Quantum suicide
From Biocrawler, the free encyclopedia.
In quantum mechanics, quantum suicide is a thought experiment which was independently proposed in 1987 by Hans Moravec and in 1988 by Bruno Marchal, and further developed by Max Tegmark in 1998, that attempts to distinguish between the Copenhagen interpretation of quantum mechanics and the Everett many-worlds interpretation by means of a variation of the Schrödinger's cat experiment. The experiment essentially involves looking at the Schrödinger's cat experiment from the point of view of the cat.
In this experiment, a physicist sits in front of a gun which is triggered or not triggered depending on the decay of some radioactive atom. With each run of the experiment there is a 50-50 chance that the gun will be triggered and the physicist will die. If the Copenhagen interpretation is correct, then the gun will eventually be triggered and the physicist will die. If the many-worlds interpretation is correct then at each run of the experiment the physicist will be split into a world in which he lives and one in which he dies. In the worlds where the physicist dies, he will cease to exist. However, from the point of view of the non-dead physicist, the experiment will continue running without his ceasing to exist, because at each branch, he will only be able to observe the result in the world in which he survives, and if many-worlds is correct, the physicist will notice that he never seems to die.
Unfortunately, the physicist will be unable to report the results because, from the viewpoint of an outside observer, the probabilities will be the same whether many worlds or Copenhagen is correct.
This thought experiment assumes the non-existence of afterlife, which cannot be proven. If afterlife exists, each time the trigger is pulled the universe will split into one universe where the brave scientist experiences survival and one universe where he experiences afterlife.
A variation of this thought experiment suggests a controversial outcome known as quantum immortality, which is the argument that if the many-worlds interpretation of quantum mechanics is correct then a conscious observer can never cease to exist.
A similar idea was explored in Greg Egan's Permutation City, where one character repeatedly had his mind uploaded and his copy eventually terminated, but found out that he always "ended up" in another world, where his survival was explained by increasingly improbable circumstances.et:Kvantenesetapp
