Volume 2 Issue 5, May 2020

As the third LIGO–Virgo operating run (O3) finishes earlier than planned owing to the COVID-19 pandemic, we look at the ups and down of the past 12 months.

The rapid progress of atomic and nuclear physics in the twentieth century changed the way scientific results are documented, preserved and disseminated. Boris Pritychenko explains how atomic and nuclear data tables have become a central resource for the community.

A paper in Communications Physics catalogues the swarming behaviour of Bacillus subtilis as a function of the colony density and the cell aspect ratio, contributing to the picture of how physical properties of cells affect their motion in groups.

A Nature Astronomy paper finds that distributing peer review amongst grant applicants, aided by a machine-learning algorithm, can lead to more democratic decisions and provide more detailed feedback.

Clouds of bubbles in low-gravity environments behave differently from those on Earth, owing to their reduced buoyancy. A paper in Soft Matter reports a study of the behaviour of bubble clouds in a vessel in freefall.

Time-periodic fields provide a versatile platform for inducing non-equilibrium topological phenomena in quantum systems. We discuss how such fields can be used for topological band structure engineering, and the conditions for observing robust topological behaviour in a many-body setting.

This Expert Recommendation provides a guide to identifying practical situations where the likelihood ratio test statistic cannot be approximated by a χ² distribution and proposes adequate solutions.

Plasmon-enhanced Raman spectroscopy (PERS) is a highly sensitive technique that can provide molecular fingerprint information. This Technical Review discusses the fundamental principles, advantages and limitations of PERS, key issues in using PERS and interpreting results, and state-of-the-art applications in materials characterization, bioanalysis and the study of surfaces.