A History of
Astronomy
astronomy in the middle ages
Ancient Astronomy
“Ancient” means from time long past, especially before the end of the
Western Roman Empire in 476
A.D.
history of astronomy
Many ancient peoples, including in ancient
China and India, made
Astronomy
Books
ancient greek astronomy detailed observations about the objects in the sky
These observations were useful in making calendars, which helped in yearly planning, and were also part of many religions
History Journal
Is the solar system geocentric or heliocentric?
“geo” = earth, “helio” = sun, “centric” = centered, so “geocentric” means “earth-centered” and “heliocentric” means “sun-centered”
Most ancient
Greek astronomers believed that the earth was the center of the solar system and the universe, with everything orbiting it, which is called a “geocentric” model or system
We now know that the earth orbits the sun, which is called a “heliocentric” model
Ancient Greek Astronomy
• Most ancient
Greeks believed that all astronomical objects were perfect, unchanging spheres and orbited in perfect circles around the earth, following different physical laws from those on
Earth
• These ideas were believed by most people until
Copernicus,
Kepler, and
Galileo disproved them more than
1000 years later
• Although they had many wrong ideas about the solar system, the ancient Greeks made many important astronomical discoveries
Astronomy in the
Middle Ages
In
European history, the Middle Ages lasted from about
500 A.D. to about 1500 A.D. (between antiquity and the modern period)
In Europe, astronomy (and knowledge in general) did not gain much during the Middle Ages, and so it has been called “
The Dark Ages”
Nicholas Copernicus (1473 - 1543)
The publication of Copernicus' book, On the
Revolutions of the
Celestial Spheres, just before his death in 1543, is considered a major event in the history of science
It argued for the heliocentric model based on the observed backward motion of
Mars
Tycho Brahe (1546 - 1601)
His model of the
Solar System put forth in
Introduction to the
New Astronomy (1588) combined the geocentric and heliocentric models
Johannes Kepler (1571 - 1630)
Published
Astronomia nova in 1609
Kepler’s work provided one of the foundations for
Isaac Newton's theory of universal gravitation
He discovered that orbits are shaped like ellipses, not circles
Galileo Galilei (1564 - 1642)
He discovered the four largest moons of
Jupiter and craters on the
Moon
His 1631 book,
Dialogue Concerning the Two
Chief World Systems, argued for the heliocentric model
He said the Earth could be moving because of the law of inertia
Isaac Newton (1642 - 1727)
Newton used the ideas of Copernicus, Galileo, and others and created the 3
Laws of Motion and the
Law of Universal Gravitation
These laws accurately described the motions of all objects everywhere, including astronomical objects
Before this it was believed that astronomical objects had different laws of motion than objects on the Earth
Published his theories in his work Principia in 1687
- published: 03 Sep 2015
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