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:
“That’s free enterprise, friends: freedom to gamble, freedom to lose. And the great thing—the truly democratic thing about it—is that you don’t even have to be a player to lose.”
—Barbara Ehrenreich (b. 1941)
“Your mock saint who stands in a niche is not a woman if she have not suffered, still less a woman if she have not sinned. Fall at the feet of your idol as you wish, but drag her down to your level after that—the only level she should ever reach, that of your heart.”
—Emmuska, Baroness Orczy (1865–1947)
“No doubt, the short distance to which you can see in the woods, and the general twilight, would at length react on the inhabitants, and make them savages. The lakes also reveal the mountains, and give ample scope and range to our thought.”
—Henry David Thoreau (1817–1862)
“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)