Diary (January 8, 2021): Difference between revisions
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=== Electron degeneracy pressure === | |||
[[Electron degeneracy pressure (nonfiction)|Electron degeneracy pressure]] is a particular manifestation of the more general phenomenon of quantum degeneracy pressure. The Pauli exclusion principle disallows two identical half-integer spin particles (electrons and all other fermions) from simultaneously occupying the same quantum state. The result is an emergent pressure against compression of matter into smaller volumes of space. Electron degeneracy pressure results from the same underlying mechanism that defines the electron orbital structure of elemental matter. For bulk matter with no net electric charge, the attraction between electrons and nuclei exceeds (at any scale) the mutual repulsion of electrons plus the mutual repulsion of nuclei; so absent electron degeneracy pressure, the matter would collapse into a single nucleus. In 1967, Freeman Dyson showed that solid matter is stabilized by quantum degeneracy pressure rather than electrostatic repulsion.[1] Because of this, electron degeneracy creates a barrier to the gravitational collapse of dying stars and is responsible for the formation of white dwarfs. | |||
* [https://en.wikipedia.org/wiki/Electron_degeneracy_pressure Electron degeneracy pressure] @ Wikipedia | |||
=== Unrealistic readers === | === Unrealistic readers === | ||
Revision as of 06:16, 8 January 2021
Online diary of Karl Jones for Friday January 8, 2021.
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Electron degeneracy pressure
Electron degeneracy pressure is a particular manifestation of the more general phenomenon of quantum degeneracy pressure. The Pauli exclusion principle disallows two identical half-integer spin particles (electrons and all other fermions) from simultaneously occupying the same quantum state. The result is an emergent pressure against compression of matter into smaller volumes of space. Electron degeneracy pressure results from the same underlying mechanism that defines the electron orbital structure of elemental matter. For bulk matter with no net electric charge, the attraction between electrons and nuclei exceeds (at any scale) the mutual repulsion of electrons plus the mutual repulsion of nuclei; so absent electron degeneracy pressure, the matter would collapse into a single nucleus. In 1967, Freeman Dyson showed that solid matter is stabilized by quantum degeneracy pressure rather than electrostatic repulsion.[1] Because of this, electron degeneracy creates a barrier to the gravitational collapse of dying stars and is responsible for the formation of white dwarfs.
- Electron degeneracy pressure @ Wikipedia
Unrealistic readers
"Unrealistic."
This from people who sit motionless for hours at a stretch, staring at ink marks on sheets of paper as they (the people, not the ink marks) experience delusional beliefs in vampires and submarines.
- Post @ Twitter
Superhump
In astronomy, a superhump is a periodic brightness variation in a cataclysmic variable star system, with a period within a few percent of the orbital period of the system.
- Superhump @ Wikpedia
- Cataclysmic variable star @ Wikipedia