What is the difference between Special and General theory of relativity

crmhaske | College Teacher | (Level 3) Associate Educator

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You can think of special relativity (SR) as a subcategory of general relativity (GR).

In special relativity the speed of light is taken to be constant, and there is no acceleration or simple force.  It is essentially a simplified form in which Cartesian co-ordinates (X,Y,Z) can be used.  All math in special realitivty is based on simple geometry.

In general relativity the effects of acceleration such as gravity are considered.  Because of this affect motion can no longer be considered to be in a straight line, so you have to consider motion moving along a curved path.

In this way special relativity is a simplification of general relativty.

If you were to calculate the trajectory of a ball on a pool table ignoring the influence of the other balls (their gravitational pull), you would be operating under the principle of SR.  If however you considred the influence of the other balls in your calculations, you would be operating under the principle of GR.  Because the influence is minimal we simplify to use SR in such calculations.

Space is warped in GR, and not so in SR.