Context: It has been 101 years since ‘Theory of Relativity’ was validated.

General theory of relativity

  • In his general theory of relativity, Einstein considered systems accelerating with respect to each other. 
  • He concluded that the effects of acceleration and gravity were equivalent
  • Applications
    • Using the theory, Einstein was able to explain a discrepancy in the slow rotation of the planet Mercury’s elongated orbit, which Newtonian mechanics had been unable to explain. 
    • He explained the effect of a large concentrated mass, in this case the Sun, by saying it ‘warped’ the space around it. 
    • Thus space, or rather spacetime, is curved. The degree of curvature depends upon the magnitude of the mass, and so matter-energy determines the curvature of space-time.

The special theory of relativity

  • It states that nothing can exceed the speed of light, which is the same in all inertial (non accelerating) time frames and that all inertial time frames are equally good for carrying out experiments. 
  • Special relativity equates space with time and matter with energy
  • In this theory time and space have to be considered as unified and not as two separate things; this merged entity is known as space-time.
  • Matter and energy are aspects of the same phenomenon, matter energy, and are linked in the famous equation: E = mc2 (E: Energy, m:Mass, c:speed of light)

Source: DTE