Infinity Magazine - Back Issue no 5

Recreational mathematics takes many forms and comes from all over the world. From South America, Diego Uribe continues his investigations into the modelling of cooling towers, whereas from North America, we have our first joint article by Stan Wagon and Dale Beihoffer. Back in the UK, Deborah Singmaster takes us on a mathematical tour of Bloomsbury and Oxford.

For the recreational mathematician who is just that and John Dabell's Matchstick Trangrams is accessible at all levels, from small children upwards. Trangrams are very good at making you think outside the box and encouraging you not to take puzzles at face value. The same type of creativity is in John Sharp's article on number spirals.

Jack Tait's development of new machines to produce mathematical art is another case where there are more possibilities suggested and now you can make your own. Continuing the theme of thinking about problems in a different way, David Wells, in his investigation of Galileo's path of cannonballs under gravity, has shown that you don't need to use deep mathematics to solve problems. Tackling them in the right way not only makes the result more approachable but also more elegant. I am all for this type of beauty since I think many mathematicians go out of their way to make a simple problem appear more difficult than it actually is. Speaking of elegance, the invention of the Zometool modelling system has opened up new avenues for studying polyhedra and higher dimensional polytopes. Paul Gailiunas has shown how just playing at making models can lead to new insights. In a similar vein, Jonny Griffiths has produced a new class of tiling.

Contents:

• Surprising Squares - Paul Gailiunas
• Postage Stamp Puzzles - Dale Beihoffer and Stan Wagon
• Pearl Tilings - Jonny Griffiths
• Metric Paper Sizes - Anthony Robin
• Matchstick Trangrams - John Dabell
• Galileo and the Cannonball - David Wells
• Puzzle Paradigms - Robert Reid
• Taitographs: Part 2 - Jack Tait
• Numbers and Spirals - John Sharp
• Mathematics on Foot - Deborah Singmaster
• Folding Cooling Towers - Part 2 - Diego Uribe