Electrons are the outer parts of atoms. Electricity happens when electrons zoom through wires, ready to light up light bulbs or make your television work. But, did you know that electrons can hop through space from one piece of metal to another? Scientists call this kind of space hopping “tunneling.” It’s hard to study tunneling electrons because electrons can only hop through gaps in space that are a few atoms wide. Plus it’s really difficult to measure the flow of these electrons.

Konrad Lehnert is a scientist at JILA who likes to study hopping electrons. He likes to make very small gadgets powered by them so he can learn more about how they behave. He recently invented a very cool detector made of gold that he uses to study the flow of hopping electrons. The device has a tiny golden point that is so small that the end of it consists of a single gold atom. The golden point sits across a tiny gap, about one or two atoms wide, from a thin golden wire. The golden wire is a thousand times thinner than a human hair.

The golden wire is so delicate that it moves in rhythmic waves when hopping electrons flow into it. The hopping electrons can make the wire wiggle about 40 million times a second! —Julie Phillips

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