Quantum immortality: Is decline of measure compensated by merging timelines?

You right - I didn't mean the merge of quantum worlds, but mean the merge of personhoods, which could happen even in classical but infinitely large universe. I wanted to show that assuming the possibility of such merger has absurd consequences. However, this absurdity is also applicable to other calculations where the "measure of an observer" changes, as it happens in the one of important objections to the quantum immortality.

In the other words, we can't kill the quantum immortality idea by saying "the measure will decline to infinitely small values", as in fact, the measure could even grow if we properly calculate it.

What could be done to resolve this conundrum? We could ignore changes of absolute measure, and look only on relative measure, that is relation between shares of the different outcomes where observer is alive. For example, if QS thought experiment has 3 outcomes: a) non existence 0.9, b) winning 1000 usd with 0.09 с) losing 100 000 with 0.01 probability (e.g. injury) , we should in that case ignore (a) and compare expected utility of (b) and (c), which are +90 and -1000, so the game in this case has negative utility of -910.

Another solution is to accept that we could change our measure in the world by forgetting things, and to build something like a magic based on it. (This idea was discussed on LW as "flux universe" on a series of posts where a person had panic attacks based on idea that if he forgets parts of his personality before sleep, he would be never able to return back to his initial self.) This "magic" may look like: (1) a person learns that he has rare deadly disease. (2) he meditates and remove from his mind all clues about this fact (3) his observer-moment becomes so simple that it is equal to zillions of observer-moments of other peoples (4) if human mind is only numbers, they "merge", (5) now he returns to awake state, but his probability to be in the world-line where he has the rare disease is equal to the level of incidents of the disease in the population, that is very low. (6) Profit. But this thing seems more absurd than quantum immortality.

Another possible solution is to get rid of the idea of identity in favor of some form of open individualism. The problem here is that most human preferences are formulated in the way that they assume existence of the some form of identity: "I want a cake"

For the sake of argument we assume that the information is erased sufficiently good for two pseudo-copies to be become exact copies - and this information is not immediately restored by interaction with the outside world. If we were digital minds, it will be simpler: I can generate a random string of data in advance and then delete bit by bit.

Most human preferences has an embedded idea of identity as a receiver of the profit. However, the idea of "beings similar to me" assumes that there are "beings which are not enough similar to me for to be regarded as me" - but still have some of my traits. In other words, any definition of identity creates possibility of "pseudo-copies": if we define the identity wider, the circle of the pseudo-copies around it will become also wider, but will not disappear until we include all possible beings and end up with open individualism.

If we assume total "open individualism", it results in perfect effective altruism and the utility function will be akin "I prefer that total wellbeing of all sentient beings in the universe will increase on 100 pounds". However, this is not how most human preferences work, and there is also a risk of starvation.

So playing with the definition of identity will not help to escape the problem of existence of pseudo-copies, which could become "real me", if some information is erased from both of us.

Even if the cut-off is not sharp, something - which was completely not me - may become partly me after my simplification. Adding diffuse personality border is a correct step to the proper calculations of "me" and "not-me", if we ever come to this level, but this doesn't change the idea of the post: The simplification of the definition of "me" results in wider "bell curve" and thus larger share of all possible observer which are me.