Riding the gravity wave

Scientists today announced that they have observed gravity waves – ancient ripples from the Big Bang. Here’s a conversation piece about the science and Nature has something on the BICEP2 discovery of primordial gravity waves too. And, here’s a gravitational playlist to give you something to listen to while you get your head around this concept, try eating an apple, it might provide nourishment for your brain too…you could of course have anything by The Fall.

NB It seems a lot of the reporting on this discovery is confusing gravitational waves with gravity waves. They are not the same thing. Gravitational waves are ripples in the curvature of spacetime that propagate as a wave as predicted in general relativity by Einstein in 1916. By contrast, gravity waves are waves formed when a liquid sloshes around, the wind waves on the sea are an example of gravity waves. Carolyn Porco is trying to educate the wider media on this point as editors seem to be using the words gravitational and gravity interchangeably in reports on the BICEP2 discovery.