Black Holes

The true killers of our universe.

There was a program on discovery channel that caught my attention, it was entitled Hyperspace and was narrated by Sam Neill. This program really intrigued me. I was astounded that the planet earth is so insignificant that it is not even a consideration given the gargantuan size of this whole universe.

The part which I liked most from the program was the topic on black holes.
So what are they? A black hole is a region of space-time from which nothing can escape, not even light.

To see why this happens, imagine throwing a ball into the air. The harder you throw the ball, the faster it is travels. If you throw it hard enough it will never return, the gravitational attraction will not be able to pull it back down. The velocity the ball must have to escape is known as the escape velocity.

When a large star has burnt all its fuel it explodes into a supernova. The stuff that is left collapses down to an extremely dense object known as a neutron star.
If the neutron star is too large, the gravitational forces overwhelm the pressure gradients and collapse cannot be halted. The neutron star continues to shrink until it finally becomes a black hole. As the body is crushed into a smaller and smaller volume, the gravitational attraction increases and hence the escape velocity gets bigger.

Things have to be thrown harder to escape the gravitational attraction. Eventually a point is reached when even light, which travels at 1000 million km/h, is not traveling fast enough to escape a black hole! At this point, nothing can get out as nothing can travel faster than light. Black holes also have the ability to bend light but more so have the ultimate ability to slow time down. An interesting theory is that one needs to run in order to stay still.

Black holes are the true killers of our universe. Black holes devour everything in their path, eating up entire planets and consuming entire galaxies. This I fear could be the ultimate end for our planet, to be nothing more than an appetizer for some hungry black hole.

Well that's it for now. Hope you enjoyed my little science lesson.