A circle is what you get if you take a straight line and bend it around so that its ends touch. You can demonstrate this by taking a piece of stiff wire and doing just that: bring the ends of the wire ... Continue reading
What 3 dimensional shape will pass through a rectangle, triangle and circle each time filling the whole space? The answer may surprise you in it's simplicity. Before I tell you what it is, see if you ... Continue reading
The origins of the meter go back to at least the 18th century. At that time, there were two competing approaches to the definition of a standard unit of length. Some suggested defining the meter as ... 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
