Vacuum Decay: Expert Survey Results

I don't think Lucius is claiming we'd be happy about it. Maybe the no anticipated impact carries that implicit claim, I guess.

It's the old argument by Epicurus from his letter to Menoeceus:

The most dreadful of evils, death, is nothing to us, for when we exist, death is not present, and when death is present, we no longer exist.

No, because getting shot has a lot of outcomes that do not kill you but do cripple you. Vacuum decay should tend to have extremely few of those. It’s also instant, alleviating any lingering concerns about identity one might have in a setup where death is slow and gradual. It’s also synchronised to split off everyone hit by it into the same branch, whereas, say, a very high-yield bomb wired to a random number generator that uses atmospheric noise would split you off into a branch away from your friends.^[1]

I’m not unconcerned about vacuum decay, mind you. It’s not like quantum immortality is all confirmed and the implications worked out well in math.^[2]

1. ^{^}

   They’re still there for you of course, but you aren’t there for most of them. Because in the majority of their anticipated experience, you explode.

2. ^{^}

   Sometimes I think about the potential engineering applications of quantum immortality in a mature civilisation for fun. Controlled, synchronised civilisation-wide suicide seems like a neat way to transform many engineering problems into measurement problems.

I don't think anything in the linked passage conflicts with my model of anticipated experience. My claim is not that the branch where everyone dies doesn't exist. Of course it exists. It just isn't very relevant for our future observations.

To briefly factor out the quantum physics here, because they don't actually matter much:

If someone tells me that they will create a copy of me while I'm anesthetized and unconscious, and put one of me in a room with red walls, and another of me in a room with blue walls, my anticipated experience is that I will wake up to see red walls with $p=0.5$ and blue walls with $p=0.5$. Because the set of people who will wake up and remember being me and getting anesthetized has size 2 now, and until I look at the walls I won't know which of them I am.

If someone tells me that they will create a copy of me while I'm asleep, but they won't copy the brain, making it functionally just a corpse, then put the corpse in a room with red walls, and me in a room with blue walls, my anticipated experience is that I will wake up to see blue walls with p=1.0. Because the set of people who will wake up and remember being me and going to sleep has size 1. There is no chance of me 'being' the corpse any more than there is a chance of me 'being' a rock. If the copy does include a brain, but the brain gets blown up with a bomb before the anaesthesia wears off, that doesn't change anything. I'd see blue walls with $p=1.0$, not see blue walls with $p=0.5$ and 'not experience anything' with $p=0.5$. 

The same basic principle applies to the copies of you that are constantly created as the wavefunction decoheres. The probability math in that case is slightly different because you're dealing with uncertainty over a vector space rather than uncertainty over a set, so what matters is the squares of the amplitudes of the branches that contain versions of you. E.g. if there's three branches, one in which you die, amplitude $\approx 0.8944$, one in which you wake up to see red walls, amplitude $\approx 0.2828$ and one in which you wake up to see blue walls, amplitude $\approx 0.3464$, you'd see blue walls with probability ca. $p=\frac{{0.3464}^2}{{0.3464}^2+{0.2828}^2}=0.6$ and red walls with probability $p=\frac{{0.2828}^2}{{0.3464}^2+{0.2828}^2}=0.4$.^[1]

1. ^{^}

   If you start making up scenarios that involve both wave function decoherence and having classical copies of you created, you're dealing with probabilities over vector spaces and probabilities over sets at the same time. At that point, you probably want to use density matrices to do calculations.