Many Worlds Interpretation February 23, 2009Posted by jfd5010 in Philosophy of physics.
The Many Worlds Interpretation (MWI) is a metatheory that seeks to solve the problems caused by a probabilistic quantum mechanics and a deterministic Newtonian and relativistic framework. The problem that MWI attempts to fix is the issue of waveform collapse. This event occurs when a probability function dictating an event spontaneously “collapses” into a single deterministic result. MWI solves this problem by removing the collapse by creating a “world” for each possibility. The result is that the universe (or in this case multiverse) is a superposition of all possible worlds. These worlds contain the sum of everything observable and present at the time of the split (essentially what we would describe as our universe). Worlds are by nature non-communicating and increasingly divergent. This means that there is no possibility of travel between worlds and even if the “determining event” was infinitely small the initial difference would slowly increase over time in each world, causing the worlds to further differentiate.
The largest philosophical issues caused by this metatheory are related to choice, free will, and personal identity. If we view decision-making and by extension, thought in general, as a physical process, then the minute changes in thought are in fact at some level quantum events. These events are governed by probability functions that will eventually result in a single deterministic event. Based on this analysis the other possible outcomes must have occurred and are proceeding in alternate worlds. So what is choice? Even more concerning is the concept of individuality. Are the people identical to you in alternate universes you?
MWI is a fairly popular metatheory and is compatible with all linear quantum mechanics. The implications of this theory are primarily mathematical but issues of self and choice have been hotbeds of debate.
Wikipedia, “Many-worlds interpretation“
Lev Vaidman, “Many-Worlds Interpretation of Quantum Mechanics,” Stanford Encyclopedia of Philosophy