Progression of Our Understanding of the Universe, by Anastasia Palmer

Ptolemy's Geocentric Universe

140

Ptolemy's theory that all celestial objects (the planets, the Sun, the Moon, the stars, etc.) orbited the Earth, while Earth did not move at all.

Newton's Universal Gravitation Theory

1697

Newton discovers and publishes his three laws of motion, which lead to the knowledge that everything in the universe attracts each other through gravity.

Heinrich Olber Argues for an Finite Universe

1800

Olber argues that, if the universe were infinite, thus containing stars throughout it, then in any direction you looked, "your out-of-line sight" would fall on the surface of a star.

Vesto Slipher Discovers Something About the Light Spectra of Celestial Objects

1912

Slipher discovers that the spectra of light from many of the previously discovered nebulous objects systematically shifted to longer wavelengths, or redshifted. Later, the aforementioned nebulous objects were revealed to be distant galaxies.

Einstein's Relativistic Space Curvature

1915

Predicted that the space-time around Earth would be warped-as well as twisted- by Earth's rotation, and used it to determine that massive objects cause a distortion in space-time, which in turn is felt as gravity.