>>11729392Think of it like this. The electrons are given some energy when travelling, then at some point they completely change direction. That requires some kind of energy right? Well, isn't the force of repulsion here stronger once they get closer? It becomes so strong, that at whatever distance, enough force is "built up" so that a photon is released, the direction is completely changed, the repulsion occured, and momentum is conserved.
As you said, this is quantum field theory, so there's no macro example to compare it to since billiard balls and everything else directly bounce off one another. (Well, not really, because it's literally electrons repelling again, but I believe you get the point)
