Some mechanical puzzles

One of the main topics in recreational math is physical, mechanical puzzles. There is a huge collection of puzzles, from jigsaw puzzles, through Tangrams and Rubiks cubes to Traffic Jam and sliding block puzzles. Which of these are considered recreational math? As always, this is really an arbitrary choice, however, jigsaw puzzles are not considered mechanical puzzles, although I’m really not sure why. Many people collect mechanical puzzles. Here in Israel we have a large group of collectors who meet regularly to share ideas and puzzles, and to show off new puzzles that we create. I’m sure there are so-called puzzle parties near where you live as well.

One of the largest puzzle collections is held at the University of Indiana in the US, Donated by one of the worlds greatest puzzlists, Jerry Slocum, it is well worth a visit. In his book, “Puzzles Old and New”, Slocum classifies puzzles into different types. Here are some examples from my own puzzle collection. Put together puzzles are puzzles where you are presented with parts of a puzzle and the object is to assemble them into one design or pattern. This puzzle here is a put-together puzzle. Take apart puzzles are the exact opposite. Given a solid object, you have to reduce it to its constituents. Secret boxes, in which some object is hidden is a take apart puzzle.

This here is from Hungary, well known for its secret boxes. Burr puzzles constitute what’s known as interlocking solid puzzles. The puzzle is made from a given set of units that interlock with each other to form the final shape. Puzzles that combine string and metal or wood are also a well-known class of puzzles. Such puzzles, like this one here, are called disentanglement puzzles. Sequential movement puzzles, require an algorithm, a strict set of sequential movements in order to solve. Rubik’s cubes are a great example of sequential movement puzzles,

as are sliding block puzzles and the best-selling game: Traffic Jam. What we’ve just seen is a tiny example of the huge, rich, world of mechanical puzzles but I hope this glimpse has wetted your appetite to learn more and perhaps start your own collection.