# Can Photons Really Influence the Curvature of Space-Time While Traveling?

• MeJennifer
In summary, there is a discussion about the influence of photons on the curvature of space-time in Special & General Relativity. It is suggested that while a photon may not have a definite momentum unless it interacts, it still has energy and therefore can affect the curvature of space-time. However, the exact effect of a single photon is not known and in solving the Einstein equations, the electromagnetic field's stress-energy tensor must be taken into account.
MeJennifer
In several posting in Special & General Relativity it is suggested that photons influence the curvature of space-time.

Now, if I understand QM correctly, a photon does not posses a definite momentum, unless it interacts. So it appears that between the times of interactions it evolves in state space but not in real space.

So then how could we possibly say that photons influence the curvature of space-time while traveling?

What am I missing?

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A photon still has energy whether it is interacting or not.So it should affect the curvature of space-time anyways isn't it?Tell me if I am wrong.xD

The electromagnetic field has an associated stress-energy tensor, see this Wikipedia article. If we are solving the Einstein equations and there is an EM field present, we must plug in the above tensor as $T_{ab}$ in addition to whatever dust there may be.

While I do not know the exact effect a single photon will have (since an EM-field is made up of many photons), classically the above approach is used.

## 1. What is a photon?

A photon is a tiny packet of light or electromagnetic radiation. It is the smallest unit of light and has no mass.

## 2. How do photons travel in space?

Photons travel through space at the speed of light, which is approximately 299,792,458 meters per second. They can travel in a straight line or be affected by the gravity of large objects, causing them to bend.

## 3. Can photons travel forever?

Yes, photons can travel forever in space unless they interact with other particles or objects. In a vacuum, photons will continue to travel at the speed of light until they are absorbed or reflected.

## 4. How are photons produced in space?

Photons are produced in space through various processes, such as nuclear fusion in stars, when electrons change energy levels in atoms, or when charged particles are accelerated by magnetic fields.

## 5. Can we see photons traveling in space?

No, we cannot see photons traveling in space because they have no mass and do not interact with other particles. We can only see the effects of photons when they are absorbed or reflected by objects, creating light that we can see.

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