The Second Law of Thermodynamics
In an isolated system, entropy tends not to decrease as energy becomes less available for work.
The Mechanism: The second law of thermodynamics states that the total entropy of an isolated system tends not to decrease. In statistical mechanics, entropy is related to the number of microscopic arrangements compatible with a macroscopic state.
The Philosophical Pivot: The law gives physical meaning to an arrow of time: many processes, such as mixing and heat flow, occur readily in one direction while their reverse is extraordinarily unlikely at large scales.
The Horizon: Entropy is often simplified as disorder, but that metaphor can mislead. The formal concepts concern probability, energy dispersal, and constraints, not a universal tendency for every local pattern to become messy.
Local order can increase when energy flows through a system, as in living organisms, while total entropy across the relevant surroundings still rises.
The law does not directly explain every experience of time, memory, or change. Those questions connect thermodynamics with cosmology and the conditions of the early universe.
A physical tendency can be overwhelming without making the future logically predetermined in every detail.
Order can grow locally while the larger accounting of energy moves in another direction.
If local order depends on flows of energy, what forms of apparent stability in my life are being sustained by costs I do not see?