Detection of gas around a type Ia supernova, a standard distance reference, implies that the progenitor white dwarf exploded after cannibalizing a red giant companion star.

The absorption spectrum of a quantum dot containing multiple atoms has the splitting characteristics and signature of a simple two-level system, as in a single atom.

The different components forming deep water in the North Atlantic, which leads to thermohaline circulation in the oceans, can vary in intensity by a factor of eight annually.