Yesterday was one of our most popular days ever at CogDaily — two posts were on the front page of Reddit and one was on the front page of Digg.com. Most of the visits went to this post, which explains an amazing illusion by Arthur Shapiro. Greta actually went to grad school with Artie, and he was a good friend of mine back in the day, so it’s great to see that he’s getting noticed.

Artie sent me another illusion that I couldn’t squeeze into the CogDaily page, so I thought I’d post it here (I also want to know whether this works on WordPress):

The illusion is in the pattern created. The central disks are oscillating in rows from light to dark. But it appears that only half of each row is alternating together. Neat stuff. There’s much more at Artie’s Lab web page.