Tag: Ptolemy

The Issue of The Universe

For hundreds of years people had believed that the earth was in the center of the universe. This theory was born of Ptolemy’s geocentric theory. This theory, in brief, stated that the sun revolved around the earth, and so did all the stars. It also stated that the earth was stationary.

Not all ancient astronomers and mathematicians came up with incorrect theories, however. The ancient Greeks knew that the earth was round and they measure the circumference of our earthly sphere using a system of shadows.

Until the time of a very important scientist, people blindly believed this theory. That is, they believed it until the time of the man who would change their beliefs forever.

Nicolaus Copernicus was born in 1473 in Royal Prussia near Poland. His father was a wool merchant, but Nicolaus decided to follow a different trade.

Nicolaus, after making observations, wrote a book called The Revolutions of the Heavenly Spheres, in which he explained his new theory: heliocentricity. Heliocentricity is a Latin word and it means the sun (helio) in the center (centric). His book was published on the day he died in 1533. His theory was not perfect, but it was a major step up the ladder of improvement. Continue reading “The Issue of The Universe”


Astronomy History, Astrophotography and Telescopes

Astronomy is the study of the stars. It is one of the oldest sciences. It is also one of the most complex and thrilling.

Astronomy History

Ptolemy was a Greek philosopher who taught the geocentric theory. Geo means earth and centric means center. So what Ptolemy was teaching was that the earth was in the center of the universe and that the stars and the rest of the heavenly bodies were revolving around it. This was the lasting theory until another scientist called Nicolaus Copernicus changed it.

Nicolaus Copernicus (b.1473 d.1543) was a Prussian who invented his own theory to counteract Ptolemy’s. His theory was heliocentricity. Helio means sun and centric is center, as mentioned before. Thus it was the sun in the center of the universe instead of the earth. The Catholic Church didn’t like his theory.

Galileo Galilei was a one of the most famous astronomers, both of his time and ours. He improved the science of the stars by discovering Jupiter’s moons. By this he proved heliocentricity, showing that not all things revolved around the earth.

Johannes Kepler was a German astronomer who advanced this science by publishing a series of books on The Laws of Planetary Motion. He, along with a contemporary named Tycho Brahe, confirmed that the planets moved in oval orbits instead of perfect circles, as was the former belief.

Isaac Newton added to it by forming the Law of Gravitation, which solved the mystery of why the planets stayed in orbit. Continue reading “Astronomy History, Astrophotography and Telescopes”