Mathematics & Logic

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
Read the piece

Listen to the episode

0:00 / 10:01

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.

How it works

  • Mathematics & Logic

    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
  • Mathematics & Logic

    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
  • Mathematics & Logic

    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
  • Mathematics & Logic

    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
  • Psychology

    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
  • Psychology

    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
  • Psychology

    The two speeds of thought

    One kind of thinking answers at once; the other checks, if it can be bothered.

    • 9min read
    • 31questions
  • Society

    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
  • 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.

    • 7min read
    • 26questions
  • 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.

    • 9min read
    • 31questions
  • 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.

    • 8min read
    • 29questions
  • Psychology

    How habits work

    Repeat an action in the same place often enough, and the place starts doing it for you.

    • 8min read
    • 27questions
  • Mathematics & Logic

    Secret codes

    A cipher hides a message's letters but not its patterns, and the patterns are what give it away.

    • 8min read
    • 29questions
  • Mathematics & Logic

    Transformers

    Attention, next-word prediction and scale — and the gap between sounding right and being right.

    • 9min read
    • 30questions
  • Mathematics & Logic

    Deep learning

    Nobody writes the rules. A network of simple calculations tunes itself on examples until its answers come out right.

    • 8min read
    • 33questions
  • Mathematics & Logic

    The bitter lesson

    Seventy years of AI research, one uncomfortable pattern: methods that scale with computing beat methods built on what we know.

    • 7min read
    • 24questions
  • Society

    The medium is the message

    Why a light bulb, a printing press and a television screen change people, whatever they carry.

    • 8min read
    • 27questions
  • Physics

    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.

    • 8min read
    • 25questions
  • Psychology

    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.

    • 6min read
    • 21questions
  • Psychology

    Spaced repetition

    Memory fades along a curve. Coming back at the right moments bends it.

    • 7min read
    • 20questions
  • Biology

    The cell

    The smallest thing that counts as alive — and the tiny machinery packed inside it.

    • 8min read
    • 31questions