Gravitational redshift

Definition

Gravitational redshift is the phenomenon where light or other electromagnetic radiation from an object is increased in wavelength, or shifted to the red end of the spectrum, due to the influence of a gravitational field. It occurs because time runs slower in stronger gravitational fields, affecting the frequency of emitted light.

5 Must Know Facts For Your Next Test

1. Gravitational redshift is predicted by Einstein's theory of General Relativity.
2. It has been confirmed through observations such as the redshift of light from stars near massive objects like black holes.
3. The amount of redshift increases with the strength of the gravitational field.
4. Gravitational redshift is different from Doppler redshift, which is due to relative motion between source and observer.
5. The Pound-Rebka experiment in 1959 provided one of the first experimental confirmations of gravitational redshift.

Review Questions

• What causes gravitational redshift and how does it relate to General Relativity?
• How does gravitational redshift differ from Doppler redshift?
• Can you explain a real-world example or experiment that confirmed gravitational redshift?

Related terms

General Relativity: A theory developed by Albert Einstein that describes gravity as a curvature of spacetime caused by mass and energy.

Event Horizon: The boundary surrounding a black hole beyond which no information or matter can escape.

Time Dilation: A difference in elapsed time measured by two observers due to relative velocity between them or a difference in gravitational potential.