Diary (January 8, 2021)
Online diary of Karl Jones for Friday January 8, 2021.
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John Russell Hind
John Russell Hind FRS FRSE LLD (12 May 1823 – 23 December 1895) was an English astronomer.
Hind's naming of the asteroid 12 Victoria caused some controversy. At the time, asteroids were not supposed to be named after living persons. Hind somewhat disingenuously claimed that the name was not a reference to Queen Victoria, but the mythological figure Victoria.
- John Russell Hind @ Wikipedia
Oh U Gem
- U Geminorum @ Wikipedia - U Geminorum (U Gem), in the constellation Gemini, is an archetypal example of a dwarf nova. The binary star system consists of a white dwarf closely orbiting a red dwarf. Every few months it undergoes an outburst that greatly increases its brightness. The dwarf nova class of variable stars are often referred to as U Geminorum variables after this star.
Wave unction
Compare Wave function (nonfiction)
- Anointing @ Wikipedia
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
- Degenerate energy levels @ Wikipedia - In quantum mechanics, an energy level is degenerate if it corresponds to two or more different measurable states of a quantum system. Conversely, two or more different states of a quantum mechanical system are said to be degenerate if they give the same value of energy upon measurement. The number of different states corresponding to a particular energy level is known as the degree of degeneracy of the level. It is represented mathematically by the Hamiltonian for the system having more than one linearly independent eigenstate with the same energy eigenvalue.[1]:p. 48 When this is the case, energy alone is not enough to characterize what state the system is in, and other quantum numbers are needed to characterize the exact state when distinction is desired. In classical mechanics, this can be understood in terms of different possible trajectories corresponding to the same energy.
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