Some have heard, some haven’t, so I’ll mention it here: Martin Gardner passed away a few days ago, age 95. If you’re saying “who?”, then you’re in for a treat, as there’s a great set of books and articles you haven’t yet discovered. He wrote about mathematical ideas and puzzles (he popularized Conway’s Game of Life, among many other things), debunked pseudoscience such as homeopathy and dianetics, explained magic tricks, annotated Lewis Carroll’s works and others, wrote about science and a little philosophy – what a great guy, and my #1 childhood hero. Need to know more? Check say this NYT article (which includes some puzzles) and Wikipedia.

I just noticed on Amazon you can get all of his Scientific American “Mathematical Games” articles on CD-ROM – cool. Me, my favorite books are “Aha! Insight” and “Aha! Gotcha” because I could give them to my children and pass on the word.

I’ll get back to graphics soon, but for now: a toast to a life well lived, and may we all do at least half as well!

Oh, come to think of it, I do have something that’s somewhat graphical, or at least geometric. This is from the book “The Mathemagician and Pied Puzzler: a Collection in Tribute to Martin Gardner”: You have a cube and you select at random three (different) corners. What is the chance that the triangle formed by these corners is acute (all angles < 90 degrees)? is a right triangle (has one angle == 90 degrees)?

Answers are here, along with another puzzle.

Bonus followup: I just noticed that the book I mentioned, “The Mathemagician…”, is available as a free PDF download.