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
Calculating the volume of a cylinder is even easier than calculating its area. All you have to do is recognize that a cylinder is no more than just a bunch of circles stacked to a certain height, just ... Continue reading
Many concepts that we all take for granted sounded strange and foreign when first introduced. Take the number zero for instance. Any first-grader can recognize and use zeros. They sound so logical and ... Continue reading
Eratosthenes (c. 276 – 194 BC) was born more than 2200 years ago in the Greek city of Cyrene, now a city in the North African country of Libya. (The Greek Empire surrounded much of the Mediterranean ... Continue reading
