Question: How does electricity react differently at very low temperatures?

Giovanna Tancredi answered on 7 Mar 2016:

Electricity is made by electrons that flow in a metal in one direction. When they flow in a normal metal they encounter a resistance in their flow, and this is why we said that a metal dissipates energy and we talk about electrical resistance. A normal metal at low temperatures would behave the same. Howeverthere are special metals, that we call superconducting metals, which show a very different behavior when cooled down. When they reach a certain temperature, that we call “critical temperature” they don’t dissipate anymore. This means that if you have electrons flowing in it, they do not encounter any resistance and the metal does not dissipate energy!