Astronomy & Space
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Gravitational Redshift

Fractional stretching of light climbing out of gravity.

Formula

z≈GMrc2z \approx \frac{GM}{rc^2}

Variables

GGravitational constant
MMass
rRadius
cSpeed of light

Example

Light leaving the Sun is redshifted by about 2×10⁻⁶

Did You Know?

The Pound–Rebka experiment in 1959 confirmed it by measuring light climbing just 22.5 m up a Harvard tower.

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