Every Loss Reveals What We Are Made of: Blue Bananas, Why Autumn Leaves Change Color, and the Ongoing Mystery of Chlorophyll


“We reach forth and strain every nerve, but we seize only a bit of the curtain that hides the infinite from us.”


Autumn is the season of ambivalence and reconciliation, soft-carpeted training ground for the dissolution that awaits us all, low-lit chamber for hearing more intimately the syncopation of grief and gladness that scores our improbable and finite lives — each yellow burst in the canopy a reminder that everything beautiful is perishable, each falling leaf at once a requiem for our own mortality and a rhapsody for the unbidden gift of having lived at all. This dual awareness is, in fact, a sign of the good fortune that comes with death.

You can have both life and deathMaria Popova. Available as both a printed copy and as stationary cards. All proceeds go to The Nature Conservancy.

But autumn is also the season of revelation, for the seeming loss unveils a larger reality: Chlorophyll is a life-force but it is also a cloak, and when trees shed it from their leaves, nature’s true colors are revealed.

Photosynthesis is nature’s way of making life from light. Chlorophyll allows a tree to capture photons, extracting a portion of their energy to make the sugars that make it a tree — the raw material for leaves and bark and roots and branches — then releasing the photons at lower wavelengths back into the atmosphere. Trees are light-catchers that grow life from air.

Although the human mind has puzzled over why leaves fall and change color at least as far back as Aristotle, chlorophyll — which shares chemical kinship with the hemoglobin in our blood — was only discovered and named in 1817, by the French pharmacist-chemist duo Joseph Bienaimé Caventou and Pierre Joseph Pelletier. In a lovely touch of humility that distinguishes, always, the scientist from the explorer — the explorer, so eager to name the lands and landmarks he has “discovered” after himself — they wrote in their landmark paper:

It is not right for us to give a name to a long-known substance, to which we have only added a few facts. But, we do have the right to suggest, sans granting any significance, that the name of chlorophyll be given. chloros, color, and φυλλον, leaf: a name that would indicate the role it plays in nature.

Oak by the self-taught 19th-century naturalist, painter, and poet Rebecca Hey from The Spirit of the Woods — the world’s first illustrated encyclopedia of wild trees. Available as a printed version.

Chlorophyll isn’t the only color found in trees, although it is still being studied. Throughout a leaf’s life, four primary pigments course through its cells: the green of chlorophyll, but also the yellow of xanthophyll, the orange of carotenoids, and the reds and purples of anthocyanins. As the sun shines brightly in the spring and summer, chlorophyll is absorbed by the leaf. The tree then converts photons to new growth. As daylight begins fading in autumn and the air cools, deciduous trees prepare for wintering and stop making food — an energy expenditure too metabolically expensive in the dearth of sunlight. The decommissioned chlorophyll is being broken down by enzymes, which allows the remaining pigments to be released. And because we humans so readily see in trees metaphors for our emotional lives, how can this not be a living reminder that every loss reveals what we are made of — an affirmation of the value of a breakdown?

The same process occurs when fruits ripen. They go through stages of ripening from green to various shades of yellow, purple, orange or orange. Two centuries after the discovery of chlorophyll, a new generation of scientists armed with a new arsenal of tools unimaginable in 1817, in that abiding way science has of only revealing new layers of reality when it lets go of its assumptions, placed bananas in various stages of ripeness under UV light and discovered that as the world’s favorite yellow fruit ripens and its chlorophyll breaks down, it not only reveals the xanthophyll of yellow, but produces the chlorophyll catabolite hmFCC — a previously unknown blue fluorescent compound.

Based on lab imaging Agewandte Chemistry: The Journal of the German Chemical SocietyInternational edition 2008

Subsequent research has found signs of this blue pigment in devil’s ivy — the evergreen golden pothos thriving in the corner of my library in Brooklyn at this very moment — rendering the mystery of chlorophyll ongoing and filling the human heart with exhilaration. How thrilling to think that something we discovered two centuries ago, something nature created more than one thousand million years ago when the first green plants evolved from prokaryotes, can still shimmer with mystery — a molecular microcosm of the ultimate thrill: the knowledge that however much we might uncover, nature will never cease to be filled with surprise ripe for the reaping. And how humbling to think that we too are animals doing their best to make sense of the world with their creaturely limitations — animals whose vision evolved to peak in so narrow a band of the spectrum, in the tiny wavelength range between red and violet, blind to everything between radio and cosmic rays, blind to uaviolet light. If we were bees, butterflies, sockeye salmon or reindeer then bananas would be blue.

“Spectra of various light sources, solar, stellar, metallic, gaseous, electric” from Les phénomènes de la physique by Amédée Guillemin, 1882. Available as both a printed version and as an embroidered mask.

The poetic astronomer Maria Mitchell captured this best in her rueful and rapturous observation that “we have a hunger of the mind which asks for knowledge of all around us, and the more we gain, the more is our desire,” and yet “we reach forth and strain every nerve, but we seize only a bit of the curtain that hides the infinite from us.”

Follow Ellen Meloy’s great conversation on the conscience and color of culture. Next, find out this interesting read about Turing, trees and how alive we really are.


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Since a decade and a half I’ve been writing for hundreds of hours each month, spending thousands of dollars every month. MarginalianIt was known for the infuriating name Brain Pickings its first 15 years. Thanks to the support of readers, it has been free from ads and still exists. I have no staff, no interns, no assistant — a thoroughly one-woman labor of love that is also my life and my livelihood. Consider donating if you feel this work makes your life easier. Every dollar counts.


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