Systems of quantum objects can be characterized by the correlations between the objects. A technique that precisely measures even the most delicate of these correlations allows models of quantum systems to be tested. See Letter p.323
A technique for manipulating molecules uses an intermediary atom to query a nearby molecule's energy state and produces 'quantum superpositions' of these states, a prerequisite for extremely high-precision spectroscopy. See Letter p.203
Understanding the prevalence and impact of personal attacks in online discussions is challenging. A method that combines crowdsourcing and machine learning provides a way forward, but caveats must be considered.
Hydrocarbons called alkenes are isolated from petroleum as mixtures of isomers, often making it hard to use them as reagents for synthesis. A reaction involving a migrating nickel atom offers a possible solution. See Letter p.84