Human brains are marvelous. Something we humans are able to do is look at a round object, like the Earth, and draw it flattened out as a map. Then, get this: other humans are able to look at the flat map and comprehend a round Earth. Yay, us!
Ptolemy was the first to think of drawing lines of longitude and latitude on a map. Longitude lines travel from north to south poles. Latitude lines travel east to west and are parallel to the Equator. Together they make a grid on a flat map. Longitude and latitude lines are man-made; they don’t exist except on maps. Longitude and latitude lines are the way we organize the Earth’s surface so we can navigate on it. You assign the lines names or numbers.
Latitude lines (also called parallels) are circles that run around the circumference of the Earth and are measured in degrees. The Equator divides the Earth into northern and southern hemispheres (hemi = half, sphere = globe). It’s at 0 degrees. The North & South poles are at 90 degrees.
Back to the beginning of The Western Civ User’s Guide to Time & Space