Famous People in Astronomy for the CSET

Feb
19

Filed Under CSET Multiple Subject |

Print this Article Print this Article

and opposite the earth from the center. If one were to stand at the equant, he would see the planet going around at a uniform rate. Finally, to explain retrograde motion, Ptolemy decided that the planet traveled along an epicycle, or a sub-orbit. This epicycle travelled along the deferent.


This model, first appearing in Ptolemy’s book Almagest, was the first to tackle apparent incongruities in the Aristotelian model. It is complicated because Ptolemy felt the need to keep Plato and Aristotle’s law that planets move in uniform circular motion at a uniform rate. His model allowed this to happen while still explaining why eccentric observations occur, and was the standard text for astronomical study until Copernicus. Michael Maestlin, the tutor of Johannes Kepler, actually owned a copy of Almagest, and Kepler was brought up with Ptolemy’s world view.

One of the most influential Greek astronomers and geographers of his time, Ptolemy propounded the geocentric theory in a form that prevailed for 1400 years.

Nicolaus Copernicus (1473-1543)

Latinized form of Niclas Kopernik, the name of the founder of the heliocentric planetary theory; born at Torun (Thorn), 19 February, 1473, died at Frauenburg, 24 May, 1543. Copernicus proposed that a rotating Earth revolving with the other planets about a stationary central Sun could account in a simpler way for the same observed phenomena of the daily rotation of the heavens, the annual movement of the Sun through the ecliptic, and the periodic retrograde motion of the planets.

Johannes Kepler (Dec. 27th 1571 - Nov. 15th 1630)

The German astronomer was the first strong supporter of the heliocentric theory of Copernicus and the discoverer of the three laws of planetary motion. Always guided by the concept of beauty in the structure of the universe, and specifically by a theory of harmony in geometric figures, numbers, and music, Kepler, in his Harmonices mundi (Harmonies of the World, 1619), announced his third law–a relationship between the orbital periods and the distances of the planets from the Sun. His belief that the Sun regulates the velocity of the planets was a milestone in scientific thought, laying the foundation for Newton’s theory of universal gravitation.

Johannes Kepler is now chiefly remembered for discovering the three laws of planetary motion

Page copy protected against web site content infringement by Copyscape

Continue Lesson - Pages: 1 2 3 4 5 6

Did you find this lesson helpful? Would you like to be alerted when a new lesson like this is posted?

 Subscribe to ACE the CSET Blog
Discover What RSS Is And Why It Is So PopularWhat is RSS?

Or, Subscribe via email:

Related Articles

Comments

Leave a Reply





The Buzz