A team of physicists at the University of Cologne has, for the first time, seen a particularly exotic behaviour of electrons on an atomic scale. Electrons normally move almost freely through three-dimensional space. However, when they are forced to move in only one dimension, i.e., in a chain of atoms, they begin to act strangely. The Tomonaga-Luttinger liquid theory predicted this decades ago. In the lab, however, this phenomenon has so far only been shown indirectly.