Notes

　　Universe has always been part of humankind since begin with, and yet, our knowledge about it is limited. We lack absolute answer to wonders before us. Therefore, there are enormous amount of theories were thought and considered to be true.

　　In this case, I will talk about two theories regarding about Greek Astronomy which known as Geocentric and Heliocentric which coming from Ancient Greece. Although, I will be focus to difference between the two.

　　However, before we do so, I will elaborate first about both theories.

1. Geocentric.

　　In astronomy, the geocentric model (also known as geocentrism, or the Ptolemaic system) is a superseded description of the universe with Earth at the centre. Under the geocentric model, the Sun, Moon, stars, and planetsall circled Earth. The geocentric model served as the predominant description of the cosmos in many ancient civilizations, such as those of Aristotle and Ptolemy.

2. Heliocentric.

　　Heliocentric is the astronomical model in which the Earth and planets revolve around the Sun at the center of the Solar System. Historically, Heliocentrism was opposed to geocentrism, which placed the Earth at the center.

　　Based on the clipped elaborations, it’s clear what’s the prominent difference is;

WHILE GEOCENTRIC BELIEVES THAT THE EARTH IS CIRCLING AROUND BY THE SUN, MOON, AND STARS, HELIOCENTRIC IS THE OPPOSITE, IT BELIEVES THAT THE SUN IS THE CENTER AND THE EARTH AND PLANETS REVOLVE AROUND IT.

As we know, Heliocentric was precise and soon is applied. However, the theory was opposed until 16th century that a geometric mathematical model of a heliocentric system was presented, by the Renaissance mathematician, astronomer, and Catholic cleric Nicolaus Copernicus, leading to the Copernican Revolution. In the following century, Johannes Kepler elaborated upon and expanded this model to include elliptical orbits, and Galileo Galilei presented supporting observations made using a telescope.