Two-dimensional projection of a three-dimensional analogy of space-time curvature described in General Relativity. In mathematics the dimension of a Space is roughly defined as the minimum number of Coordinates needed to specify every point within it Three-dimensional space is a geometric model of the physical Universe in which we live

The theory of relativity , or simply relativity, refers specifically to two theories of Albert Einstein: special relativity and general relativity. Albert Einstein ( German: ˈalbɐt ˈaɪ̯nʃtaɪ̯n; English: ˈælbɝt ˈaɪnstaɪn (14 March 1879 – 18 April 1955 was a German -born theoretical Special relativity (SR (also known as the special theory of relativity or STR) is the Physical theory of Measurement in Inertial General relativity or the general theory of relativity is the geometric theory of Gravitation published by Albert Einstein in 1916 However, "relativity" can also refer to Galilean relativity. Galilean invariance or Galilean relativity is a Principle of relativity which states that the fundamental laws of physics are the same in all Inertial

The term "theory of relativity" was coined by Max Planck in 1908 to emphasize how special relativity (and later, general relativity) uses the principle of relativity. A principle of relativity is a criterion for judging physical theories, stating that they are inadequate if they do not prescribe the exact same laws of physics in

Special relativity

Main article: Special relativity

Special relativity is a theory of the structure of spacetime. Special relativity (SR (also known as the special theory of relativity or STR) is the Physical theory of Measurement in Inertial SpaceTime is a patent-pending three dimensional graphical user interface that allows end users to search their content such as Google Google Images Yahoo! YouTube eBay Amazon and RSS It was introduced in Albert Einstein's 1905 paper "On the Electrodynamics of Moving Bodies". Albert Einstein ( German: ˈalbɐt ˈaɪ̯nʃtaɪ̯n; English: ˈælbɝt ˈaɪnstaɪn (14 March 1879 – 18 April 1955 was a German -born theoretical The Annus Mirabilis Papers (from Latin, Annus mirabilis, for 'extraordinary year' are the papers of Albert Einstein published in the " Special relativity is based on two postulates which are contradictory in classical mechanics:

1. The laws of physics are the same for all observers in uniform motion relative to one another (Galileo's principle of relativity),
2. The speed of light in a vacuum is the same for all observers, regardless of their relative motion or of the motion of the source of the light. Classical mechanics is used for describing the motion of Macroscopic objects from Projectiles to parts of Machinery, as well as Astronomical objects In Physics, an inertial frame of reference is a Frame of reference which belongs to a set of frames in which Physical laws hold in the same and simplest Galileo Galilei (15 February 1564 &ndash 8 January 1642 was a Tuscan ( Italian) Physicist, Mathematician, Astronomer, and Philosopher A principle of relativity is a criterion for judging physical theories, stating that they are inadequate if they do not prescribe the exact same laws of physics in This vacuum means "absence of matter" or "an empty area or space" for the cleaning appliance see Vacuum cleaner. Light, or visible light, is Electromagnetic radiation of a Wavelength that is visible to the Human eye (about 400–700

The resultant theory has many surprising consequences. Some of these are:

• Time dilation: Moving clocks are measured to tick more slowly than an observer's "stationary" clock. This article discusses a concept in physics For the concept in sociology see Time displacement. Circadian Locomotor Output Cycles Kaput, or Clock is a gene which encodes proteins regulating Circadian rhythm.
• Length contraction: Objects are measured to be shortened in the direction that they are moving with respect to the observer. Length contraction, according to Hendrik Lorentz, is the physical phenomenon of a decrease in Length detected by an observer in objects that travel at any non-zero
• Relativity of simultaneity: two events that appear simultaneous to an observer A will not be simultaneous to an observer B if B is moving with respect to A. The relativity of simultaneity is the concept that simultaneity is not absolute but dependent on the observer
• Mass-energy equivalence: E = mc², energy and mass are equivalent and transmutable. In Physics, mass–energy equivalence is the concept that for particles slower than light any Mass has an associated Energy and vice versa.

The defining feature of special relativity is the replacement of the Galilean transformations of classical mechanics by the Lorentz transformations. The Galilean transformation is used to transform between the coordinates of two Reference frames which differ only by constant relative motion within the constructs of Newtonian In Physics, the Lorentz transformation converts between two different observers' measurements of space and time where one observer is in constant motion with respect to (See Maxwell's equations of electromagnetism and introduction to special relativity). In Classical electromagnetism, Maxwell's equations are a set of four Partial differential equations that describe the properties of the electric Electromagnetism is the Physics of the Electromagnetic field: a field which exerts a Force on particles that possess the property of In Physics, special relativity is a fundamental Theory about Space and Time, developed by Albert Einstein in 1905 as a modification

General relativity

Main article: General relativity

General relativity is a theory of gravitation developed by Einstein in the years 1907–1915. General relativity or the general theory of relativity is the geometric theory of Gravitation published by Albert Einstein in 1916 The development of general relativity began with the equivalence principle, under which the states of accelerated motion and being at rest in a gravitational field (for example when standing on the surface of the Earth) are physically identical. The equivalence principle Gravitation is a natural Phenomenon by which objects with Mass attract one another The upshot of this is that free fall is inertial motion: In other words an object in free fall is falling because that is how objects move when there is no force being exerted on them, instead of this being due to the force of gravity as is the case in classical mechanics. Free fall is motion with no Acceleration other than that provided by Gravity. The vis insita or innate force of matter is a power of resisting by which every body as much as in it lies endeavors to preserve in its present state whether it be of rest or of moving In Physics, a force is whatever can cause an object with Mass to Accelerate. Gravitation is a natural Phenomenon by which objects with Mass attract one another Classical mechanics is used for describing the motion of Macroscopic objects from Projectiles to parts of Machinery, as well as Astronomical objects This is incompatible with classical mechanics and special relativity because in those theories inertially moving objects cannot accelerate with respect to each other, but objects in free fall do so. Special relativity (SR (also known as the special theory of relativity or STR) is the Physical theory of Measurement in Inertial To resolve this difficulty Einstein first proposed that spacetime is curved. In Mathematics, curvature refers to any of a number of loosely related concepts in different areas of geometry In 1915, he devised the Einstein field equations which relate the curvature of spacetime with the mass, energy, and momentum within it. The Einstein field equations ( EFE) or Einstein's equations are a set of ten equations in Einstein 's theory of General relativity in which the

Some of the consequences of general relativity are:

• Time goes more slowly at lower gravitational potentials. This is called gravitational time dilation. Gravitational time dilation is the effect of time passing at different rates in regions of different Gravitational potential; the higher the local distortion of Spacetime
• Orbits precess in a way unexpected in Newton's theory of gravity. Precession refers to a change in the direction of the axis of a rotating object (This has been observed in the orbit of Mercury and in binary pulsars). A binary pulsar is a Pulsar with a binary companion, often another Pulsar, White dwarf or Neutron star.
• Even rays of light (which are almost weightless) bend in the presence of a gravitational field. Light, or visible light, is Electromagnetic radiation of a Wavelength that is visible to the Human eye (about 400–700 General relativity or the general theory of relativity is the geometric theory of Gravitation published by Albert Einstein in 1916
• The Universe is expanding, and the far parts of it are moving away from us faster than the speed of light. The metric expansion of space is the averaged increase of metric (i This does not contradict the theory of special relativity, since it is space itself that is expanding.
• Frame-dragging, in which a rotating mass "drags along" the space time around it. Albert Einstein 's theory of General relativity predicts that rotating bodies drag Spacetime around themselves in a phenomenon referred to as frame-dragging

Technically, general relativity is a metric theory of gravitation whose defining feature is its use of the Einstein field equations. In Mathematics, a metric or distance function is a function which defines a Distance between elements of a set. Gravitation is a natural Phenomenon by which objects with Mass attract one another The solutions of the field equations are metric tensors which define the topology of the spacetime and how objects move inertially. This article discusses metrics in General relativity, for a discussion of metrics in general see Metric tensor. Topology ( Greek topos, "place" and logos, "study" is the branch of Mathematics that studies the properties of

References and links

See the special relativity references and the general relativity references. Special relativity (SR (also known as the special theory of relativity or STR) is the Physical theory of Measurement in Inertial General relativity or the general theory of relativity is the geometric theory of Gravitation published by Albert Einstein in 1916 For information on the silent film produced on this subject, see The Einstein Theory of Relativity. The Einstein Theory of Relativity is a Silent film released in 1923 by Fleischer Studios.

External links

• Relativity: The Special and General Theory by Publicliterature.org
• Yale University Video Lecture: Special and General Relativity at Google Video
• Wikibooks: Special Relativity
• Relativity Animations
• Relativity tutorial
• Living Reviews in Relativity — An open access, peer-referred, solely online physics journal publishing invited reviews covering all areas of relativity research.
• MathPages - Reflections on Relativity — A complete online course on Relativity.
• Relativity explained in one-syllable words
• Relativity explained in words of four letters or less
• 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.
• Relativity Gravity and Cosmology — A short course offered at MIT.
• Relativity in film clips and animations from the University of New South Wales.
• Animation easy to understand Animation for Pirelli Ralativity Award.
• What is the experimental basis of Special Relativity?
• Animation clip visualizing the effects of special relativity on fast moving objects.
• Relativity Calculator - Learn Special Relativity Mathematics The mathematics of special relativity presented in as simple and comprehensive manner possible within philosophical and historical contexts.