Dhaval Rathod
No, the answer has nothing to do with numerology, but with astronomy.
Although telescopes and spaceships give it a modern outlook, astronomy has been in practice for several centuries. People have always looked up at the sky, and wondered, marveled, and at times discovered the secrets of the universe. Many ancient civilizations, and visionary astronomers belonging to them, have even recorded their observations. Celestial objects have not only been the points of interest for scientists, but for religious leaders, cartographers, explorers, navigators, writers and scholars from several other niches as well.
These celestial objects that we see in the night sky, especially those of the solar system, have been named after Greek, Roman and other deities, and it is worth noting that these very spheres also played a key role in the process of defining the week as we know it.
The ancient Babylonian and Egyptian astronomers were decently sharp with their observations. It goes without saying that they must have been able to trace the paths, positions and cycles of the sun and the moon without considerable difficulty. However, they had done the same to a lot of stars that were visible to the naked eye as well. Thanks to the regular revolution of the earth and its quite precisely regular trip around the sun, a particular star would appear at the same position at a specific time of the year. These observations proved to be quite helpful in agriculture, religious events and navigation. But then they discovered an anomaly in the pattern.
There were five other celestial objects visible in the night sky with a naked eye that did not follow this regular set path. The scholars of that time regarded these five as having some kind of extra-ordinary powers, a power that put them even beyond the regularity of the mighty stars. The sun and the moon were already given the status of deities in most of the cultures, and then these five new bodies, due to their irregular trajectory that earned them a respectable attention, became quite important. The Greeks called them 'planetai' which means 'wandering', and the word later became to be known as 'planet' in English.
These five celestial objects whose paths defied the understanding of the ancient observers were none other than Mercury, Venus, Mars, Jupiter and Saturn. It seems quite obvious now that they would not be at the same place in the sky at the same time every year. This is because all of them have a different orbital time than that of Earth. If we try to see them in the sky after their every orbital period, they would be there at the same position every time.
Planet | Orbital Period (in Earth days) |
|---|---|
Mercury | 88 |
Venus | 225 |
Mars | 687 |
Jupiter | 4,333 (12 years) |
Saturn | 10,756 (29.4 years) |
These details were not known at the time, and as discussed earlier, the five planets were regarded as having a special power to wander and move about in the sky at their will. In addition to the sun and the moon, the ancient astronomers decided to honor them by dedicating a day to each one, making it a seven-day week.
Let us conclude on a funny note. Think about it: If the ancient observers had seen one less planet at that time, Sunday would arrive a day early. And then imagine, if they would have been able to see Uranus, Neptune and Pluto as well with their naked eye...