*I would like to preface this by saying I am not philosopher and have not studied any philosophy. This is just something I have been curious about for a long time and finally decided to ask. I am kinda stumbling through figuring out how to phrase this question. I saw something about quantum immortality theory but I am unconvinced that it is the same thing."

From what I think understand about the many worlds interpretation, there are an infinite amount of universes existing at the same time where new ones are created by every quantum-level "decision". From there, I reasoned that a theoretical worldview could be that you live forever within the exact, highly unlikely multiverses where you live.

I assume this view already exists but is ithe the quantum immortality theory? I feel like it is a little different though I may just be confused.

  • IIRC there was a generic subjective continuity theory not unlike John Rawl's veil of ignorance which has nothing to do with QM or MWI once discussed in this site which you may further search... Commented Mar 9 at 19:44
  • "Quantum immortality" refers to some future branches of the current "I" surviving indefinite number of Schrödinger's cat-like assassinations, not to "living forever". And even that is predicated on rather naive assumptions about the process of death.
    – Conifold
    Commented Mar 10 at 7:26
  • If we live in a truly infinite universe, then there may be (depending on assumptions) an infinite number of duplicates of ourselves that live forever in this universe (as well as an infinite number of duplicates of us that die or have already died). This is simply because there are a finite number of arrangements of matter (Planck length?), so in an infinite universe there is space for an infinite number of each arrangement. Caveat lector: I am not a physicist! Commented Mar 12 at 11:30
  • Yes, this is exactly quantum immortality, and the currently accepted answer is completely wrong.
    – Anixx
    Commented Mar 12 at 18:48

2 Answers 2


There are several problems with what you are proposing.

(1) As pointed out in the previous answer in many universes you die anyway even if in some you live forever.

(2) Would it be rational for you to bet on staying alive indefinitely if it is possible? There is already an Everettian explanation of how you should bet that sez you should weight outcomes by their square amplitude:



Suppose there is no way to make you immortal through advanced medicine or whatever, then there will be a probability of you dying each year. Since the probability of the universes in which you stay alive decreases over time and gets arbitrarily close to zero, it won't be rational for you to bet on immortality.

(3) Would it be rational for you to get addicted to crystal meth or whatever cuz in some universe it won't kill you but might cause pleasure? This is a dangerous road to go down.

(4) Another problem is that the division of the multiverse into parallel universes is a result of information flowing within universes but not between universes:



Branches of the multiverse with very small and exponentially decreasing probabilities may not fit this criterion and might get mangled by interference:



So it's not clear that quantum immortality is physically possible.

  • "Suppose there is no way to make you immortal through advanced medicine or whatever" - the thing is, advanced medicine and artificial intelligence are parts of quantum immortality.
    – Anixx
    Commented Mar 12 at 18:46
  • @anixx No, they're not.
    – alanf
    Commented Mar 13 at 9:06
  • If not for quantum immortality, we would not have internet, healthcare, AI.
    – Anixx
    Commented Mar 13 at 9:35

One problem with your theoretical worldview is that the supposed other Universes are not the Universe in which the you reading this answer exists. In your Universe you die, just like the rest of us.

Another problem with your idea is that it supposes that whether or not you die depends on individual quantum interactions, so that in one branched Universe you can be alive and in another you can be dead. Perhaps you might like to try to explain to me how you suppose that works.

  • 1
    I think your first paragraph is a misunderstanding of the idea (I don't think the idea is necessarily true, but if we're taking it seriously then you've misunderstood it). Your second paragraph just seems like a question about how many worlds is conceptualised, and why many worlds is considered by some to be a consequence of quantum mechanics. I don't know that OP is the best person to answer that question.
    – TKoL
    Commented Mar 12 at 10:30

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