Directory

Illusion site directory

Every kind of illusion on illusions.im will get its own site. Here’s the plan for the first ten. None is open yet; size illusions and impossible objects come first.

Open now

This hub, illusions.im. The illusion sites below will be listed as open, with a link, on the day each one goes live.

Coming soon

• Size illusionsFirst wavesize-illusions.illusions.im

  Planned: equal lines that look unequal, circles that grow and shrink, the moon on the horizon, and how to measure each trick with a ruler.

  Coming soon
• Impossible objectsFirst waveimpossible-objects.illusions.im

  Planned: shapes that can be drawn but never built, the devil’s fork, step-by-step drawing guides and where the idea came from.

  Coming soon
• Ambiguous figuresambiguous-figures.illusions.im

  Planned: one picture, two answers. The vase and the faces, the flipping wire cube and the hollow face that won’t stay hollow.

  Coming soon
• Pareidoliapareidolia.illusions.im

  Planned: faces in clouds, plugs and rocks, the “face” on Mars, and why the brain is so quick to see faces everywhere.

  Coming soon
• Stereogramsstereograms.illusions.im

  Planned: how two flat pictures make one solid one, the Victorian stereoscope craze, and making your own 3D pictures.

  Coming soon
• Camera obscuracamera-obscura.illusions.im

  Planned: the “dark chamber” that turns the world upside down, building a pinhole viewer, and the ancestor of the camera.

  Coming soon
• Moving picturesmoving-pictures.illusions.im

  Planned: zoetropes, flip books and spinning toys, the phi phenomenon, and why wheels on screen spin backwards.

  Coming soon
• Afterimagesafterimages.illusions.im

  Planned: colours that appear after you look away, the green dot that isn’t there, and dots that fade while you stare.

  Coming soon
• Colour and shadecolour-illusions.illusions.im

  Planned: two identical greys that look different, colours from a black-and-white spinning top, and grids with ghostly spots.

  Coming soon
• Op artop-art.illusions.im

  Planned: the art movement built on optical illusion, the café wall, and patterns that seem to move and shimmer.

  Coming soon

How we chose the ten

We grouped well-known illusions and optical devices into families, then ranked the families by how many people read about them online over a year. Size illusions and impossible objects come first because they are the easiest to draw, measure and print.

Our own pictures

Many famous illusion images belong to the people who made them, so we draw our own versions from the published descriptions. Where an illusion is named after its creator, we say so.

Independent, not official

Our facts come from Michael Bach’s illusion collection, Encyclopaedia Britannica and the Exploratorium. illusions.im is not affiliated with, or endorsed by, any of them.

How the network works

The list of sites lives in network.json. This page and sitemap-index.xml are built from it, and only open sites go into the sitemap index. Each illusion site will have a link back here at the top of every page.

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