Natalie Angier in The New York Times:
By all evidence, Nero’s favorite color was green. The Roman emperor dressed in green, collected emeralds, cheered at the chariot races for the “green stable” team, and was particularly fond of eating green leeks. Goethe praised green as the “soothing” marriage of the chromatic opposites yellow and blue. George Washington called green “grateful to the eye,” and painted his Mount Vernon dining room a brilliant verdigris. And let’s not forget that everybody’s favorite elephant, Babar, wore a dapper suit in a “becoming shade of green.” Scientists, too, appreciate green’s many charms and for manifold reasons, starting with one best grasped through a walk in a newly spring-sanctioned park. Chlorophyll, the pigment that makes plants green, lies at the heart of photosynthesis, the fundamental electrochemical enterprise that continues to dazzle the scientists who study it, and who say it should dazzle us, too. After all, not only does photosynthesis spin sunlight and water into the sugars we eat, it spawns as a happy waste product the oxygen we breathe. “All food comes from photosynthesis,” said Petra Fromme, a professor of chemistry and biochemistry at Arizona State University. “There would be no higher life on Earth without it.”
Green, she added, “is the color of life.” In surprising new research on the evolution of different forms of photosynthesis, scientists have found that the prized oxygen-making variety may be much older than anybody suspected, and that the greening and aerating of Earth could well have begun soon after the earliest living cells appeared.
More here.