Equivalence Principle

Physical Principle

On a local scale, the physical effects of a uniform acceleration of a given frame of reference imitate completely the effects of a gravitational field.

Examples

Spaceship

Consider a spaceship $\SS$ far out in space, under the influence of no gravitational fields.

Everything in $\SS$ would be weightless.

Let a uniform acceleration be applied to $\SS$, corresponding to Acceleration Due to Gravity on the surface of Earth.

Then everything within $\SS$ would behave as though $\SS$ were stationary on the surface of Earth.

Also see

• Results about equivalence principle can be found here.

Historical Note

The Equivalence Principle was introduced by Albert Einstein in his General Theory of Relativity.

Sources

• 1998: David Nelson: The Penguin Dictionary of Mathematics (2nd ed.) ... (previous) ... (next): equivalence principle
• 2008: David Nelson: The Penguin Dictionary of Mathematics (4th ed.) ... (previous) ... (next): equivalence principle