Ancient Astronomers

  • 500 BCE

    Eratosthenes

    Eratosthenes's most famous accomplishment was his measurement of circumference of the Earth. The original documents to his work are lost, but this is believed to be around 500 B.C. link text
  • 150 BCE

    Claudius Ptolemy

    In 150 CE, Ptolemy wrote his first major work, published as Almagest, containing reports of astronomical observations that he made during the century. Ptolemy believed that subjects could be explained mathematically. link text
  • 1500

    Nicolaus Copernicus

    Nicolaus Copernicus
    In the early 1500s, it was believed that Earth was the center of the universe. Polish scientist Nicolaus Copernicus provided a theory that the planets revolved around the sun, instead.
    [link text' (https://www.space.com/15684-nicolaus-copernicus.html)
  • 1572

    Tycho Brahe

    Tycho Brahe
    In 1572, Brahe observed a supernova. Because it was so bright, it was visible for over a year and a half. Later, in 1577, Brahe observed a comet.
    [link text] )https://www.space.com/19623-tycho-brahe-biography.html)
  • Johannes Kepler

    In 1600, Danish astronomer Tycho Brahe invited Kepler to join his court of discovering a new set of planetary observations. When Brahe suddenly died in 1601, Kepler continued his work. Using Brahe's old data, he came discovered a new law that Mars moved in an elliptical period. link text
  • Sir Isaac Newton

    In 1665, Sir Isaac Newton examined the elements of circular motion. When he applied his analysis to the moon and the planets, it obtained the inverse square relation that the radically directed force acting on a planet decreases with the square of its distance from the sun. This became crucial to the law of universal gravitation.
    link text
  • Albert Einstein

    Albert Einstein was a German scientist physicist that developed the special theories of gravity. He won the Nobel Prize for his physics in 1921. During 1905, Einstein published a paper, applying the quantum theory to light in order to explain the photoelectric effect. link text