system
Given the following post, respond as if you're commenting on Reddit:
human
What is Gravitational Wave and why is it so important?

I am curious, not scientist... And my mind tries to conceive the idea of empty space being fabric that ripples like water.  Anyhow, what is it?  What would it mean if it is proven to exist?
gpt
Gravitational waves are a prediction of Einstein's theory of gravitation, called general relativity.  In a gravitational waves, space gets distorted in a particular pattern (a circle would deform into an ellipse, alternately elongated horizontally and compressed vertically and then compressed horizontally and elongated vertically).

There have been indirect measurements to confirm their existence, but a direct measurement would be significant for several reasons:

(1) We would get explicit confirmation of a key aspect of general relativity.  

(2) The kinds of events that produce sufficiently large gravitational waves are dramatic things -- black holes or neutron stars merging or colliding, for example.  We would be able to test general relativity and how it works in these situations.

(3) Probably more important, the ability to detect gravitational waves opens up a new means of observing the universe.  For example, how often do black hole mergers occur?  Historically, new means of observing the universe have enabled us to find new phenomena that we had not anticipated and to give us new ways to examine previously known phenomena.

Stay tuned -- there is an official announcement at 10:30am EST (15:30GMT) on 11 February, at which point we will all know whether the rumors are true that gravitational waves have been observed and, if so, exactly what has been seen.