Courses
Every course teaches the system behind one subject, from the ground up.
- A lesson tells you something simple first, in plain words and usually with a picture.
- Then it asks you to try it. Nothing is scored.
- Nothing here assumes you know anything first.
- courses
- 13
- courses
- lessons
- 184
- lessons
- subjects
- 7
- subjects
- a lesson
- 5 min
- a lesson
- no account
- Free
- no account
World News
How a story becomes news
Work out why you heard about today's stories, and name the ones you never will.
The chapters
- 1What gets noticed4 lessons
- 2How it gets made4 lessons
- 3What reaches you4 lessons
Finance News
Compliance: how a rule gets followed
Work out where a rule comes from, how a company turns it into something a hand does, which rules every organisation meets, and what happens when one is broken.
The chapters
- 1Where a rule comes from4 lessons
- 2How a company builds it4 lessons
- 3The rules everyone meets4 lessons
- 4When it goes wrong3 lessons
Information Technology
How the feed decides what you see
Work out who pays for a free app, how every post is scored for you, why the feed narrows, and who holds the dial.
The chapters
- 1Free, and paid for3 lessons
- 2The ranking machine4 lessons
- 3What rises3 lessons
- 4The hands on the dial3 lessons
Information Technology
AI ethics: how a machine learns to decide
An AI ethics course taught as mechanism: how a computer copies a pattern from the past, what rides along in the examples, what is new when a machine makes the mistake, and who answers for it.
The chapters
- 1What a machine learns3 lessons
- 2What rides along in the data4 lessons
- 3What is new about a machine4 lessons
- 4Who answers for it4 lessons
Mind & Body
How a workplace stays safe
Work out what a hazard is and what a risk is, how a risk is made smaller, where the harm at work really comes from, and why a disaster is never one mistake.
The chapters
- 1Why work hurts people3 lessons
- 2How the risk gets smaller4 lessons
- 3The hazards on the floor5 lessons
- 4The harm that takes years3 lessons
Mind & Body
How a person bounces back
Trace what a silence does to a mind, what an alarm does to a body, why another person's envy is about their own place, and how long a body takes to come back round.
The chapters
- 1A silence becomes a storm4 lessons
- 2The other side of the silence4 lessons
- 3The body keeps its own clock4 lessons
- 4The whole circle3 lessons
Mind & Body
How a mind decides what is true
Trace where a belief comes from, what a count can hide, what makes a reason reach its claim, and how a belief with a size moves when a clue arrives.
The chapters
- 1Where a belief comes from4 lessons
- 2What a count can hide4 lessons
- 3The shape of a reason4 lessons
- 4Moving the number3 lessons
Mind & Body · Information Technology
Peace of mind: how attention is taken, and how it is kept
Work out what pulls at a mind all day, what a shown self costs to keep up, what grows in the gap between a feeling and an act, and what a quiet mind can do and is joined to.
The chapters
- 1What pulls at a mind4 lessons
- 2The shown self and the lived one4 lessons
- 3The gap, the word and the line4 lessons
- 4Quiet, and the whole3 lessons
Climate & Energy
How the planet holds its heat
Work out where the extra heat comes from, where it goes, and why swapping the energy behind it is slow.
The chapters
- 1The blanket4 lessons
- 2What one degree does4 lessons
- 3Where the energy comes from4 lessons
- 4Changing it3 lessons
Climate & Energy
Sustainability: what can keep going
Work out whether a thing is being used faster than it comes back, who pays when a cost lands next door, how a footprint is counted, and who checks the claim.
The chapters
- 1What sustainable means4 lessons
- 2Who pays4 lessons
- 3How a footprint is counted4 lessons
- 4Who checks3 lessons
Personal Money
How money loses value
Work out what a sum of money is really worth — this year, in ten, and in forty.
The chapters
- 1What a price is4 lessons
- 2Money and time4 lessons
- 3The system behind it4 lessons
Gaming
How a free game makes its money
Work out who pays for a free game, why a chest sells a chance and not a prize, how a streak and an energy bar bring you back, and what the game counts.
The chapters
- 1Free to play, paid by a few3 lessons
- 2The chest with a chance inside3 lessons
- 3Why you come back every day3 lessons
- 4The other side of the screen3 lessons
Gaming
Canon and continuity: why big stories tangle
Work out what canon is and who decides it, why a story told by many hands over decades piles up promises it cannot all keep, the three ways a promise gets broken, and the four ways a franchise untangles itself.
The chapters
- 1What a long story is made of4 lessons
- 2Why it tangles4 lessons
- 3The four fixes4 lessons
- 4Keeping it straight3 lessons