The Greeks had it figured out that the earth was round. How did they manage it? Learn more on this Moment of Science.
How did the metric system come to be? Did the French have something to do with it? Find out on this Moment of Science.
How fast anything spins is partly determined by how its weight is distributed. The closer an object’s weight is to its axis of rotation, the faster it spins. To picture this, imagine an ice skater doing a pirouette. When her arms are extended, she spins slowly.
The North Star is the brightest star in the constellation known as the Little Dipper. It is called the North Star because of the special position it occupies relative to the earth’s axis. If you were to stay up all night gazing at the stars, you’d slowly see them revolve around a point in the sky known as the North Celestial Pole.