subquantum

Subquantum is a term used to describe hypothetical phenomena, structures, or processes believed to exist beneath or beyond conventional quantum phenomena. It is not a formal part of established physics, but it appears in discussions about the foundations of quantum theory and in some speculative or fringe proposals.

In Bohmian mechanics, particles have definite positions guided by a wave function through a quantum potential. Some writers describe aspects of this framework as subquantum because they view the quantum potential as arising from deeper, subquantum dynamics. However, Bohmian mechanics is generally regarded as an interpretation of standard quantum theory rather than a separate subquantum theory.

Other uses of the term appear in fringe theories such as subquantum kinetics, which posit an underlying medium or ether-like substrate that, through nonlinear dynamics, produces quantum behavior. These proposals are not supported by the mainstream physics community due to a lack of empirical verification and inconsistencies with well-tested quantum mechanics.

The concept of subquantum remains speculative and is not universally defined. There is no widely agreed-upon description of what a subquantum level would entail or how it would be experimentally distinguished from standard quantum phenomena. As such, the term is mainly of interest in discussions about the interpretation and foundations of quantum mechanics rather than as a part of an established physical theory.

See also: hidden-variable theories, quantum potential, Bohmian mechanics, quantum foundations.