On Friday, July 24, 2020 at 11:47:07 PM UTC-6, Alan Grayson wrote: > > > > On Friday, July 24, 2020 at 6:59:20 PM UTC-6, Bruce wrote: >> >> On Sat, Jul 25, 2020 at 10:19 AM 'Brent Meeker' via Everything List < >> [email protected]> wrote: >> >>> On 7/24/2020 4:26 PM, Bruce Kellett wrote: >>> >>> On Sat, Jul 25, 2020 at 9:13 AM Lawrence Crowell < >>> [email protected]> wrote: >>> >>>> >>>> It is not the case that gravitons come out of a black hole to >>>> intermediate a force between it and some other mass. From the perspective >>>> of an exterior observer all mass-energy and quantum fields that make up a >>>> black hole are on the event horizon or just above. This is why I got into >>>> the whole Tortoise coordinates and so forth. I will have to leave it here >>>> I >>>> think. >>>> >>> >>> Why does the perspective of an exterior observer have preferred status? >>> This is an absurdly intstrumentalist/positivist idea. What matters is the >>> objective reality, not what you might chance to see from some perspective >>> or the other. The idea of all the mass-energy residing on the stretched >>> horizon is just so much positivistic twaddle...... >>> >>> >>> I agree. The question would be "Residing there *when?*" The only >>> interest in the distant observers viewpoint is to compare it to what we >>> distant observers observe. >>> >> >> >> A while ago you, Brent, made an observation that seemed to me to be the >> perfect answer to all thoughts of black hole complementarity -- we could >> call it "bent stick complementarity". When you partially submerge a >> straight stick in water, it appears bent to the external observer; but when >> you take it out of the water it appears straight. You can't have it both in >> the water and out of the water at the same time, so the two observations >> are complementary. Complementarity would say that, from the point of view >> of the exterior observer, the stick is in fact bent when it is partially >> immersed in water; and it is in fact straight when it is wholly out of the >> water. No observer can see both situations at the same time -- they are >> complementary. >> >> Similarly for the observations of the observer exterior to the black hole >> and the observer who plunges through the horizon..... The exterior view is >> entirely illusory. >> >> Bruce >> > > IIRC, LC introduced tortoise coordinates in an objection to my claim that > the gravitational field of the BH at the center of our galaxy can be > observed, or inferred, from the rotation rate of stars near our galactic > core. Is this observation not sufficient? AG >
As far as I can tell, the advantage of tortoise coordinates is that they obfuscate the relevant issues. Still waiting for some argument why a quantum theory of gravity is needed. TIA, 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/1faa65da-8f68-4f76-9cc8-86ab72094331o%40googlegroups.com.
