Time

From the beginning of time people have left records that tell us that they knew that the Sun moved and that they could use this movement to mark the passing of days, or tell time.

The Egyptian pyramids could have been used to tell time and to keep track of the seasons. Some archaeologists think they even tried to tell the weather so that they could predict when the Nile was going to flood with their knowledge of the Sun's movements. The great pyramid, the Cheops Pyramid, is probably a huge stone calendar. By studying Cheops archaeologists believe that the Egyptians used the Sun to figure out the size and shape of the Earth long before the Greeks.

The archaeologists discovered that many of the pyramid's corridors point accurately to some of the brighter stars. Light would pass through the corridors to illuminate, or light up, 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 very 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 believed that Stonehenge may have been built as an astronomical observatory. Even after years of study this monument still remains a mystery in many aspects.

In Mexico the Mayans developed an accurate calendar which predicted eclipses, marked the position of the Sun years in advance, and at times predicted the weather. This calender was very accurate and was made hundreds of years before there were any instruments to help.

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 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 set to measure for exactly 24 hours each day but the length of Sun days change every day. This makes every day of the year the same length of time which in astronomical terms is not accurate.