On Sunday, April 21, 2019 at 5:59:25 PM UTC-6, [email protected] wrote: > > > > On Sunday, April 21, 2019 at 5:54:33 PM UTC-6, Brent wrote: >> >> >> >> On 4/21/2019 2:20 AM, [email protected] wrote: >> >> >> >> On Saturday, April 20, 2019 at 9:51:13 PM UTC-6, Brent wrote: >>> >>> >>> >>> On 4/20/2019 2:14 PM, [email protected] wrote: >>> >>> The following (long!) video can also help (well, it did help me) >>>> >>>> https://www.youtube.com/watch?v=foRPKAKZWx8 >>>> >>>> >>>> Bruno >>>> >>> >>> *I've been viewing this video. I don't see how he established that the >>> metric tensor is a correction for curved spacetime. AG * >>> >>> >>> The metric tensor is the quantified embodiment of curved spacetime. But >>> How else would you define curvature, if not with the metric? >>> >>> Brent >>> >> >> *At 49:42 he defines the metric tensor. It has a Kronecker delta as the >> leading term. So all cross terms will be zero in its matrix representation. >> * >> >> >> But then he says that in a curved space g_mn must be something else, that >> does have cross terms. I don't find his presentation very enlightening. >> He ends up wit ds^2 = g_m_n dx^r dx^s He doesn't even have the indices >> match as in Einstein's summation forumula. >> >> Brent >> > > Thanks. I'm going on to Susskind's lectures on GR. AG >
*Here's something odd. At 9:45 in Susskind's Lecture 2 on GR, he says the metric tensor is a Kronecker delta function. But I could swear that the diagonal of -1,1,1,1 represents flat space in SR. AG * > >> *Listen; this is pure mathematics. If what he calls the metric tensor is >> the general correction for curved spacetime, it can be proven >> mathematically, strictly by mathematics. What I see is a hand-waving >> argument at best! Ball in your court. 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 [email protected]. >> To post to this group, send email to [email protected]. >> Visit this group at https://groups.google.com/group/everything-list. >> For more options, visit https://groups.google.com/d/optout. >> >> >> -- 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 post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
