The 3rd person perspective assumes the existence (or at least possibility) of some observer X who knows everything and can observe how events evolve across all branches.
However, this idea assumes that this observer X will be singular and unique, will continue to exist as one entity, and will linearly collect information about unfolding events.
These assumptions clearly relate to ideas of personal identity and copying: it is assumed that X exists continuously in time and cannot be copied. Otherwise, there would be several 3rd person perspectives with different observations.
This concept can be better understood through real physical experiments: an experiment can only be performed if the experimenter exists continuously and is not replaced by another experimenter midway through.
They might persistently exist outside concrete instantiation in the world, only communicating with it through reasoning about their behavior, which might be a more resource efficient way to implement a person than a mere concrete upload
Interesting. Can you elaborate?
For example, impossibility of sleep – a weird idea that if quantum immortality is true, I will not be able to fall asleep.
One interesting thing about the impossibility of sleep is that it doesn't work here on Earth because humans actually start having night dreams immediately as they go into sleep state. So there is no last moment of experience when I become asleep. Despite popular misconception, such dreams don't stop during deep stages of sleep, just become less complex and memorable. (Do we have dreams under general anesthesia is unclear and depends on the depth and type of anesthesia. During normal anesthesia some brain activity is preserved, but high dose barbiturates can temporarily stop it; also, an analogue of impossibility of sleep can be anesthesia awareness – under MWI it is more likely.)
It could be explained by anthropic effects: if two copies of me are born in the two otherwise identical worlds, one of which has protection from impossibility of sleep via constant dreaming – and another not, I will eventually find myself in the world with such protection as its share will grow relative to QI survivors. Such effects, if strong can be observed in advance – see our post about "future anthropic shadow".
This meta effect can be used instead of the natural experiments.
If we observe that some natural experiment is not possible because of some peculiar property of our world, it means that we somehow were naturally selected against that natural experiment.
It means that continuity of consciousness is important and the world we live in is selected to preserve it
Furthermore, why not just resurrect all these people into worlds with no suffering?
My point is that it is impossible to resurrect anyone (in this model) without him reliving his life again first, after that he obviously gets eternal blissful life in real (not simulated) world.
This may be not factually true, btw, - current LLMs can create good models of past people without running past simulation of their previous life explicitly.
The discussion about anti-natalism actually made me think of another argument for why we are probably not in a simulation that you've described
It is a variant of Doomsday argument. This idea is even more controversial than simulation argument. There is no future with many people in it. Friendly AI can fight DA curse via simulations - by creating many people who do not know their real time position which can be one more argument for simulation, but it requires rather wired decision theory.
Your comment can be interpreted as a statement that theories of identity are meaningless. If they are meaningless, then copy=original view prevails. From the third-person point of view, there is no difference between copy and original. In that case, there is no need to perform the experiment.
This thought experiment can help us to find situations in nature when similar things have already happened. So, we don't need to perform the experiment. We just look at its result.
One example: notoriously unwelcome quantum immortality is a bad idea to test empirically. However, the fact of biological life's survival of Earth for the last 4 billion years, despite the risks of impacts, irreversible coolings and warming etc – is an event very similar to the quantum immortality. Which we observe just after the event.
It all started from Sam's six words story. So it looks like as organized hype.
She will be unconscious, but still send messages about pain. Current LLMs can do it. Also, as it is simulation, there are recording of her previous messages or of a similar woman, so they can be copypasted. Her memories can be computed without actually putting her in pain.
Resurrection of the dead is the part of human value system. We need a completely non-human bliss, like hedonium, to escape this. Hedonium is not part of my reference class and thus not part of simulation argument.
Moreover, even creating new human is affected by this arguments. What if my children will suffer? So it is basically anti-natalist argument.
New Zealand is a good place, but everyone can't move there or guess correctly right moment to do it.
Several random thoughts:
Only unbearable suffering matters (the threshold may vary). The threshold depends on whether it is measured before, during, or after the suffering occurs.
If quantum immortality is true, then suicide will not end suffering and may make it worse. Proper utility calculations should take this into account.
Most suffering has a limited duration after which it ends. After it ends, there will be some amount of happiness which may outweigh the suffering. Even an incurable disease could be cured within 5 years. Death, however, is forever.
Death is an infinite loss of future pleasures. The discount rate can be compensated by exponential paradise.