Neutron degeneracy pressure is a common phenomenon of quantum degeneracy pressure.Pauli exclusion principleTwo particles with the same half integer spin (electron, neutron or otherFermion）Occupy the samequantum stateTherefore, a pressure resistant to compression is generated.
Degeneracy pressureDegeneracy pressure means that some particles (such as electrons, neutrons, protons, etc.) are exclusive and cannot occupy the same position in space.Based onquantum mechanics(Quantum Mechanics) Pauli's exclusion principle.In short, there are some particles (such asElectronics、neutron、protonIt is exclusive. They cannot occupy the same position in the space, just like a group of naughty children. If you want them to lean together, they will always push, push and bump, and drive the children nearby far away. The closer they are, the greater the force will be used. This mutual repulsion force between particles is called degenerate pressure.
White dwarf
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Neutron degeneracy pressure
When the star mass is less thanChandraseka limitChandrasekhar Limit is 1.44 times the mass of the sun. When a star is dying, it will generate enough radiation pressure because there is no fuel inside to offset its own gravityGravitational collapse(Gravitational collapse)Electronic degeneracy pressure(Electron degeneracy pressure) can support its own weight, thus eventually formingWhite dwarf（White dwarf）。
When the mass of a star is greater than 1.44 times the mass of the sun and less than 3.2 times the mass of the sun, if gravitational collapse occurs, thenElectronic degeneracy pressure(Electron degeneracy pressure) is not enough to support the weight of the star itself. The electrons are forced to compress and the protons in the nucleus merge into neutrons untilNeutron degeneracy pressure(Neutron degeneracy pressure) can support its own weight and formneutron star（Neutron star）。
Neutron degeneracy pressure
If the mass of the star is more than 3.2 times the mass of the sunNeutron degeneracy pressure(Neutron degeneracy pressure) can not support the weight of the star itself. At this time, nature has no natural force to compete with gravity, and matter can only collapse indefinitely, so it collapses intoQuark starOrblack hole(Black hole)。
Degeneracy pressureIt is not "force", it is exchangeInteraction(Exchange interaction), but it is completely different from the interaction of the four basic forces we usually talk about. It does not need to exchange media particles.Exchange interaction only occurs between identical particles, which is essentially awave functionNo "force" is involved.It is similar toMolecular thermal motionWhen the temperature rises, the thermal movement of molecules intensifies, and the volume of the object increases. At this time, we cannot think that it is some force that makes the volume of the object increase.Therefore, we can think of the electron degeneracy pressure as the "electron pressure" generated by the "thermal movement of electrons".
Pressure is a statistical property produced by a large number of molecular collisions, and the formula is
Energy E is the internal energy of gas molecule
Merging pressure is the effect superimposed on the air pressure. The pressure formula is the same, but the difference is that E is the Fermi kinetic energy of particles
Degenerate neutron pressure - internal structure model diagram
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Neutron degeneracy pressureIt's not like a force in classical mechanics.Fermion compliancePauli exclusion principle, butBosonWithout this limitation, the particles appearProbability amplitudeEvolutionary compliance ofSchrodinger equationInstead of the concept of "force field", exchange media particles transfer interactions. There is no so-called "force" in Pauli's exclusion principle. Here there is a concept called exchange interaction, but it is completely different from the interaction of the four basic forces we usually talk about. It does not need exchange media particles.Exchange interaction only occurs between identical particles, which is essentially awave functionNo "force" is involved.A quantum state can only contain oneFermionIt is the "property" of quantum mechanics, which can also be understood as "the probability that two particles are in the same quantum state is zero".
