Gravity 032909

Development of Gravitational Theory

  • 200

    Claudius Ptolemy

    Claudius Ptolemy
    Wrote a book: Ptolemy synthesized and extended Hipparchus's system of epicycles and eccentric circles to explain his geocentric theory of the solar system. Ptolemy's system involved at least 80 epicycles to explain the motions of the Sun, the Moon, and the five planets known in his time. He believed the planets and sun to orbit the Earth in the order Mercury, Venus, Sun, Mars, Jupiter, Saturn . This system became known as the Ptolemaic system.
  • 212

    Roman Empire Liberation

    Roman Empire Liberation
    All inhabitants at liberty of the Roman Empire get the civil rights.
  • 300

    Churchbuilding Empires

    Churchbuilding Empires
    Churchbuildingprograms in Rome, Jerusalem and Constantinople.
  • Jan 30, 1099

    First Crusade

    First Crusade
    First Crusade. Jerusalem is re-taken from the Muslims on the urging of Pope Urban II
  • Jul 28, 1121

    Al-Khazini publishes "The Book of the Balance of Widom"

    Al-Khazini publishes "The Book of the Balance of Widom"
    In 1121 Al-Khazini published "The Book of the Balance of Wisdom." In this, Al-Khazini described a hydrostatic balance for measuring gravity and proposed that the gravity acting on an object is dependent on it's distance rom the center of the Earth.
  • Jan 30, 1492

    Christopher Columbus

    Christopher Columbus
    Christopher Columbus sails to find America!
  • Jan 30, 1507

    First Map of America

    First Map of America
    Johannes Ruysch produced the first printed map of America
  • Jan 30, 1514

    Heliocentric Hypothesis

    Heliocentric Hypothesis
    Copernicus introduced his friends to the idea of the sun being in the center of the solar system. His work on Heliocentrism was published in 1542.
  • Jan 30, 1516

    The New Testament Was Published

    The New Testament Was Published
    Erasmus published his version of the New Testament. He began by copying manuscripts found in monasteries and given to him by his friend Thomas More. His Latin translation and commentary and an improved Greek text differed in many places from the Vulgate of St. Jerome, and was immediately recognized as the most accurate translation so far.
  • Galileo Galilei

    Galileo Galilei
    An Italian scientist who formulated the basic law of falling bodies, which he verified by careful measurements. He constructed a telescope with which he studied lunar craters, and discovered four moons revolving around Jupiter and espoused the Copernican cause.
  • Colonizing of Jamestown

    Colonizing of Jamestown
    Jamestown is colonized by English in the Americas (near present-day Virginia).
  • Keplar's 1st & 2nd Laws of Planetary Motion

    Keplar's 1st & 2nd Laws of Planetary Motion
    Johannes Kepler published his first two laws of planetary motion in 1609. The first law stated "The orbit of every planet is an ellipse with the Sun at one of the two foci." The second law stated "A line joining a planet and the Sun sweeps out equal areas during equal intervals of time." Keplar's third law was published at a later date in 1619. The third law stated "The square of the orbital period of a planet is directly proportional to the cube of the semi-major axis of its orbit."
  • King James Bible finished

    King James Bible finished
    King James Bible is finished
  • Issac Newton

    Issac Newton
    Issac Newton published his book Principia which held his classical theory of gravitiational force.
  • US Declares Independence

    US Declares Independence
    US adopts the Declaration of Independence and declares independence against Britain.
  • Wood-block printing in China

    Wood-block printing in China
    Chinese printers adapt Wood-block printing to mass produce classical books.