2006-09-13 03:15:54 · 8 answers · asked by goring 6 in Science & Mathematics ➔ Astronomy & Space
No one has seen dark matter.
When we look at galaxies, we are able to estimate how much matter is in those galaxies based on the light that is emitted from them and transmitted to us. Based on those matter estimates, we can estimate the expected motion of those galaxies. However, observational evidence shows us that the real motion of those galaxies doesn't match. Those galaxies move as if they are much more massive. (imagine the difference between swinging an empty bucket and a full bucket)
Additionally, since gravity bends light similar to how a lens bends light, we can use observations about the lensing we see in the sky to give us information about how much mass is in an area. Again, certain observations have shown that "dark" areas that should contain much less mass have a lensing effect consistent with a huge amount of mass.
This extra mass is thought to be the contribution of "dark" matter -- matter that does not emit light and thus does not "communicate" with us through any means but its effect on other light-emitting matter and its effect on the curvature of spacetime (i.e., gravity).
2006-09-13 03:25:06 · answer #1 · answered by Ted 4 · 1⤊ 1⤋
It was determined that matter was dark after they found out that the big bang theory didn't distribute matter the way they thought is would. Since the matter was not distributed even close to uniformely they had to come up with a solution for the this problem or state that the big bang theory was no longer a valid theory.
2006-09-13 10:18:50 · answer #2 · answered by Theodor 2 · 0⤊ 1⤋
In the 1960s, astronomers discovered that galaxies spun around too fast for the collective pull of the stars' gravity to keep them from flying apart. Something unseen appears to be keeping the stars from flinging themselves away from the center: unilluminated matter that exerts extra gravitational force. This is dark matter.
2006-09-13 10:20:26 · answer #3 · answered by blues 2 · 2⤊ 0⤋
They observed it quite like a Black hole. they can see minor discrepincies with light from other Galaxies. They also wondered how the galaxies that exist manage to stay together. With dark matter and tiny black holes everywhere, They could see how the galaxies stay together. There was one example os a cylinder like galaxy that keeps moving in one direction. It's spiralling near the suppossed "center" of the galaxy and passed by a black hole. The galaxy itself has stayed together while traveling near this black hole, which helps support the idea of tiny miniture black holes created by dark matter.
Also, they're beginning to theorize the reason they can't actually see or weigh the object is because it exists outside of our dimension, but pokes a hole into our dimension that with it's mass and such creates a gravitaional force that's exerted on our dimension.
2006-09-13 10:27:35 · answer #4 · answered by DarkWolf_1st 4 · 0⤊ 1⤋
light bends at obstacles , the obstacle in this case was not "visible" , and hence was dark.
They found light bending at unseen obstacles , and hence dark matter was infered.
I hope u understood what i mean
2006-09-13 10:56:44 · answer #5 · answered by venkat Subramaniam 2 · 0⤊ 0⤋
Dark matter is theoretical at this time. It cannot be seen or demonstrated.
2006-09-13 10:18:53 · answer #6 · answered by October 7 · 1⤊ 1⤋
By observing object near it react to its gravity
2006-09-13 10:24:12 · answer #7 · answered by N3WJL 5 · 0⤊ 0⤋
They look at how it behaves or how it affects the other matter around it.
2006-09-13 10:17:46 · answer #8 · answered by Anonymous · 0⤊ 0⤋