After proving that the earth is round, third century B.C. thinker Eratosthenes had the information he needed to measure the earth’s circumference.
In our high-tech world it’s easy to forget the simpler things. Take a bicycle, for instance. No engine, no computerized braking system, no fancy fuel injection: all you need is air in the tires and off you go. Simple, that is, until you take a closer look at bicycles with multiple speeds. How do all [...]