If you were asked to picture how electrons move, you could be forgiven for imagining a stream of particles sluicing down a wire like water rushing through a pipe. After all, we often describe electrons as “flowing” in an “electric current.” In reality, water and electricity flow in completely different ways. Whereas water molecules move together to form a swirly, coherent substance, electrons tend to fly past one another. “Water is seeing nothing but other water,” said Cory Dean, a physicist at ...