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 circle is the round counterpart of a square. To find the area of a square, one multiplies the length by the width. A circle doesn't have these, however, so there has to be a different way to ... 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
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
