Calculate Black Hole Gravitational Redshift

The calculator calculates the Gravitational Redshift for given Constant of Gravitation, Mass of Body, Distance from Mass Center and Speed of Light.




When an electromagnetic radiation emitted from an object is shifted to the red end of the spectrum, it is said as gravitational redshift or einstein shift. The gravitational redshift or einstein shift at the black hole region which does not allow anything to pass out with such a gravity pull.


v / vr = (1 - (2GM / rc2))1/2


v = Frequency at Infinity,

vr = Frequency at r,

G = Constant of Gravitation,

M = Mass of Body,

r = Distance from Mass Center,

c = Speed of Light

Einstein's theory of general relativity predicts that the wavelength of electromagnetic radiation will become longer as it exits the gravitational well. The photon must expend energy to escape, but at the same time must always travel at the speed of light, so this energy must be lost through a change of frequency rather than a change in momentum. If the energy of the photon decreases, the frequency also decreases. This corresponds to an increase in the wavelength of the photon, or a shift at the red end of the electromagnetic spectrum – hence the name: gravitational redshift. In the 1960s, this effect was confirmed through the laboratory experiments.

Redshift and blueshift

When light get shifted to the red end of the spectrum (its wavelengths get longer) means object moves away from us. Redshift and blueshift describe how light shifts toward shorter or longer wavelengths as objects in space (such as stars or galaxies) move closer or farther away from us.