Don't Try This While On Drugs

An outstanding optical illusion. This gave me the spins. And I don't do drugs...

I can't imagine having dropped some acid a few hours ago and then looking at this. "Bummer, please?"

What I can't figure out is how people come up with stuff like this. Was it serendipity or did this person actually try to design something to do what this does without knowing if such an effect exists?

While I'm at it, here's the blog of the woman who digs up interesting stuff like this on the web: http://hyatts.org/BecBlog/Archives/2004_09.html