And, we wouldn't have mirrors. I always say to people (i.e., children) if you want to see what electrons look like, look into a mirror. Its reflective surface is just a sheet of pure electrons made smooth by polishing -- smoothing the metallic surface atoms out. That sheet of electrons is very sensitive to the propensity of the electrons to both hold the atoms together and be shared among them, so as to absorb and emit photons as we see them. And we see ourselves. Otherwise the electrons would be too wildly out of control or too bound to reflect properly. Even though, facts be facts, the reflection off a mirror is less than the reflection off a dull but pure white surface and a mirror doesn't emit heat (infrared) very well unlike the dull white surface. Electrons are pretty cool but not too cool.