What is Soma?

# Soma

The Soma puzzle cube was created years ago by the Danish mathematician and poet Piet Hein. He came up with all the different ways that three or four cubelets could be joined together, but not all in a straight line:

 L T V Y Z 3 9

These seven pieces can be assembled to form the 3 x 3 x 3 Soma cube, as well as thousands of other designs.

In order to distinguish these pieces from each other, we can use a simple naming convention based on letters of the alphabet. Most of the pieces suggest obvious choices. For the last two, we've chosen names based on a clock, which usually has its minute hand in front of its hour hand. The 3 piece suggests the appearance of the hands at 3 o'clock: the minute hand is in front pointing upward, and the hour hand is in back pointing to the right. Similarly, the 9 piece corresponds to a front clock hand pointing upward and a back hand pointing to the left ("9 o'clock"). In addition to this notation, our solutions show each Soma piece uniquely colored, with each of its visible faces labeled with the piece name.

Most of the designs shown on these pages can be constructed with a single 7-piece Soma set (27 cubelets), but a few are larger designs that can be made from two identical Soma sets. Multiple solutions are often possible for many of the designs. Some of the wooden versions of the Soma cube puzzle have cubelets of alternating light and dark colors, making it possible to create certain designs in a "checkerboard" pattern, increasing the puzzle difficulty.

Use the Interactive Soma Machine to create your own Soma designs!