On SciAm guest blogs: The Unexpected Dangers of Recreational Counting

Magician with cards

Image by Flickr user jin.thai, CC BY 2.0

From an article reviewed by SNF and posted yesterday on Scientific American’s guest blog:

The cleverest card trick I’ve ever seen was performed not by a magician, but by a math professor.

A teaching assistant (let’s call him Nick), acting as magician’s assistant, recruited five student participants. Each student picked a card from a 52-card deck and handed it back to Nick, face up but invisible to Tom, the professor. Nick laid out four of these cards in front of Tom. To our astonishment, Tom immediately identified the missing fifth card.

The professor revealed the trick at the end of class. But when I came back to my dorm, bursting with excitement, my suitemate Benjamin refused to let me explain it; he had to figure this out on his own. He wandered off to his room muttering to himself, blissfully unaware that within twenty-four hours, this puzzle would prove disastrous to his dignity.

Read the whole article on the Scientific American website.