(sorry for the premature previous post)
Random832 <random...@fastmail.com>:
> All objects, not just black holes, have those properties. The point
> here is that we are in fact observing those properties of an object
> that is not yet (and never will be) a black hole in our frame of
> reference.
A physicist once clarified to me that an almost-black-hole is
practically identical with a black hole because all information about
anything falling in is very quickly red-shifted to oblivion.
However, there is some information that (to my knowledge) is not
affected by the red shift. Here's a thought experiment:
----------
/ \
/ (almost) \ N
| black | |
| hole | S
\ /
\ /
----------
We have a stationary, uncharged (almost) black hole in our vicinity and
decide to send in a probe. We first align the probe so it is perfectly
still wrt the black hole and let it fall in. Inside the probe, we have a
powerful electrical magnet that our compass can detect from a safe
distance away. The probe is also sending us a steady ping over the
radio.
As the probe approaches the event horizon, the ping frequency falls
drastically and the signal frequency is red-shifted below our ability to
receive. However, our compass still points to the magnet and notices
that it "floats" on top of the event horizon:
----------
/ \
/ (almost) \ N
| black ||
| hole |S
\ /
\ /
----------
/
/ compass needle
/
The compass needle shows that the probe is "frozen" and won't budge no
matter how long we wait.
Marko
--
https://mail.python.org/mailman/listinfo/python-list
