evidence: The above quote is often attributed to Einstein, though according to QI it does not originate from him. My question is: isn't the quote completely untrue, as quantum mechanics & nuclear decay completely disprove it, as in both there are examples where doing the same action can lead to completely different outcomes. If you conduct a quantum experiment then according to quantum mechanics you may obtain different outcomes in accordance with the probabilistic interpretation of quantum mechanics. However the number of possible outcomes for each similar experiment will always be the same. So no matter how many times you perform this same experiment you will get the same possible results over and over again. Consider flipping a coin. You have two possible outcomes. If you were to do this over and over again and expect a result other than heads or tails, will this be considered sane?