timeless quantum immortality

Algernoq

Summary: The world looks normal despite Quantum Immortality, because the most likely Universe in which you're immortal is one where your immortality doesn't require much luck.

Recap of Quantum Immortality: The Many-Worlds Interpretation of Quantum Mechanics states that every time some event is observed (e.g. a coin flip), the Universe splits into separate universes, one for each possible outcome (e.g. Heads universe and Tails universe), and the conscious observer will find themselves in one of these universes (e.g. either see the coin come up Heads or see it come up Tails) with a likelihood proportional to the number of ways this event can happen (e.g. you'll probably never see a coin land on edge). Quantum Immortality states that my consciousness will follow the path of branchings in which it survives (e.g. if I set up a highly reliable system that will kill me if the coin ever comes up tails, I can flip and flip the coin and I will only ever see it come up heads).

New idea: Let's take a timeless perspective, and ask "what entire life path am I most likely to observe, from the set of all possible life paths?" Quantum Immortality restricts me to observing life paths in which I do not die. Some life paths are more probable than others. It's not clear what this probability is, but simpler life paths seem more likely than others (e.g. I'm more likely to observe a life path that can be described with any of many sets of physical laws and initial conditions, and less likely to observe a life path that requires a unique, complicated description.) I'm most likely to observe a world that follows physical laws all the time, in which many different sets of simple physical laws could create the world I see. I'm less likely to see a world in which I get improbably lucky.

Thus, I expect to live forever but I don't expect to get lucky.

2nd new idea: Let's generalize this timeless perspective across multiple individuals and lifetimes. Zooming out again and looking at the set of all possible evolutionary paths for a lifeform: it's most likely that I'm one of a lifeform that exponentially grows about as rapidly as possible. Over a long time horizon, the most numerous lifeform is the one that has the highest rate of growth. Thus, because I am conscious and Quantum Immortality appears to be correct, there's a good chance that I will spawn huge numbers of conscious immortal beings during my infinitely-long life.

Summary: The world looks normal despite Quantum Immortality, because the most likely Universe in which you're immortal is one where your immortality doesn't require much luck.

Thus, I expect to live forever but I don't expect to get lucky.

The Many-Worlds Interpretation of Quantum Mechanics states that every time some event is observed (e.g. a coin flip), the Universe splits into separate universes, one for each possible outcome (e.g. Heads universe and Tails universe), and the conscious observer will find themselves in one of these universes (e.g. either see the coin come up Heads or see it come up Tails) with a likelihood proportional to the number of ways this event can happen (e.g. you'll probably never see a coin land on edge)

This is false and misleading in various ways.

1) in MWI, splitting events are gradual, in the sense that the relevance of one 'world' to another continuously drops from 'high' to 'utterly negligible' without a sharp cutoff. There is a connection to observation, but it's a confusing one that MWI ought to be helping one avoid making.

2) splitting events produce thermodynamically large quantities of worlds.

3) the likelihood is indeed a sum over the various paths, but the coefficients on the paths are complex-valued and span many orders of magnitude. I grant that these details might normally not be relevant for such coarse-grained matters as biology, but if you're going to survive, say, a heavy object smacking into your head at high speed, this is going to be a major issue - all of your survival paths are much smaller than the fatality paths.

4) Nothing is keeping you off of such doomed states, so once you find yourself in one, you're about to get really lucky (or die). Nothing except going timeless, but...

5) You can't both take the timeless perspective and invoke quantum immortality. QI is all about the subjective case, and the timeless perspective requires, among other things, not taking the subjective case.

Thanks for the criticism.

summary: If, hypothetically, I tried to catch a terminal-velocity bowling ball with my face, your theory says I would experience the bowling ball doing nonfatal damage and then stopping just before killing me, and my theory says I would experience changing my mind and getting out of the way of the bowling ball. It looks like our key disagreement is whether Quantum Immortality only operates over short timescales. You say it only acts in an instant, and I say it acts over long time intervals as well.

longer argument: I'm not convinc... (read more)