Brain Pickings

Posts Tagged ‘science’

17 JULY, 2014

The Book of Trees: 800 Years of Visualizing Science, Religion, and Knowledge in Symbolic Diagrams


How the humble tree became our most powerful visual metaphor for organizing information and distilling our understanding of the world.

Why is it that when we behold the oldest living trees in the world, primeval awe runs down our spine? We are entwined with trees in an elemental embrace, both biological and symbolic, depending on them for the very air we breathe as well as for our deepest metaphors, millennia in the making. They permeate our mythology and our understanding of evolution. They enchant our greatest poets and rivet our greatest scientists. Even our language reflects that relationship — it’s an idea that has taken “root” in nearly every “branch” of knowledge.

How and why this came to be is what designer and information visualization scholar Manuel Lima explores in The Book of Trees: Visualizing Branches of Knowledge (public library) — a magnificent 800-year history of the tree diagram, from Descartes to data visualization, medieval manuscripts to modern information design, and the follow-up to Lima’s excellent Visual Complexity: Mapping Patterns of Information.

'Genealogical distribution of the arts and sciences' by Chrétien Frederic Guillaume Roth from Encyclopédie (1780)

A remarkable tree featured as a foldout frontispiece in a later 1780 edition of the French Encyclopédie by Denis Diderot and Jean le Rond d'Alembert, first published in 1751. The book was a bastion of the French Enlightenment and one of the largest encyclopedias produced at that time. This tree depicts the genealogical structure of knowledge, with its tree prominent branches following the classification set forth by Francis Bacon in 'The Advancement of Learning' in 1605: memory and history (left), reason and philosophy (center), and imagination and poetry (right). The tree bears fruit in the form of roundels of varying sizes, representing the domains of science known to man and featured in the encyclopedia.

'Notabilia' by Mortiz Stefaner, Dario Taraborelli, and Giovanni Luca Ciampaglia (2011)

A visualization of the 100 longest online discussions on Wikipedia articles up for deletion, part of the collaborative editing process that defines the encyclopedia of our time. These discussions last for at least seven days, until consensus is reached on which of a series of proposed actions (such as keep, merge, rename, or delete) should be performed on a page. Starting from a common root, this visualization maps each of the 100 articles as an individual branch, with color segments and shape determined by the sequence of 'keep' (green) and 'delete' (purple) votes. The final arch of each branch indicates the voting results, bending toward either left (keep) or to the right (delete).

'Tree of virtues' by Lambert of Saint-Omer, ca. 1250

Palm tree illustration from the 'Liber floridus (Book of flowers),' one of the oldest, most beautiful, and best-known encyclopedias of the Middle Ages. Complied between the years 1090 and 1120 by Lambert, a canon of the church of Our Lady in Saint-Omer, the work gathers extracts from 192 different texts and manuscripts to portray a universal history or chronological record of the most significant events up to the year 1119. This mystical palm tree, also known as the 'palm of the church,' depicts a set of virtues (fronds) sprouting from a central bulb. The palm tree was a popular early Christian motif, rich in moral and symbolic associations, often used to represent the heavens or paradise.

'Plan of Organization of New York and Erie Railroad' by Daniel Craig McCallum (1855)

Diagram viewed by economists as one of the first organizational charts. The plan represents the division of administrative duties and the number and class of employees engaged in each department of the New York and Erie Railroad. Developed by the railroad's manager, the engineer Daniel Craig McCallum, and his associates, the scheme features a total of 4,715 employees distributed among its five main branches (operating divisions) and remaining boughs (passenger and freight departments). At the roots of the imposing tree, in a circular layout, are the president and the board of directors.

Lima writes in the introduction:

In a time when more than half of the world’s population live in cities, surrounded on a daily basis by asphalt, cement, iron, and glass, it’s hard to conceive of a time when trees were of immense and tangible significance to our existence. But for thousands and thousands of years, trees have provided us with not only shelter, protection, and food, but also seemingly limitless resources for medicine, fire, energy, weaponry, tool building, and construction. It’s only normal that human beings, observing their intricate branching schemas and the seasonal withering and revival of their foliage, would see trees as powerful images of growth, decay, and resurrection. In fact, trees have had such an immense significance to humans that there’s hardly any culture that hasn’t invested them with lofty symbolism and, in many cases, with celestial and religious power. The veneration of trees, known as dendrolatry, is tied to ideas of fertility, immortality, and rebirth and often is expressed by the axis mundi (world axis), world tree, or arbor vitae (tree of life). These motifs, common in mythology and folklore from around the globe, have held cultural and religious significance for social groups throughout history — and indeed still do.


The omnipresence of these symbols reveals an inherently human connection and fascination with trees that traverse time and space and go well beyond religious devotion. This fascination has seized philosophers, scientists, and artists, who were drawn equally by the tree’s inscrutabilities and its raw, forthright, and resilient beauty. Trees have a remarkably evocative and expressive quality that makes them conducive to all types of depiction. They are easily drawn by children and beginning painters, but they also have been the main subjects of renowned artists throughout the ages.

'The Tree of Life' by Gustav Klimt (1901), one of the most reproduced oil paintings in human history

Among the legions of artists captivated by trees was the great Leonardo da Vinci. Shortly before his death, in one of his voluminous notebooks, Da Vinci worked out a mathematical formula for the relationship between the size of a tree’s trunk and that of its branches — he found that as a tree grows, the total cross-sectional area of all new branches is roughly equal to the area of the mother trunk or branch, no matter the height of the tree. Centuries later, scientific tests using computer-generated models of trees have not only found Leonardo’s formula to hold up across nearly every tree species, but also to explain trees’ remarkable resilience to wind and other external forces.

'Tree Branching' by Leonardo da Vinci (ca. 1515)

Study of a tree branching. Leonardo's rule is fairly simple, stating that 'Every year when the boughs of a tree have made an end of maturing their growth, they will have made, when put together, a thickness equal to that of the main stem.'

Indeed, Leonardo’s formula touched on the very thing that makes the tree such a powerful metaphor for organizing knowledge — its natural function not merely as a static object, but also as a system of relational dynamics. Lima writes:

Our primordial, symbolic relationship with the tree can elucidate why its branched schema has provided not only an important iconographic motif for art and religion, but also an important metaphor for knowledge-classification systems. Throughout human history the tree structure has been used to explain almost every facet of life: from consanguinity ties to cardinal virtues, systems of laws to domains of science, biological association to database systems. It has been such a successful model for graphically displaying relationships because it pragmatically expresses the materialization of multiplicity (represented by its succession of boughs, branches, twigs, and leaves) out of unity (its central foundational trunk, which in turn connected to a common root, source, or origin.)

Anonymous, 'Yggdrasil tree' (ca. 1680)

A depiction of the world tree or cosmic ash tree, from an Icelandic manuscript containing several illustrations from Norse mythology. Yggdrasil is drawn surrounded by various animals, which live in and on it. Of particular relevance is Ratatoskr, a green squirrel on the bottom left, who, according to Norse mythology, runs up and down Yggdrasil to carry messages between the eagle, shown at the top, and the dragon, Niohöggr, who gnaws at the roots.

Kabbalistic tree of life from 'Oedipus AEgyptiaus' (1652)

Illustration by the Jesuit scholar and polymath Athanasius Kircher. Kabbalah is a Jewish mystical tradition; the term translates as 'received,' in reference to teachings passed through generations or directly from God. A pivotal element of the Kabbalah wisdom is the tree of life, an image composed of a diagram of ten circles, symbolizing ten pulses, or emanations, of divine energy.

'Vortices' by René Descartes, from Principia Philosophiae (1644)

A model of the universe that was widely accepted in the 17th century, based on the Cartesian system of vortices: large whirlpools of tenuous or ethereal matter that were thought to move the planets and their satellites by contact.

'Voronoi treemap' by Michael Balzer, (2005)

A pioneering alternative to conventional rectangular treemaps that relied on Voronoi tessellation to map hierarchies. In contrast to layout algorithms based on rectangular subdivisions, the Voronoi treemap layout algorithm was the first to generate flexible polygonal subdivisions, eliminating analogous shapes and aspect ratios, while also producing extremely alluring organic layouts.

I was delighted to see a longtime favorite among the selections — Stefanie Posavec’s brilliant Writing Without Words project, a hand-drawn visualization of the “literary organism” in Jack Kerouac’s novel On the Road, depicting the sentences, words, and rhythm structures in the book.

'Writing Without Words' by Stefanie Posavec, (2008)

The Book of Trees is a treasure trove of visual literacy, symbolic history, and cultural insight. Complement it with this visual history of tree diagrams explaining evolution and these glorious drawings of trees from Indian mythology, then revisit Rachel Sussman’s gorgeous photographs of Earth’s oldest living trees.

Images courtesy of Princeton Architectural Press

Donating = Loving

Bringing you (ad-free) Brain Pickings takes hundreds of hours each month. If you find any joy and stimulation here, please consider becoming a Supporting Member with a recurring monthly donation of your choosing, between a cup of tea and a good dinner.

You can also become a one-time patron with a single donation in any amount.

Brain Pickings has a free weekly newsletter. It comes out on Sundays and offers the week’s best articles. Here’s what to expect. Like? Sign up.

14 JULY, 2014

A Brief History of How Bees Sexed Up Earth and Gave Flowers Their Colors


How a striped, winged, six-legged love machine sparked “the longest marketing campaign in history.”

The great E.O. Wilson is credited with having once said, “If all mankind were to disappear, the world would regenerate back to the rich state of equilibrium that existed ten thousand years ago. If insects were to vanish, the environment would collapse into chaos.” But while the one million or so named species of insects make up about 70% of all known species on Earth, one type of insect is more vital to our planet’s survival — as well as our own — than any other: the humble, mighty bee. In A Sting in the Tale: My Adventures with Bumblebees (public library), British biologist, lifelong wildlife enthusiast and Bumblebee Conservation Trust founder Dave Goulson explores how bees gave our cosmic home not only its beauty but also its bounty of nourishment, and what responsibility we have — as Jane Goodall once eloquently urged — in repaying that existential gesture.

Inviting us into his evolutionary time machine, Goulson takes us back to the Cretaceous period, between 145.5 and 65.5 million years ago, when Earth was covered in lush forests of giant greenery. The dinosaurs had just taken to the air as newly evolved feathers produced the first birds. Our own ancestors at the time were small and unseemly rat-like creatures lurking under the ferns and feeding on insects and fallen fruit. Goulson writes:

If we could travel to this ancient land, we might be too concerned with the dangers posed by the larger wildlife to notice that there were no flowers; no orchids, buttercups or daisies, no cherry blossoms, no foxgloves in the wooded glades. And no matter how hard we listened, we would not hear the distinctive drone of bees. But all that was about to change.

So why did it change? It turns out that sex does indeed rule the world — two hundred million years after the first ejaculation in Earth’s recorded history, bees stepped in to perform a vital function in our planet’s blossoming into maturity:

Sex has always been difficult for plants, because they cannot move. If one cannot move, then finding a suitable partner and exchanging sex cells with them poses something of an obstacle. The plant equivalent of sperm is pollen, and the challenge facing a plant is how to get its pollen to the female reproductive parts of another plant; not easy if one is rooted to the ground. The early solution, and one still used by some plants to this day, is to use the wind. One hundred and thirty-five million years ago almost all plants scattered their pollen on the wind and hoped against hope that a tiny proportion of it would, by chance, land on a female flower. This is, as you might imagine, a very inefficient and wasteful system, with perhaps 99.99 per cent of the pollen going to waste – falling on the ground or blowing out to sea. As a result they had to produce an awful lot.

Nature abhors waste, and it was only a matter of time before the blind stumbling of evolution arrived at a better solution in the form of insects. Pollen is very nutritious. Some winged insects now began to feed upon it and before long some became specialists in eating pollen. Flying from plant to plant in search of their food, these insects accidentally carried pollen grains upon their bodies, trapped amongst hairs or in the joints between their segments. When the occasional pollen grain fell off the insect on to the female parts of a flower, that flower was pollinated, and so insects became the first pollinators, sex facilitators for plants. A mutualistic relationship had begun which was to change the appearance of the earth. Although much of the pollen was consumed by the insects, this was still a vast improvement for the plants compared to scattering their pollen to the wind.

Photograph of bee abdomen by Rose-Lynn Fisher from her project 'Bee'

But this system presented our proto-bees with a serious wayfinding problem: Because flowers were as drably brownish-green as the surrounding vegetation, spotting them was no small task. In order to attract insects, they had to get better at standing out over the competition and “advertising” their delicious pollen. Goulson writes:

So began the longest marketing campaign in history, with the early water lilies and magnolias the first plants to evolve petals, conspicuously white against the forests of green. The first pollinators may have been beetles, which many water lilies still rely on to this day. With this new reliable means of pollination, insect-pollinated plants became enormously successful and diversified. Different plants now began vying with one another for insect attention, evolving bright colors, patterns and elaborate shapes, and the land became clothed in flowers. In this battle to attract pollinators, some flowers evolved an additional weapon — they began producing sugar-rich nectar as an extra reward. As these plants proliferated, so the opportunities for insects to specialize grew, and butterflies and some flies evolved long, tubular mouthparts with which to suck up nectar. The most specialized and successful group to emerge were the bees, the masters of gathering nectar and pollen to this day.

And so, around 130 million years ago, the first true bees appeared. The oldest preserved bee, a stingless specimen immortalized in amber, is 80 million years old. Bumblebees, a particularly beloved hero of children’s books and pop-culture iconography, appeared sometime between 30 and 40 million years ago in the mountains of Central Asia, to this day the area of greatest bumblebee diversity, during a period when Earth’s temperature dropped and the cooler climate caused bees to grow larger and furrier to stay warm. Today, some 25,000 species of bees are known to exist and while many are yet to be discovered, some are already waning. Our beloved bumblebees account for just 1% of the known bee species, or a total of 250 bumblebee species, and three of them — Bombus rubriventris, Bombus melanopoda and Bombus franklini — have gone extinct globally.

Poem and illustration from Joanna Tilsley's science poetry project '30 Days.' Click image for more.

Indeed, central to Goulson’s message is a bittersweet lament that bees are incredibly vulnerable to the general extinction epidemic of our era, as species are going extinct at anywhere between 100 and 1,000 times the natural rate due to habitat destruction, largely of our own doing. Scientists estimate that one species goes extinct every twenty minutes. There has never been a more urgent time to pay heed to E.O. Wilson’s admonition, for if bees once gave our planet its glorious colors and vibrant plant life, it doesn’t take a great leap of the imagination to envision what would happen if they were to disappear.

But despite the urgency of the conservation message, A Sting in the Tale is ultimately an optimistic book, written with profound love and respect for the creatures that gave Earth its colors and us our vitality. Complement it with Jon Mooallem’s heartbreaking and heartening, immeasurably moving Wild Ones.

Donating = Loving

Bringing you (ad-free) Brain Pickings takes hundreds of hours each month. If you find any joy and stimulation here, please consider becoming a Supporting Member with a recurring monthly donation of your choosing, between a cup of tea and a good dinner.

You can also become a one-time patron with a single donation in any amount.

Brain Pickings has a free weekly newsletter. It comes out on Sundays and offers the week’s best articles. Here’s what to expect. Like? Sign up.

11 JULY, 2014

Beloved British Artist Ralph Steadman Illustrates the Life of Leonardo da Vinci


A visual “autobiography” of the legendary polymath that grants equal dignity to the grit and the glory.

Freud once observed that the great Renaissance polymath Leonardo da Vinci was “like a man who awoke too early in the darkness, while the others were all still asleep.” And how blazingly awake he was — his Vitruvian Man endures as one of the most iconic images of all time, his visionary anatomical illustrations changed the course of modern medicine, and he knew how to play the long game of the creative life.

Perhaps this is why in the early 1980s, when he was in his mid-forties, the celebrated British cartoonist Ralph Steadman developed a great obsession with Leonardo. He began to paint the polymath’s fanciful inventions, as well as countless drawings of Leonardo himself, and eventually even travelled to Italy to stand where Leonardo stood, seeking to envision what it was like to inhabit that endlessly imaginative mind and boundless spirit.

In 1983, more than a decade before he illustrated Orwell’s Animal Farm and exactly ten years after his visual interpretation of Alice in Wonderland, Steadman released I, Leonardo (public library) — a remarkable “autobiography” of Da Vinci as imagined by Steadman, written in the first person and illustrated in the cartoonist’s unmistakable style. Funny, poignant, sometimes gory, sometimes optimistic, always intensely intelligent, Steadman’s story stretches from Leonardo’s boyhood experiments to his dying words, granting equal dignity to his triumphs as a genius and his doubts and disappointments as a human being, to the grit and the glory.

Steadman writes in the introduction:

In the Middle Ages the world was still flat, the center of the universe, ruled by villainous warlords, witchcraft and alchemy, superstition and disease. Few dared ask the question “What are the elephants standing on” for fear of being soundly whipped and told to shut up and keep rowing… Not a good time to be born poor, though no worse if you were born a bastard, rich or poor.


Leonardo da Vinci was born twenty years before Michelangelo in 1452. Knowledge through experience was his maxim and his experience showed him that man was not what he appeared to be, despite the prevailing atmosphere of fine thoughts and high aspirations. Yet the purity of his painting set the divine standard of Renaissance art — and of any art for that matter. I believe he preserved intact a part of his private self which found an outlet in his more personal notes and drawings… The wealth of his activities overpowered those who revered him, so that they were virtually unable to employ him. If that were not disability enough, his most beloved disciple kept from the world his inheritance, the notebooks which contained the essence of his master’s spirit. Like a guard dog he hoarded them all his life. After his death they were dismembered and dispersed, only to be rediscovered four hundred years later in a world where Leonardo’s ideas had already come about.

Much of Steadman’s narrative is woven from Leonardo’s own musings, collected in his Thoughts on Art and Life (which is available as a free download and highly recommended). Take, for instance, this passage accompanying Steadman’s terrific drawing of Leonardo’s optic studies:

The eyes … are the chief means whereby the understanding may most fully and abundantly appreciate the infinite works of nature.

The eye counsels all the arts of mankind … it is the prince of mathematics … it has given birth to architecture and to perspective and to the divine art of painting. Painting encompasses all the ten functions of the eye, that is, darkness, light, body, color, shape, location, remoteness, nearness, motion and rest.

Because of the eye the soul is content to stay in its bodily prison, for without it such imprisonment is torture. Who would believe that so small a space could confirm the image of all the universe?

All those coarse jests inside the court serve now to lash my pride. His Holiness the Pope surrounded himself with none but craven guzzlers, gross pretenders and a host of fawning dignitaries who grimaced through their days at court with no more grace than beggars I had entertained in days gone by — though they had neither choice nor wit to rise above themselves and in that they had a reason.

Oh that I had ways to surely serve their putrid masquerades and twittery to make a dragon from the very menagerie within the Vatican itself.

If I could take for its head that of a mastiff or setter, for its eyes those of a cat, for its ears those of a greyhound, with the eyebrows of a lion, the temples of an old cock and the neck of a water tortoise.

O vile monster! How much better it for men that thou shouldst go back to hell! For this the vast forests shall be stripped of their trees; for this an infinite number of creatures shall lose their lives.

Complement I, Leonardo, a masterpiece in its own right, with The Provensens’ spectacular vintage pop-up book on Leonardo’s life and legacy, then revisit Steadman’s sublime illustrations for Animal Farm and Alice in Wonderland.

Donating = Loving

Bringing you (ad-free) Brain Pickings takes hundreds of hours each month. If you find any joy and stimulation here, please consider becoming a Supporting Member with a recurring monthly donation of your choosing, between a cup of tea and a good dinner.

You can also become a one-time patron with a single donation in any amount.

Brain Pickings has a free weekly newsletter. It comes out on Sundays and offers the week’s best articles. Here’s what to expect. Like? Sign up.