In 1932, William Beebe wedged his lanky body into a cramped submersible and became the first scientist to descend into the sea’s inky darkness. A tiny window let him gaze out. Later, he described an unfamiliar world of dancing lights, pale glows and beguiling shimmers.
“It seemed to explode,” he said of one luminous creature. Nothing, he added in his book, “Half Mile Down,” had prepared him for the spectacular displays.
The colors included pale greens, blues, reds and especially blue-greens, which by nature can travel far in seawater.
Over the decades, biologists learned that the creatures of the deep sea use light much as animals on land use sound — to lure, intimidate, stun, mislead and find mates.
The living lights emanated from tiny fish with needlelike fangs, and gelatinous brutes with thousands of feeding tentacles. The sheer variety suggested that bioluminescence was fairly common, but no scientist came up with a measurement of the phenomenon…