- #1
jorgdv
- 29
- 0
Hello everyone, thanks for reading
I'll explain my question. At first, light was described as electromagnetic waves, until Einstein proposed the photoelectric effect and thus creating the concept of photon, a particle of light with momentum and energy, but no mass. It could explain why the atoms become excited at discrete levels of energy, and why they emit only in specific frequencies knowing basics of quantum mechanics.
Nevertheless, quantum mechanics could explain successfully why electrons get excited to the next level in a resonance-like phenomenon, viewing light as a periodic potential in time and the electron as a wave function, without the need for light particles. If we observe the electron and we find it in the next eigenfunction of the unperturbed Hamiltonian, we can say that the electron has absorbed one photon of the electromagnetic field. However, that's a quantum of energy, an energy unit, not a particle.
So after all this, and without entering quantum field theory, there goes my question: If the quantum excitation of an electron can be explained treating light as a classical field, why do we need photons? Do they really exist as particles or it is just a misconception?
Thank you
I'll explain my question. At first, light was described as electromagnetic waves, until Einstein proposed the photoelectric effect and thus creating the concept of photon, a particle of light with momentum and energy, but no mass. It could explain why the atoms become excited at discrete levels of energy, and why they emit only in specific frequencies knowing basics of quantum mechanics.
Nevertheless, quantum mechanics could explain successfully why electrons get excited to the next level in a resonance-like phenomenon, viewing light as a periodic potential in time and the electron as a wave function, without the need for light particles. If we observe the electron and we find it in the next eigenfunction of the unperturbed Hamiltonian, we can say that the electron has absorbed one photon of the electromagnetic field. However, that's a quantum of energy, an energy unit, not a particle.
So after all this, and without entering quantum field theory, there goes my question: If the quantum excitation of an electron can be explained treating light as a classical field, why do we need photons? Do they really exist as particles or it is just a misconception?
Thank you