# Gravitational force affected by refraction?

• Rlam90
In summary, light slows down in a refractive medium, increasing the density of photons within it. This can contribute to the effects of gravity. In a purely theoretical scenario, if two mediums with equal mass but different optical densities are compared, the more refractive medium may have a higher gravitational force due to its higher photon density. This also relates to the stress-energy tensor in General Relativity, which explains how photons contribute to gravity.

#### Rlam90

So I understand that light "slows down" in a refractive medium. This obviously would increase the density of photons within the medium. Also, from what I understand, photons do contribute slightly to the effects of gravity.

Now, suppose we take two purely theoretical mediums of equal volume and shine light of equal intensity through them both. One of the mediums is more refractive than the other, but both have equal mass. Would the more refractive medium therefore contain more photons and as a result produce higher gravitational forces than the other?

This raises another question: does the gravitational force of individual particles have anything to do with some form of energy being refracted within or around the particles? Say particles with a greater mass refract more of this energy within or around themselves so that their energy density would be higher. What form of energy would this be?

Bear with me, I have no official education in any field of physics. I study what I can understand in my spare time.

Yes, if a stream of photons pass through two mediums with different optical densities, there would be more photons in one of the mediums, and it would increase the gravitational field from it by a very tiny amount.

Photons generate a small amount of gravity by contributing to something called the stress-energy tensor, an idea from General Relativity

http://en.wikipedia.org/wiki/Stress-energy_tensor

This may be what you were referring to as "energy refracted within or around particles themselves" in a way.

## 1. How does refraction affect the gravitational force?

Refraction does not directly affect the gravitational force. Gravitational force is a fundamental force of nature and is not affected by other factors such as refraction.

## 2. Does the angle of refraction change the strength of the gravitational force?

No, the angle of refraction does not change the strength of the gravitational force. The strength of the gravitational force is determined by the masses of the objects and the distance between them, and is not affected by the angle of refraction.

## 3. Can refraction change the direction of the gravitational force?

No, refraction does not change the direction of the gravitational force. The direction of the gravitational force is always towards the center of mass of an object, and this does not change due to refraction.

## 4. Does refraction affect the acceleration due to gravity?

No, refraction does not affect the acceleration due to gravity. The acceleration due to gravity is a constant value on Earth (9.8 m/s²) and is not affected by other factors such as refraction.

## 5. Can light refraction affect the trajectory of a falling object due to gravity?

No, light refraction does not affect the trajectory of a falling object due to gravity. The trajectory of a falling object is determined by the gravitational force and the initial velocity, and is not affected by the refraction of light.