(physics) also known as the stationary action principle. In complex systems, the tendency for any movement or change to use the least action, and therefore amount of energy possible. This is true on a subatomic level, on the population level (evolution), and on a macro level. Not considered a law of physics because it is not true 100% of the time.

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) A conjecture asserting that it is impossible to create paradoxes by time travel because the past cannot be changed.

(physics) Synonym of Ritz's combination principle