Light from the oldest and farthest stellar explosion yet seen was emitted when the Universe was a mere infant. It provides a close-up view of how and when stars formed, and how they affect the primordial gas around them.

Ways of evolving proteins, and assessing the vast numbers of variants needed to identify those with novel enzymatic activity, are themselves evolving. Oil droplets containing basic cell machinery provide a promising approach.

Rhythmic activities such as walking need tight coordination. In mice, pace is tweaked by a specific set of spinal-cord neurons that, surprisingly, make the animals walk faster by inhibiting the underlying circuit.