The bizarre discovery, detailed in a study that has yet to be peer-reviewed, stems from an experiment in which photons were fired into a cloud of atoms cooled to just above absolute zero. In cases where the photons passed through without interacting, researchers found that the atoms were still briefly excited, as though the photons had been absorbed and re-emitted. Meanwhile, when the photons were absorbed, they seemed to reappear before the atoms could even become excited.