[edwin hubble]

Thanks for the ping.

The most fascinating thing about this experiment is not that it confirmed the speed of gravity equal to light speed,
but rather that it was not confirmed earlier.

Think how many ways there must be to confirm this speed...orbital mechanics: the precise velocity and position measurements of a comet, for instance. Certainly this information must yield an approximation of the speed of gravity.

[PatrickHenry]

Think how many ways there must be to confirm this speed...orbital mechanics: the precise velocity and position measurements of a comet, for instance. Certainly this information must yield an approximation of the speed of gravity.

Yes, but with our present equipment, I'm guessing that it takes something as massive as Jupiter to get any useful data. Still, it could have been done earlier, as you say.