Our understanding of the origin of birds took a major step forward in 1998, thanks to the reported discovery of a remarkable fossil that unveiled the existence of feathered dinosaurs. Fossil publications that year caused a sensation.

An anomalous measurement from a nuclear reactor triggered a three-year campaign to find an elusive particle called the sterile neutrino. The search shows definitively that sterile neutrinos don’t exist — but the anomaly persists.

CRISPR–Cas is a bacterial defence system that can attack invading DNA to protect host cells, or help to insert DNA safely into the genome. Structures of this latter type of CRISPR–Cas system have now been visualized.

Electric motors convert electrical energy into mechanical motion. A molecular motor has been designed in which electricity drives redox reaction cycles that lead to the movement of two small rings around a large circular loop. The small rings make one full revolution around the loop for every two redox cycles.