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Eratosthenes was a Greek astronomer and mathematician. He was born in 276 BC and died in 194 BC. He made the first measurement of the size of the Earth by figuring out its circumference. He invented longitude and latitude and made a map of the known world. He is known as the father of Modern Geography.
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Claudius Ptolemy was an astronomer, mathematician, and astrologer. He lived from approximately 100 to 170. He came up with the notion of geocentricity, which says that the Earth is the center of the universe and all the planets and stars revolve around it. He also recorded longitude and latitude for approximately 8000 locations on a map of the world at that time. His ideas helped form our understanding of the stars and planets.
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Copernicus was a Polish mathematician and astronomer. He was born in February 1473 and died in May 1543. In 1497 he observed a lunar eclipse. He also thought that the sun was stationary and all the planets revolved around the sun and that the Earth did this once per year. Around 1514, He also estimated the amount of time it takes Mercury, Venus, Mars, and Jupiter to revolve around the sun. He theorized that the Earth tilts on its axis and accounts for the equinoxes.
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Johannes Kepler was a German astronomer. He was born in December 1571 and Died in November 1630. In 1596, He discovered the three laws of planetary motion, which include that the planets have an elliptical orbit around the sun, a line between a planet and the sun covers equal areas in equal time and the time it takes for a planet to go around the sun is related to the planet’s orbit.
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Brahe was a Danish astronomer who developed astronomical instruments and measured the stars. He lived from Dec 1546 to Oct 1601. From 1572 to 1588, he discovered many different things. He found a supernova in 1572, then in 1577, he observed a comet. He also had an observatory built in Denmark that finished in 1580 that had the ability to measure the altitude of the stars. His celestial predictions were much more accurate than any other astronomer.
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Sir Isaac Newton was an English mathematician, astronomer, and physicist. He lived from December 1642 to March 1726. His major contribution to science was in 1655 when he saw an apple fall from a tree and came up with the three laws of motion and gravity. He also invented calculus. He also invented reflective lenses for the telescope.
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Einstein was a German theoretical physicist. He was born in March 1879 and died in April 1955. In 1905, he published the theory of relativity. He also helped develop the theory of quantum mechanics. His theories helped us to understand how space, time, gravity, and the universe work together. In 1905, he discovered the law of the photoelectric effect, which states that if metals are exposed to lights then electrical sparks occur. These light waves have a frequency and have electrons.