Introduction :-
Dark matter is (almost) like normal matter; it has mass and volume. The difference is small, but very important. Unlike regular matter, it does not scatter Electromagnetic wave, so we cannot see it with telescope.
Gravitational Lensing :-
Even though it cannot be observed directly, we can use Einstein's Theory of General Relativity to calculate the mass of Dark Matter. He stated that light follows the curvature of space-time, hence when light passes through massive object, it is bent. The angle of deflection is :
Recent Discoveries :-
Sources :-
Wikipedia : Dark Matter
Wikipedia : Gravitational Lensing
NASA Picture of the Day
Dark matter is (almost) like normal matter; it has mass and volume. The difference is small, but very important. Unlike regular matter, it does not scatter Electromagnetic wave, so we cannot see it with telescope.
Gravitational Lensing :-
Even though it cannot be observed directly, we can use Einstein's Theory of General Relativity to calculate the mass of Dark Matter. He stated that light follows the curvature of space-time, hence when light passes through massive object, it is bent. The angle of deflection is :
 |
| G = gravitational constant M = mass of an object r = distance between mass and radiation c = speed of light |
 |
| Bent rays when passed through heave mass |
Discovered in 2007, Luminous Red Galaxy 3-757 interacts with another much more distant blue galaxy. This galaxy was re-observed in December 11, 2011 with Hubble Space Telescope.
 |
| LRG 3-757 in front of distant blue galaxy creating Einstein Rings |
Approximate Mass of Dark Matter :-
Dark matter is believed to constitute 83% of all matter in the universe, and 23% of total mass-energy in the universe.
Dark matter is believed to constitute 83% of all matter in the universe, and 23% of total mass-energy in the universe.
Sources :-
Wikipedia : Dark Matter
Wikipedia : Gravitational Lensing
NASA Picture of the Day
Like magic
ReplyDeleteSo how did you know that it was observed on Dec. 11? Those were my observations!
ReplyDeleteThis was the picture of the day.
ReplyDeleteThis is pretty cool. I didn't know they were your observations.
http://apod.nasa.gov/apod/ap111221.html
Gravitational lenses are awesome! Great post! :)
ReplyDelete