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Period: 240 BCE to 250 BCE
Eratosthenes (276bce – 194bce)- Earth's circumference
Eratosthenes is known for his measurement of the Earth's circumference, which he calculated using the angle of the sun's rays at two different locations. By measuring the angle of the sun's rays at noon on the summer solstice in Syene (now Aswan, Egypt) and Alexandria, and knowing the distance between the two cities, he was able to calculate the Earth's circumference with remarkable accuracy. -
Period: 100 BCE to 170 BCE
Claudius Ptolemy (100 ce- 170 ce)- Geocentric Model of the Universe
Ptolemy's work on the geocentric model helped to establish the foundations of modern astronomy, and it was an important step in the development of our understanding of the universe. -
1543
Nicolaus Copernicus (1473- 1543)- Heliocentric Model
Nicolaus Copernicus made one of the most important discoveries in history, the heliocentric model of the solar system. This model proposed that the sun was at the center of the solar system, with the planets orbiting around it. -
1572
Tycho Brahe (1546- 1601)- The Supernova
Brache discovered of a new star, the observation of a supernova, and the creation of a catalog of more than 1,000 stars. -
Period: to
Johannes Kepler (1571- 1630)- Three Laws of Planetary Motion
Kepler is best known for his three laws of planetary motion. Kepler's laws describe the motion of planets around the sun, and they helped to establish the heliocentric model of the solar system. His laws are still used today to describe the orbits of planets and other celestial objects. -
Period: to
Sir Isaac Newton (December 1642 - March 1727)- Laws of Motion and Universal Gravitation
Sir Isaac Newton discovered the laws of motion and universal gravitation. Newton's laws describe the motion of objects in the universe. His law of universal gravitation explains how all objects in the universe are attracted to each other, and it helped to explain the motion of planets and other celestial objects. -
Period: to
Albert Einstein (1879-1955)- Theoretical Physics
Einstein's theory of relativity, changed our understanding of space and time. The theory helps to explain the behavior of objects in space and the nature of the universe as a whole.