Quantum Suicide Thought Experiment

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The Experiment and Proof for MWI

A particularly dedicated researcher can use the Quantum Suicide experiment in order to determine that the Many-Worlds Interpretation (MWI) is the correct one.The basic idea behind this experiment is that if an event is left down to probability (and only two events are possible) then both probabilities are possible. For example, if you were to hit a large red button which has a 50% probability setting off a nuclear device that you are standing on top of then the MWI interpretation says that there are two separate universes created(?) one in which you survive the pressing of the button, one in which you are immediately vaporised. Provided there is no way for the conscious mind to survive this vaporisation (we assume death is instant and there is no afterlife), we can say that the only conscious experience will be one of surviving.

Thus we can say that if you design a probabilistic pistol, one that measures the spin state of a particle and fires accordingly (i.e. when it is measured as 'up' fire a bullet, when 'down' simply click), there is a 50% chance that this pistol will fire.

If you then get yourself a willing lab assistant that is happy to see you get brutally murdered, first, hand them the gun and tell them to fire it 100 times. Both you and them should hear something along the lines of 'BANG, click, click, BANG, click, BANG, BANG, BANG, BANG, click, click, BANG, click, BANG...' where over time the ratio of shots to clicks roughly approaches 1:1. Once you are happy that there is a 50% change of the gun firing a real bullet hand your assistant a mop and take the gun. Place it against your head at a point where if it fires you will die immediately. Then, proceed to fire the gun 22 times. You should hear 22 clicks in a row provided the MWI is correct. After you have done this, hand the gun back to your assistant and get them to fire the gun another 100 times, getting another pattern of 50% bangs and clicks.

By surviving this experiment you will have demonstrated to more than five standard deviations from the mean (the significance value that is necessary for something to be accepted at CERN) that the MWI is correct (as you will have a 0.0000002384% chance of survival naturally). Your assistant, however, or more accurately 21 different versions of your assistant will have had to mop up 21 separate version of your blood and brains from the laboratory floor. This means that in only the universe you survive do you prove anything at all, and the experiment isn't exactly a repeatable one, as it can only be done from the perspective of a single observer.