When did Albert Einstein publish the Einstein field equations?
Albert Einstein published the Einstein field equations in 1915 as a tensor equation relating the geometry of spacetime to the distribution of matter and energy within it.
Questions about Einstein field equations
Short answers, pulled from the story.
What do the Einstein field equations describe?
The Einstein field equations determine the metric tensor of spacetime for a given arrangement of stress-energy, momentum, and stress. From that metric, the inertial paths of particles and light can then be calculated using the geodesic equation.
How many independent equations are in the Einstein field equations?
Although the Einstein field equations involve ten coupled partial differential equations, the four Bianchi identities reduce the number of truly independent equations to six, leaving four gauge-fixing degrees of freedom that correspond to the freedom to choose a coordinate system.
Why did Einstein add and then abandon the cosmological constant?
Einstein added the cosmological constant to allow for a static, non-expanding universe, but abandoned it after Edwin Hubble's observations showed the universe is expanding. Einstein reportedly called introducing the cosmological constant the biggest blunder of his life, according to physicist George Gamow.
What are the Schwarzschild and Kerr solutions to the Einstein field equations?
The Schwarzschild solution and the Kerr solution are exact vacuum solutions to the Einstein field equations. The Kerr solution describes the spacetime geometry around a rotating black hole.
How do the Einstein field equations relate to Newton's law of gravitation?
The Einstein field equations reduce to Newton's law of gravitation in the limit of a weak gravitational field combined with velocities much less than the speed of light. This correspondence principle fixes the value of the gravitational constant that appears in the equations.