Coordinates are not the basis of physics. Curvatures are covariant, while connections and coordinates are not. These can be imposed in many ways, similar to a gauge choice.
LC On Thursday, July 23, 2020 at 6:49:44 AM UTC-5 [email protected] wrote: > > > On Thursday, July 23, 2020 at 5:41:42 AM UTC-6, Lawrence Crowell wrote: >> >> On Thursday, July 23, 2020 at 5:56:32 AM UTC-5 [email protected] wrote: >> >>> >>> >>> On Saturday, July 18, 2020 at 6:31:23 AM UTC-6, Alan Grayson wrote: >>>> >>>> >>>> >>>> On Saturday, July 18, 2020 at 6:18:28 AM UTC-6, Lawrence Crowell wrote: >>>>> >>>>> The tortoise coordinates is found from the Schwarzschild metric >>>>> >>>>> ds^2 = (1 - 2m/r)dt^2 - (1 - 2m/r)^{-1}dr^2 - r^2dΩ^2 >>>>> >>>>> where for a signal leaving a point near the black hole with ds = 0 >>>>> (null path) and propagating radially out, dΩ = 0, we have dt = dr/(1 - >>>>> 2m/r) which then leads to >>>>> >>>>> T = t - t0 - 2m ln|r - 2m|. >>>>> >>>>> That is the tortoise coordinate. Please look this up to read further. >>>>> I can't spend beaucoup time going over this for weeks to come. >>>>> >>>>> LC >>>>> >>>> >>>> You don't have to. We're done. But you should IMO address Brent's >>>> objection, maybe on another thread. AG >>>> >>> >>> When it comes to GR, you're a genius; no question about it. I wouldn't >>> want to waste your valuable time. But consider this; the Schwartzschild >>> metric applies to NON-ROTATING masses. Do you really think a massive >>> contracting star which forms a BH will be non-rotating? Obviously, it will >>> be RAPIDLY rotating, like an ice skater who contracts her arms. Brent also >>> had some substantive questions about your model. But I see you prefer your >>> illusions than to address his objections. AG >>> >> >> The result is similar, but more complex. The same calculation can be done >> for the Kerr solution. It is just a lot more complicated mathematically. >> >> LC >> > > If you say so. In any event, the idea that an objectively existing > gravitational field outside a BH should depend on the choice of a > particular coordinate system, seems a non-starter. 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 view this discussion on the web visit https://groups.google.com/d/msgid/everything-list/e5a4bdc5-8418-437e-8633-f1a4b3560cf8n%40googlegroups.com.
