Gravitational Waves

Written by: Tony Harris, February 11, 2016


So it seems that Einstein was right. Did you doubt him? Today it has been announced that for the first time ‘gravitational waves’ have been detected. Einstein predicted their existence in his theory of General Relativity. But, he didn’t think that we would ever be able to detect them. However, it seems that the collision of two black holes caused gravitational waves large enough for us to detect, with our most sensitive measuring equipment.

What is a ‘black hole’ anyway? The earth is not one. But if you want to leave ‘Planet Earth’ you need to overcome the earth’s gravitational force. To do so you need to be going above a certain speed. The amount of speed you need is proportional to the mass of the planet. If you are on the moon and decide that it is time to go home, you don’t need as much speed. Just think about the speed at which the Apollo rocket took off from the Kennedy Space center and think about the speed at which the ‘lunar module’ left the moon. That was much slower, as the mass of the moon is so much less.

So what happens if you have a planet that is so massive that its gravitational pull is so great that the speed that you need to leave it is faster than the speed of light? Well there’s a problem because nothing can go faster than the speed of light – so nothing can ever leave it. It is like a whole planet that is Hotel California; it is programmed only to receive. This type of planet we call a ‘Black Hole’. The well known physicist, Stephen Hawking, (well known due to his appearances on ‘Big Bang Theory’) likened it to Niagara Falls. You can get close and then turn around and go the other way, but get too close and… you fall in.

Imagine then you have two black holes and they start to get close to each other and even too close. They collide and there is a massive increase in gravitation of the resulting planet and a major disturbance in the surrounding fields and this produces waves bigger than Niagara Falls. This is what scientists detected on the 14th of September last year and confirmed today.

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