Thursday, July 10, 2008

Black Hole Wars

I saw this at, and it was too juicy not to comment on.

Professor Susskind says

A black hole is what you get if you compress so much mass into a region of space that it collapses, under its own weight, to an infinitely small, dense, point called the “singularity.” Everything that gets too close to the black hole gets sucked in, and squashed beyond recognition. There is no escape from the singularity, even for a light ray. Someone falling into a black hole might try to send a message, on a beam of light, to the outside world: “Help, I’m being sucked in.” But even the light ray gets pulled back to the singularity.

There is a certain radius—a particular distance from the dangerous singularity—that I like to call “the point-of-no-return.” If you accidentally pass the point-of-no-return there is nothing you can do to escape; you and all your messages will get swept to the singularity and destroyed. The point-of-no-return is also called the horizon of the black hole.

Passing the horizon seems very innocent while it is happening. It’s like being in a rowboat above Niagara Falls. If you accidentally pass the point where the current is moving faster than you can row, you are doomed. But there is no sign—DANGER! POINT OF NO RETURN—to warn you. Maybe on the river there are signs but not at the horizon of a black hole.

When has religion ever produced such magnificent views? That's right, never.

One interesting point raised in the comments were about what was meant the by the scrambling of information. If the information is "scrambled", then does it not mean that the information has been destroyed, as Hawkings had suggested?

But Susskind seems to say otherwise, which seems to mean that the information is, theoretically at least, recoverable. If it's simply a random scrambling, then the original information would not be recoverable, and hence the information can be considered to be destroyed. Or have I utterly failed to understand the concept of information in theoretical physics?

On a different note, I am quite excited by the notion that Quantum Physics and the General Theory of Relativity are on a collision course. It should be entertaining.

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