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Fundamental concepts

The ideas the rest of the notes stand on, one to a note: what energy is, how a cell works, what a standard deviation measures, how an algorithm or an incentive does its job, and how to weigh a piece of evidence. Each note defines its idea in plain words, works an example with real numbers, and links to the notes that use it.

100 notes from Graphite. Free to read, with no account. Nothing here is for sale.

Start here

Where to begin.

The note that answers the topic’s biggest question, then the two it leads to most directly.

  1. Start here

    What is energy? The idea that ties physics, chemistry and life

    Energy is the capacity to do work or to heat something, measured in joules. It changes form, from motion to heat to chemical bonds, but the total never changes.

    Graphite7 min read

  2. Then

    What is standard deviation? Measuring spread, step by step

    Standard deviation measures how far values typically sit from their mean: small means bunched together, large means spread out. How to calculate it by hand, and why some formulas divide by n - 1.

    Graphite7 min read

  3. And then

    Correlation vs causation: why linked doesn't mean caused

    Correlation means two things move together; causation means one actually changes the other. A correlation worked out by hand, the four ways it misleads, and how researchers find real causes.

    Graphite7 min read

Every note · 100 notes

Each section is one field, its notes in the order to read them: each answers one question and links to the notes it leads to.

Physics and chemistry

Energy and matter, the particles and forces everything is made of, and how substances change.

Life

Cells, genes and proteins, and how living things get their energy and keep themselves steady.

Mathematics

Numbers, functions and change, and the statistics used to read any set of data.

Computing and information

Algorithms, bits and code, and how information is stored, compressed and kept secret.

Economics

Scarcity, trade-offs and incentives, and why markets and shared resources behave as they do.

Thinking and knowledge

How people know things: logic, evidence, testing ideas, and the mistakes minds tend to make.

Other topics

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