(February 12, 2016 at 7:35 am)Alex K Wrote:(February 12, 2016 at 7:10 am)Brian37 Wrote: I am guessing. The fabric of space time wouldn't seem to me different than the motion of a water buoy in the ocean bobbing up and down left and right because of waves.
Meaduring lengths in relativity is a subtle thing because there is so much freedom to choose coordinates. The simplest way to understand it is that you have two freely floating test masses at a distance which get hit by a gravity wave. The wave changes the distance measure between the masses just as cosmic expansion increased the distance between galaxies.
... and because the Hubble Constant is a known factor, they can discriminate the additional motion and adduce it to gravitational waves?
