Oh wow Lumo has written an article because another scientist got it wrong on the event horizon in GR smile

It basically runs thru everything we have been discussing and in extreme detail and fluent English .. unlike mine.


Haha he is right and I did.

Everyone who got a well-deserved A in any general relativity course will agree with me. The event horizon is not a special locus "locally". Locally it looks like any "fictitious" surface we imagine anywhere in space which is moving by the speed of light.

He also basically covers off the situation I was trying to make that a solid inside a black hole defies SR/GR. Dave is on one hand using GR to create the black hole and then contradicting GR, all I want is consistency. Either Dave thinks GR is right or wrong it can't be both without heavy explaining.

In particular, no plastic foil may be sitting at the event horizon because the event horizon is a lightlike surface which means that the plastic foil would be basically obliged to move at the speed of light which the massive objects aren't allowed to do. Also, you may stand on the surface of Earth because of the pressure from the solid matter that our planet is made of. But there can't be any "solid surface" inside the black hole (lower than the event horizon) because that surface would be a purely spacelike, 3+0-dimensional surface, and massive objects' trajectories can't be spacelike (a spacelike trajectory only occurs for the forbidden faster-than-light tachyons). So any idea that you may "stand on a permanently solid surface" at a fixed Schwarzschild R inside the black hole contradicts the strictest laws of physics the most universal laws of relativity. There cannot be anything to safely stand on inside the black hole.

Subjectively that boundary is very much like the sound barrier you don't want to try and sit on it the "vibrations" for want of a better word would be horrific. The same arguments ran on the sound interface for years before someone had the courage to just try and push thru it.

You really would want to pass thru it fast, having said your goodbyes to the world smile

I had forgotten about the funny partially collapsed star idea that used to circulate because time was really slowing ... it has been a while.

Really that is probably no better or worse than that article by Ethan. Scientists sometimes have gaps in there knowledge and sometimes they don't know them smile

Edited by Orac (09/02/15 04:07 AM)
I believe in "Evil, Bad, Ungodly fantasy science and maths", so I am undoubtedly wrong to you.