Quantum mechanics is always good for a head-scratching idea – in part, due to its seeming incompatibility with classical physics. One of the major conundrums it offers is the concept of superposition – the ability of a particle to exist in a range of possible states. That certainly doesn’t gel with our everyday experience. We appear to be living in one consistent reality where the objects we can observe aren’t fluctuating in and out of existence. The reason why might lie in Quantum Darwinism, a theory bolstered by a trio of recent experiments.
The unification of classical and quantum mechanics has been the holy grail of physics. Quantum Darwinism, a theory first proposed in 2003 by the Polish theoretical physicist Wojciech Zurek of the Los Alamos National Laboratory, looks to reconcile the two by explaining the process of decoherence – the way a quantum system turns to a classical state. Zurek’s theory proposes that it’s how the system is interacting with its environment that causes decoherence, rather than the observation of it. The ubiquity of environmental influences is why we don’t see big objects like ourselves or the moon, for instance, being in quantum states.
Zurek says that quantum systems exhibit “pointer states” – characteristics like a particle’s location or speed that can be measured. During interactions with the environment around it, a particle’s superpositions (like alternative speeds or locations) decohere, with only the pointer state remanning. That is the state people can observe as it “imprints” its replica on the environment. According to Zurek, only the “fittest” state that is best adapted for the environment will come out of decoherence. Hence, the connection to Darwinism.
Read more: Big Think