Gregory Ewing <greg.ew...@canterbury.ac.nz>: > Marko Rauhamaa wrote: >> We cannot get any information on black holes proper because black holes >> cannot come into existence according to the very theory that predicts >> black holes. It will take infinitely long for an event horizon to form. > > Only in some frames of reference. > > By your reasoning, Zeno's paradox proves that a runner can never reach > the finish line in a race.
In Zeno's case, the limit is finite. Zeno's error is not realizing that you can pack an infinite number of jiffies in finite time. In the black hole case, the limit is infinite. > But it really only proves that if you measure time in such a way that > the finishing time is infinitely far in your future, you will never > see him finish. An external observer never experiences any effect whatsoever (direct or indirect) from an event horizon or a black hole. > But there's no reason you have to draw the coordinates that way; there > are plenty of others in which the time axis does cross the horizon. Not where I'm standing. Marko -- https://mail.python.org/mailman/listinfo/python-list
