Why 1 Week = 7 Days? Learn Astronomy
Why are we using seven days a week? Why not five days, reducing two working days? Or ten-day week, extending few more weekend days? Is it because seven is a prime number?
Calendars have been used as records of past events and as a tool to predict the future events. Ancient Egypt and Chinese had a 10-day week. USSR changed from the 7-day week to a 5-day week and then to 6-day week. The Igbo of Nigeria have a traditional calendar with a 4-day week. The Javanese people of Indonesia have a 5-day week. But seven-day week is used now all over the world. Historically there were three types of calendars followed namely, Lunar, Lunisolar and Solar.
Emperor Constantine introduced the seven-day week in the calendar in 321 AD. Before that there were three fixed dates the calends(1st day of the month), the ides(the 15th of few months) and the nones(the 13th in other months). Constantine made Sunday as the first day of the week and set it aside as the Christian day of worship.
Two theories are attributed to the selection of seven day week. Some believe that it was based on the story of creation as narrated in the Book of Genesis. According to the Bible, the world was created in six days and the seventh day was a day of rest. Others believe that the number of days in a week was based on the number of celestial objects known at that time – Sun (Sunday), Moon (Monday), Mars (Tuesday), Mercury(Wednesday), Jupiter(Thursday), Venus(Friday) and Saturn(Saturday). The second theory seems to be more appropriate as the days are named after the above planets.
- Six Tests for Divisibility
Division is fun We need to divide a number occasionally. Students are interested to learn new and short-cut methods. Most of them are afraid of numbers. Numbers are like flowers. You should handle them ...
- Aerial Photography My Passion
Houses at New Delhi Shooting places from mid-air through your camera is a nice experience you cannot express. The name of this game is aerial photography. I have taken few photos from the air. I, an...
- Vailankanni My Pilgrimage Center
We visit Vailankanni every year from the nearest airport at Tiruchy (154 kms). No words can express the happiness and peace that we feel in the presence of our beloved Mother. Vailankanni, a hamlet on...