Electronic degeneracy pressure

Announce discuss Upload video

The concrete manifestation of the common phenomenon of quantum degeneracy pressure

Collection

see My Collection

zero Useful+1

zero

The electron degenerate pressure is quantum Degeneracy pressure The concrete manifestation of a common phenomenon of. Pauli exclusion principle Two identical Semiinteger Spinning particles (electrons or other Fermion ）Occupy the same quantum state Therefore, a pressure resistant to compression is generated. Freeman Dyson (Freeman Dyson) shows that the Impermeability It is caused by quantum degeneracy pressure rather than what was previously thought electrostatic repulsion 。 In addition, the pressure of electron degeneracy prevents Dying star Of Gravitational collapse To form White dwarf 。

Chinese name: Electronic degeneracy pressure
Foreign name: Electron degeneracy pressure

Discipline: Physics 、 quantum mechanics
Principle: Pauli exclusion principle

catalog

one principle
two application

principle

Announce

edit

The electron degeneracy pressure is determined by Pauli exclusion principle Generated. In stellar physics, it creates White dwarf The exists of.

The electron degeneracy pressure is not a "force", it is an exchange interaction, but it is different from the four Fundamental force The interaction of is completely different, it does not need to exchange media particles. Exchange interaction only occurs in Identical particle In essence wave function No "force" is involved. It is similar to Molecular thermal motion When 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".

Electronic degeneracy pressure

Air pressure is determined by Molecular collision The generated statistical property, the formula is

Electronic degeneracy pressure

Energy E is the internal energy of gas molecule

Electronic degeneracy pressure

Degeneracy Pressure is the effect superimposed on the pressure. The pressure formula is the same, but the difference is that E is the Fermi kinetic energy of particles

Electronic degeneracy pressure

So the electron degeneracy pressure is

In fact, the pressure of electron degeneracy is ubiquitous, but in general, the pressure is so small that it can be ignored. But when electrons Number density （ n/V） When the temperature is high enough and low enough, it will dominate. In white dwarfs, interatomic Electromagnetic force Unable to withstand the violent squeezing of gravity, atomic Electron shell Be crushed to form free electron Walk through the lattice, or Nucleus The state of floating in an ocean of electrons. We can imagine that all nuclei and electrons together form a super molecule, and according to the Pauli exclusion principle, molecular orbital One of Atomic orbital Only two Spin direction The opposite electron. The lower the orbital energy level, the closer the electron is to the nucleus. When matter is compressed to a great density, gravity will try to close the distance between electrons and atomic nuclei Low energy level The orbit will be filled with electrons. The Pauli exclusion principle does not allow two electrons to be in the same state, and the electrons close to each other will generate a new repulsive force, preventing the volume from further shrinking.

Electronic degeneracy pressure

The possible explanation related to the electron degeneracy pressure is heisenberg uncertainty principle ：

here h Is Dirac constant（ Reduced Planck constant ），Δ x Is the uncertainty value in position during measurement, while Δ p Momentum measurement indeterminate standard deviation 。

A kind of material that will be compressed when the pressure increases in essence. The uncertainty of position measurement Δ of internal electrons x Therefore, according to the uncertainty principle, the uncertainty of the electronic momentum Δ p , will increase. However, no matter how low the temperature drops, the electrons must move at Heisenberg speed and contribute pressure because of the temperature. When the pressure generated by the "Heisenberg speed" of the electron exceeds Thermal movement When above, the electron will enter the degenerate state, and this material will become Degenerate matter 。

application

Announce

edit

Electronics Degeneracy pressure When the star mass does not exceed Chandraseka limit (1.44 Solar mass ）It can prevent the core from collapsing, which is to prevent White dwarf Collapse pressure. Stars with mass beyond this limit and no fuel for nuclear fusion will not be able to resist the degeneracy pressure provided by electrons Universal gravitation And continue to collapse to form neutron star Or black holes.

Novice on the road

Growth task Getting Started with Editing Edit Rule Edit by myself

I have questions

Content query Online Service Official post bar Feedback

Complaints and suggestions

Report bad information Failed to appeal through entries Complaint of infringement information Blocking query and unblocking

© 2024 Baidu Read Before Using Baidu | Encyclopedia protocol | Privacy Policy | Baidu Encyclopedia cooperation platform | Jing ICP Certificate No. 030173

Jinggong Network Anbei No. 1100000200001