A gravitational wave is an invisible ripple in space. Gravitational waves speed is same as speed of light.

By complete coincidence, last night I had my amateur radio telescope pointed at a certain part of the sky. I had left the recording equipment on, and when I played it back this morning there was this strange message:

"Oh freddled gruntbuggly,

Thy micturations are to me

As plurdled gabbleblotchits in a lurgid bee.

Group, I implore thee, my foonting turlingdromes,

 

And hooptiously thrangle me with crinkly bindlewurdles,

For otherwise I will rend thee in the gobberwartswuh

With my burglecruncheon."

See if I don't!"

(*Douglas-Adams-turning-in-his-grave*)

If you're into Physics and Smelly Socks, read on.