This video tutorial provides a brief overview of the 'Copernican Revolution'. And this video is about Kepler and Galileo.

History of Astronomy

  1. The Greeks are generally acknowledged as the first people to elevate astronomy from the level of prediction to that of explanation and understanding.
  2. Aristotle (384 - 322 BC) was one of the most influential Greek philosophers. He made important contributions to logic, criticism, rhetoric, physics, biology, psychology, mathematics, metaphysics, ethics, and politics  He believed (incorrectly) in separate laws for Earth and Heavens.
  3. After Alexander the Great (356-323 BC) conquered Egypt in 332 BC, he founded the city of Alexandria, which became a leading center of Greek civilization. Much of the significant work of later Greek astronomers was carried out in or near Alexandria.
  4. Ptolemy, also Claudius Ptolemaeus, (ca A.D. 150) formulated a geocentric model of the universe that was widely accepted until it was superseded by the heliocentric system of Copernicus, some 1500 years later.
  5. Nicolaus Copernicus (1473-1543, Poland) developed the most coherent model at the time for the heliocentric cosmology.
  6. Tycho Brahe (1546-1601) collected the best astronomical data before the age of the telescope.
  7. Johannes Kepler (1571-1630) carried out the analysis of Tycho's data and developed a few empirical laws which described the behavior of the planets in their orbits.
  8. Galileo Galilei (1564-1642), using the newly-invented telescope, made critical observations which demonstrated once and for all the correctness of the heliocentric model.
  9. Isaac Newton (1643-1727), discovered the law of gravity and formulated the laws of motion to explain why the planets move as they do. In this, he was encouraged by Edmond Halley, who brought his work to a wider audience.
  10. Harlow Shapley (1885-1972) was the first to realize that the Milky Way Galaxy was much larger than previously believed and extended the Copernican principle: Not only is the Earth not the center of our Solar System, but the Sun is also not unique, central, or special in any way. He participated in the "Great Debate" of 1920 with Heber D. Curtis on these and other issues. Up to that point, most people believe the Sun to be center of the Universe.
  11. Edwin Hubble (1884-1953) extended the Copernican principle even further in the 1920's by demonstrating that even our Galaxy is not special in any way but rather one of myriad other galaxies in a much, much larger cosmos.

Geocentric vs Heliocentric

geocentric heliocentric
In the geocentrism model, the Sun and the other six visible objects in the sky revolve around the Earth. In the heliocentric (Sun-centered) model, the Earth is just one out of many planets, all of which orbit the Sun in elliptical orbits.

 


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Last changed: 05/01/23.