[math-fun] neutron star (electric field?)
oward: As has been mentioned in this thread, at the pressures in a neutron star a neutron is stable relative to a proton + electron. Electrostatic force pulls e + p => n together long before they can separate gravitationally. --R
--also, this is refuted thus: the binding energy of electron & proton is 13.6 electron volts, which is tiny versus the thermal energies of order 10^9 celsius, far far more than enough to separate an e and p by infinite distance. --so I conclude there DEFINITELY will be large e & p "separation" both possible, and expected to, happen. So the "electrostatic force" Howard here is worried about, is basically neglectible on the microscale; the only effects worth discussing are macroscopic collaborative effects, which indeed is what I was speaking about, yielding a macroscale electric field.
Sounds like you are making a buoyancy argument that protons will sink and electrons float in a neutron star. I think that is a very complex argument, made even more so by the extreme gravity and quantum effects (they are both fermions with all that implies.) I suspect that saying protons are heavy and electrons light is just scratching the surface. Remember that collapsing P+e => n is reducing the number of particles in half and, thus, reducing the gravitational energy (they are fermions). A core collapse during a supernova is driven by the same energy considerations--fusion of nuclei that allows the diameter to be reduced (rather quickly) under gravitational force. In a neutron star, that collapse has happened with p+e => n already. Next step is when the gravitational force exceeds the exclusion principle energy and the neutrons combine--taking it all the way to a black hole... --R -----Original Message----- From: math-fun [mailto:math-fun-bounces@mailman.xmission.com] On Behalf Of Warren D Smith Sent: Thursday, June 26, 2014 11:29 AM To: math-fun@mailman.xmission.com Subject: [math-fun] neutron star (electric field?)
oward: As has been mentioned in this thread, at the pressures in a neutron star a neutron is stable relative to a proton + electron. Electrostatic force pulls e + p => n together long before they can separate gravitationally. --R
--also, this is refuted thus: the binding energy of electron & proton is 13.6 electron volts, which is tiny versus the thermal energies of order 10^9 celsius, far far more than enough to separate an e and p by infinite distance. --so I conclude there DEFINITELY will be large e & p "separation" both possible, and expected to, happen. So the "electrostatic force" Howard here is worried about, is basically neglectible on the microscale; the only effects worth discussing are macroscopic collaborative effects, which indeed is what I was speaking about, yielding a macroscale electric field. _______________________________________________ math-fun mailing list math-fun@mailman.xmission.com https://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun
I have essentially zero comprehension of quantum mechanics. But it might be slightly relevant that in a jar filled with large marbles and small-enough ones, the small ones end up at the bottom. --Dan On Jun 26, 2014, at 9:54 PM, Richard E. Howard <rich@richardehoward.com> wrote:
Sounds like you are making a buoyancy argument that protons will sink and electrons float in a neutron star. I think that is a very complex argument, made even more so by the extreme gravity and quantum effects (they are both fermions with all that implies.)
I suspect that saying protons are heavy and electrons light is just scratching the surface. Remember that collapsing P+e => n is reducing the number of particles in half and, thus, reducing the gravitational energy (they are fermions).
A core collapse during a supernova is driven by the same energy considerations--fusion of nuclei that allows the diameter to be reduced (rather quickly) under gravitational force. In a neutron star, that collapse has happened with p+e => n already.
Next step is when the gravitational force exceeds the exclusion principle energy and the neutrons combine--taking it all the way to a black hole...
participants (3)
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Dan Asimov -
Richard E. Howard -
Warren D Smith