Force carrier particles mediate the fundamental forces, and for electromagnetism the force carrier is the photon. That’s what I was taught in high school. I (sort of) understand the idea that these are “virtual” particles though, not real. They mathematically model how the force acts but they aren’t actually there.
Pretending I’m an electron, I can throw a ball (photon) at a bottle (another electron) to knock away (magnetically repel) the bottle. Makes sense. But if I were a proton, then the electron is attracted. How can bouncing a particle (much less a mass less, virtual one) off the electron ever “knock it” towards a positive charge?
In: Physics
Your idea of particles hitting eachother isn’t very accurate. These virtual photons are waves interacting with the other electron. They are interacting, not hitting.
Photons are always absorbed, they cannot “bounce” off the electron. The electromagnetic wave of the photon shakes the electron like a boat on a stormy sea. This electron now produces its own wave because it is a moving charge at a 90° angle to both the direction of the wave and it’s polarisation.
If the photon is energetic enough, the electron will move to a different energy level within the atom, and when it then de-excites, may fall go between many different energy levels, releasing a photon with different energy each time depending on the size of the jump down. This is how fluorescence works.
So confusingly, when describing forces with virtual particles, you end up with negative energy virtual photons. They don’t have to follow the usual rules of E^(2) = (mc^(2))^(2) + (pc)^(2) so are able to have any energy they want. This negative energy is what causes attraction.
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