| A | B |
|---|
| Tycho Brahe | Believed data supported an earth-centered universe. |
| Johannes Kepler | Used Brahe's data to prove a sun-centered universe. Developed three laws of planetary motion. |
| Galileo Galilei | Discovered gravity affects all objects equally. |
| Sir Isaac Newton | Discovered law of universal gravitation (inverse square law). |
| Albert Einstein | Predicted black holes. |
| Henry Cavendish | Used torsional balance to determine the universal gravitational constant (G). |
| Michael Faraday | Discovered electrical FIELDS which was then applied to gravitational FIELDS. |
| Kepler's First Law | Planets travel in elliptical paths. |
| Kepler's Second Law | Planets sweep equal areas in equal time intervals. |
| Kepler's Third Law | The ratio of the square of the periods equals the ratio of the cubes of the average orbital radii. |
