From: "Jesse Mazer" <[EMAIL PROTECTED]> To: everything-list@eskimo.com Subject: RE: many worlds theory of immortality Date: Thu, 14 Apr 2005 04:04:48 -0400

From: "Stathis Papaioannou" <[EMAIL PROTECTED]> To: [EMAIL PROTECTED], everything-list@eskimo.com Subject: RE: many worlds theory of immortality Date: Thu, 14 Apr 2005 17:22:34 +1000

Jesse Mazer wrote:

You're right, alas. If QTI is correct, then each of us can expect to be the last conscious being in some branch of the multiverse. On the brighter side, we will have probably billions or trillions of years during which even the most sociable amongst us may well tire of sentient company!

What's your reasoning? If QTI is correct, I think each of us should more likely expect that civilization (a community of sentient beings) will last as long as allowed by the laws of physics, and any being finding himself approaching the physical limit (whether the limit is due to increasing entropy, a big crunch, or a big rip) is probably more likely to find that everything he's experienced up until then has really been a simulation in some larger meta-universe than he is to find himself lasting on thanks to an endless string of hugely unlikely quantum events or something like that.

Jesse

The probability that my consciousness will survive in some branch of the MW is exactly 1, if QTI is correct. The probability that my friend will survive in the same branch as me may be close to 1 - for example, if we are surgically joined, or if we are both implemented on the same chip - but it must be less than 1, unless it is actually physically impossible for only one of us to die. Therefore, over many branchings, my friend is sure to die and I will be left on my own. From the symmetry of the situation, my friend will in turn survive in some branch of the MW, but as t->infinity the probability that I will be still alive in that branch approaches zero.

For any given friend, sure. I thought you meant "alone" in the sense of having no other sentient beings to talk to. Also, if you live in some sort of "Omega Point" scenario where the computing power available to civilization grows without bound (not necessarily in the specific way Tipler proposed), maybe it'd be possible to reconstruct lost friends by simulating all possible past histories of the universe up until a certain time, then looking at the subset of universes that produced a being with your exact mental state at that time, so you can find a past history that's consistent with your memories.

Jesse

Also, another thought occurred to me--if the amount of computing power available to civilization were to grow without bound, the number of backups of any given being might grow forever too, meaning that the probability that all backups would be erased could decrease from year to year; so if, for example, the probability of all copies of your friend being erased was 1/8 in one century, 1/16 in the next century, 1/32 in the next, and so on, then the sum of this infinite series would give only a 1/4 chance that all copies of your friend would be ever be erased.

Also, another thought occurred to me--if the amount of computing power available to civilization were to grow without bound, the number of backups of any given being might grow forever too, meaning that the probability that all backups would be erased could decrease from year to year; so if, for example, the probability of all copies of your friend being erased was 1/8 in one century, 1/16 in the next century, 1/32 in the next, and so on, then the sum of this infinite series would give only a 1/4 chance that all copies of your friend would be ever be erased.

Jesse