On Thursday, April 18, 2019 at 8:08:58 PM UTC-6, agrays...@gmail.com wrote: > > > > On Thursday, April 18, 2019 at 6:53:33 PM UTC-6, Brent wrote: >> >> Sorry, I don't remember what, if anything, I intended to text. >> >> I'm not expert on how Einstein arrived at his famous field equations. I >> know that he insisted on them being tensor equations so that they would >> have the same form in all coordinate systems. That may sound like a >> mathematical technicality, but it is really to ensure that the things in >> the equation, the tensors, could have a physical interpretation. He also >> limited himself to second order differentials, probably as a matter of >> simplicity. And he excluded torsion, but I don't know why. And of course >> he knew it had to reproduce Newtonian gravity in the weak/slow limit. >> >> Brent >> > > Here's a link which might help; > > https://arxiv.org/pdf/1608.05752.pdf > > AG >
I'm coming to the view that what I have been seeking these many years - namely, a mathematical derivation of Einstein's field equations, somewhat like a mathematical theorem -- doesn't exist. It's more a case of a set of highly subtle physical intuitions about how the universe functions, which, when cobbled together, result in the field equations. For this reason, most alleged explanations of GR involve, at some point, essentially pulling the field equations out of the proverbial hat. As with the Principle of Relativity and the Least Action Principle, the latter say applied to asserting geodesic motion for freely falling bodies, they're not provable as "true", but assuming them "false" would be a dead-end for physics and would, as well, make our lives miserable. AG -- 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 everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
