If gravity has waves then would gravitational waves ripple back to the center once it reached the edge of the expansion? - similar to when a rock is thrown in a pond and it the wave reaches the edge of the pond and bounces back toward where the rock entered.
If it did would the resulting interference/cancellation result in an approximation of the delta between the current expansion rate and the anticipated rate?
Awesome thought!
If gravitational waves travel at the Speed of light and the universe is expanding at greater than the speed of light (currently accepted) the waves will never reach an edge.
By using Laser Interferometer Gravitational-Wave Observatory (LIGO) we have detected gravitational waves created when two black holes collided over 3 billion years ago.
I don’t know if they were able to determine the speed of those waves.