On immortality

Mathematician here. I wanted to agree with @pianoforte611 - just because you have infinite time doesn't mean that every event will repeat over and over.

For those interested in some reading, the general question is basically the question of Transience in Markov Chains; I also have some examples. :)

Let us say that we have a particle moving along a line. In each unit of time, it moves a unit of distance either left or right, with probability 1/10 of the former and 9/10 of the latter. How often can we expect the particle to have returned to its starting point? Well, to return to the origin, we must have moved left and right an equal number of times. At odd times, this is impossible; at time 2n, the probability of this is %5En%20\cdot%20\left(\frac9{10}\right)%5En%20\cdot%20\binom{2n}{n}) (this is not difficult to derive, and a simple explanation is given here). Summing this over all n, we get that the expected number of returns is one in four - in other words, we have no guarantee of returning even once, much less an infinite number times!

If this example strikes you as somewhat asymmetric, worry not - if the point was moving in three dimensions instead of one (so it could up, down, forward, or back as well as left or right), then a weighing of 1/6 to each direction means that you won't return to the starting point infinitely often. If you don't like having a fixed origin, use two particles, and have them moving independently in 3 dimensions. They will meet after time zero with less-than-unit-probability (actually, the same probability as in the previous problem, since the problems are equivalent after you apply a transformation).

I hope this helps!

This sounds like quantum immortality. The problem is that the probability measure of survival goes down. The further future yous don't exist nearly as much as the present yous, so they don't matter as much.

Every universe existing explains everything. Its simplicity is matched by its lack of explanatory power, so it's not particularly likely.

Wild speculations on quantum physics aside, I would like to use the regular pedestrian definition of immortality that is distinguishable from this and any other version of afterlife being discussed:

Immortality is eternal life or the ability to live forever

By this definition, a friend of mine who has recently and unexpectedly died from lung cancer is quite dead and in no way immortal. I can visit her grave, or see the grief of her friends and relatives, religious or otherwise. Reading about Boltzmann brains, Infinite multiverses or the Second Coming of the Messiah is not in any way comforting, because I still cannot undo her death.

From that point of view, and the only one that matters to me, Algon's recipe of doing "nothing" is admitting defeat.

Yay, the Eternal Recurrence Lives!

Not so much.

Identity as intertemporal solidarity with any other being is a choice, whether the being has "identical" structure or not. It's a choice for your attitude toward the "you" of tomorrow morning. Or your attitude toward a parakeet 3000 years ago.

But going back to a recurrence of "the same" structure, the notion of a low probability of a being with "the same" structure popping into existence is based on an ultra extreme tail end extrapolation from our current models. Have you validated those models to the gazillionth decimal point? Me neither.

Also, the math is just wrong. An infinite number of chances (let's make them independent, but not necessarily equal) need not sum to a certainty.

An exact copy of me may be "me" from an identity perspective, but it is a separate entity from a utilitarian perspective. The death of one is still a tragedy, even if the other survives.

You should know this intuitively. If a rogue trolley is careening toward an unsuspecting birthday cake, you'll snatch it out of the way. You won't just say, "eh, in another time that cake will survive," and then watch it squish. Unless you're some sort of monster.

This seems significantly shakier than even the idea of quantum immortality.

Lets call your idea "Boltzmann Brain Immortality". That is, the idea that "because a Boltzmann Brain version of me might possibly pop into existence somewhere in the multiverse at some point in time, ever, I am immortal".

I have two main objections to this: 1) Boltzmann Brains are generally considered a problem in theories of physics which allow them. That is, if a model of physics allows Boltzmann Brains to be possible, with non vanishing probability in comparison to 'real' intelligent life, this is considered generally considered a flaw in the theory.

2) I wouldn't consider a Boltzmann Brain version of me to qualify as 'life' or 'immortality', since there si no continuity of experience - the Boltzmann Brain just vanishes again an instant later.

A new article on the topic:

Boltzmannian Immortality* Christian Loew†

https://core.ac.uk/download/pdf/157868191.pdf

Hysteresis exists. Complex models are often time-dependent, and initial states may not always be retrievable under any circumstances.

In the immediate sense, the world we experience obviously has the quality of irreversible change. On a larger scale, our cosmos could easily be such a system- even without ChaosMote's excellent statistical treatment, we can't be sure that, just because things in general continue to happen, an event like the big bang could happen an infinite number of times. No matter how wide the scope of your analysis, it may be that the 'final answer' is that we are indeed working within a single time-dependent system.

I think that the most reasonable thing to assume is that every possible kind of reality exists. Why? Well, there seems to be no good reason for it not to. To assume that the universe is the sole reality is one assumption too many for me, and I say the fewer assumptions there are, the better.

If I'm not mistaken, this is the strong assumption underlying the whole post. And I would encourage you to consider this claim in probabilistic terms, rather than just working within a believe/disbelieve binary. What is your degree of confidence in this proposition, and why?

I think Yvain did it better, and went a more interesting direction with it. Good try though, I think this issue doesn't get discussed enough.

I've had this thought before, however, is it true that given an infinite amount of time a mind will spontaneously form? I don't think that's necessarily true. Suppose an event E has a probability of occurring at any given time:

P = e ^ (-1- t)

That has a finite probability of occurring given an infinite amount of time. That's sort of cheating, but it illustrates that an infinite amount of time doesn't guarantee that anything that can happen will happen. Maybe the universe does become exponentially less likely to support the existence of a mind over time.

Your premise is wrong. "So, let's get started with the basic idea. In this universe, things seem to run on probabilistic laws known as quantum mechanics. These allow for very strange consequences, which were previously thought eradicated." It's based on the Copenhagen interpretation of QM! (QED for example does not allow the delayed choice quantum eraser paradox existing in QM).

The problem with the Copenhagen interpretation is: "... that the probability density function from Schroedinger's time-independent equation when averaged over time is just the proportion of the time spent in the allowable states given the dynamics of the system. It is thus the probability of finding the system in any of its allowable states at a randomly chosen time. There are no metaphysical perplexities involved with this probability density function. The time-averaged effect of a particle executing a periodic path is the same as if its generic charge (gravitational mass or electric charge) is spread over its path in proportion to its time spent probability density distribution; i.e., to the proportion of the time it spends at various locations on its path" http://www.sjsu.edu/faculty/watkins/bellth.htm

We need to solve the problem - first - of turning death from a permanent off-state into a temporary and reversible off-state, instead of worrying about "immortality," whatever that means. I keep trying to get cryonicists to adopt this as a new way of explaining the idea, but the older generation of cryonicists apparently can't form the new neural pathways.

See Preference For (Many) Future Worlds (it's linked from Quantum immortality article on LW wiki).

A situation with given structure may matter to different degrees. The familiar special case is probability, when it's uncertain whether the situation will occur. Depending on situation's weight, you'd be willing to trade it for different alternatives, so this measure of situations is relevant for decision making. When a situation weights almost nothing compared to available alternatives, it's irrelevant.

So in the case of quantum immortality or Boltzmann brains, the situations being discussed don't matter compared to our world. They matter only for someone who happens to live in them and know it, to someone who can't affect more. But why care for that guy of measure epsilon?