Photons moving in a gravity field increase in mass in proprotion to the Earth 's gravitational Mass?

Answer 1

The photon can't change its mass coz it doesn't have a rest mass (what we normally consider mass) but it does have a relatavistic mass. Einsteins equation makes that quite plain. You simply take out the c-squared coz its a constant and change the units to suit then the equation is e=m, in other words energy and mass are the same. A photon responds to a gravity field not by changing its mass but by changing its energy (or wavelength) however the gravity field would need to be immensely strong for you to notice any change.

Answer 2

No. Photons are strictly energy, not inertial mass. The energy each photon has is E = hf; where h = Plank's constant and f = frequency of the photon. Inertial mass is affected by gravity, not energy. Newton's gravity force equation is F = GmM/r^2; where the m's are inertial mass.

Now, having said that, space itself is bent by the presence of a mass. A so-called gravity lens can be formed around very large masses (BIG planets or galaxies) and the light from a star will be bent around that mass according to predictable and observed effects. [See source.]

Although gravity lenses have been observed, there is still some question as to what causes light to bend around them. For example, is it gravity (some yet undiscovered gravitron) that pulls on the energy of a photon? If so, how does that jibe with the fact that gravity pulls inertia mass, not energy in other circumstances?

Or, as some physicists claim, does the gravity pull on space itself and, therefore, bend it; so that light simply follows the path of least resistance, which follows the bend in space. That is, gravity does not pull light, but it does pull the space through which light travels.

In any case, photons have no mass at all; so they have no mass to increase...gravity or not.

Answer 3

Photons don't have any mass at all. There is a thing called relativistic mass but that doesn't depend on gravity.

Answer 4

Photons have only REST mass, and since photons are never at rest they have no mass. Period..!