In the last two months, I’ve become fascinated with clocks and automatons. My family never owned a mechanical clock, but I had an aunt with a musical cuckoo clock, and a grandfather clock that showed the phases of the moon. I wondered what made the pendulum keep swinging (was it magnets or batteries?), and what […]

The book cover for the book Paul and I wrote is now available on Amazon, and here’s what it look like. Here’s the Amazon listing, should you care to pre-order 1 or 2 hundred copies… :) UPDATE: Can’t wait for the book? You can get early access to an online edition using O’Reilly’s new Rough […]

Eduyng Castano writes to me about a Sudoku solving technique he has discovered. Here is his paper describing what he calls Golden Chains (pdf). The technique is a generalization of XY-Wing that identifies exclusion pairs connected by chains of arbitrary length. It solves many (but not all) of the same puzzles that can be solved […]

LEGO unveiled their next generation robotic system, Mindstorms NXT at the Consumer Electronics Show this week. As reported in Wired, the kit features a boatload of new features, including a sleeker RCX with a 32-bit CPU and larger LCX, server-style motors, an ultra-sonic sensor (for motion & obstacle detection) and lots of other robot sweetness. […]

An Astounding Test of Skill Tell a friend (it helps if the friend is in the same room…) that you are going to prove that, although you both are relatively good typists, you are the faster one handed typist. To begin the test, tell your friend to put one hand behind her back, and one […]

Puzzle Japan is the puzzle website for Nikoli, a popular puzzle publisher in Japan that popularized sudoku puzzles. Their website offers eight different logic puzzles, including sudoku and kakuro, available in online and printable formats. Many of the puzzles involve building walls or boundaries, an activity reminiscent of the game of Go. One of my […]