I've been reading up on the recent positron findings at our galaxy center and wondered if we know that electron-positron annihilation always yields energy in the gamma-ray band?
Annihilation- total destruction of matter in a burst of energy
Anthropic principle- we see the universe the way it is because if it were different we would not be here to observe it ...
Annihilation - The mutual destruction of a matter-antimatter pair of particles. The charges on the two particles cancel and the mass of the particles is entirely converted to energy ...
Annihilation
A reaction between a particle and its antiparticle; for example, between an electron and a positron. The energy released is equal to the sum of the rest energies of the particles and their kinetic energies.
Pair Annihilation
Mutual destruction (annihilation) of an electron-positron pair with the formation of gamma rays, or of a proton-antiproton pair with the formation of pions.
The annihilation of a positron and an electron releases two high-energy photons.
Symbolic annihilationSymbolic anthropologySymbolic capital
Symbolic communicationSymbolic dynamicsSymbolic images
Symbolic interactionismSymbolic linguistic representationSymbolic link ...
matter-antimatter annihilation A highly efficient process in which equal amounts of matter and anti-matter collide and destroy each other, producing a burst of energy, primarily in the form of gamma rays.
Four protons are, in net, converted into an alpha particle and two positrons (with accompanying neutrinos); and three gamma-ray emissions are emitted directly in addition to the two gamma emissions that ensue from annihilation of the positrons by ...
The presence of matter-antimatter annihilation, plus all the X-rays and radio emission suggest that unusual things are happening in the center of our Galaxy. One hypothesis is that the center of our Galaxy contains a black hole.
Possible means of annihilation include nuclear war, biological warfare or accidental contamination, nanotechnological catastrophe, ill-advised physics experiments, or a Malthusian catastrophe after the deterioration of a planet's ecosphere.
To illustrate the significance of these formulae, the annihilation of a particle with its antiparticle must result in the creation of at least two photons for the following reason.
Lingenfelter explains why the bulge-to-disc annihilation ratio is about twice as large as that expected for positron production from the decay of radioactive nuclei ejected from supernova explosions.
In 1965, Cowan, Atluri, and Libby suggested that the Tunguska event was caused by the annihilation of a chunk of antimatter falling from space.
When the universe had expanded for another few seconds, it cooled to a temperature of "only" 6 × 109 K and the electron-positron production and annihilation process ceased.
I am the creation and the annihilation, the basis of everything, the resting place and the eternal seed."
"But what need is there, Arjuna, for all this detailed knowledge? With a single fragment of Myself I pervade and support this entire universe." ...
The energy range covers energies common in many nuclear reactions (especially the electron-positron annihilation emission line at 511 keV).
Recall that the positrons immediately interact with nearby free electrons, producing high-energy gamma rays through matter"antimatter annihilation. The neutrinos rapidly escape, carrying energy with them but playing no direct role in nucleosynthesis.
Stable in a vacuum, positrons quickly react with the electrons of ordinary matter by annihilation to produce gamma radiation.
The combination of an electron and a positron results in an annihilation which transforms both particles into high-energy photons.
bioluminescence
sonoluminescence
triboluminescence
radioactive decay
particle-antiparticle annihilation ...
The original photon no longer exists, its energy having gone to the two resulting particles. The inverse process, pair annihilation, creates two gamma-ray photons from the mutual destruction of an electron/positron pair.
All the matter in the universe condensed out of pure energy over a period of about 700,000 years shortly after the Big Bang, and today, stars shine because matter at their centers is being slowly converted back into energy. Both annihilation of ...
When a particle and its antiparticle collide, both may disappear with the creation of lighter particles; this process is called annihilation . antipode (NASA Thesaurus / NASA SP-7, 1965) Anything exactly opposite to something else.
 See also: Energy, Time, Electron, Light, Universe
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