Civilizations from all over the world have left records which indicate that they knew exactly how the Sun moves and used this knowledge to tell time.
One of the most astonishing uses of the Sun to tell time is probably the Egyptian pyramids. The Egyptians marked the seasons, could tell what the date was and could even predict when the Nile was going to flood with their knowledge of the Sun's movements. Their great pyramid, Cheops Pyramid, is thought to be a huge stone calendar. From their study of this ancient pyramid archaeologists believe that the Egyptians used the Sun to figure out the size and shape of the Earth long before the Greeks. These same archaeologists discovered that many of the pyramid's corridors point accurately to some of the more prominent stars. Light would pass through the corridors to illuminate a certain statue only when the Sun was at a precise angle. Because some of the passageways are up to 600 feet long, the Egyptians could be extremely accurate in knowing what time it was inside their pyramids. There was even a way to mark how many years had gone by, a certain peephole pointed a beam of light at a statue of the buried pharaoh only once a year, illuminating it for only the briefest of minutes.
In Europe a mysterious monument was built that recorded the movements of the Sun. Astronomer Gerald Hawkins theorized that Stonehenge may have been built as an astronomical observatory. Even after years of study this monument still remains a mystery in many aspects.
"Anyone who has lived
through an English winter can see the point of building Stonehenge
to make the Sun come back."
- Alison, Jolly 1988
The Greeks also recorded some surprisingly accurate measurements of the Earth's size by studying the Sun from different locations.
Some cultures used a sundial to tell time. A sundial makes a shadow fall on itself as the Sun moves across the sky. This shadow shows the apparent solar time. When you study the length of a solar day you will see that not all days are 24 hours long, some days are longer than 24 hours, and some days are shorter, each day is a little different than the next. Modern clocks aren't nearly as "accurate", they don't change every day which is kind of good for scheduling meetings and events. Clocks are arbitrarily set to measure to be as long as the length of an average day which is 24 hours. This makes every day of the year the same length of time which in astronomical terms is not accurate.
©Copyright 1998 Elizabeth
Beckett, Holly Bernitt, and Vishwa Chandra.