What gives photons the energy to move at the speed they do

[MaoIragorri]

I have a question...
what gives photons the energy to move at the speed they do?

 

[nicksauce]

Photons always travel at the speed of light, regardless of their energy, because they are massless.

 

[ernestpworrel]

A photon is pure kinetic energy. It alway travels at the speed of light, from the moment it is created. It's more accurate to say a photon has no rest mass than to say that it's massless.

 

[mikelepore]

In wording that "what gives photons the energy", I wonder if the intent was to ask where the energy came from. There is always a source of the energy. If an electron in an atom drops to a lower energy state, for example, making a transition from the n=2 quantum number to the n=1 quantum number, it emits one photon. A nucleus that is in an excited state sometimes falls to a lower energy state, and gives off a gamma ray. An x-ray is given off when a moving electron hits a metal and loses its kinetic energy.