# The Theory of Relativity
Einstein's Theory of Relativity functions on these premises:
- The laws of nature are the same in different inertial frames of reference.
- The speed of light is constant in a vacuum. (Special Relativity)
- Gravitational mass is
__equivalent__ to inertial mass.(General
Relativity)
The Theory of Relativity is a description of gravity at high speeds; it
is a completion of Newton's Laws of Motion. Newton's Laws apply to bodies
of matter at low speeds, while Einstein's model applies to matter high speeds.
Although Einstein's model can account for and describe matter and gravity
at low speeds, Newton's Laws fail at accurately describing the relationship
between gravity and matter at high speeds.
EINSTEIN | SPECIAL RELATIVITY | GENERAL RELATIVITY |