Can photons have mass and momentum?

In summary, photons do not have mass but they have energy due to their momentum. They can be affected by gravity through gravitational lensing. While it is currently believed that photons cannot have mass in any conditions, some theories suggest that they could acquire mass through interactions with certain particles. The theory of relativity states that energy and mass are equivalent, allowing for the existence of massless particles like photons.
  • #1
mysteriously
12
0
do the photons have mas?or just the momentum?or both??
 
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  • #2


Photons have zero rest mass m=0. So the equation

E² = (mc²)² + (pc)²

relating energy E, rest mass m and momentum p reduces to

E = pc

Using Planck's constant h the energy E can be written in terms of frequency f as

E = hf
 

FAQ: Can photons have mass and momentum?

Do photons have mass?

No, photons do not have mass. They are considered to be massless particles.

If photons have no mass, how do they have energy?

Photons do not need mass to have energy. They have energy because they have momentum and can transfer that momentum to other particles.

Can photons be affected by gravity?

Yes, photons can be affected by gravity, even though they have no mass. This is known as gravitational lensing, where the path of a photon is bent by the gravitational pull of a massive object.

Is it possible for a photon to have mass in certain conditions?

There is currently no evidence to suggest that photons can have mass in any conditions. However, some theories, such as the Higgs mechanism, suggest that a photon could acquire mass if it interacts with certain particles.

How does the concept of massless photons fit into the theory of relativity?

The theory of relativity states that energy and mass are equivalent, and that massless particles, such as photons, can have energy. This is represented by the famous equation E=mc², where c is the speed of light. Therefore, even though photons have no mass, they still play a significant role in the theory of relativity.

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