Astronomy in ancient times. The knowledge of the cyclical movements of the Sun, the Moon and the stars showed its usefulness for the prediction of phenomena such as the cycle of the seasons, on whose knowledge the survival of any human group depended.
Summary
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- 1 History
- 1 Cyclical movements
- 2 For the primitives
- 2 Source
History
Human curiosity regarding day and night , the Sun , the Moon, and the stars , led primitive men to the conclusion that the heavenly bodies seem to move regularly. The first utility of this observation was, therefore, to define time and orient oneself.
Astronomy solved the immediate problems of the first civilizations: the need to establish with precision the suitable times for sowing and harvesting crops and for celebrations, and the need to orient oneself when traveling and traveling.
For primitive peoples the sky showed a very regular behavior. The Sun that separated the day from the night rose every morning from one direction, the east , moved uniformly during the day and set in the opposite direction, the west . At night thousands of stars could be seen that followed a similar trajectory.
In temperate zones, they found that day and night did not last the same throughout the year. On long days, the Sun rose further north and rose higher in the sky at noon. On days with longer nights the Sun rose further south and did not rise as much.
Cyclical movements
Soon, the knowledge of the cyclical movements of the Sun, the Moon and the stars showed its usefulness for the prediction of phenomena such as the cycle of the seasons, on whose knowledge the survival of any human group depended. When the main activity was hunting , it was essential to predict the moment when the seasonal migration of the animals that served as food occurred and, later, when the first agricultural communities were born, it was essential to know the opportune moment to plant and collect the crops. harvests.
The alternation of day and night must have been a fact explained in an obvious way from the beginning by the presence or absence of the Sun in the sky and the day was surely the first universally used unit of time.
The fact that the quality of the night light depended on the phase of the Moon must also have been important from the beginning, and the twenty-nine to thirty-day cycle offers a convenient way of measuring time . In this way the primitive calendars were almost always based on the cycle of the phases of the Moon. As for the stars, it must have been obvious to any observer that stars are bright spots that retain a fixed pattern night after night.
For the primitives
The primitives, naturally, believed that the stars were fixed in a kind of vault above the earth . But the Sun and the Moon should not be included in it.
From the Megalithic, stone engravings of the figures of certain constellations are preserved : the Ursa Major, the Ursa Minor and the Pleiades. In them each star is represented by a circular alveolus excavated in the stone.
From the end of the Neolithic we have received menhirs and stone alignments, most of them oriented towards the rising sun, although not exactly but always with a deviation of a few degrees to the right. This fact suggests that they assumed the Pole Star to be fixed and were ignorant of the precession of the equinoxes.
