Abstract

Although we use randomness when we don’t know any better, a principle of indifference cannot be used to explain anything interesting or fundamental. For example, in thermodynamics it can be shown that the real explanatory work is being done by the Second Law, not the equal a priori probability postulate. But to explain the interesting Second Law, many physicists try to retreat to a “random explanation,” which fails. Looking at this problem from a different perspective reveals a natural solution: boundary-based explanations that arguably should be viewed as no less fundamental than other physical laws.