The three principal experimental tests of general relativity are the perihelion shift of the planet Mercury's orbit, the bending of starlight by a massive object and the existence of gravitational waves. These tests will be described below. Atmospheric characteristics Atmospheric pressure trace Potassium 31. ... In physics, gravitational radiation is energy that is transmitted through waves in the gravitational field of space-time, according to Albert Einsteins theory of general relativity: The Einstein field equations imply that any accelerated mass radiates energy this way, in the same way as the Maxwell equations that any...

Perihelion shift of Mercury

Although planets move around the Sun in ellipses with the Sun at a focus, the ellipse actually changes its orientation, i.e., the orbit precesses. For the case of Mercury, this precession is approximately 570 seconds of arc per century. Newton's theory can account for most of this precession by taking into account the perturbations of the orbit due to the presence of other planets. The remaining precession of 43 arcseconds per century cannot be accounted for by Newtonian gravitation, but general relativity can account for it exactly (within experimental error). The assumption of curvature created by the Sun causes a greater precession than without this assumption. This article covers the physics of gravitation. ... Two-dimensional visualisation of space-time distortion. ...

Bending of starlight

When light passes by a massive object, the path of light will appear to be curved as a consequence of the curvature created by the object (see the image on the right). The image shows that starlight appears to bend around a massive object, the apparent location of the star appearing to be on the right, but the actual location is on the left. On May 29, 1919, observations by Arthur Eddington of shifted star positions during a solar eclipse lent strong support to this prediction. Newton's theory of gravitation also predicts that starlight will bend around a massive object, but the predicted effect is only half the value predicted by general relativity (which gives a bending effect much closer to the observed value). The bending of starlight is important in modern astronomy, one of the important phenomena in this field being gravitational lensing where a massive object (usually a galaxy) distorts the light emitted from a distant object, so that the observer sees distorted images of the distant object. In some cases, the distant object appears to be a ring (Einstein ring). May 29 is the 149th day of the year in the Gregorian calendar (150th in leap years). ... 1919 was a common year starting on Wednesday (see link for calendar). ... One of Sir Arthur Stanley Eddingtons papers announced Einsteins theory of general relativity to the English-speaking world. ... For Solar Eclipse, the alien friend of the rubber doll Betty Spaghetty, see Betty Spaghetty Photo taken by John Walker during the Zambia 2001 eclipse A solar eclipse occurs when the Sun, Moon and Earth are on a single line with the Moon in the middle. ... A gravitational lens is formed when the light from a very distant, bright source (such as a quasar) is bent around a massive object (such as a massive galaxy) between the source object and the observer. ... A beautiful example of an Einstein ring is the radio source B1938+666 discovered with the UK radiotelecope MERLIN. The optical image shown here, taken with the Hubble Space Telescope, shows the Einstein ring most prominently. ...

Existence of gravitational waves

If the Sun blinked into nothingness, the planets orbiting it would not begin linear (as opposed to elliptical) motion instantaneously. The Sun's absence would cause a "gravitational wave" in space that would start the planets on their linear paths as it reached each one. These gravitational waves are predicted to travel at the speed of light. Thus, in a sense, the planets would not immediately 'know' that the Sun had disappeared, but would 'know' this only after a certain time delay. Gravitational waves may also be generated by other means. In physics, gravitational radiation is energy that is transmitted through waves in the gravitational field of space-time, according to Albert Einsteins theory of general relativity: The Einstein field equations imply that any accelerated mass radiates energy this way, in the same way as the Maxwell equations that any... Cherenkov effect in a swimming pool nuclear reactor. ...

References

• http://pancake.uchicago.edu/~carroll/grbook/

See Also

the USENET Relativity FAQ experiments page (http://www2.corepower.com:8080/~relfaq/experiments.html)