5.8 ancient astronomers

  • 240 BCE

    Eratosthenes

    DOB 276 BC
    Was thought to have been the first to use the word geography. He invented a system of longitude and latitude and made a map of the known world. He also designed a system for finding prime numbers in 240 BC. The importance of his discoveries was very big, creating the best world map as well as inventing very important mathematical advancements.
  • 150

    Claudius Ptolemy

    DOB 100 AD
    Ptolemy synthesized Greek knowledge of the known Universe. Ptolemy's most famous work is a textbook and star catalog named Almagest. Almagest was published around 150 ce. But it was printed in 1528. Ptolemy’s work was important because His work enabled astronomers to make accurate predictions of planetary positions and solar and lunar eclipses, promoting acceptance of his view of the cosmos in the Byzantine and Islamic worlds and throughout Europe for more than 1400 years.
  • 1532

    Nicolaus Copernicus

    DOB 02/19/1473
    Nicolaus Copernicus was a Polish astronomer and mathematician known as the father of modern astronomy. He was the first to propose that the earth and the other planets revolve around the sun, the heliocentric theory of the solar system. Finished his first manuscript in 1532. The importance of this was that it dramatically altered the scientific perspective of how we view our world.
  • 1572

    Tycho Brahe

    DOB 12/14/1546
    Tycho discovered the geo-heliocentric model, the supernova, and the greater altitude of stars observed near the horizon due to refraction of light. When he discovered the supernova in 1572 he challenged the widely accepted and ancient theory that stars were unchanging. Tycho Brahe made accurate observations of the stars and planets. His study of the “new star” that appeared in 1572 showed that it was farther away than the Moon and was among the fixed stars.
  • Johannes Kepler

    He impacted today's world by making the Kepler's Laws. They describe how (1) planets move in elliptical orbits with the Sun as a focus, (2) a planet covers the same area of space in the same amount of time no matter where it is in its orbit, and (3) a planet's orbital period is proportional to the size of its orbit (its semi-major axis). Publishing was around 1609-1619.
  • Sir Isaac Newton

    DOB 01/04/1643
    Newton made the first reflecting telescope. Newton also proposed that every object in the universe pulled onto each other because of gravity. Therefore the reason why planets move in orbit and why objects fall to the earth. Newton formulated the gravitational theory in 1665 or 1666. The significance of Newton and his discoveries is that scientists now still use his work, as he was almost accurate on everything he believed in.
  • Albert Einstein

    Essentially Einstein thought space and time were intertwined in an infinite “fabric”, like an outstretched blanket. Einstein came up with the general relativity theory. With relativity, cosmology and astrophysics predicted extraordinary astronomical phenomena such as neutron stars, black holes, and gravitational waves. The development was around 1905-1915