Theory of relativity
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Two-dimensional analogy of space-time distortion. Described in General Relativity |
The
theory of relativity, or simply
relativity, refers specifically to two theories:
Albert Einstein's
special relativity and
general relativity.
The term "relativity" was coined by
Max Planck in
1908 to emphasize how special relativity (and later, general relativity) uses the
principle of relativity.
Albert Einstein's
1905 paper "
On the Electrodynamics of Moving Bodies" introduced the
special theory of relativity. Special relativity considers that observers in
inertial reference frames, which are in uniform motion relative to one another, cannot perform any experiment to determine which one of them is "stationary". This is actually
Galileo's
principle of relativity; Einstein's contribution was to explicitly include
electromagnetism within this principle, which required that the
Galilean transformations be replaced by the
Lorentz transformations. The resultant theory has many surprising consequences. In particular, it requires that the
speed of light in a
vacuum be the same for all these observers, regardless of their motion, or the motion of the source of the
light, since the invariance of the speed of light is a consequence of
Maxwell's equations of
electromagnetism.
General relativity was developed by Einstein in the years
1907 -
1915. General relativity replaces the
global Lorentz symmetry of special relativity with a
local Lorentz symmetry in the presence of matter. The presence of
matter "curves"
spacetime, and this
curvature affects the path of free particles (and even the path of light). General relativity uses the mathematics of
differential geometry and
tensors in order to describe
gravitation as an effect of the
geometry of
spacetime. This theory is based on the general principle of relativity, which requires all observers to experience the same laws of physics, not just those moving with uniform speed, hence its name.
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List of publications in physics: Theory of relativity*
Special relativity including
Introduction to special relativity*
General relativity including
Introduction to general relativity*
Galilean relativitySee the
special relativity references and the
general relativity references.
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Living Reviews in Relativity — An open access, peer-referred, solely online physics journal publishing invited reviews covering all areas of relativity research.
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Reflections on Relativity — A complete online course on Relativity.
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Relativity explained in words of four letters or less*
Briefing on Einstein's Theory of Relativity — A terse dose of insight on the subject.
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On the Electrodynamics of Moving Bodies*
Special Relativity Simulator*
A Relativity Tutorial at Caltech — A basic introduction to concepts of Special and General Relativity, as well as astrophysics.
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Relativity Gravity and Cosmology — A short course offered at MIT.
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Relativity in film clips and animations from the University of New South Wales.
