Ancient Astronomers

Eratosthenes

194 BCE

Eratosthenes is famous for many things, including a mapping method that used latitudes and longitudes, and his accurate computation of the circumference of earth. He worked on the assumption that because the sun was very far from earth, its rays could be considered parallel. This is important because without hm we wouldn't know how far the sun was from Earth.

Claudius Ptolemy

120 BCE

Ptolemy presented the so-called geocentric theory, which stated that the earth was the center of the solar system, and that the other planets and the sun revolved around it. Ptolemy, based on that earth-centered theory, managed to come up with a sophisticated mathematical model that predicted with surprising accuracy the motions and positions of the planets. This is important because back then he gave them an eye opener of the universe and its planet layout.

Nicolaus Copernicus

1520

In the early 1500s, when virtually everyone believed Earth was the center of the universe, Polish scientist Nicolas Copernicus proposed that the planets instead revolved around the sun. Although his model wasn't completely correct, it formed a strong foundation for future scientists to build on and improve mankind's understanding of the motion of heavenly bodies. This is important because now we have a better understanding of the universe so we could judge things better like weather and seasons.

Tycho Brahe

1593

Tycho is not known for discovering anything.
What he is known for is making accurate measurements of the positions of planets. This is considered important because without him people in the 15th and 16th century wouldn't known where all the planets are positioned.

Johannes Kepler

1730

German astronomer who discovered three major laws of planetary motion, conventionally designated as follows: (1) the planets move in elliptical orbits with the Sun at one focus; (2) the time necessary to traverse any arc of a planetary orbit is proportional to the area of the sector between the central body and that arc (the “area law”). This is important because now we know that the planets don't move in an exact circle which explains some of the seasons.

Sir Isaac Newton

1748

Besides his work on universal gravitation (gravity), Newton developed the three laws of motion which form the basic principles of modern physics. His discovery of calculus led the way to more powerful methods of solving mathematical problems. His work in optics included the study of white light and the discovery of the color spectrum. It was his experiments with light that first made him famous.This is important because calculus wouldn't be a thing without him.

Albert Einstein

1921

One of the most famous equations ever written came from Albert Einstein : E = mc 2 . This equation shows that mass can be turned to energy. Because the speed of light square is such a high number even a small amount of mass can be turned into a lot of energy. This is important because there is enough energy in a glass of water to give power to a city like London for a whole week.