Is a principle referring to the idea that firms responsible for causing pollution should be charged the full external costs for the damage that it inflicts on society.

(physics) The observation that the sums and differences of the frequencies of spectral lines often equal other observed frequencies; a consequence of quantum mechanics.

(physics) the principle that the laws of gravity are independent of velocity and position

(physics, quantum mechanics) The principle that there is an absolute limit on the combined accuracy of certain pairs of simultaneous, related measurements, especially that of the position and momentum of a particle. Originally posited as a problem of measurement, it was soon refined as an inherent property of the universe.

(chemistry) A principle stating that, if a chemical system at equilibrium experiences a change in concentration, temperature, or total pressure, the equilibrium will shift in order to minimize that change.

The axiom that "machines should work; people should think".

A principle in biology stating that allele and genotype frequencies in a population will remain constant from generation to generation in the absence of other evolutionary influences.

(logic) principle of explosion

(physics) A principle in quantum mechanics that states that no two identical fermions may occupy the same quantum state simultaneously.

(business) A rule according to which decisions and transactions need approval from two individuals, typically the CEO and CFO.