How Systems Work: the rules we live inside
Much of daily life is governed by systems that were not designed with you specifically in mind — the way a product is built to be replaced, the reason a form asks exactly what it asks, the incentive that quietly shapes how a company behaves. This hub takes those systems apart. Not conspiracy: design and incentive, explained so you can see the machine you are actually dealing with.
Design and incentive, not conspiracy
Most systems do what they do because someone was optimising for something — cost, speed, repeat custom, control of risk — and the effect on you fell out of that. Seeing the incentive is usually enough to explain the behaviour, and it beats both naïve trust and lazy cynicism. Each explainer here names the incentive and follows it through.
Where to start
The first guide is planned obsolescence: why some products are designed to wear out or feel outdated sooner than they need to, the forms it takes, and how governments and consumers are starting to push back. It is a clean example of the hub’s method — a familiar frustration, traced to the design decision and the incentive behind it.
Last reviewed 10 July 2026
Understand it
Designing a product to wear out or feel outdated sooner than it needs to — by intent, not accident — and what is being done about it.
Guide What the right to repair movement is fighting forThe campaign to make products fixable again — spare parts, manuals, repairable design — and what stands in its way.
Guide The lightbulb cartel that defined planned obsolescenceHow a 1920s agreement to shorten lightbulb life became the clearest documented example of built-in obsolescence.
Guide How the Global Supply Chain WorksFrom factory to doorstep: the hidden system behind everything you buy.
Guide How Internet Search Engines WorkWhat happens when you type a query? The technology behind finding information instantly.
Guide How the Global Financial System WorksThe invisible infrastructure that lets you send money across borders in seconds.
Guide How the Water Cycle WorksThe endless journey of Earth's water, from clouds to rivers and back again.
Guide How the Immune System WorksThe body's defense network: how it fights infections and remembers past invaders.
Guide How the Electricity Grid WorksThe invisible network that delivers power from plants to your plug, 24/7.
Guide How the Human Digestive System WorksStep-by-step breakdown of digestion and nutrient absorption.
Guide How the Human Circulatory System WorksThe heart’s pumping action and the double-loop circulation pathway.
Guide How the Solar System WorksThe structure and dynamics of the Sun, planets, and orbits.
Guide How GPS WorksSatellite signals, time synchronization, and position calculation.
Guide How the Human Brain WorksNeural communication and the functions of major brain areas.
Guide How the Climate System WorksEnergy balance, greenhouse effect, and feedback loops.
GuideFollow the rabbit hole
One idea leads to the next. Start anywhere.
- What is compound interest?A plain explanation of compound interest, why it accelerates, and why it matters for anyone saving or borrowing.
- How compound interest worksThe four moving parts — principal, rate, frequency and time — and how each one changes what you end up with.
- The compound interest formula, explainedWhat FV = P(1 + r/n)^(nt) actually says, term by term, with a worked calculation you can follow.
- The Rule of 72A mental shortcut for how long money takes to double — how it works, how accurate it is, and where it breaks down.
- Compound interest and inflation: real returnsWhy the growth you see is not the growth you get, and how to think about returns after inflation.
- Why compound interest makes pensions workHow decades of compounding do most of the work in a pension, and why starting earlier beats contributing more.
Questions people ask
Is planned obsolescence illegal?
In some places. France, for example, made deliberately shortening a product’s lifespan to force replacement a criminal offence, and the EU has strengthened durability and repair rules. In many countries it is not specifically outlawed, and intent is hard to prove.
What is the difference between planned obsolescence and normal wear?
Deliberateness. Normal wear and genuine improvements happen anyway; planned obsolescence is when a shorter lifespan is designed in — through a part built to fail, a repair made uneconomic, or updates that degrade a working device.