Make a reasonable judgment before the answer can shape it.
Interactive critical thinking puzzles
Make a judgment. Then inspect the model.
Each page catches one hidden assumption in the act, lets you rerun the mechanism, and gives you a sourced rule worth taking into the next discussion.
Launch collection · 19 experiences
Pick the model you trust most.
- game-modelMake the verdict →
Braess Paradox: Can a Zero-Minute Shortcut Slow Everyone Down?
A new road changes what every driver is responding to.
- randomness-illusionMake the verdict →
Law of Small Numbers: Which Hospital Records More 60%-Boy Days?
Two hospitals, one threshold, and a denominator you cannot see at a glance.
- aggregation-illusionMake the verdict →
Simpson's Paradox: Can Every Segment Improve While the Total Gets Worse?
Segment rates and the total can tell different stories.
- projection-distortionMake the verdict →
Great Circle or Rhumb Line: Which Is Shorter?
Two familiar map lines, one route rule you have to identify.
- semantic-stateMake the verdict →
Does a 200 Status Code Mean the User's Action Succeeded?
The status stays 200 while the application result changes underneath it.
- semantic-stateMake the verdict →
Does setTimeout(callback, 600) Run 600 ms Later?
The delay tells a callback when it may become eligible. The main thread still decides when it can actually run.
- tilt-vs-distanceMake the verdict →
Is Summer Caused by Earth Being Closer to the Sun?
Northern summer arrives when Earth is farthest from the Sun. Distance is real; it is not the main seasonal switch.
- scale-distortionMake the verdict →
Could 42 Folds of Paper Reach the Moon?
Forty-two folds feels like nothing. The 42nd fold adds exactly the thickness already present after fold 41.
- repeated-gameMake the verdict →
Does Being Selfish Actually Win?
Betrayal wins one round. Repetition adds a variable the one-shot proof never prices.
- scale-distortionMake the verdict →
Is There Really No Gravity on the Space Station?
How much of Earth's pull is still present where astronauts float?
- quantity-frameMake the verdict →
Why Does a 1 TB Drive Show Only 931 GB?
One byte count, three plausible explanations. Which one survives a unit switch?
- perceptual-inferenceMake the verdict →
Are These Checker-Shadow Squares Really Different Shades?
Two gray squares sit in different visual contexts. Trust your eyes, then sample the render.
- randomness-illusionMake the verdict →
Can You Tell Real Randomness From Fake?
True randomness clumps. Evenness is the fingerprint of design.
- representationMake the verdict →
What Does the Scrollbar Thumb Really Tell You?
This proportional thumb maps what is loaded. A growing feed keeps changing the map.
- base-rate-neglectMake the verdict →
Does Switching Doors Change Your Odds?
Two doors remain, but the host did not remove one at random.
- projection-distortionMake the verdict →
How Much Bigger Does Mercator Make Greenland Look?
A map can preserve local shape while destroying area comparison.
- representationMake the verdict →
Why Does 0.1 + 0.2 Not Equal Exactly 0.3?
The decimal you typed is not always the number the machine stored.
- randomness-illusionMake the verdict →
How Many People Before Two Share a Birthday?
The room is small. The number of possible pairs is not.
- semantic-stateMake the verdict →
Does a Progress Bar Actually Know How Much Time Is Left?
Motion can say ‘still working.’ It cannot tell you what the system knows.
The page contract
Not an article with a slider.
See the missing variable without a gotcha or a confidence trick.
Change one variable and reproduce the relationship yourself.
Leave with sources, a boundary, and a rule that survives outside the page.