Is E mc2 applicable to photons?

Does E=mc2 apply to photons? Photons are massless, but if m=0 and E=mc2, then E=0c2=0. This would say that photons have no energy, which is not true. However, given the formula E=ℎf, a photon does have energy as ℎ is a non-zero constant and photons with a zero frequency do not exist.

Are there any massless particles other than photons?

The two known massless particles are both gauge bosons: the photon (carrier of electromagnetism) and the gluon (carrier of the strong force). However, gluons are never observed as free particles, since they are confined within hadrons. Neutrinos were originally thought to be massless.

Why do photons have energy but no mass?

Since photons (particles of light) have no mass, they must obey E = pc and therefore get all of their energy from their momentum. If a particle has no mass (m = 0) and is at rest (p = 0), then the total energy is zero (E = 0). But an object with zero energy and zero mass is nothing at all.

Are photons massless or massless?

If there was a way (there isn’t; special relativity prohibits it) to observe a photon at rest, you would find it massless. All the relativistic mass of the photon comes from it’s energy. In particle physics when we say mass, we usually refer to the rest mass. This is why we usually say that photons are massless.

How does the general equation work for photons with no mass?

In contrast, for a particle with no mass (m= 0), the general equation reduces down to E= pc. Since photons (particles of light) have no mass, they must obey E= pcand therefore get all of their energy from their momentum. Now there is an interesting additional effect contained in the general equation.

Is it possible for a particle to have no mass?

But that’s not quite correct. One way to prove it: Try to imagine that tiny ball as a particle with no mass. Sometimes the word “mass” is used interchangeably with the word “weight.” That’s not entirely wrong. The mass of an object is measured by its resistance to a force.

What is the mass of a photon at rest?

Or, we could think of it as the mass not attributed to the kinetic energy, but the particle itself. If there was a way (there isn’t; special relativity prohibits it) to observe a photon at rest, you would find it massless. All the relativistic mass of the photon comes from it’s energy.