What are neutrino's?
Neutrino's are the latest stir in the science community.
They are composed of tiny particles which are neutral (no charge) and
have a very weak nuclear force. Because they have such a weak nuclear force,
matter is almost transparent to them. By the time you have finished reading
this sentence, billions of neutrinos will have passed through every inch of
your body.
<- most neutrinos pass right through the Earth without ever being detected
Each nuclear reaction which the sun undergoes produces one neutrino.
The total number of neutrinos produced for all the suns reactions is
about 8x1010 per square centimetre per second towards the Earth.
At such high concentrations, any form of matter, no matter how hard to
detect individually, should be detected. From experiments during the
last 50 years however, only about 1/3 to 1/2 of the theoretical number
have ever been detected.
So where have all the neutrino's gone?
There have been many experiments to try to determine where the 'missing'
neutrinos went to. Recently, a Canadian science team (located in Sudbury, On)
have solved the scientific mystery that has baffled scientists for decades.
In an underground laboratory, two kilometers below the Earths surface, where some
neutrino's are trapped, and most other solar radiation and interference has been
filtered out, scientists found an answer.
The results of their data recently released, showed that the theory was correct,
and the number produced was right. The missing neutrino's however, weren't actually
missing at all. Instead, they discovered that the two-thirds of neutrinos which had
left the sun had instead changed form.
The second major discovery is that neutrino's have mass. It is believed that in order
for a particle to change form, it must have mass. The certainty that the neutrino has
mass not only raises many other debates, but it also adds fuel to the debate of the
true composition of
dark matter. A particle which has mass such as the neutrino, is now an even better
contender for the mysterious "extra mass" of the universe. It was discovered early in
the search for dark matter that if the neutrino had a mass in the range 1050 eV c2,
then the enourmous amount of neutrinos produced during the big bang could be what accounts
for this dark matter. The Standard Model of the neutrino has zero mass, which resulted
in it being dismissed by many scientists as a dark matter candidate. This new
discovery suggests otherwise.
<- most neutrinos pass right through the Earth without ever being detected
