_{TOYS, TRICKS, AND TEASERS} Putting a spin on a puzzle. _{By Donald E. Simanek}

Sometimes it’s not easy to decide which toys, tricks, or puzzles to include in these pages. Of course, any that are new to me seem appropriate, but a little research may reveal that they’re not as novel as I thought. A puzzle I’ve never seen may be dismissed as “old hat” by puzzle collectors; I may even discover that it was commercially marketed. A physics demonstration may cause a teacher to comment, “That one was discussed in one of the physics journals, oh, maybe 15 years ago,” with an implication that every teacher knows it, so it’s not worth discussion.

Magic tricks are often marketed, but seldom patented. Anyone who is a bit curious can find out the secrets of small tricks and large stage illusions with a trip to the library. When you start digging, you discover that very few of these things are new, and many have precedents going quite far back in history.

So I am resisting dismissive reactions from insiders. What’s common knowledge among experts is not necessarily known to the general public, and just might be of interest to quite a few MAKE readers; some may be inspired to make the devices I discuss here, or something like them, perhaps improving the idea in the process. The rest can skip this and move on to all the other good stuff in this magazine.

An Elegant Puzzle The Solution

Many puzzles are based only on geometry or topology. Close examination reveals that the dowel in the A few require a principle of physics for their solution, center goes all the way through the maple piece and and these have a special appeal for me. I especially protrudes just a bit from the bottom. This provides like puzzles that have everything out in the open, a pivot so that the entire puzzle can be spun like a with no hidden mechanisms. Naturally I like puzzles top, causing the marbles to rise up the ramps and that people have constructed with their own hands. settle into their respective depressions. The puzzle Here’s a beautiful puzzle (photos at right) must be constructed so that it is very well balanced shown to me by Mary Nienhuis, a retired high school about the pivot point. mathematics teacher. It was made some years ago This homemade puzzle is the cleanest and most by Paul Hooker, then an industrial arts instructor at elegant application of this principle that I’ve seen. West Ottawa High School in Michigan. So far as I know, this particular design has not been The construction is of purpleheart and hard marketed. Anyone who enjoys woodworking can maple (it says so on the bottom), with a transparent easily make one, or use the idea in other designs. lucite cover that allows you to see two marbles Quite a few classic puzzles employ spinning inside, separated by a wooden dowel. The marbles as part of their solution. Marketed “centrifugal” can move on curved ramps that have a depression puzzles of this sort include the original Spoophem, partway up each slope. The object is to get both patented by Fred Swithenbank in 1913 and released marbles to rest in those two depressions — simulta- by R. Journet & Company in 1929; Moses’ Cradle by neously. Tilting or shaking the puzzle does no good. 1970s game maker Skor-Mor; and the S.S. Adams You can easily get one marble into its hole, but any Co.’s Dipsy Ball. ThinkFun’s All Uphill is still available attempt to get the other one in just dislodges the in a plastic version for just a few dollars. first one.

Photography of handmade puzzles by Donald E. Simanek; photography of manufactured puzzles by Robert Stegmann, robspuzzlepage.com

Donald Simanek is emeritus professor of physics at Lock Haven University of Pennsylvania. He writes about science, pseudoscience, and humor at www.lhup.edu/~dsimanek.

188 Make: Volume 12