Sunday, 8 September 2013

Into a Black Hole-Stephen Hawking

...A black hole has a boundary, called the event horizon. It is where gravity is just strong enough to drag light back, and prevent it escaping. Because nothing can travel faster than light, everything else will get dragged back also. Falling through the event horizon, is a bit like going over Niagra Falls in a canoe. If you are above the falls, you can get away if you paddle fast enough, but once you are over the edge, you are lost.There's no way back. As you get nearer the falls, the current gets faster. This means it pulls harder on the front of the canoe, than the back. there's a danger that the canoe will be pulled apart. It is the same with black holes. If you fall towards a black hole feet first, gravity will pull harder on your feet than your head, because they are nearer the black hole. The result is, you will be stretched out longwise, and squashed in sideways.. If the black hole has a mass of a few times our sun, you would be torn apart, and made into spaghetti, before you reached the horizon. However, if you fell into a much larger black hole, with a mass of a million times the sun, you would reach the horizon without difficulty. So, if you want to explore the inside of a black hole, choose a big one. There is a black hole of about a million solar masses, at the center of our Milky way galaxy. ...

Wormhole entanglement solves black hole paradox


WORMHOLES – tunnels through space-time that connect black holes – may be a consequence of the bizarre quantum property called entanglement. The redefinition would resolve a pressing paradox that you might be burned instead of crushed, should you fall into a black hole.

Knowing which hazard sign to erect outside a black hole isn't exactly an everyday problem. For theoretical physicists, though, it reveals an inconsistency between quantum mechanics and general relativity. Solving this conundrum might lead to the sought-after quantum theory of gravity.


Don't know what a blackhole is?

A black hole is a place in space where gravity pulls so much that even light can not get out. The gravity is so strong because matter has been squeezed into a tiny space. This can happen when a star is dying. 

Because no light can get out, people can't see black holes. They are invisible. Space telescopes with special tools can help find black holes. The special tools can see how stars that are very close to black holes act differently than other stars. 



How long animals live?