On Wed, 25 Jun 2014 09:12:12 -0700 (PDT), wrote:

On Friday, June 20, 2014 8:54:05 PM UTC-4, Tim Wescott wrote:
On Fri, 20 Jun 2014 14:12:14 -0700, etpm wrote:

Stephan Hawking, "A Brief History of Time". There's a sequel, which I
haven't read, but I do like the guy's writing.
I've read it. It does not explain the "hovering" phenomena very well.
Eric

Maybe we all need to learn special relativity and work through it
ourselves.

"Space time physics" by Taylor and Wheeler is (IMHO) the best special relativity (SR) book. Easy to do as a self study.
http://www.amazon.com/Spacetime-Phys.../dp/0716723271


I do know that the biggest challenge presented by black holes is that,
basically, the math breaks down. Relativity is a theory that's tacked
onto classical mechanics, so it works just peachy as long as quantum
effects don't come into play. Quantum mechanics is formulated assuming a
flat space-time, so it works just peachy as long as relativistic effects
don't come into play.

So it's not surprising that the explanations should be a bit shaky and
hard to wrap your head around -- theoretical physicists can't agree on
the details, so why should we be able to understand?

Yeah I think there are lots of different ideas, but we just don't have much data
on black holes so it's hard to pick between them.

To Eric, I don't have any books. And I still have plenty of things I don't understand about SR*, let alone GR. But let me start simple.
(Oh and this is my understanding and may be totally full of holes,
black, blue or otherwise.)
1.) according to SR photons don't experience any time!
(OK that just blows me away! But apparently it's true.)
2.) Let's first start from inside the black hole.
The gravity is so strong that photons can't get out.
(That's what makes it black.)
But how do you stop a photon that doesn't experience time?
The solution (I'm told) is to say there is no such thing as time at the event horizon.
3.) Well at this point I'm totally stuck. (as I think most people are.) We don't have any idea how to deal the event horizon. It's kinda outside all our physics ideas, maybe another beer is a good idea!
4.) Then coming at the event horizon from the other side.. well there is still this "no time" point.

And now back to my soldering iron.

George H.
*I'm still very much puzzled by the twin paradox.
It seems to me there must be some such thing as the ether
(or Aether if you prefer) that defines some sort of fixed (low velocity) coordinate system to the universe.
There's an idea (I've lost the guys's name...) that the vacuum, (with all it's virtual particles) forms this ether.



--



Tim Wescott

Wescott Design Services

http://www.wescottdesign.com
Thanks for the book suggestion. I'll look it up. As for photons being
stopped by the whatever if they don't experience time I don't see how
that is a problem. As gravity gets stronger the path the photon takes
gets more and more curved. Eventually the path is curved to the point
that the path curves back into the black hole. Where, I assume, the
photon is absorbed and converted into some other form of energy or
matter. Maybe just energy. I'm not clear as to whether matter can
exsist inside a black hole. Maybe just degenerate matter.
Eric