"Problems worthy of attack prove their worth by hitting back." - Piet Hein, "Problems"

Besides beings known for his short poems, or “Grooks,” Piet Hein is also the inventor of one of the most classic 3-D puzzles: The Soma Cube.

Even if you're not familiar with the name, you've probably seen it. It's consists of several pieces, each made up of 3-4 cubic units, and the basic challenge is to put these pieces together to form a cube.

It was popularized in the US by no less than Martin Gardner, when he wrote about it in his Sept. 1958 “Mathematical Games” column in Scientific American, and later reprinted in his book, The Second Scientific American Book of Mathematical Puzzles and Diversions. Most of the chapter is excerpted here online.

There are numerous versions, the most commonly available today being ThinkFun's Block by Block version. Puzzles.com features links to several do-it-yourself versions, some requiring little more than tape, strips of paper, and a little time. Some of the links there are no longer functioning, but can still be viewed with help from the Internet Archive's Wayback Machine.

Even if you don't already have the puzzle, and don't want to make one, but still want to play around with it, you can play with it on the computer. The version that caught my eye was one that used Google's free 3-D program Sketchup. Once you learn the basics of rotating and moving objects in Sketchup, and download a free set of Soma Cubes for the program, you're ready for the challenge.

I haven't yet discussed solving the classic Soma Cube challenge, so if you want to solve it for yourself without learning how to solve it, stop reading NOW.

You're still here? OK, then I assume you want to learn how to solve it, and more importantly, how to remember the solution. YouTube user MisterCorzi has posted probably the best Soma Cube solving video I've seen, as it emphasizes the points that make the solution easy to recall:



Once you have the basic idea, here's a diagram of MisterCorzi's approach, for quick and easy reference:



I should emphasize that this is only 1 of 240 possible ways (not including rotations or reflections) to solve the Soma Cube, so you can still find plenty of challenge by trying to find the other solutions. There are also many other shapes you can try to make, so create, have fun, and explore!