I’ve been reading a
bit today about this recent discovery of gravitational waves from LIGO. My hope was to get enough of an understanding of what gravitational waves are to explain them to readers here. Turns out, I can’t do a better job of explaining them nor covering the discovery than what this Science News video does, so I’ll just share it rather than try to do better:
I can tell you that 
gravitational waves are effectively ripples in the fabric of spacetime, spreading much like ripples on the surface of a pond do when a rock is tossed into the pond. They were predicted about a century ago by Einstein as part of his Theory of Relativity, although apparently he didn’t think we’d ever have the technology to detect them. For measurable gravitational waves to even make it to earth, a massive ripple has to be started by an enormous release of energy, such as what happens during the collision of two black holes.
To find out more, read the links offered up above. And if you are interested in helping find more gravitational waves, download and install the Einstein@Home screensaver and make your own contribution to science!