Anchoring Effect
A random wheel-of-fortune spin changes your estimate of how many African nations are in the UN. The spin was meaningless. The effect was real. Why?
19746 min read
Some ideas reshape how you see everything.
102 paradoxes, laws, and effects — from a puzzle told 2,500 years ago to a principle coined last decade. Each one starts as a story anyone can follow and goes as deep as you care to take it.
The ones you have probably heard of
Famous for a reason. Any of these is a good first door.
Bystander Effect
If you collapse on a busy street, your chances of getting help may be worse than on a quiet one. Why does a crowd of witnesses make you less safe?
19688 min read
Hilbert's Grand Hotel
A hotel with infinitely many rooms is completely full. At two in the morning, one more guest arrives. The manager finds them a room.
1924 (lectures), 1947 (popularised)13 min read
Moore's Law
A pattern that held for fifty years: every two years, computers got twice as powerful for the same price. What happens when it stops?
19657 min read
Occam's Razor
When two explanations fit the evidence equally, which should you believe? The one that assumes less.
c. 13206 min read
Pareto Principle
80% of results come from 20% of effort. 80% of bugs from 20% of code. Is this a law of nature, or a coincidence with a catchy ratio?
18966 min read
Laws that named what nobody had words for
Heuristics and principles durable enough to earn a name.
Moore's Law
A pattern that held for fifty years: every two years, computers got twice as powerful for the same price. What happens when it stops?
19657 min read
Murphy's Law
If anything can go wrong, will it? The saying is a joke — but the engineering principle behind it is dead serious.
19497 min read
Parkinson's Law
Give yourself a week for a task that takes an hour, and it will take a week. Why does work expand to fill available time?
19556 min read
Effects that changed what we thought was possible
Named phenomena where reality behaves differently than expected.
Anchoring Effect
A random wheel-of-fortune spin changes your estimate of how many African nations are in the UN. The spin was meaningless. The effect was real. Why?
19746 min read
Bystander Effect
If you collapse on a busy street, your chances of getting help may be worse than on a quiet one. Why does a crowd of witnesses make you less safe?
19688 min read
Dunning-Kruger Effect
The less you know, the more confident you feel. The more you know, the more you see how much you don't. Why?
19996 min read
Or go by what you are in the mood for
You do not need to know the classification to start exploring.
Good places to start
No background needed at any point. Suitable for younger readers.
Dunning-Kruger Effect
The less you know, the more confident you feel. The more you know, the more you see how much you don't. Why?
19996 min read
Halo Effect
Why does being attractive make you seem smarter, or sounding confident make you seem right — even when neither is true?
19208 min read
Murphy's Law
If anything can go wrong, will it? The saying is a joke — but the engineering principle behind it is dead serious.
19497 min read
Follow a thread
Ordered sequences where each idea sets up the next.
Understanding InfinityStart with a runner who can never finish a race and end with a solid ball cut into five pieces and reassembled into two of the same size. Nothing along the way is a trick — each step is the honest consequence of the one before it.
- Zeno's Dichotomy Paradox
- Achilles and the Tortoise
- Galileo's Paradox
- Hilbert's Grand Hotel
- Cantor's Diagonal Argument
- +1 more
- The Liar Paradox
- The Barber Paradox
- Berry's Paradox
- Russell's Paradox
- Gödel's Incompleteness Theorems
- +1 more
- The Birthday Problem
- Bertrand's Box Paradox
- The Monty Hall Problem
- The Boy or Girl Paradox
- Simpson's Paradox
- +1 more
- The Halting Problem
- The Two Generals' Problem
- The Byzantine Generals Problem
- The FLP Impossibility Result
- The CAP Theorem
- +1 more
Less famous, no less strange
Well known inside one field and almost nowhere else.
The Easterlin Paradox
Richer people are happier than poorer people. Yet a whole country getting richer does not seem to get happier.
197423 min read
The C-value Paradox
An onion carries five times more DNA than you do. A single-celled amoeba carries a hundred times more. Nobody expected that.
1971 (named), 2001 (renamed the C-value enigma)17 min read
The Productivity Paradox
Computers arrived in every office through the 1970s and 80s. Measured productivity did not move for two decades.
1987 (Solow's remark), debate ongoing17 min read
Pick a field
The same handful of problems keeps turning up in all of them.
- PhilosophyQuestions about reality, knowledge, and meaning.38
- LogicThe rules of valid reasoning — and where they break.16
- MathematicsInfinity, sets, and results that defy intuition.28
- ProbabilityChance behaves nothing like people expect.12
- StatisticsWhat data does and does not tell you.8
- PhysicsSpace, time, matter, and observation.12
- AstronomyThe sky, the cosmos, and its silences.3
- BiologyLife, evolution, and genomes.9
- PsychologyHow minds misjudge themselves and the world.34
- EconomicsValue, incentives, markets, and choice.30
- SocietyGroups, voting, tolerance, and cooperation.30
- Computer ScienceComputation, algorithms, and distributed systems.24
- AIMachine intelligence and its unexpected shapes.6
Or start from a century
The same questions keep resurfacing in new clothes.