Learning by reward
Nobody tells the learner the right answer, only how well it did. How that one number teaches, and where it misleads.
- 9min read
- 29questions
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EdenMind is a flashcard app you answer out loud.
Your phone marks what you say and brings each question back just before you’d forget it, so you remember what you read. Your voice never leaves the phone.
Learning with no one to mark the answers
Labels are slow and costly to make. So machines learned to set their own questions: group what is alike, rebuild what was squeezed, guess what was hidden.
- 8min read
- 26questions
How much is a surprise worth?
Information is measured by how much a message surprises you, and a machine that learns to be less surprised by text learns a great deal about it.
- 9min read
- 31questions
Changing your mind by the numbers
Start from what you already knew, weigh the new clue, and end up exactly as sure as the evidence allows.
- 9min read
- 28questions
Thinking in lists of numbers
Vectors and matrices, the school maths that search engines, recommendations and every neural network quietly run on.
- 8min read
- 29questions
When famous findings fall apart
Some of the best-known stories about the mind met the simplest test in science: doing the study again.
- 9min read
- 30questions
What really happened in the Stanford prison
One of psychology's most famous lessons says a uniform can make a good person cruel. The full story is stranger, and it hands the responsibility back to the person.
- 8min read
- 27questions
The two speeds of thought
One kind of thinking answers at once; the other checks, if it can be bothered.
- 9min read
- 31questions
Why prices rise
When nearly everything in the shop costs more, the goods haven't changed. The money has, because each unit of it now buys less.
- 8min read
- 30questions
Mathematics & Logic
Secret codes
A cipher hides a message's letters but not its patterns, and the patterns are what give it away.
8 min read
Transformers
Attention, next-word prediction and scale — and the gap between sounding right and being right.
9 min read
Deep learning
Nobody writes the rules. A network of simple calculations tunes itself on examples until its answers come out right.
8 min read
Physics
The search for a steady beat
Every clock is something that repeats at a steady pace, plus a way to count the repeats. The rest of the story is the hunt for something steadier.
9 min read
Ibn al-Haytham
Lamps in a dark room, a tube on a ruler and a book of doubts — how one scholar rebuilt the science of sight.
8 min read
Electricity
The doorknob zap and the lightning bolt are the same event at different sizes — meet the charge that runs the world.
9 min read
Chemistry
How soap cleans
Water alone can't lift grease or break open a flu virus. Soap does both, with a molecule that holds water at one end and grease at the other, and Nablus made it from olive oil and plant ash for centuries.
7 min read
Acids and bases
One scale from battery acid to drain cleaner, and the truce called neutralisation.
8 min read
Biology
How animals find their way
Every navigator needs a compass and a map. A young bird is born with its heading, but its map comes from experience.
8 min read
Blood and breath
How oxygen reaches every cell you own — and the Muslim physician who first traced its path through the lungs.
8 min read
The cell
The smallest thing that counts as alive — and the tiny machinery packed inside it.
8 min read
Psychology
How habits work
Repeat an action in the same place often enough, and the place starts doing it for you.
8 min read
The testing effect
We think of a test as a way to measure learning. Done well, it is one of the best ways to cause it.
6 min read
Spaced repetition
Memory fades along a curve. Coming back at the right moments bends it.
7 min read
Society
The medium is the message
Why a light bulb, a printing press and a television screen change people, whatever they carry.
8 min read
The archive: all 25 pieces, by month.