I understand that the Shapiro time delay effect is one of the four classic solar system GR tests.
I understand the EM waves have to pop back from a planet beyond the star and then pass next to the sun coming backwards.
- has anybody ever done the same test interstellar, so with another solar system? Alpha Centauri is only 4.37 light years away, so it sounds doable. (It might be harder to time for the planet orbitals in that solar system, but it sounds still doable, just like with the Shapiro effect, the EM wave has to pop back from a planet from beyond Alpha Centaury, we know the planets' orbit in that solar system too, so we can calculate the right position when the EM wave gets there to pop back from it.)