Sometimes, there is an absolute limit on the number of terms an officeholder can serve, while, in other cases, the restrictions are merely on the number of consecutive terms.
For example, Maxwell's Equations would always be capitalized, while quantum mechanics is usually un-capitalized. I searched half a dozen sites for an answer to this but found no clue about a rule. So go either way that makes you happy, but (most of all) be consistent.
Full Definition of QUANTUM THEORY. 1. : a theory in physics based on the concept of the subdivision of radiant energy into finite quanta and applied to numerous processes involving transference or transformation of energy in an atomic or molecular scale. 2.: quantum mechanics. See quantum theory defined for English-language learners.uantum theory. noun. Tweet. physics: a theory in physics that is based on the idea that energy (such as light) is made of small separate units of energy.