## If you stare at this image, it allegedly "disappears"

From @rainmaker1973 on Twitter: "Your visual system constantly adapts to all the external stimuli, and this is why if you stare at this picture, it will slowly disappear"

Doesn't work for me!

Previously: Optillusions. Read the rest

## Watch this fantastic "Circle in Circle" optical illusion machine in action

When this curious contraption is switched on, an inner circle of white balls appears to be rolling inside the outer circle, but that's actually not the case at all. Below is a video explaining this circular motion illusion. Learn more about the mathematics behind it, specifically Copernicus’ Theorem, and the ingenious hypocycloid mechanical gear design by Girolamo Cardano (1501-1576) over at The Kid Should See This.

## Shake your head to see this image

And if shaking your head really fast is, er, problematic, you can also just look at an angle or move away from the screen until the image appears.

Here's an Instructable on how to make your own head-shaking illusions.

(via r/interestingasfuck)

## Here's the winner of the 2018 Best Illusion of the Year Contest

Kokichi Sugihara of Japan is the winner of the 2018 Best Illusion of the Year Contest with his mind-bending entry, "Triply Ambiguous Object."

## In this video, the beeps make you see something that isn't there

In this video, Caltech demonstrates the Rabbit Illusion, a "time-traveling illusion trick." It tricked me.

Caltech researchers have developed these two new illusions that reveal how the senses can influence each other—in particular, how sound can give rise to visual illusions. These illusions occur so quickly that they illustrate a phenomenon called postdiction (as opposed to prediction) in which a stimulus that occurs later can retroactively affect our perceptions of an earlier event.

## This aerial photo of lake is actually a mossy puddle on a box

My new favorite subreddit is Accidental Maps, specializing in a pareidolia of places.

## Simple way to draw a 3D optical illusion of cubes falling through the paper

Circle Line Art School explains how to draw this simple but effective anamorphic illusion of cubes falling into a hole in the page.

(via The Kid Should See This)

## Tour this impressive 3D selfie museum

After hitting the mute button (YouTube should have a terrible music reporting option), check out this delightful Malaysian selfie museum with lots of trompe-l'œil paintings and optical illusions. Read the rest

## Watch this dog get tossed from an airplane (Don't worry though)

Karma the Corgi says it's all about attitude not altitude: Read the rest

## Explaining the flashed face distortion effect

Steve Mould offers a couple of explanations for the flashed face distortion effect. I've seen this before and it's very strange. When you put pictures of two different people side-by-side and flash several pairs, the faces look like gross caricatures. By way of explaining it, he also presents a couple of other cool visual effects. Read the rest

## Your perception of this graph is a graph of your perception

Look at the above image. The higher the peaks, the more sensitive your eyes are to contrasts at those frequencies. Ian Goodfellow spotted the image in a scientific paper about spatial frequency analysis and brilliantly observed that "It's like a graph that is made by perceiving the graph itself." Over at Mind Hacks, Tom Stafford explains the science of spatial frequency, the same concept behind the classic "Marilyn Einstein" image below that was created by Aude Oliva in 2007. From Mind Hacks:

Spatial frequency means how often things change in space. High spatial frequency changes means lots of small detail. Spatial frequency is surprisingly important to our visual system – lots of basic features of the visual world, like orientation or motion, are processed first according to which spatial frequency the information is available at...

Spatial frequency is also why, when you’re flying over the ocean, you can see waves which appear not to move. Although your vision is sensitive enough to see the wave, the motion sensitive part of your visual system isn’t as good at the fine spatial frequencies – which creates a natural illusion of static waves.

See Einstein below? Now go a few steps back from your screen and look again:

## Impossible objects, explained

Vsauce3's Jake Roper reveals the wondrous perceptual paradoxes of "impossible objects" from Escher's cube to the Penrose triangle.

(via Laughing Squid)

## Does this baby have a man's head?

As the original Reddit headline states, "Took me longer than I care to admit."

## Cool animated examples of the Muller-Lyer illusion

German sociologist Franz Carl Müller-Lyer (1857-1916) created an optical illusion that showed how changing the direction of angle brackets on line segments can make the segments look longer or shorter than they actually are. Artist Gianni A. Sarcone made a animated versions of the illusion and the effect is even more pronounced.

## Why you might see flying boats

A Fata Morgana is a spectacular optical illusion in which you may see boats floating above the sea or city skylines in the clouds. (The term is named after the Arthurian sorceress Morgan le Fay as her castle was said to hover above the coast of Sicily.) In the video below, Seeker explains the science behind the magic.

(via Daily Grail)

## Mesmerising stroboscopic Easter egg designs

"No computer graphics tricks were used in this video," writes Jiri Zemanek of Czech Technical University in Prague.

Various patterns are generated in MATLAB using mathematical equations similar to ones describing Spirograph (or harmonograph) and Phyllotaxis. The patterns are calculated in such a way that when rotated under a stroboscopic light of suitable frequency or when recorded by a camera, they start to animate. It is kind of zoetrope---early device for animation. Eggs were painted using EggBot (designed by Bruce Shapiro as open hardware and available as a kit from http://www.evilmadscientist.com/). To draw on eggs, we used standard permanent markers and an electro kistka with bee wax followed by dying. Eggs are rotated at a constant speed, special for each pattern, by a brushless motor.

Here's more: "This apparatus creates stroboscopic patterns on an egg covered in photochromic paint"

## Behold these trippy optical illusion centerpieces

Valerio Sommella just won a 2018 design award from The German Design Council for these disorienting centerpiece plates he created for Il Coccio. Read the rest