Ancient Astronomers

By rbeaumont
  • 240 BCE

    Eratosthenes

    Eratosthenes
    He was the first person to accurately estimate the size of the Earth.his was a moment of triumph for the human intellect: first to recognize our planet is a sphere, then to use the powers of observation, deduction, and mathematics to calculate its size.https://www.famousscientists.org/eratosthenes/
  • 170 BCE

    Claudius Ptolemy

    Claudius Ptolemy
    Greek mathematician, astronomer and geographer. Much of medieval astronomy and geography were built on his ideas: his world map, published as part of his treatise Geography in the 2nd century, was the first to use longitudinal and latitudinal lines. This was important because we use this information in every physical study of planet and in our communities. https://www.geographyrealm.com/ptolemys-geographia/
  • Jan 1, 1514

    Nicolaus Copernicus

    Nicolaus Copernicus
    He rediscovered the heliocentric model of the solar system in the middle ages. This was so important for additional advancement of studies that came after this discovery.Nicolaus Copernicus wrote a short astronomical treatise commonly called the Commentariolus, or “Little Commentary,” which laid the basis for his heliocentric (sun-centered) system. The work was not published in his lifetime. https://www.history.com/topics/inventions/nicolaus-copernicus#section_2
  • Jan 1, 1577

    Tycho Brahe

    Tycho Brahe
    "He was able to measure angles and hence positions of stars to an accuracy approaching 1 arcmin, equivalent to 1/30 the diameter of the full moon. This was important to help measure the stars accurately. "https://www.britannica.com/biography/Tycho-Brahe-Danish-astronomer

  • Johannes Kepler

    Johannes Kepler
    There are actually three, Kepler's laws that is, of planetary motion: 1) every planet's orbit is an ellipse with the Sun at a focus; 2) a line joining the Sun and a planet sweeps out equal areas in equal times; and 3) the square of a planet's orbital period is proportional to the cube of the semi-major axis. This is important because he brought evidence into orbiting that we know. https://www.universetoday.com/55423/keplers-law/

  • Sir Isaac Newton

    Sir Isaac Newton
    In 1686, he presented his three laws of motion in the “Principia Mathematica Philosophiae Naturalis.” He discovered the 3 laws of motion, the theory of gravity. It's important because it describes the physical relations between the forces acting on a body and the motion of the body.
    https://sciencing.com/did-newton-discover-laws-motion-5349637.html

  • Albert Einstein

    Albert Einstein
    He developed the theories of relativity that explain the evolution of the expanding universe. This was so important to the future studies in this field. This opened the window dramatically for physics.https://www.nature.com/