The Four Colour Theorem proves that no more than four colours are required to colour the regions of any map in such a way that no two adjacent regions have the same colour.
While not exactly related to the math content, I was interested in the Siciliy map, partly because I've always been fascinated by the four color theorem but also becasue I was recently there. Last summer, I visited Siciliy with friends, and made a point of climbing to the summit while I was there. As we sat at an outside bar in the evening with a view of the mountain, it erupted. It has been much more active this year, but I caught it just as it was starting to get more active. I'm sorry to say I hadn't appreciated the map implications at the time, but I do now. Thanks.
While not exactly related to the math content, I was interested in the Siciliy map, partly because I've always been fascinated by the four color theorem but also becasue I was recently there. Last summer, I visited Siciliy with friends, and made a point of climbing to the summit while I was there. As we sat at an outside bar in the evening with a view of the mountain, it erupted. It has been much more active this year, but I caught it just as it was starting to get more active. I'm sorry to say I hadn't appreciated the map implications at the time, but I do now. Thanks.