do photons relax?

[surajc0504]

imagine a photon (travelling with the speed of light) is moving straight towards a huge mass say 10^10 Msun. what will happen to its speed/energy as it comes closer to it?

[Nabeshin]

imagine a photon (travelling with the speed of light) is moving straight towards a huge mass say 10^10 Msun. what will happen to its speed/energy as it comes closer to it?

The speed remains constant, the energy increases as it falls into the gravitational potential well of the large mass.

[Drakkith]

As the energy increases the wavelength of the photon shortens. It blue shifts!