Sunday, March 6, 2016

Wavy Gravity


Physics was making big news again just recently. When Albert Einstein created his general theory of relativity it suggested that gravity was actually warping space. And that's the model that people have been using since many of it's predictions have been verified. Like gravity bending light, and slight differences in the flow of time between the Earth's surface and out in space (which has to be accounted for to make your GPS work). 


Well another prediction was that gravitational waves would exist. And these were just detected by the Advanced LIGO (Laser Interferometer Gravitational-Wave Observatory). This device (or devices) use lasers to detect very minute changes in the shape of space itself. And it was a tiny change. A fraction of the size of a proton.

Imagine a rope fastened down at the far end and you flip the rope to create a wave. This wave deforms the rope, that is changes the shape of the rope. And this change decreases in size the further you get from the event creating the wave.

This is kind of what happened 1.3 billion years ago. There were two black holes circling each other and getting closer together. And they collided and merged. This was like the jerk in the rope. It generated a wave in the “fabric” of space, that traveled 1.3 billion light-years to reach Earth recently. But like the rope the wave had decreased in size the further away from the event it traveled. So it was only a tiny wave that was detected.

Now will this help us out like the GPS? Probably not. But it does mean we're a little closer to understanding how the Universe works. (And just how much is explained by Einstein's theories.) There will be more experiments developed to study gravity and certain high mass astronomical objects (black holes, neutron stars, etc.). And there will a better understanding of gravity itself.


 Though I doubt that that will help me much the next time I knock something off the kitchen counter.

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