With what is delightfully being called “The Atomic Pen,” a team of researchers has created what are likely the world’s smallest letters. At left is an array of silicon atoms measuring two nanometers in height, or .000007086614175 points to you.

Their technique, documented in today’s issue of Science magazine, makes use of an earlier discovery: that within a certain proximity, individual atoms from the silicon tip of an atomic force microscope will exchange with tin atoms on the surface of a semiconductor. “It’s not possible to write any smaller than this,” said researcher Masayuki Abe, which sounds like a challenge to me: I can already think of one way to make letters that are 8% smaller, using the team’s own technique. Can you? Answers next week. —JH