XKCD on Chaos: "Can You Do That Weird Laugh?"

The topic for today's XKCD is chaos, which is of course near and dear to my heart. I love the mouseover: "Although the oral exam for the doctorate was just 'can you do that weird laugh?'"

Hmmm... I got my PhD in quantum chaos, and I never got that question on my oral exam to defend my thesis. :(