Relativity Formula

As per the theory of Special relativity, length, time, momentum, and energy depends on the velocity of one reference frame relative to another. A person on a spaceship moving almost closer to the speed of light will measure length, time, momentum, and energy differently than an observer that is outside the ship. The Lorentz factor (γ) is the factor by which time, length, and relativistic  mass change for an object while that object is moving

The following equation is  used very often in special relativity:

where β =  v/c

v is the relative velocity between two internal frames

c is the speed of light (c = 3 x 10⁸ m/s)

For two frames at rest, γ = 1, and increases with the relative velocity between the two inertial frames. As the relative velocity approaches the speed of light, γ → ∞.