General relativity

Definition

General relativity is a theory of gravitation formulated by Albert Einstein, describing gravity as the curvature of spacetime caused by mass and energy. It extends Newtonian mechanics to account for the effects observed in strong gravitational fields and at high velocities.

5 Must Know Facts For Your Next Test

1. General relativity predicts that massive objects cause a distortion in spacetime, which is experienced as gravity.
2. The theory was confirmed by the observation of light bending around the sun during a solar eclipse in 1919.
3. Einstein's field equations, $G_{\mu\nu} + \Lambda g_{\mu\nu} = \frac{8\pi G}{c^4} T_{\mu\nu}$, describe how matter and energy determine spacetime curvature.
4. Predictions of general relativity include black holes, gravitational waves, and time dilation near massive objects.
5. The Global Positioning System (GPS) must account for relativistic time dilation to provide accurate positioning data.

Review Questions

• How does general relativity describe gravity differently from Newtonian mechanics?
• What observational evidence supports the theory of general relativity?
• Explain how general relativity affects modern technology like GPS.

Related terms

Spacetime: A four-dimensional continuum combining the three dimensions of space and one dimension of time into a single construct.

Gravitational Waves:

Ripples in spacetime caused by accelerating masses, predicted by general relativity and first directly detected in 2015.

Black Hole: A region of spacetime where gravity is so strong that nothing, not even light, can escape from it; predicted by solutions to Einstein's field equations.