There are lots of other possible frames. They would share this generic feature of delay.
LC On Thursday, July 23, 2020 at 9:33:40 AM UTC-5 [email protected] wrote: > > > On Thursday, July 23, 2020 at 8:27:52 AM UTC-6, Lawrence Crowell wrote: >> >> 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 >> > > That right; coordinates are not the basis of physics. That's why Einstein > had to cast his GR equation in tensor form, so the laws of physics would be > independent of coordinate systems. But you're asserting, or so it seems, > that there is a unique coordinate system wherein the external gravitational > effect of a BH can be calculated. This is what I object to. AG > >> >> >> 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/a6fac3c1-3435-472e-b781-4972edeb9485n%40googlegroups.com.
