Recent content by eugene pletcher

Thanks Chalnoth, What about velocity, due exclusively to cosmic expansion?

As an astronomer observes a galaxy, which is receding, Does time dilation occur between the two comoving galaxies? If so, which (rf) is (t) longer in, as observed here on Earth (Our local Milkyway galaxy or the remote galaxy)? Thank you.

May I ask just one more question? Does expansion separate individual photons, which are massless? I'm not referring to geodesics, or curved space. I'm interested to know if expansion itself can cause two, almost parallel, photons to separate. I suspect that the answer is no. Thanks :)

Again thanks. Even when viewing several billion light years away, the light paths (travelling toward Earth) are not converging in the remote past?

Appreciated. Was the distance between galaxies not smaller in the past? If so, does that not imply light beams were closer then they are now?

Thank you, for sharing and celebrating our mutual passion for physics.

Regarding expansion, from the present to the past: Do light beams (generally) converge to a single point, in the remote past, as geometry and matter was also condensed to a single point, prior to the big bang? Thank you.