Quantum Logic

Many of the problems we run across in trying to understand quantum physics are apparent conflicts with standard logic. To avoid the need to go too deeply into formal logic, we have usually presented arguments that appeal to common sense (based on our experience with the everyday world). The rules of formal logic are abstract, but most people who think about such things consider them as real and as valid as the laws of physics or mathematics. That’s what makes it so difficult when quantum physics says something that is contradicted by logic. But who is to define what logic is?

There is a school of interpretation that says logic must yield in such conflicts. Quantum physics shows us the truth about how the universe works. If logic brings us to a different conclusion, then we should change the rules of logic, not quantum physics. A new system of logic, created to conform to quantum reality, has been referred to as quantum logic.

This does make a certain amount of sense. We can trace the development of formal logic through history, and consider it to be a product of the human intellect. As such, it developed in the context of our experience with the macroscopic world, the way ordinary objects behave, which is all well described by the laws of classical physics. This logical system could simply be an approximation that works fine in everyday situations, much like classical physics is.

Beyond just considering the possibility, there has not been much real progress in this area. Nothing that quantum logic proponents have come up with so far is regarded as serious competition for the time-honored edifice of traditional logic. The majority of those thinking about quantum physics are still seeking ways to resolve the conflicts between logic and physics.