What is theory of relativity by Einstein?

Question

i want the summary of theory of relativity..

Answer 1

General relativity (GR) is Albert Einstein's theory of gravitation, first published in 1916. It is the result of Einstein's attempts to reconcile the basic properties of gravity (such as the universality of free fall – in a gravitational field, all bodies fall at the same rate) with the radically new ideas about space and time that he had introduced in 1905 with his special theory of relativity. In contrast with Newton's law of universal gravitation, general relativity posits that gravitation is not due to a force in the conventional sense, but is an aspect of the geometry of space and time.
+++++++++
read more at the following links.
Life's Lovely! Love & Live Life!

Answer 2

It's a theory that's based on the idea that physical laws work the same way no matter what frame of reference you're observing them from. Einstein first came up with the "special" theory of relativity (meaning it applies to special cases). The Special theory is based on two postulates:

1. When two observers move relative to each other in a straight line and a constant speed, there is no way to tell which one is "really" moving. In other words, velocity is relative. (This was actually thought of by Galileo).

2. Light through a vacuum travels at the same speed relative to all observers (no matter how those observers are moving).

That second postulate especially leads to all kinds of unusual predictions, such as the slowing-down of time, and the idea that you can't exceed the speed of light.

Einstein later came up with the "General" theory of relativity (meaning it holds for all cases). The General theory unifies the Special theory with a new theory of gravity. It says that gravity is not so much a "force," but rather a side effect of the "shape" of space-time. Massive bodies warp space-time, which in turn causes things to accelerate. This theory of gravity is more successful at making predictions than the "old" theory that Newton came up with.

Answer 3

In his special theory of relativity, Einstein showed that time and length are not as absolute as everyday experience would suggest: Moving clocks run slower, and moving objects are shorter. Those are just two of the unusual properties of Einstein's world! Another consequence of special relativity is the most famous formula of all: E=mc², stating that two physical quantities which physicists had defined separately, namely energy and mass, are in fact equivalent.

Einstein's special theory of relativity (special relativity) is all about what's relative and what's absolute about time, space, and motion. Some of Einstein's conclusions are rather surprising. (Like the idea that time slows down as your speed increases.) They are nonetheless correct, as numerous physics experiments have shown. And they have forced physicists to revise the way they think about some of their science's most basic concepts.

In Einstein's general theory of relativity, space and time become even more flexible. "Your mileage may vary," and so may the time intervals you measure, depending on where and when you are. This flexibility has an analogue in the geometry of surfaces like that of a sphere - there is a curvature of space and time. Distorted space and time influence the way that material objects or light move. In fact, there is a direct connection to the cosmic interaction that holds the universe together, makes the earth orbit the sun and keeps our feet on the ground: gravity.

The consequences of that theory are spectacular. For instance, general relativity predicts that even light is deflected by gravity - a prediction that has been confirmed by numerous astronomical observations. In addition, it predicts exotic phenomena like gravitational waves and black holes.

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.

Special relativity is a theory of the structure of spacetime. It was introduced in Albert Einstein's 1905 paper "On the Electrodynamics of Moving Bodies". Special relativity is based on two postulates which are contradictory in classical mechanics:

The laws of physics are the same for all observers in uniform motion relative to one another (Galileo's principle of relativity),
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.

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

Time dilation: Moving clocks tick slower than an observer's "stationary" clock.

Length contraction: Objects are observed to be shortened in the direction that they are moving with respect to the observer.

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.

Mass-energy equivalence: per the relationship E = mc², energy and mass are equivalent and transmutable.

The defining feature of special relativity is the replacement of the Galilean transformations of classical mechanics by the Lorentz transformations.

Answer 5

Einstein offered first his special theory of relativity. The famous E=MC squared was NOT mentioned in the original paper. It was brought out shortly thereafter in another paper as a consequence of relativity. General relativity followed after that, including gravity.

Relativity was NOT a revolutionary concept, and was actually fairly well understood long before Einstein. He quantified it and made it mainstream. Einstein's Nobel Prize was for the photoelectric effect, not relativity, btw.

To understand relativity, Einstein tried to imagine what a light wave or photon would look like to someone moving alongside it at exactly the same speed (or better yet, just a short distance in front of it). Obviously, if you could "see" the photon/wave at that time, then somehow the light from the photon/wave had moved faster than you. Since you were already moving at the speed of light, there had to be no absolute speed of light, or no absolute frame of reference.

From this, he postulated the speed of light was an absolute. Nothing could move at the speed of light and have a rest mass. From that, all sorts of weird, non-newtonian, non-aristotlian effects arise such as mass increasing as you go faster, time going slower as you go faster, and so on.

The essentials of relativity can be summed up in that objects with mass cannot move at the speed of light; information (that is the effect of an action someplace else in the universe) cannot be transferred at faster than the speed of light; and time is a fourth dimension in our universe (note this is NOT time as we usually think of it... that is simply an accumulation of events, not time in the space-time sense).

It does not say objects with mass cannot travel FASTER than light, just that they cannot travel at exactly the speed of light.

Also, although quantum mechanics may violate relativity for rather large masses (on a quantum scale) at a small distance, or for small masses (on a quantum scale) at a large distance, uncertainty does not permit large masses to violate relativity at large distances.

Answer 6

special relativity: E=mc^2, mass is equivalent to energy in other words. Special relativity also states that the speed of light is constant to all observers, and the laws of physics must present themselves in the same form regardless of relative motion between observers.

general relativity basically deals with the curvature of space-time, there's another equation like E=mc^2 but written in tensorial (think of a tensor as a triple-vector) and to weird to write out. The idea behind general relativity is "matter and energy travels in straight lines" summed with the fact that "mass curves space-time, and this curvature tells matter how to move"....

hope that helps.

Answer 7

There are two postulates :-
(1) All the laws of Physics are the same in all inertial reference frames;
(2) The speed of light in vacuum is constant.

Inertial reference frames are those that move with a constant relative velocity with respect to one another.

Answer 8

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:
Special relativity is a theory of the structure of spacetime. It was introduced in Albert Einstein's 1905 paper "On the Electrodynamics of Moving Bodies". Special relativity is based on two postulates which are contradictory in classical mechanics:

The laws of physics are the same for all observers in uniform motion relative to one another (Galileo's principle of relativity),
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.
The resultant theory has many surprising consequences. Some of these are:

Time dilation:
Moving clocks tick slower than an observer's "stationary" clock.
Length contraction: Objects are observed to be shortened in the direction that they are moving with respect to the observer.
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.
Mass-energy equivalence: per the relationship E = mc², energy and mass are equivalent and transmutable.
The defining feature of special relativity is the replacement of the Galilean transformations of classical mechanics by the Lorentz transformations. (See Maxwell's equations of electromagnetism and introduction to special relativity).


General relativity:
General relativity is a theory of gravitation developed by Einstein in the years 1907–1915.

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 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. 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. To resolve this difficulty Einstein first proposed that spacetime is curved. In 1915, he devised the Einstein field equations which relate the curvature of spacetime with the mass, energy, and momentum within it.

Some of the consequences of general relativity are:
Time goes slower at lower gravitational potentials. This is called gravitational time dilation.
Orbits precess in a way unexpected in Newton's theory of gravity. (This has been observed in the orbit of Mercury and in binary pulsars).
Even rays of light (which are weightless) bend in the presence of a gravitational field.
The Universe is expanding, and the far parts of it are moving away from us faster than the speed of light. 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.
Technically, general relativity is a metric theory of gravitation whose defining feature is its use of the Einstein field equations. The solutions of the field equations are metric tensors which define the topology of the spacetime and how objects move intertially.

Answer 9

E=MC^2 Energy which is erg= mass * (C*C); C is the coefficient of light multiplied by itself, mass is kg/lbs/ erg is energy the mass produces because of the energy it gives off;
rub two sticks together, they become hot two of them both masses so the light they give off is doubled so that is the square energy is the heat or reaction given off in the two sticks rubbing together.

Answer 10

Everything is relative and nothing equals to me. Who am I ?