What We're Following This Afternoon

Einstein vindicated: Scientists have announced that gravitational waves, which he postulated a century ago, have been detected for the first time. It marks, Matthew Francis writes, “the beginning of a new era in the study of the universe: the advent of gravitational-wave astronomy.”

NATO to police Aegean Sea: The alliance says its vessels will patrol the waters to stem illegal traffickers and illegal migration. But, Jens Stoltenberg, NATO’s secretary general, said in Brussels: “This is not about stopping or pushing back refugee boats.”

A prison riot in Mexico: The violence near Monterey killed 52 people. A dozen others were also injured in the fighting overnight at the Topo Chico prison between prisoners from rival factions.

News from the morning here