A little freaky…
WTF?
Stare at the “+” sign in the middle of the square above for a little while. You will see a green dot circling between the pink dots… pretty cool, eh? Keep looking at the “+” sign for a while longer… the pink dots eventually disappear. (Cool becomes freaky).
I’m somewhat of a fan of whacky visual phenomena (witness past posts such as this, this, and this). Though I have encountered the above example before, I stumbled across it again today on Eric Karjaluoto’s fine blog, here. (There is a Wikipedia entry that attempts to explain: Lilac Chaser).