Marine research and conservation institutions band together to expand whale-saving technology to the San Francisco Bay.

Among ancient Maya, cacao was not a food exclusive to the elite, but was important — and common — to all.

Physicists answer a decades-old question about interacting quantum particles in a disordered system.

On Wednesday, Whale Safe, an A.I.-powered detection system, began operating around San Francisco Bay. Its goal is to warn large ships in the area’s waters when whales are nearby. About 25 miles out to sea from the Golden Gate on Monday afternoon, a yellow buoy bobbed not far from the great white shark hunting grounds of the Farallon Islands. On a boat close by called the Nova, Douglas McCauley, director of the Benioff Ocean Initiative at the University of California, Santa Barbara, donned a wet suit and snorkel and jumped into the brine to give the buoy some T.L.C. before its big day. The buoy, tethered to an underwater microphone, is an integral part of Whale Safe.