Saturday, August 17, 2013

Black Holes, Quantum Mechanics and Death

The New York Times recently (August 13) published an article about the problem of what happens to an object that falls into a black hole; more specifically, what happens to the information encoded in such an object: will that information be lost or (somehow) preserved?That was the gist of it anyway; the problem is complicated and elicited a wide range appropriately learned comments, arguments and explanations. By the time the editors had stopped accepting such contributions there were 372 of them, one of which was mine which was neither complicated nor learned but was accepted anyway.

Why all the fuss? Because that question about the loss or preservation of information is at the center of quantum mechanics in the form of a law, which says that information is always conserved. As you probably know there are a number of such conservation laws in Physics. All of these have been repeatedly tested and confirmed. Until now, perhaps.

I think that the law of conversation of information is violated every time an organism dies, or a great library is burned, and I said so:

Why has no one mentioned death in this controversy about information and whether or not it is conserved? Dead men tell no tales, right? (Well, there are those who believe that there is life after death, of which I am not one.) When we die ALL the information that has been somehow encoded in our brains disappears. When the sun becomes a red giant and gobbles up this planet, all the information stored in it and on it will be gone, forever. Can I prove that? No. But I know it and so do you—most of you, at any rate.

These remarks were mostly ignored or received with hostility—one fellow said I had my facts wrong, another that by saying I knew something which I could not prove I was revealing a religious bias.

Now, having given the problem a little more thought, I realize that I ought to have more forcefully acknowledged the fact that the conservation of information law is one of the foundation principles of the Standard Theory, and has been verified over and over again. Then, the point I should have made is that information has only been shown to be conserved in laboratory experiments at the atomic or sub-atomic level; never in the macroscopic world that we live in. A black-hole, however, brings both realms together; we know or think we know what happens to a macroscopic object that gets pulled into a black hole and disappears.  Though it will probably never happen, it is theoretically and practically possible for a spaceship with people in it to encounter the gravitational field of a black-hole and be sucked into it. At that point it makes sense to ask what happens to the information encoded in that spaceship and in the bodies and brains of people in it. What I am claiming is that all that information will be lost forever. Which, of course, is what happens when we die; or, when a great library, like the one in Alexandria, burns.