The Trouble with Many Worlds
I find this article rather hand-wavy. I mean, we have a very good understanding of the measurement process in quantum mechanics through experiments performed e.g. by Haroche&#x27;s and Siddiqi&#x27;s groups, which demonstrate that quantum measurements are continuous, deterministic processes. Irreversibility and the transition of a quantum state to a &quot;classical&quot; state can be explained very well using entanglement and decoherence, which originate from the coupling of the measured system with a very large, external quantum system. With this approach, no magical wave-function collapse or breaking of time reversal symmetry is required to explain the observed collapse of quantum oscillations after measurement.<p>The interpretations of quantum mechanics that rely on wave-function collapse need to provide a plausible mechanism for how the irreversibility within the measurement process comes about, as a collapsed wave function is no longer time-reversible (i.e. if we would flip the sign of the Hamiltonian we would not be able to go back to a previous state as the wave function was irreversibly changed during the measurement) and I haven&#x27;t seen any physically plausible attempt at this so far. So personally I still favor the many-worlds hypothesis, if only because it doesn&#x27;t require invoking a so-far unknown process that destroys reversibility during quantum evolution.