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276 BCE
Eratosthenes
Eratosthenes, (born in 276 BC- died in 196 BC)was a Greek polymath: a mathematician, geographer, poet, astronomer, and music theorist. He is best known for being the first person known to calculate the circumference of the Earth, which he did by using the extensive survey results he could access in his role at the Library; his calculation was remarkably accurate. He was also the first to calculate Earth's axial tilt, which also proved to have remarkable accuracy. -
100 BCE
Claudias Ptolemy
Claudias Ptolemy, (born on 100 CE—died on170 CE), was an Egyptian astronomer, mathematician, and geographer of Greek descent who flourished in Alexandria during the 2nd century CE. In several fields his writings represent the culminating achievement of Greco-Roman science, particularly his geocentric (Earth-centred) model of the universe now known as the Ptolemaic system. -
Feb 19, 1473
Nicolaus Copernicus
Nicolaus Copernicus, (born February 19, 1473, died May 24, 1543), Polish astronomer who proposed that the planets have the Sun as the fixed point to which their motions are to be referred; that Earth is a planet which, besides orbiting the Sun annually, also turns once daily on its own axis; and that very slow long-term changes in the direction of this axis account for the precession of the equinoxes. -
Dec 14, 1546
Tycho Brahe
Tycho Brahe, (born December 14, 1546, Knudstrup, Scania, Denmark—died October 24, 1601, Prague), Danish astronomer whose work in developing astronomical instruments and in measuring and fixing the positions of stars paved the way for future discoveries. His observations were the most accurate possible before the invention of the telescope. Including a comprehensive study of the solar system and accurate positions of more than 777 fixed stars. -
Dec 27, 1571
Johannes Kepler
Johannes Kepler, (born on December 27, 1571-died on November 15, 1630) was a German astronomer, mathematician, and astrologer. He is a key figure in the 17th-century scientific revolution, best known for his laws of planetary motion, and his books Astronomia nova, Harmonices Mundi, and Epitome Astronomiae Copernicanae. -
Sir Isaac Newton
Sir Isaac Newton (born on January 4, 1643- died on March 31,1727) was an English mathematician, physicist, astronomer, theologian, and author who is widely recognised as one of the greatest mathematicians and most influential scientists of all time and as a key figure in the scientific revolution. -
Albert Einstein
Albert Einstein, (born on March 14, 1879, died on April 18, 1955), was a German-born theoretical physicist, widely acknowledged to be one of the greatest physicists of all time. Einstein is known for developing the theory of relativity, but he also made important contributions to the development of the theory of quantum mechanics.