Collision cosmic

In summary, three or four large collisions on one to four asteroids are responsible for two thirds of all H chondrites. It is often assumed that all H chondrites ultimately derive from a single asteroid, having broken up and partly reassembled early in solar system history (Keil et al. 1994). In this scenario, the parent bodies from which meteorites get delivered to Earth today would have been formed in these early or in later collisions. Cosmic ray exposure age studies cannot decide whether these immediate parent bodies— if more than one—indeed derive from a common ancestor. 

In the kinetic model of gases, we picture the molecules as widely separated for most of the time and in ceaseless random motion. They zoom from place to place, always in straight lines, changing direction only when they collide with a wall of the container or another molecule. The collisions change the speed and direction of the molecules, just like balls in a three-dimensional cosmic game of pool. 

Carbon-12 is the principal isotope of carbon, but a small proportion of carbon-14 is present in all living organisms. Its nuclei are produced when nitrogen nuclei in the atmosphere are bombarded by neutrons formed in the collisions of cosmic rays with other nuclei ... 

Big Bang nucleosynthesis (cosmic nucleosynthesis) Proton-proton cycle Triple He collisions Alpha capture CNO cycle Neutron capture High-energy photon collisions produce antimatter-matter pairs. This leads to H,D, He and some Li nuclei Hydrogen burning to produce He 12C production Addition of 4He to the nucleus Production of 13C, 13N, 14N and 150 Post-Fe nuclei... 

Rate constant temperature dependence Processing threshold Calculation of rate constants at different temperatures, including collision numbers and concentrations of species in steady state Calculation of the rate of photodissociation and cosmic ray-induced molecular processing from photon and particle fluxes... 

The penetration depth of cosmic radiation is of the order of 1 m and therefore isotopes are produced by spallation only in the surface layers of meteorites and the moon. After collisions of meteorites with each other or with the moon, newly formed surfaces get exposed to cosmic radiation and production of stable and radioactive isotopes starts. If P is the production rate of a... 

A large increase in the O/Fe ratio in stars at low metallicity was reported by Israelian et al. in 1998 and by Boesgaard et al. in 1999, contradicting earlier data which suggested an approximately constant O/Fe ratio. Now oxygen is particularly relevant to the astrophysics of cosmic rays. This is because spallation products under collision include the light nuclei lithium, beryllium and boron. 

Trillions of neutrinos are flying through your body as you read this. Created by the Big Bang, stars, and the collision of cosmic rays with the earth s atmosphere, neutrinos outnumber electrons and protons by 600 million to 1. [For more information, see. Gibbs, W. (1998) A massive discovery. Scientific American. August, 279(2) 18-19.]... 

J. Schafer and W. Meyer. Collision induced dipole radiation of normal hydrogen gas in frequency range of the cosmic background. In J. Eichler, I. V. Hertel, and N. Stolterfoht, eds., Electronic and Atomic Collisions,... 

Atmospheric pressure plasmas, just like most other plasmas, are generated by a high electric field in a gas volume. The few free electrons which are always present in the gas, due to, for example, cosmic radiation or radioactive decay of certain isotopes, will, after a critical electric field strength has been exceeded, develop an avalanche with ionization and excitation of species. Energy gained by the hot electrons is efficiently transferred and used in the excitation and dissociation of gas molecules. In a nonequilibrium atmospheric pressure plasma, collisions and radiative processes are dominated by energy transfer by stepwise processes and three-body collisions. The dominance of these processes has allowed many... 

Neutrino oscillations have up to now been detected in two systems. Atmospheric muon neutrinos, which originate from the collision of cosmic rays... 

For the first time a universe composed of H and He has a scientific explanation. Only 1H, 2H, 3He, 4He and much 7Li seem to have inherited their abundances as ashes of that Big Bang. The stars manufactured the remainder of the elements, except for small abundances created by cosmic-ray collisions. Stars in fact slowly destroy 2H by fusing it into He. Cecelia Payne s discovery in stellar spectra that H dominates the abundances in stars became aprime factof the cosmology of the universe. The origin of both isotopes of hydrogen, the first and seventh most abundant nuclei in the universe, as well as ofhelium, in the initial fireball is one of the great achievements of thattheory. 

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