Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Quantum suicide and immortality

  1. Jun 3, 2010 #1
    Hey guys, I'm having a bit of trouble getting my head around the quantum suicide and immortality thought experiment,

    http://en.wikipedia.org/wiki/Quantum_suicide_and_immortality" [Broken](Sorry to quote Wikipedia, lol)

    IF the Many Worlds interpretation of QM is true, would this imply that the experimenter, if he dies, would have his consciousness "shifted" to the parallel universe where he survives the experiment, thus he is essentially "immortal", or is my understanding wrong here?
    Last edited by a moderator: May 4, 2017
  2. jcsd
  3. Jun 3, 2010 #2
    The idea would be that "your" universe always takes the path that leads to your survival, as far as I can interpret it.
  4. Jun 3, 2010 #3
    So it just seems that the results of your experiment always have the same outcome...I suppose you would start to question that after a while, why you keep surviving when there is an equal chance of dying.
  5. Jun 3, 2010 #4


    User Avatar
    Science Advisor
    Homework Helper

    And start to question why you're so much older than everybody else.

    I like David Lewis's thoughts about the thought experiment.
  6. Jun 4, 2010 #5
    Ok with that in mind, does MWI imply that if you are killed in, for example, a car accident, would your consciousness be "shifted" to an alternate reality where you survive? Or would it only apply to situations where there are only 2 possible outcomes (because if you die in a car accident, there are pretty much infinitely many possible alternatives)?
  7. Jun 4, 2010 #6
    Well seeing as how many worlds is total make believe they can really say it says anything about everything.
  8. Jun 4, 2010 #7
    Basically, it's just a take on branching events that create new worlds. Consider the following binary sequences: (1,1,1,1,1,1,0...) and (1,1,1,1,1,1,1) where 0 represents dead and 1 represents alive. Now if we look at these two sequences up to the 6th term, they're the same sequence. So until we hit that 7th term, only one sequence exists. But when we branch at the 7th term, we have two sequences. Essentially, quantum suicide is saying that for every universe in which there exists an element 0 for your life, there is an alternate universe that was 100% identical up until the branch point, for which there is an element 1 for your life instead. The theory is that, given an infinite number of parallel universes, you're essentially immortal because there will always be a 1 in some other universe to compensate for a 0 in another.

    The flaw in this theory is that convergence is not addressed. The theory tends to look at pairs of universes at a time rather than looking at the entire infinite set. If we were to look at all universes at some point in your life, we might see that 71% are 1's and 29% are 0's. If we move further ahead in time, we might see that 54% are 1's and 46% are 0's. Due to the obvious fact of old age, it's my believe that the percentage of 1's in all universes will eventually converge to 0 at some point in time. Therefore there is no real quantum immortality.
  9. Jun 4, 2010 #8
    I think one of the most interesting things to take from this theory is that any time in the future could just be seen as an different universe instead of the "future" and that if we ever have computers with the ability to map out universes we might be able to use them to see into the future.
  10. Jun 4, 2010 #9
    I thought you said this MWInterpretation was make believe?
  11. Jun 5, 2010 #10


    User Avatar
    Science Advisor

    Personally, I'd like to see a non-lethal form of this put to a wide-scale test. Here's my thought: Construct a box, like Schroedinger's cat-box, but instead of cyanide gas being released if the radioactive material activates a mechanism, have it just release an agent which renders the human subject inside unconscious.

    You would of course, need to have a large number of participants, in identical (as far as practical) apparatuses. In fact, what I propose is many such trials, with some subtle variations between how they are run. In one set of trials, External observers make no direct observations, but merely calculate the predicted outcome. In another, no external observers are present at all. In a third, the participants signal they are still conscious by some mean at regular intervals to the outside observers. In a fourth, the events inside the box are recorded, but not analyzed or communicated in any way until after the experiment is concluded. Various other methods might be used to change the time interval between recording of the events, and knowledge of the events.

    It would be interesting to see if there was any meaningful deviation at all from expected results.
  12. Jul 17, 2010 #11
    I would like to propose another similar thought experiment. First we replace the scientist with a Highlander. Next we replace the gun with a samurai sword set to swing directly at his neck. If the Highlander is killed where does the Quickening go? Doesn't MWI violate the Law of There Can Be Only One? If he is the last immortal left, can there be none?

    EDIT: This is not a serious question, I've just always wondered what might happen if an immortal from the movies/tv show were to commit suicide.
    Last edited: Jul 17, 2010
  13. Aug 1, 2010 #12

    All such ideas as posited here (derived from the Many worlds interpretation of Quantum physics) or other idealistic Copenhagen interpretation of Quantum mechanics are basically variations upon the same theme, which is the basic question wether or not a world exist outside, apart and independend from our perception and consciousness of it.

    This is the basic philosophical question. The major split in thought is that for Materialism, the question is answered affirmative, while Idealists answer the question negative.

    In it's most consequential (and subjective) form, Idealism resorts to solipsism, which has the envision that the only "real" reality is one's own mind, and all other are creations or inventions of that mind.

    Most philosophers (including Idealist) dismiss such a philosophy (there would not be much talking and discussion necessary, if the solipsist position would be affirmed) outright as non-sensical.

    About this core idea then, let's phrase it as follows:

    The only world in which I can exist, is a world in which I was born and did not die prematurely, and for this to be true a very broad spectrum of events must have taken or not taken place, which is only a narrow bandwith of possible worlds amongst all possible worlds.

    From this then we conclude that just based on our very existence and our perception and consciousness of it, a whole range of things had to have happened or not happened, else this 'I' would not exist in its present form and state. So, does the fact that "I" do exist make any unique feature to the world, or even more, is it just because of my presence in the world and me being me, that this world is the way it is?

    But then, this idea misses the point that - if things indeed were different (for example I died at young age at a car accident or my mother died in the war before she gave birth, etc. etc. etc.) - there would not be a 'me' to talk about it, and if I were never born, there still could be others that - same like me - express the same thing about reality.

    Or, as another way of stating it, a different world, a world which would not contain 'me' would be a different world, but also possible world, so this is then to dismiss the idea that the fact that I am me, is not a unique feature of the world that 'had to be true', rather that fact is realy indifferent to the world.
    Last edited by a moderator: May 4, 2017
  14. Aug 8, 2010 #13
    To become world famous and show this theory to be correct all I have to do is put half the bullets in a revolver, point the gun at my head and pull the trigger. Spin the revolver again and repeat. In the world where I never die I will be a legend who never dies, and this will ne the only universe I am aware of. On the other hand this also means I will be aware that evertime I did this I also killed myself and caused much greive among my loved ones, many many times. That is a big price to pay.
  15. Aug 13, 2010 #14
    A few thoughts on this:

    1) It would seem to allow for you to engineer which universe you would end up in, simply by changing the setup of the suicide procedure. You want to be rich? Buy a lottery ticket and have a machine kill you if you don't win. You would find that you won.

    Also, the more ridiculous the circumstances, the more bizarre the universe could become. What if you arranged for an asteroid to fall on your head. The universes in which you survive this must surely be quite different from ours. It might require you being beamed out at the last minute by aliens.

    2) Would it not eventually create a situation where you are the oldest person in the world by far. What are the implications of this? To reference the post above, it seems inevitable that we all would eventually become famous for our longevity.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Discussions: Quantum suicide and immortality
  1. Quantum suicide (Replies: 8)

  2. Quantum immortality (Replies: 12)

  3. Physics of Immortality (Replies: 17)