Our disc-shaped galaxies are moving too quickly - thousands of kilometers per second - and in theory these systems should have been dispersed or flung out to the edge of space. So how do they stay intact? The theory is 'dark matter' which is essentially extra mass and gravity that allows the systems to stay bound together. The problem is that we can't see dark matter through the telescope - it's 'dark'.
Many theories have been put forward. Could dark matter just be 'ordinary matter' that isn't luminous; brown dwarfs, planets, gas clouds..? But ordinary matter in the 'necessary quantities' should give off some light or radiation that would be detectable. Could it be that in distant space a different set of physical laws apply?
Dark Matter is only 'theoretical evidence' as to why galaxies remain intact, without light, however, the existence of this 'invisible' matter is very hard to prove but it is thought to be central to everything in the universe. All we can do is look at the effect that dark matter has on its 'environment' and go from there. After all, we cannot see gravity, we are just aware of what it does.
The big problem is that Physicists can come up with the existence of all kinds of particles - Neutrinos for instance (the existence of which has been largely proven) WIMPS (Weakly Interacting Massive Particles) and MACHOS (Massive Astro-Physical Compact Halo Object) the latter two being touted as probable dark matter candidates, yet in the end it will be harder to show that this is actually the 'stuff' of dark matter, due to the fact that it rests in galaxies thousands of light years away.
If the Hadron Collider can prove the existence of dark matter, it would be one of the greatest scientific discoveries of our time. Physicists appear surprisingly bullish. I'm not holding my breath!
No comments:
Post a Comment