Explains bioluminescence in ocean life, giving examples of sea creatures that glow, such as ostracods, Bermuda fire worms, and flashlight fish.

"Edith Widder grew up determined to become a marine biologist. But after complications from a surgery during college caused her to go temporarily blind, she became fascinated by light as well as the power of optimism. Her focus turned to oceanic bioluminescence, a scientific frontier in our last earthly one, and with little promise of funding or employment she took a leap into the darkness. On her first visit to the deep ocean, in an experimental...