Dark matter...comes from the observation that galaxies should not
be able to rotate at the speed they seem to rotate at based on their
visible mass alone (and this is a huge effect - approximately 84% of the
mass required for our observations seems to be invisible). It's 23% of
the mass-energy total in the universe. If dark energy is 73% and dark
matter is 23%, then there's only 4% left for the visible mass and energy
in the universe, which is amazing. (Alex Kritchevsky on Quora)
Seeing the invisible (observing the dark side of the universe): It seems that most of the universe is made up of mysterious ingredients
which we cannot see directly. I will describe in pictures "gravitational
lensing", the bending of light by gravity, which is predicted by
Einstein's General Relativity. The dark components of the universe do
not emit or absorb light, but do exert a gravitational attraction, and
it turns out that gravitational lensing is one of the most promising
methods for finding out more about them.(sarah bridle from royalsociety.org)Importance: "Because the amount of matter and energy in the universe determines the rate of expansion," Dr. Michio Kaku tells us. "We now know there is a lot more dark energy than we previously thought. Therefore, the universe is undergoing an inflationary exponential expansion. It is in a runaway mode, but here is the catch: we don't know how long that runaway mode is going to last."(brightthink.com)
A whiff of dark matter on the ISS :
On April 3rd, researchers led by Nobel Laureate Samuel Ting of MIT
announced that the Alpha Magnetic Spectrometer, a particle detector
operating on board the International Space Station since 2011, has
counted more than 400,000 positrons, the antimatter equivalent of
electrons. There’s no danger of an explosion, but the discovery is
sending shock waves through the scientific community.
 |
| The Alpha Magnetic Spectrometer mounted outside the International Space Station. |
"These data show the existence of a new physical phenomenon," wrote Ting and colleagues in an article published in the Physical Review Letters. "It could be a sign of dark matter."
But where do the positrons come from? The Universe is almost completely devoid of antimatter,
One idea is dark matter. Astronomers know that the vast majority of the
material Universe is actually made of dark matter rather than ordinary
matter. They just don't know what dark matter is. It exerts gravity,
but emits no light, which makes it devilishly difficult to study.
A leading theory holds that dark matter is made of a particle called the
neutralino. Collisions between neutralinos should produce a large
number of high-energy positrons, which the AMS should be able to detect
with unprecedented sensitivity. (science.nasa.gov) (April 15, 2013)
# for Dark Matter formation fundamental facts, go through the google search ..
amateur astronomy series
nucleosynthesis
nucleosynthesis
star > white dwarf > black dwarf
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