4thB Geocentric and Heliocentric systems

Claudius Ptolemaeus or Ptolemy (about 87-165)

Ptolemy was a Greek astronomer who lived between 85-165 A.D. He put together his own ideas with those of Aristotle and Hipparchus and formed the geocentric theory. This theory states that the Earth was at the center of the universe and all other heavenly bodies circled it, a model which held for 1400 years until the time of Copernicus.

Ptolemy is also famous for his work in geography. He was the first person to use longitude and latitude lines to identify places on the face of the Earth.

Copernicus

Nicolaus Copernicus was an astronomer who changed how we viewed the positioning of the Sun, Earth and other celestial objects in space. He reasoned that it was the Sun at the middle of the known Universe and not the Earth, an idea that was strongly opposed at the time. Read on for interesting facts, quotes and information about the scientist Nicolaus Copernicus. Copernicus was born on the 19th of February, 1473 and died on the 24th of May, 1543. He was born in Thorn, Royal Prussia, part of the Kingdom of Poland at the time. The astronomical model that Copernicus developed was called heliocentrism (helios means Sun). It has the Sun motionless at the center of the Universe while the Earth and other planets rotate around it in circular paths. A much earlier geocentric model (geo means Earth) created by Ptolemy featured Earth at the center of the Universe. This model was used by astronomers and other scientists for centuries before Copernicus developed his heliocentric model. Many believe that the theory and ideas put forward by Copernicus started modern astronomy and were the beginning of a scientific revolution. Copernicus's work ‘On the Revolutions of Celestial Spheres’ was published shortly before he died in 1543. Copernicus's skills were not limited to just astronomy. Among other things, Copernicus was also a physician, scholar, economist, translator, mathematician, artist and diplomat. The chemical element Copernicum is named after Copernicus. It has the symbol Cn and atomic number 112. Famous Nicolas Copernicus quotes include: “Finally we shall place the Sun himself at the center of the Universe.” “For when a ship is floating calmly along, the sailors see its motion mirrored in everything outside, while on the other hand they suppose that they are stationary, together with everything on board. In the same way, the motion of the earth can unquestionably produce the impression that the entire universe is rotating.” Click here to watch the video: