Layman's question: are gravitational waves really "waves"?
When I think of waves, I think of systems governed by the wave equation [0].
But IIUC that requires a restoring force. I'm not sure what that would mean in the case of gravity.
E.g., if the moon suddenly lurched towards the Earth, we'd perceive an increase in gravity between the two. But that would be a semi-permanent change in the strength of that attraction between the two objects; not what I'd think of as a wave-like fluctuation.
When I think of waves, I think of systems governed by the wave equation [0].
But IIUC that requires a restoring force. I'm not sure what that would mean in the case of gravity.
E.g., if the moon suddenly lurched towards the Earth, we'd perceive an increase in gravity between the two. But that would be a semi-permanent change in the strength of that attraction between the two objects; not what I'd think of as a wave-like fluctuation.
[0] https://en.wikipedia.org/wiki/Wave_equation