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Jan 30, 1000
Abu Rayhan al-Biruni
He developes experimental scienific methods in static and dynamics, for determining specific weights. He also generalizes the theory of the centre of gravity and applies it to three-deminsional bodies. -
Jun 30, 1000
Ibn al-Haytham
He discusses the theory of attraction between masses and states that the heavenly bodies are "accountable to the laws of physics". -
Apr 27, 1121
Al-Khazini
He publishes The Book of the Balance of Wisdom, in which he invents a hydrostatic balance for measuring specific gravity and proposes that the gravity and gravitational potential energy of a body vary depending on its distance from the centre of the Earth. -
Jan 30, 1543
Nicolaus Copernicus
He places the sun at the gravitational center, starting a revolution in science. -
Galileo Galilei
He induces the period relationship of a pendulum from observation. -
Galileo Galilei
He describes a hydrostatic balance for measuring specific gravity. -
Galileo Galilei
He formulates modified Aristotelean theory of motion based on density rather than the weight of objects. -
Galileo Galilei
Galileo Galilei conducts experiments on pendulum motion. -
Galileo Galilei
Galileo Galilei creates a mathematical formula of the law of falling objects based on his earlier experiments. -
Galileo Galilei
Galileo Galilei discovers the parabolic arc of projectiles through experiment. -
Ismael Bullialdus
Ismael Bullialdus suggests an inverse-square gravitational force law. -
Isaac Newton
Isaac Newton introduces an invers-square universal law of gravitation uniting terrestrial and celestial theories of motion and uses it to predict the orbit of the moon and the parabolic arc of projectiles. -
Isaac Newton
Isaac Newton proves that planets moving under an inverse-square force law will obey Kepler's laws. -
Isaac Newton
Isaac Newton uses a fixed length pendulum with weights of varying composition to test the weak equivalence principle to 1 part in 1000. -
Henry Cavendish
Henry Cavendish measures the force of gravity between two masses, leading to the first accurate value for the gravitational constant. -
William Kingdon Clifford
William Kingdon Clifford suggests that the motion of matter may be due to changes in the geometry of space. -
Simon Newcomb
Simon Newcomb observes a 43 arcsecond per century excess precession of Mercury's orbit. -
Henri Poincaré
Henri Poincaré presents the principle of relativity for electromagnetism. -
Albert Einstein
Albert Einstein completes his theory of special relativity and states the law of mass-energy conservation. E=mc^2 -
Albert Einstein
Albert Einstein introduces the principle of equivalence of gravitation and inertia and uses it to predict the gravitational redshift. -
Albert Einstein
Albert Einstein completes his theory of general relativity. The new theory perfectly matches Mercury's strange motions. -
Karl Schwarzschild
Karl Schwarzschild publishes the Schwarzschild metric about a month after Einstein published his general theory of relativity. This was the first solution to the Einstein field equations other than the trivial flat space solution. -
Albert Einstein
Albert Einstein shows that the field equations of general relativity admit wavelike solutions. -
Arthur Eddington
Arthur Eddington leads a solar eclipse expedition which claims to detect gravitational deflection of light by the sun. -
Theodor Kaluza
Theodor Kaluza demonstrates that a five-dimensional version of Einstein's equations unifies gravitation and electromagnetism. -
Fritz Zeicky
Fritz Zeicky states that galaxies could act as gravitational lenses. -
Albert Einstein, Leopold Infeld, and Banesh Hoffmann
Albert Einstein, Leopold Infeld, and Banesh Hoffmann show that the geodesic equations of general relativity can be deduced from its field equations. -
John Wheeler
John Wheeler discusses the breakdown of classical general relativity near singularities and the need for quantum gravity. -
Robert Pound and Glen Rebka
Robert Pound and Glen Rebka test the gravitational redshift predicted by the equivalence principle to approximately 1%. -
Irwin Shapiro
Irwin Shapiro predicts a gravitational time delay of radiation travel as a test of general relativity. -
Muhammad Musa
He hypothesizes that the heavenly bodies and celestial spheres are subject to the same laws of physics as Earth. In his Astral Motion and The Force of Attraction, he proposes that there is a force of attraction between heavenly bodies.