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
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:
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.
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)
Read the rest
"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"
Perhaps this is the chair Socrates was talking about.
Rest in peace, Kosmo. Read the rest
The hollow-face illusion is put to good effect here.
The Hollow-Face illusion (also known as Hollow-Mask illusion) is an optical illusion in which the perception of a concave mask of a face appears as a normal convex face.
While a convex face will appear to look in a single direction, and the gaze of a flat face, such as the Lord Kitchener Wants You poster, can appear to track a moving viewer, a hollow face can appear to move its eyes faster than the viewer: looking forward when the viewer is directly ahead, but looking at an extreme angle when the viewer is only at a moderate angle.
Is the hollow-face illusion not working for you? Again, from Wikipedia:
The Hollow-Face illusion is weaker among people with schizophrenia and other populations with psychotic symptoms perhaps as a result of reduced tendency to interpret any kind of ambiguous 3D object as convex. It appears to be related to current mental state, namely in regard to current positive symptoms, inappropriate affect, and need for structure. The illusion seems to strengthen among successfully treated patients.