![gravity curved space geometry einstein general relativity gravity curved space geometry einstein general relativity](http://2.bp.blogspot.com/-D2Z6z3UOzkU/Txo12ujE8oI/AAAAAAAAAy4/PFipm4STD1o/s1600/lightbending.jpg)
The existence of black holes is one of the major predictions of general relativity.
![gravity curved space geometry einstein general relativity gravity curved space geometry einstein general relativity](https://i.pinimg.com/originals/83/d6/1e/83d61e06986a16949770f5bacdfc182a.jpg)
The size of this error is significant enough to give incorrect GPS predictions within hours of a satellite launch. GPS "triangulation" actually requires four satellites: three to identify the position and a fourth to calibrate for the error in timing incurred by gravitational time dilation. Gravitational time dilation turns out to affect the times measured by GPS satellites to non-negligible extents. The physical consequences of general relativity are in fact quite applicable to everyday life. The atomic clocks onboard the planes were compared to atomic clocks on the ground and the airborne clocks were found to have experienced a slightly slower passage of time precisely in agreement with gravitational time dilation predicted by general relativity. In the modern era of physics, countless other experimental tests of general relativity have been performed, with the theory agreeing spectacularly with experiment.Įinstein's original prediction of gravitational redshift was the last to be confirmed-not until the famous Pound-Rebka experiment in 1959, where the redshifting of gamma rays was measured in a laboratory at Harvard University.Īnother well-known later experiment was the Hafele-Keating experiment in 1971, where two American physicists flew with several atomic clocks in commercial airliners around the world twice. Similar early evidence also came from astronomy: it had been known since the mid-nineteenth century that the axis of Mercury's orbit rotated by a small angle each revolution, the so-called "perihelion precession." Einstein's computation of this rotation in general relativity matched the anomalous angle spectacularly. In terms of experimental verification, the British astronomer Sir Arthur Eddington led an astronomical expedition that confirmed the gravitational deflection of light by the sun in 1919. In later years, Einstein famously spoke of regretting this error. Convinced the universe was static, Einstein did not accept these solutions, adding a cosmological constant term to his equations to ensure that the universe had to be static. Several years later, the Russian physicist Alexander Friedmann and others found solutions that admitted an expanding or contracting universe, leading to modern cosmology and the Big Bang. The first was the gravitational redshift the other two were the deflection of light due to the gravity of large masses and the perihelion precession of mercury.Īt around the same time, the German physicist Karl Schwarzschild discovered his black hole solution to Einstein's equations, the Schwarzchild metric. Shortly after, in 1916, Einstein proposed three concrete experimental tests of the extensive geometric theory that he had developed over about a decade. The equivalence of inertial and gravitational mass led to one of Einstein's first predictions as a result of general relativity: the gravitational redshift of light, in which light loses energy as it climbs out of a gravitational field. This theory was what would eventually become general relativity. In the next decades, Einstein worked with several mathematicians of the era, particularly David Hilbert, in developing a geometric theory of gravity. In this picture, Einstein reimagined gravity as indistinguishable from accelerated frames, and used these ideas to recast gravity as objects accelerating through curved geometries. Einstein's equivalence principle is a statement of equivalence of the inertial and gravitational masses: the mass due to the acceleration of a frame is the same as the mass due to gravity.
![gravity curved space geometry einstein general relativity gravity curved space geometry einstein general relativity](https://i.pinimg.com/originals/fa/b7/34/fab734854d76f160a38d1b6ff341bc3c.jpg)
" ``\textrm F g = r 2 G M m , called the gravitational mass. ‘ ‘ Spacetime tells matter how to move matter tells spacetime how to curve. The amount that spacetime curves depends on the matter and energy present in the spacetime, as summarized by a famous quote by the physicist John Archibald Wheeler: In general relativity, objects moving under gravitational attraction are merely flowing along the "paths of least resistance" in a curved, non-Euclidean space. General relativity is Einstein's theory of gravity, in which gravitational forces are presented as a consequence of the curvature of spacetime.