Long ago, people discovered that shadows point north when the sun is highest. A shadow is long in the morning as the sun appears in the east. It is shortest around noon. Then it gets longer again until the sun sets in the west — but the shadow was on the other side of the object. (It had moved "clockwise"!) How do you think they used this information to keep track of time? Jot your ideas. Then read on!
Photo: Owen Rose