Democratic principle
Encyclopedia
In the context of General Relativity
, the democratic principle allows quick, order-of-magnitude calculations for the strength of gravitomagnetic effects such as frame-dragging
. While the principle is fairly intuitive, it does not have a rigorous mathematical definition.
John Wheeler (1990) on the practical application of Mach's principle
to experiment (pp.232-233):
According to the general principle of relativity, rotation
is a relative property, and a state of motion that a satellite senses as being "absolutely non-rotating" is a local state, dictated partly by the relative rotation of the background stars, but also partly by the rotation of the body that the satellite orbits. Applying the democratic principle, we can calculate the influence of these two rotations on the satellite by calculating the relative contributions of these two collections of massenergy to the background gravitational field strength at the satellite's location, and then weighting their contributions on the satellite's "sense of rotation" accordingly.
General relativity
General relativity or the general theory of relativity is the geometric theory of gravitation published by Albert Einstein in 1916. It is the current description of gravitation in modern physics...
, the democratic principle allows quick, order-of-magnitude calculations for the strength of gravitomagnetic effects such as frame-dragging
Frame-dragging
Einstein's general theory of relativity predicts that non-static, stationary mass-energy distributions affect spacetime in a peculiar way giving rise to a phenomenon usually known as frame-dragging...
. While the principle is fairly intuitive, it does not have a rigorous mathematical definition.
John Wheeler (1990) on the practical application of Mach's principle
Mach's principle
In theoretical physics, particularly in discussions of gravitation theories, Mach's principle is the name given by Einstein to an imprecise hypothesis often credited to the physicist and philosopher Ernst Mach....
to experiment (pp.232-233):
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- "It is not necessary to enter into the mathematics of the theory to state its simple consequence ... Each mass has an "inertia-contributing" power, a voting power, equal to its mass, there, divided by the distance from there to here. "
According to the general principle of relativity, rotation
Rotation
A rotation is a circular movement of an object around a center of rotation. A three-dimensional object rotates always around an imaginary line called a rotation axis. If the axis is within the body, and passes through its center of mass the body is said to rotate upon itself, or spin. A rotation...
is a relative property, and a state of motion that a satellite senses as being "absolutely non-rotating" is a local state, dictated partly by the relative rotation of the background stars, but also partly by the rotation of the body that the satellite orbits. Applying the democratic principle, we can calculate the influence of these two rotations on the satellite by calculating the relative contributions of these two collections of massenergy to the background gravitational field strength at the satellite's location, and then weighting their contributions on the satellite's "sense of rotation" accordingly.