There has long been scepticism about the geochemical evidence that the ancient ocean was markedly warm. A fresh approach bolsters the case for an ocean that, in the distant past, was indeed quite hot.

A rotation in light's electric-field vector can alter the light's frequency. This rotational equivalent of the Doppler effect has proved surprisingly elusive, but has now been spotted in the laboratory.

Is the anomalously high electrical conductivity seen in part of Earth's mantle caused by protons derived from hydrous defects in the mineral olivine? Two groups investigate this possibility — and draw different conclusions.