General relativity

This page features an overview of all our Spotlights on Relativity dealing with the basic features of general relativity. The spotlight texts under the heading Fundamentals deal with the equivalence principle, the equal rights of all observers and the question which properties of a body determine its gravitational influence. The section General relativity and light examines gravity's influence on the propagation and properties of light, while Singularities takes a look at some of the theory's more disturbing predictions for the interior of black holes and the beginning of our universe. The mathematics of general relativity is all about the more mathematical aspects of Einstein's theories - from the surprising connection to the theory of soap bubbles to the question of how much variety Einstein's equations admit. The focus of the section Numerical relativity are computer simulations of complex relativistic phenomena, such as merging black holes. Under Miscellaneous, there is a text on the relativistic Nobel prizes.

Many more Spotlights concerned with specific consequences and applications of general relativity can be found on the overview pages Gravitational Waves, Black Holes & Co., Cosmology and Relativity and the Quantum.

Useful background information can be found in our introduction Elementary Einstein, especially in the chapter General Relativity.

Fundamentals

	The elevator, the rocket, and gravity: the equivalence principle Information about the principle that Einstein took as a starting point for developing his general theory of relativity
	Gravity: From weightlessness to curvature So what is gravity in Einstein's theory? The answer: in part, an illusion; in part, an aspect of geometry.
	...that all coordinate systems are created equal Why, in general relativity, all observers are on an equal footing - and why, nevertheless, you can say that the earth orbits the sun, but not the other way around
	Mass and more An account of which physical properties act as sources of gravity - includes consequences for collapsing stars and for cosmology
	The gravity of gravity An important property of gravity in Einstein's theory is that it can create more gravity. The result is "non-linearity" - the gravitational influence of two bodies isn't just the sum of their separate influences!

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Light in general relativity

	Gravitational deflection of light On one of the fundamental consequences of general relativity: the deflection of light by gravity.
	The equivalence principle and the deflection of light The connection between one of the fundamental principles of general relativity and the gravitational deflection of light
	A brief history of gravitational lensing Historical sketch of the derivation of general relativity's prediction of gravitational lenses and subsequent astronomical observations
	Gravitational redshift and White Dwarf stars One of the fundamental effects predicted by general relativity, and some of its astronomical applications

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Singularities

	Spacetime singularities Information about the most disturbing feature of Einstein's theory - ragged edges of spacetime known as singularities.
	Of singularities and breadmaking About some characteristic properties of spacetime near singularities - and the violent deformations they cause for any object unlucky enough to approach a singularity

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The mathematics behind general relativity

	The many ways of building an empty, unchanging universe More information on one particular answer to the question of how much variety is permitted in general relativity - how many ways are there of constructing a universe that is completely empty of all matter?
	Einstein and soap bubbles The surprising mathematical connection between space-time geometry and soap bubbles

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Numerical relativity

	The realm of relativistic hydrodynamics    Modeling relativistic fluids and the phenomena associated with them - from supernovae and jets to merging neutron stars

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Miscellaneous

	Einstein's Noble Heritage (also in Special relativity) Overview of the Nobel prizes connected with relativity

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