Swift kick from a supernova could knock a black hole askew

Gravitational waves are providing new hints about how black holes get their kicks. The Advanced Laser Interferometer Gravitational-Wave Observatory’s detection of spacetime ripples from two merging black holes on December 26, 2015, indicated that one black hole was spinning like a tilted top as it orbited with its companion (SN: 7/9/16, p. 8). That off-kilter […]

When should babies sleep in their own rooms?

When we brought our first baby home from the hospital, our pediatrician advised us to have her sleep in our room. We put our tiny new roommate in a crib near our bed (though other containers that were flat, firm and free of blankets, pillows or stuffed animals would have worked, too). The advice aims […]

Why midsize animals are the fastest

Speed has its limits — on the open road and the Serengeti. Midsize animals tend to be the speedsters, even though, in theory, the biggest animals should be the fastest. A new analysis that relates speed and body size in 474 species shows that the pattern holds for animals whether they run, fly or swim […]

Polluted water: It’s where sea snakes wear black

Maybe it’s more than reptile fashion. The high percentage of citified sea snakes wearing black might be a sign that pollution is an evolutionary force. Off the coasts of Australia and New Caledonia, some turtle-headed sea snakes (Emydocephalus annulatus) sport pale bands on their dark skins. Others go all black. In 15 places surveyed, the […]

Some secrets of China’s terra-cotta army are baked in the clay

China’s first emperor broke the mold when he had himself buried with a terra-cotta army. Now insight into the careful crafting of those soldiers is coming from the clays used to build them. Custom clay pastes were mixed at a clay-making center and then distributed to specialized workshops that cranked out thousands of the life-size […]

50 years ago, engineers tried catching commercial planes in nets

A gigantic emergency arresting gear system, capable of stopping the largest four-engined jet aircraft without discomfort to passengers, is being developed for the French Ministry of Transportation. The system consists of a nylon net … which engages the aircraft for the full width of its wingspan. Net and airplane are brought to a slow stop […]

Oldest traces of a dysentery-causing parasite were found in ancient toilets

Giardia has plagued people for a long time. The parasite can bring about dysentery — a miserable (and occasionally deadly) mixture of diarrhea, cramps and fever. Scientists have now uncovered traces of the giardia parasite in the remains of two roughly 2,600-year-old toilets once used by the wealthy denizens of Jerusalem. The remains are the […]