ALL ABOUT NEUTRINO..

Neutrinos are subatomic particles produced by the decay of radioactive elements and are elementary particles that lack an electric charge, or, as F. Reines would say, "...the most tiny quantity of reality ever imagined by a human being"."The name neutrino was coined by Enrico Fermi as a word play on neutrone, the Italian name of the neutron."Of all high-energy particles, only weakly interacting neutrinos can directly convey astronomical information from the edge of the universe - and from deep inside the most cataclysmic high-energy processes and as far as we know, there are three different types of neutrinos, each type relating to a charged particle as shown in the following table:

Neutrino	ve	vµ	vτ
Charged Partner	electron (e)	muon (µ)	tau (τ)

Copiously produced in high-energy collisions, travelling essentially at the speed of light, and unaffected by magnetic fields, neutrinos meet the basic requirements for astronomy. Their unique advantage arises from a fundamental property: they are affected only by the weakest of nature's forces (but for gravity) and are therefore essentially unabsorbed as they travel cosmological distances between their origin and us.Where are they coming from?From what we know today, a majority of the neutrinos floating around were born around 15 billions years ago, soon after the birth of the universe. Since this time, the universe has continuously expanded and cooled, and neutrinos have just kept on going. Theoretically, there are now so many neutrinos that they constitute a cosmic background radiation whose temperature is 1.9 degree Kelvin (-271.2 degree Celsius). Other neutrinos are constantly being produced from nuclear power stations, particle accelerators, nuclear bombs, general atmospheric phenomenae, and during the births, collisions, and deaths of stars, particularly the explosions of supernovae.