Some numbers are more special than others. According to Pythagoras (569 BC - 475 BC) and Euclid (325 BC - 265 BC), some are so special that they called them mystical or perfect numbers. The first ... Continue reading
Leap years are years with 366 days, instead of the usual 365. Leap years are necessary because the actual length of a year is 365.242 days, not 365 days, as commonly stated. Basically, leap years ... Continue reading
Originally, each country had its own, and rather poorly reproducible, unit of luminous intensity; it was necessary to wait until 1909 to see a beginning of unification on the international level, when ... Continue reading
A Mobius Strip is an amusing three-dimensional object whose surface has only one side. Huh? Well, most objects you can imagine have a surface with two sides. For example, an ordinary piece of paper ... Continue reading
