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Gravitational Redshift (General Relativity)
Compact Object
Custom
Earth
Sun
Neutron Star
Black Hole (r=2r_s)
Mass M (M_sun)
1.0
Radius R (km)
695700
Emitter r (R units)
1.5
Receiver r (R units)
5.0
Redshift Calculation
Schwarzschild r_s
—
r_s / R (compactness)
—
z (gravitational)
—
Δλ/λ₀
—
Freq ratio f_obs/f_emit
—
Time dilation factor
—
Schwarzschild Metric
ds² = −(1−r_s/r)c²dt²
+ (1−r_s/r)⁻¹dr²
+ r²dΩ²
r_s = 2GM/c² (Schwarzschild radius)
Gravitational redshift:
z = f_emit/f_obs − 1
1+z = √[(1−r_s/r₁)/(1−r_s/r₂)]
Pound-Rebka 1959: Δν/ν = gh/c²
= 2.5×10⁻¹⁵ (22m on Earth)
GPS correction: +45.9 μs/day (GR)
−7.1 μs/day (SR time dilation)