Quantum Suicide is a scientific thought experiment. The scientist sits in front of a gun that is set up to either trigger or misfire, depending on the decay of a radioactive atom. With each run of the experiment, there is a 50% chance the gun will trigger. Under the Copenhagen interpretation of quantum mechanics, the gun will eventually kill the scientist. But if the ‘many-worlds’ interpretation is correct, then at each run of the experiment there will be a universe in which the scientist lives, and another in which he dies. The scientist can only ever be conscious of the world in which he LIVES, and so never seems to die. This leads to the fanciful speculation that the many-worlds interpretation implies all conscious beings are immortal.
(Imagine the scientist, realizing he cannot die, stepping outside the lab and seeing for the first time what is worthwhile about existence).