Classical Physics Is Non-Deterministic

It’s not just quantum mechanics that’s weird.  Reality—no matter the scientific foundation—is weird, too.

A team of physicists claims that classical mechanics is just as weird as quantum mechanics. The explanation is on PhysOrg by Lisa Zyga:

In a new study published in Physical Review Letters, physicists Radu Ionicioiu, et al., have shown that the three apparently reasonable classical assumptions mentioned above—objectivity, determinism, and independence—are mutually incompatible with any theory, not only with quantum mechanics. The scientists show that, while any two of the three assumptions are compatible, all three are not. All told, our seemingly reasonable classical assumptions may not be so reasonable after all.

“Sometimes classical ideas may seem ‘natural’ and ‘logical’ simply because we do not test them too strongly,” coauthor Daniel Terno at Macquarie University in Sydney, Australia, told Phys.org. “Quantum mechanics may be weird, but our classical illusions may be weird too—or simply impossible to maintain, no matter how the world really operates.“

One of the assumptions that may have to go is determinism. If you can only pick any two of the three, it would seem your choice is arbitrary, depending on your goals. These authors want to keep determinism, but look what they give up:

Because any two of the three ideas are mutually compatible, the physicists suggest that it seems most natural to drop the objectivity assumption, while keeping determinism and independence. This choice requires that wave-particle duality be accepted, regardless of its counterintuitive nature. However, knowing for sure will be a subject of future research.

But having given up objectivity, they make “knowing for sure” impossible. Since independence seems logically necessary for coherent thinking, determinism seems the best assumption to discount.

It’s interesting that the laws of logic, not being made of particles or forces, are not subject to the weirdness. After all, who’s making the determination that things are weird? Human minds do, because they are capable of using logic to make judgments about things outside of their minds. In essence, the mind says “nature is weird, because I know what normal is by which to compare it.” The mind also retains its free will whether or not nature can be described by deterministic equations. Evolutionary philosophy, which assumes mind is an emergent property of matter, has no such confidence.