What is entropy as a mental model?

It’s the principle that things naturally drift toward disorder unless energy is spent to maintain order. Borrowed from physics, it captures why rooms, organisations, and systems decay without continuous upkeep.

What is an example of entropy in everyday life?

A tidy room becomes messy on its own but never tidies itself — order requires energy (cleaning), while disorder is automatic. The same one-way drift toward mess affects teams, code, and relationships.

Does entropy mean everything inevitably decays?

In a closed system, yes. But living things and organisations are open systems that import energy to create and maintain local order. The lesson is that order is costly and temporary, not that decay can never be resisted.

Entropy

Physics & information

Entropy is a measure of disorder, and physics says it always increases in a closed system. As a mental model, it captures the universal tendency for things — rooms, organisations, relationships — to drift toward disorder unless energy is continually spent to maintain order.

How it works

Treat order as costly and temporary. Anything organised — a tidy house, a coherent strategy, a healthy team — requires ongoing energy input just to stay as it is, because the natural drift is toward decay, mess, and disorganisation.

How to use it

Understanding why maintenance, not just creation, is required to keep anything good alive.
Anticipating that systems, codebases, and organisations rot without continuous upkeep.
Budgeting energy for "holding the line," not only for building new things.

Worked example

A clean kitchen doesn’t stay clean — left alone, it gradually fills with clutter and grime. Keeping it ordered takes constant energy (cleaning); the disorder is free and automatic. The same drift afflicts every organised system.

Where it fails

The physics applies strictly to closed systems; life and organisations are open systems that import energy to create local order. Over-literal use ("everything inevitably decays") ignores that sustained effort genuinely can maintain and even grow order.

The deeper point

It reframes maintenance as heroic, not boring: keeping something good in working order is a constant fight against the universe’s default. Most things don’t fail from a dramatic event — they fail from the slow, free, automatic accumulation of neglect.

Frequently asked

What is entropy as a mental model?: It’s the principle that things naturally drift toward disorder unless energy is spent to maintain order. Borrowed from physics, it captures why rooms, organisations, and systems decay without continuous upkeep.
What is an example of entropy in everyday life?: A tidy room becomes messy on its own but never tidies itself — order requires energy (cleaning), while disorder is automatic. The same one-way drift toward mess affects teams, code, and relationships.
Does entropy mean everything inevitably decays?: In a closed system, yes. But living things and organisations are open systems that import energy to create and maintain local order. The lesson is that order is costly and temporary, not that decay can never be resisted.

Systems thinking Antifragility Compounding

Editorial synthesis © ReadGlobe 2026, drawing on the mental-models tradition (Charlie Munger, Farnam Street) and the primary sources for each model. · Last reviewed 2026-05-29.