>I've come across a blog post that attempts to show that general
>relativity (GR) contradicts itself about black holes. No, I didn't
>write it so please don't lambaste me. I just want to know what's wrong
>with it. I hope this isn't yet another group where not even an
>imagined problem with mainstream physics can be discussed. I hope the
>charter isn't a cruel trick.
>
>There's been some discussion about the blog (note I didn't start it)
>in another forum. You can find both the blog (called "On Cosmology")
>and the discussion thread (at scienceforums) by googling for "No Black
>Holes (General Relativity Contradicts Itself)" (put within double
>quotes). I'd put the links here but Google Groups doesn't allow that
>for some reason.
>
>The best problem about the blog they've come up with in the thread is
>that it lacks math. I don't see that as a major problem. The way I see
>it, the blog post is a paradox, just like the twin paradox or Bell's
>spaceship paradox, both of which are described in words, without math.
>I'm confident there's a simple solution, also describable in words,
>that shows a problem with the blog. The blog uses only a few widely
>published predictions of GR.
>
>In brief, the blog's argument is that GR demands that a freely falling
>frame that is falling through the horizon of a black hole is not
>equivalent to a freely falling frame that is wholly above a horizon.
>This would contradict GR's own equivalence principle, hence GR would
>contradict itself. The blog attempts to show that under certain
>conditions, in the frame falling through the horizon, GR allows you to
>determine that two bodies are moving relative to each other, knowing
>no more info about one of the bodies than its location in the frame.
>Such cannot be determined in a frame that is wholly above a horizon.
>But read the blog for whole story.
>
>It's making me crazy trying to figure out the solution. I have a
>decent layman's knowledge of GR (for example I well understand the
>solutions to the other paradoxes mentioned), but the blog's paradox
>seems airtight to me. It can't be!
>