The demonstration is an extension of the 2009 Curveball illusion (http://illusionoftheyear.com/cat/top-10-finalists/2009/).
In the ZigZag, the internal spin moves back and forth, while in the Curveball, the internal phase moves in a … See Demonstration
Question: Are the disks in the center of the black and yellow rings blinking together, or are they alternating?
Blinking together — if you consider light level: The disks … See Demonstration
A tweet that I recently posted–which was retweeted over 1.5K times–featured a visual illusion called the Perpetual Diamond (see my December 2018 article in i-Perception, co-authored with Oliver Flynn).
Here … See Demonstration
“Freedom is the freedom to say that two plus two make four. If that is granted, all else follows.”
–Winston Smith’s journal in George Orwell’s 1984
But is 2+2=4 always true?
… See Demonstration