Relativity: Relativity can be described as the study that highlights about how several observers estimate the same event. The word relativity might conjure with the likeness of Einstein, but the concept did not originate from him.
The concept of relativity has been under investigation for many centuries. Classical relativity was clearly explained by Galileo and Newton and “Theory of relativity” or “simply relativity” was given by Albert Einstein and generally refers to two theories “Special Theory of Relativity’ of 1905 and “General Theory of Relativity” of 1916. Modern Physics is based on the theory of relativity. These theories are of utmost significance as they are widely used in nuclear physics, astronomy and cosmology.
Special relativity throws light on the observers who are showing movement at constant velocity and General relativity focusses on observers who are experiencing acceleration. Einstein made a name in the world of physics because his theories of relativity made revolutionary forecasts. Most importantly, his theories have been substantiated to correctness in a wide range of experiments, modifying forever our explanation of space and time.
What are Special relativity and General relativity?
Special relativity
According to the theory of special relativity, all laws of physics are the same in all inertial frames (frame of reference that shows movement with constant velocity relatively with an inertial set up is called inertial frame). As per the theory of Special Relativity, space and time are not different notions.
If an object is brought into motion relative to another, the time is a blend of space and time. That means, the events which are considered as simultaneous by one observer may not be considered as simultaneous by another observer moving in relation to the first.
Special relativity details about the scientific laws remaining same irrespective of their location or the direction in which these laws are moving in the absence of gravitation. It is relatively easy to take care of relativity with respect to space-time coordinate.
In the theory of special relativity, only flat space-time is dealt. In combination with several laws of physics, the two postulates of theory special relativity anticipate that mass and energy are equal, as explaned in the mass–energy equivalence formula E = mc2, where c is the speed of light in a vacuum.
General relativity
The “General Theory of Relativity’ is related to gravity. It describes gravitational force as continuous non-spatial whole of space and time. The general theory of relativity is considered as more advanced and is widely applicable special theory of relativity.
The theory of General Relativity was published in 1916 and has been drawn from the theory of special relativity. The theory of General Relativity was developed by Einstein when he felt that the theory of Special Relativity was insufficient to describe the whole universe.
The difference between the two theories is that the theory of general relativity throws light on the force of gravity with respect to curving four-dimensional space-time. As per Einstein, the accelerative and gravitational forces are equal and same. His findings and written document also states that all physical laws can be formulated so as to be well-founded and logical for any observer, regardless of the observer’s movement.
As per the theory of general relativity, there is nothing that can travel faster that the rate and speed at which light travels. However, the force of gravity or the gravitational pull between two different objects would be stronger in the advent of the objects being closer to each other. The explanation is that if we move far away or we move closer together, the change in the attraction is expeditious. This theory of general relativity also explains a much wider case of space-times and emphasizes that laws of physics are the same in all reference frames.
The general relativity concept ensures that we work on gravity to define a local Lorentz frame along with the equivalence principle as well as the principle of general relativity.
The general theory of relativity is given as: The equation tells us how a given amount of mass and energy distorts space-time. The left-hand side of the equation,
describes the curvature of space-time whose influence we recognize as the gravitational force. It’s the analogue of the term on the left-hand side of Newton’s equation. The term on right-hand side of the equation explains about the way mass, energy, momentum and pressure are distributed throughout the Universe
Summary:General Relativity vs Special Relativity
The points of difference between the theory of special re lativity and general relativity have been summarized below:
Special Relativity |
General Relativity |
| Special relativity theory was announced in 1916 | General relativity theory was announced in 1916 |
| Velocity differences between inertial frames | Acceleration differences between non-inertial frames |
| Special relativity explains that there are some events and things that can look different to people in different locations or in motion at different speeds- other than the things that involve the speed of light in a vacuum. Things that are moving at the speed of light will always move at the speed of light in comparison to you, regardless how fast you are showing your movement. | General relativity throws light on the fact that space and time are actually different characteristic of the same thing–space-time–and that space-time is curved. How much is the curved space-time at any point in the universe will depend on how much the gravitational force is present in that area. In addition to twisting space-time, gravity is also capable of warping light, radio waves, and several other things. |
| Kinetic Energy statesEscape velocity = Gravity | Potential Energy statesAcceleration = Gravity |
| E = mc2 | |
| Simple, not detailed and did not cover the whole universe. | Complex, comprehensive and covered greater part of the universe |