Comment by winter_blue

On a slightly different topic: do you think it would theoretically be possible to build stable 3D structures composed on positrons and electrons (and not have them annihilate each other)? I don't really understand the physics of why electrons don't collapse into the positive nucleus, since positives and negatives should attract, but I'm wondering if the same interaction keeping protons and electrons apart in an atom could come into play with smaller particles like electrons and positrons alone.