science timeline - Timeline

Aristotle describes the geocentric (Earth-centered) model of the universe

Aristarchus proposes a heliocentric (Sun-centered model of the universe that is widely ignored

Ptolemy refines the geocentric model of the universe to try to explain the retrograde (east to west) motion of the planets.

Ferdinand Magellan is the first European to observe the Magellanic Clouds, which are later recognised as galaxies outside the milky way

Nicholas Copernicus publishes a paper that presents the heliocentric model with a number of improvements on aristarchus' version.

Giordano Bruno is burnt at the stake. One of his 'crimes' is promoting the heliosentric model of the universe.

Kepler publishes Astronomia Nova, explaining the motion of the planets by using a heliocentric model of the universe and elliptical (oval-shaped) orbits.

Galileo Galilei observes the moons of Jupiter.

Galileo publishes his Dialogue on Two World Systems, which argues in favour of the heliocentric model of the universel

Isaac Newton publishes Principia Mathematica in which, among other things, he explains the law of the universal gravitation (gravity).

Thomas Wright suggests that the Milky Way galaxy is a flattened disk of stars and that the nebulae might be other galaxies

William Herschel discovers Uranus

William Herschel constructs the first map of the milky way

Friedich Bassel Observes stellar parallax - the apparent movement of the stars due to the Earth;s movement around the sun

John Couch Adams Discovers Neptune