Did you solve it? The joy of grids

Alex Bellos’s Monday puzzle The solutions to today’s puzzles On the grid: a scene from 1982 film Tron. Photograph: Allstar/Cinetext/DISNEY On my puzzle blog earlier today I set you the following three problems about this grid: A polygon is a shape where each side is made from a straight line. Draw a polygon in the…

Can you solve it? The joy of grids

Alex Bellos’s Monday puzzle Dot-to-dot puzzles that hit the spot Part of the poster for TRON, the joyous 1982 film set in a grid.Photograph: Everett Collection / Rex Feature Hi guzzlers, Today, three challenges using this grid of 16 dots: 1. A polygon is a shape where each side is made from a straight line.…

Detecting tsunamis

Credit: Cardiff University Mathematicians have devised a way of calculating the size of a tsunami and its destructive force well in advance of it making landfall by measuring fast-moving underwater sound waves, opening up the possibility of a real-time early warning system. The sound waves, known as acoustic gravity waves (AGWs), are naturally occurring and…