Why the Sea Is Blue: Rachel Carson on the Science and Splendor of the Marine Spectrum
“The deep blue water of the open sea far from land is the color of emptiness and barrenness; the green water of the coastal areas, with all its varying hues, is the color of life.”
By Maria Popova
“The world is blue at its edges and in its depths,” Rebecca Solnit wrote in her contribution to history’s most beautiful meditations on the color blue. And yet blue itself is a universe of color — the world is woven not of blue but of blues. “Each blue object could be,” Maggie Nelson observed in her stunning serenade to the most existential color, “an X on a map too diffuse ever to be unfolded in entirety but that contains the knowable universe.”
Nowhere is this chromatic cosmos richer than in the marine world, and no one has had more profound an impact on impressing its science and splendor upon the popular imagination than marine biologist and author Rachel Carson (May 27, 1907–April 14, 1964).
In 1937, a quarter century before she catalyzed the modern environmental movement with her epoch-making book Silent Spring, Carson pioneered a new storytelling aesthetic by making science a literary subject in an exquisite Atlantic Monthly essay titled Undersea. This lyrical, unprecedented invitation to imagine our blue planet from the perspective of nonhuman creatures — creatures that inhabit the aquatic mystery Walt Whitman called “the world below the brine” — earned Carson a book deal. It became the basis of her 1951 book The Sea Around Us (public library), which won Carson the National Book Award and soon rendered her the most respected science writer in America.
With her uncommon gift for bridging the scientific and the poetic — a gift rooted in Carson’s conviction that science is part and particle of our spiritual bond with nature — she writes:
To the human senses, the most obvious patterning of the surface waters is indicated by color. The deep blue water of the open sea far from land is the color of emptiness and barrenness; the green water of the coastal areas, with all its varying hues, is the color of life. The sea is blue because the sunlight is reflected back to our eyes from the water molecules or from very minute particles suspended in the sea. In the journey of the light rays into deep water all the red rays and most of the yellow rays of the spectrum have been absorbed, so when the light returns to our eyes it is chiefly the cool blue rays that we see. Where the water is rich in plankton, it loses the glassy transparency that permits this deep penetration of the light rays. The yellow and brown and green hues of the coastal waters are derived from the minute algae and other microorganisms so abundant there. Seasonal abundance of certain forms containing reddish or brown pigments may cause the “red water” known from ancient times in many parts of the world, and so common is this condition in some enclosed seas that they owe their names to it — the Red Sea and the Vermilion Sea are examples.
But the sea’s truest blue is its blackest — the result of the subtraction of light from the fathomless sum of all colors. In a chapter hauntingly titled “The Sunless Sea,” Carson writes:
The unrelieved darkness of the deep waters has produced weird and incredible modifications of the abyssal fauna. It is a blackness so divorced from the world of the sunlight that probably only the few men who have seen it with their own eyes can visualize it. We know that light fades out rapidly with descent below the surface. The red rays are gone at the end of the first 200 or 300 feet, and with them all the orange and yellow warmth of the sun. Then the greens fade out, and at 1000 feet only a deep, dark, brilliant blue is left. In very clear waters the violet rays of the spectrum may penetrate another thousand feet. Beyond this is only the blackness of the deep sea.
Complement this particular portion of the wholly enthralling The Sea Around Us with a lovely animated adaptation of Carl Sagan’s Pale Blue Dot, then revisit Carson on writing and the loneliness of creative work, her brave and prescient letter protesting the government’s assault on nature, and her almost unbearably moving farewell to her soul mate.
UPDATE: For more on Carson, her epoch-making cultural contribution, and her unusual private life, she is the crowning figure in my book Figuring.
Published August 21, 2018