what is the theory of relativity?

Answer 1

Here's some basic background covering how mathematical models of space and time have evolved since ancient times, from the Pythagorean Rule to Newtonian mechanics, Special Relativity and General Relativity.
http://www.theory.caltech.edu/people/patricia/st101.html

Einstein and Special Relativity give us a mathematical model for spacetime that reflects the observed behavior of Nature in that nothing can go faster than the speed of light. (At least not anything observed in a laboratory or in outer space as of yet.)

In Einstein's time they were already learning about differential geometry, but Einstein motivated this field of mathematics even more when he came up with an equation relating the curvature tensor of the spacetime distance function to the distribution of matter and energy in spacetime, encoded in a tensor Tuv called the stress-energy tensor.
This equation is now called the Einstein equation:
Ruv - (1/2) guv R = (8 Pi G/c4) Tuv
This equation (or actually, set of equations, for there is an equation for every combination of tensor indices u and v) models a lot of phenomena in the Universe that was impossible to describe with mathematics just using Newton's law of gravity. For example, observations of the bending of light by gravity, gravitational radiation emitted by pulsars, new observations of black holes and the observed expansion of the visible Universe can all be modelled rather successfully using this elegant formalism uncovered by Einstein.

Answer 2

The theory of relativity is simply the observation that all motion of bodies can only be described relative to the motion of other bodies. It was originally developed by Galileo and is implicit in Newtons theories of motion.

To this theory Einstein added the experimentally observed fact that everyone gets the same result for the speed of light. This causes some of the assumptions of Newtonian mechanics to break down. The resulting theory was termed the theory of Special Relativity.

Later he added another observation, deduced from thought experiments, called the principle of equivalence. This states that the effect of gravity is indistiguishable from a uniform acceleration. This causes the notion of infinitely extendible reference frames in special relativity to break down. This led to the theory of General Relativity.

Answer 3

word relativity is naturally derived form the word relative.
relativity considered as a whole studies the phenomenons which occure due to relativeness in measurement. if u try to determine the absolute position at which ur standing u would obviously fail
because it is not even possible to define absolute motion in any intelligible way and without violeting physics we already know.
there are two different theories of relativity
the special theory which precisely says what i have said above.
special theory of relativity does not apply to gravitational force. so einstein produced another theory of relativity in 1915 called general theory of relativity which applies to gravitation as well.
a major achiement of general relativity is it explaines why gravity exists (in a way)

Answer 4

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.

Answer 5

The theory of relativity is very complex, but can be easily understood by the classic equation, E=mc^2. What it means is Energy is equal to mass times the speed of light squared.

Now what that really means to say is that Energy and Matter are 'relative' to each other and are interchangeable.

Answer 6

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.

Special relativity

Main article: Special 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.

[edit] General relativity

Main article: General relativity

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.

Answer 7

Special relativity deals with object in a non accelerated moving frames and the speed of light is constant.

General relativity deals mainly with gravity

Answer 8

Theory of relativity tells nothing is absolute everything is relative.

Answer 9

one of the easiest ways to state Einstein's theory of relativity is this:

an absolute inertial frame of reference does not exist
all observations are relative to your frame of reference

a lot is implied by this. try checking with a college physics department for a good introductory text.

Answer 10

Albert Einstein equation ,the relativity between matter and time