Free Fall in General Relativity
In GR, an object in free fall is subject to no force and is an inertial body moving along a geodesic. Far away from any sources of space time curvature, where spacetime is flat, Newtonian theory of free fall agrees with GR but otherwise the two disagree. The experimental observation that all objects in free fall accelerate at the same rate, as noted by Galileo and then ambodied in Newton's theory as the equality of gravitational and inertial masses, and later confirmed to high accuracy by modern forms of the Eötvös experiment, is the basis of the Equivalence Principle, from which basis Einstein's theory of general relativity initially took off.
Read more about this topic: Free Fall
Famous quotes containing the words free, fall, general and/or relativity:
“Her voluntary fruits, free without fees;”
—Torquato Tasso (1544–1595)
“There are women in middle life, whose days are crowded with practical duties, physical strain, and moral responsibility ... they fail to see that some use of the mind, in solid reading or in study, would refresh them by its contrast with carking cares, and would prepare interest and pleasure for their later years. Such women often sink into depression, as their cares fall away from them, and many even become insane. They are mentally starved to death.”
—Ellen Henrietta Swallow Richards (1842–1911)
“Pleasure is necessarily reciprocal; no one feels it who does not at the same time give it. To be pleased, one must please. What pleases you in others, will in general please them in you.”
—Philip Dormer Stanhope, 4th Earl Chesterfield (1694–1773)
“By an application of the theory of relativity to the taste of readers, to-day in Germany I am called a German man of science, and in England I am represented as a Swiss Jew. If I come to be regarded as a bête noire the descriptions will be reversed, and I shall become a Swiss Jew for the Germans and a German man of science for the English!”
—Albert Einstein (1879–1955)