[weebull]

Stellar event produces a gravity wave and a light pulse coincidentally at the source. As they travel through space together the gravity wave is compressing and expanding spacetime in the vacinity of the light pulse.

I could very easily believe that interaction by itself would be enough to have measurable effects over interstellar distances.

[abdullahkhalids]

Yes. But our explanation should argue for the direction of difference (whether light arrives first or the gravity wave).

[dTal]

Aha! So the light pulse could be riding a kind of naturally-occuring Alcubierre warp bubble?