On Tue, Jul 22, 2025 at 3:53 PM Alan Grayson <[email protected]> wrote:
*>I think I get it. Although light from ancient galaxies left those > galaxies in the distant past, the red shift we observe reflects the > expansion of the cosmos since then, and represents their recessional > velocity at this time, NOW. This is consistent with Hubble's law, which > tells us how fast galaxies outside the local group are receding in real > time, NOW. AG * *Yes, but you have to be careful with "recessional velocity" because in cosmology the term can be ambiguous; sometimes it means how fast an object is moving away from us through space, and sometimes it means how fast the space between us and the object is expanding. I think cosmologists should have two different words for those two different things but unfortunately they don't. * *John K Clark See what's on my new list at Extropolis <https://groups.google.com/g/extropolis>* &,s > -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion visit https://groups.google.com/d/msgid/everything-list/CAJPayv3t_OObeZixiyNSnTgCAR8WT1fShgn3Fkvu%3DKnSZLePqw%40mail.gmail.com.
