Timeline of Human Knowledge

--------325 BCE---------- Alexander The Great forms library in the city of Alexandria

---------30 BCE--------- Romans Conquer Egypt, including the city of Alexandria

Claudius Ptolemy is born in Egypt ---------85 CE--------

Claudius Ptolemy Dies in Egypt -------165 CE--------

-----641 CE------ Muslim Arabs Conquer Egypt

Ptolemy believes the Earth is at the center of the universe, planets, the sun and stars revolving around it.

Claudius Ptolemy was a Mathematician, Geographer, and Astrologer.

Aristarchus of Samos arrives in the City of Alexandria, theorizing that the Earth revolves around the sun, but lacks evidence to back it up.

Ptolemy rejects Aristrachus' theory.

Nicolaus Copernicus Dies in Frombork. ------------1543-------------

Muslim Arabs mostly accept Ptolemy's astronomy, correcting some of his errors, but don't make the leap to a sun-centered universe.

Galileo Galilei is born in Italy. Feb 15, 1564

Nicolaus Copernicus is born in Poland. Feb 19, 1473

-----1483------ Copernicus' parents die.

Copernicus studies in the University of Krakow from 1492 to 1496, studying mathematics and Greek and Islamic Astronomy.

Copernicus continues to study Law and Medicine for several years.

Copernicus becomes aware of the contradictions between Aristotle and Ptolemy's theories of how the universe is set up.

Copernicus introduces his theory of a heliocentric universe in 1514, called "The Little Commentary," providing mathematical equations that the Earth spun on it's axis and that it revolved around the Sun.

Copernicus is close to finishing his manuscript providing evidence for his theory of a heliocentric universe. 1532.

Copernicus publishes his astronomical manuscript titled "On the Revolutions of the Celestial Spheres." 1541.