12th Century
- 1121 – Al-Khazini: variation of gravitation and gravitational potential energy at a distance; the decrease of air density with altitude
- Ibn Bajjah (Avempace): discovery of reaction (precursor to Newton's third law of motion)
- Hibat Allah Abu'l-Barakat al-Baghdaadi (Nathanel): relationship between force and acceleration (a vague foreshadowing of a fundamental law of classical mechanics and a precursor to Newton's second law of motion)
- Averroes: relationship between force, work and kinetic energy
Read more about this topic: Timeline Of Scientific Discoveries
Famous quotes containing the word century:
“Last night I watched my brothers play,
The gentle and the reckless one,
In a field two yards away.
For half a century they were gone
Beyond the other side of care
To be among the peaceful dead.”
—Edwin Muir (1887–1959)