The Many-Worlds Interpretation (MWI) of quantum mechanics, proposed by physicist Hugh Everett in 1957, suggests that all possible outcomes of quantum measurements are realized in separate, non-interacting parallel universes. This interpretation challenges the traditional Copenhagen view, which posits that quantum systems exist in a superposition of states until observed, at which point they collapse into a definite state. MWI posits that the wave function does not collapse; instead, it branches into multiple outcomes, each corresponding to a different universe.
Building upon MWI, the concept of quantum immortality emerges. This idea posits that an individual's consciousness continues in a universe where they survive a life-threatening event, effectively experiencing immortality from their subjective perspective. The thought experiment involves scenarios where, despite the high probability of death, the observer's consciousness would persist in the branch where survival occurs. This perspective raises profound questions about the nature of consciousness, identity, and the afterlife, suggesting that our experiences are tied to the specific branches of the universe in which we exist.
Critics of quantum immortality argue that it relies on speculative assumptions and lacks empirical evidence. They point out that the theory does not account for the biological and physical processes of aging, decay, and disease, which are independent of quantum mechanical effects. Additionally, the concept challenges traditional notions of personal identity and continuity, as it implies that consciousness could shift between parallel universes, leading to questions about the persistence of the self. The debate continues, highlighting the need for further exploration into the implications of quantum mechanics on our understanding of reality and existence.