One of the wonderful mathematical notebook videos from Vi Hart. This one contains a curious puzzle – can you identify Wau?

I first saw the Peter Sellers movie “Being There” in 1979, and fell in love with Johnny Mandel’s two piano pieces on the soundtrack. For years, pre Internet, I didn’t know what the pieces were. Although they sounded like classical piano music, they are not credited in the film, there is no soundtrack album, nor […]

David Millar, of the excellent puzzle site The Griddle, has launched a new collaborative puzzle site called Perplexible. The intent is to provide a forum for diverse puzzle authors to post new creations. I’ve posted an unusual Slitherlink there, and hope to post more unique puzzles, in the future. I occasionally get emails from puzzle […]

Happy National Puzzle Day! The Jerry Slocum Mechanical Puzzle Collection is now online, featuring images from the collection of over 34,000 mechanical puzzles. This Dutch puzzle shoe from 1790 contains a hidden snuff compartment. via MetaFilter

I’ve added two new collections of Dinosaur mazes to the puzzle collection, which are great for kids. Each collection contains 50 booklets, with 12 mazes per booklet. Within each booklet, the mazes start out easier, and then get progressively harder. If you’d like to see mazes in other shapes, let me know! Easy Dinosaur Mazes […]

In the first few years of Flickr‘s existence, I made a lot of interesting composite images, using large quantities of Flickr photos, Perl, and the ImageMagick library. A few of these images have historical interest, illustrating the rapid growth of both Flickr and YouTube. This slideshow shows a few of these images, and provides descriptions […]

The science journal Nature reports that a mathematician has proven that it takes 17 clues to make a Sudoku. Gary McGuire of University College Dublin showed this in a proof posted online on January 1st (apparently he wasn’t partying on new year’s eve). This means that sudoku puzzles with 16 or fewer clues do not […]

This is a Visualization of traffic on my Wheel of Lunch website. The wheel is often accessed around lunch time in the US, to find local restaurants. It only works in the US because it was easy to get working with ZIP codes, and I’m lazy. This visualization shows the ZIP Codes that are being […]

I just found a book in the Kindle bookstore that (incompetently) rips off some of my sudoku puzzles. The book is called “The Most Difficult and Hardest Sudoku Puzzles” and is “copyrighted” by one Johnny Cohen. Here’s the cover: The cover helpfully informs you that the book is a BEST SELLER. Here’s a sample of […]

At the request of a few persistent (and possibly masochistic) puzzle fans, I’ve added four collections of Hexadecimal Sudoku to the puzzle collection. These are 16 x 16 puzzles that use the 16 hexadecimal digits (0-F), instead of the nine digits used in regular Sudoku puzzles. This is a good puzzle to take on your […]