearranges the material of the solid and transforms the crystal structure.  In neutron degenerate matter you have the strong nuclear force rather than the electromagnetic force dictating the maximum speed and consequently energy of the kinetic energy wave.  

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