This ghostly face appears to mysteriously change its features when you look at it for a while (some viewers said they have experienced traumatic visions!). Moreover, if you unfocus your eyes and just look steadily through the image, you will notice that after approximately 10-15 seconds the face gradually disappears…
This spooky portrait is made by merging together 50 common human faces. The process of averaging multiple exposures of human faces isn’t really new. Already in 1879, Sir Frances Galton was experimenting with this photographic process. Others followed, and borrowed this technique for artistic or social purposes: Ken Kitano, Jason Salavon, Donald Scott Bray…
This is an old technique that uses the “color assimilation” effect to colorize pictures. This perceptual effect, also known by scientists as the Von Bezold spreading effect, occurs when our visual system transfers perceived colors to their adjacent areas.
Is the first photo of a variety of pumpkins in color?
Geometric shapes are not limited only to the figurative aspect, they can also play active roles, for instance, serving in microelectronics to build operational printed circuits such as: small inductors (magnified, fig. a below), resistors (fig. b) and capacitors (fig. c). (image taken from my book “Almanach du Mathématicien en Herbe“)
A math-magic article I wrote for the German magazine Zeit Wissen: with the 13 triangular and square pieces (fig. 1) it is possible to form two large squares shown in fig. 2. Though the second large square has an extra piece the dimensions of the squares seem to be the same! Can you explain why this is possible?
In 1997, I remixed the Leonardo da Vinci’s famous painting Mona Lisa into 142 perfectly spaced color beads placed at the intersections of an imaginary two-dimensional triangular network. Close up, the picture of the set of beads makes no sense, but if you see it from a distance you will perceive (or at least ‘guess’?) the portrait of Mona Lisa, the most famous Leonardo Da Vinci’s painting.