About six thousand years ago, the Egyptians relied on the solar calculation on which the nations and peoples who came after them relied. Their year consisted of 365 days divided into 12 months of thirty days each, and the remaining five days were holidays. The Egyptians were the ones who invented the sundial, i.e. sundial, which was around 1500 BC.
Astronomy in ancient Egypt - The sundial - the sundial in the Pharaonic civilization:
The ancient Egyptians used several types of sundial, depending on the measurement of the shade caused by sunlight to the pole or string fixed in front of it; In addition to using the column facing the sunlight and measuring its length, the Egyptians used two other types of simple tools, such as a wooden or ivory ruler with a vertical edge and a vertical thread.
Astronomy in ancient Egypt - Water Clock - Clipsidre:
The water clock consists of a vessel decorated on the outside with images of stars, constellations, and hieroglyphic inscriptions, some of which say: "Each image has its hour to determine the hours of the night when the constellations or ranks are not visible, and thus the correct hour for sacrifice can be determined at all times."
The bowl's inner surface contained the following phrase (for each month, there is a vertical row of twelve signs, each sign indicating one of the twelve hours of the night in that month). This phrase came to consider the different hours of the night and the hours of the day in summer and winter.
This vessel was equipped with a whistling hole at the bottom that allowed the liquid to pass gradually. The vessel was inserted from within it according to a regular and constant rate of water descent during each hour.
The market for observing the stars and determining the hour at night:
It is a dual device consisting of:
A split date branch is in its widest part. The slit is placed next to the eye and looks through it towards the lead thread (the plumb).
The shawl is held by an assistant who sits near the observer holding the Marquette (the dating branch). This shawl consists of a horizontal ruler on which lead thread is hung so that the instrumented line matches a mark on the wood.
Ancient Egyptian calendars:
Egyptian myths mentioned that the god Thoth was the one who invented all sciences and brought them down to the Earth, where he ruled for three thousand years, dividing the day into ten hours, each hour one hundred minutes, and each minute one hundred seconds. According to Egyptian mythology, Thoth is the first teacher of humanity and the inventor of writing.
This information shows that the mathematical system in the calendar was a decimal system and was not a sexagesimal system like the Sumerians. But it is the myths that told us that there is a sexagesimal system implicit within the decimal system because the Egyptian calendar science divided the six (12) months and each month into (20) days and distributed the (360) days into three equal seasons. This means that it combines the decimal system and the sixty, which happened with the Babylonian astronomical system.
Astronomy in ancient Egypt - the Lunar Calendar:
There is a name for each lunar month, but there is a name for each day in the lunar month, which consists of 28 days, and it seems that the lunar calendar had two phases: early (leap) and late (dotted).
The first fourteen days, which are the days of the moon's growth from the crescent to the full moon, had fourteen deities who graze every day and the second fourteen days of the moon's waning from the full moon to the crescent.
Astronomy in ancient Egypt - Seasons of the year at the Pharaohs:
The month of the flood (sister) is the appearance of water on Earth, which is the flood of the Nile, which starts from mid-July until mid-November
The month of winter (burt), i.e. the seed leaving the ground, is the season of germination and rain, and it starts from mid-November to mid-March.
Summer month (Shimo), i.e. lack of water; It is the season of burning, and it starts from mid-March to mid-July, during which the plant is matured and harvested.
Astronomy in ancient Egypt - Palm Calendar:
The Egyptians used the inside of the right palm also to detect the horoscope and know the sign to which man belongs, where the hour of birth is placed on the pinky, the day of birth is written on the ring finger. The month of birth is written in the middle, the lunar day of birth is written on the fourth finger, and the year is written on the thumb. Back to the tables Horoscopes Through this information, it is possible to know the sign from which a person descends and to read his horoscope from it.
Astronomy at the Pharaohs - General Egyptian (Coptic and Pharaonic) calendar table:
They used to divide the month into three sections, each comprising ten days, and we cannot call it a week.