The understanding that the Earth takes approximately 365 days to orbit the Sun is attributed to ancient civilizations and their observations of celestial movements. One of the earliest recorded civilizations to have knowledge of this astronomical phenomenon was the ancient Egyptians.
The Egyptians observed the regular flooding of the Nile River, which coincided with the appearance of the star Sirius on the eastern horizon at sunrise. They noticed that this event occurred roughly every 365 days. By making these observations over a long period of time, they were able to establish a connection between the annual flooding and the solar year.
Similarly, other ancient civilizations, such as the Babylonians and the Greeks, also made significant contributions to the understanding of the Earth's orbit. They developed mathematical models and astronomical theories to explain the apparent motions of the Sun, Moon, and planets in the sky. These observations and calculations allowed them to determine the length of the Earth's orbit and estimate its duration.
It's important to note that these ancient civilizations were able to make these calculations without physically leaving the Earth. They relied on careful observations of celestial bodies over extended periods, tracking their positions and motions relative to each other. These observations, combined with mathematical and geometric principles, formed the basis of their understanding of astronomical phenomena.
Over time, advancements in astronomy and the development of more sophisticated instruments, such as telescopes, allowed for more precise measurements and calculations. Eventually, the introduction of the heliocentric model by Nicolaus Copernicus in the 16th century and Johannes Kepler's laws of planetary motion in the 17th century further refined our understanding of the Earth's orbit around the Sun.
Today, with the help of space exploration, satellites, and advanced scientific instruments, we have even more precise measurements and a deeper understanding of Earth's orbit and the solar system.