(Roughly) Daily

Posts Tagged ‘Leonardo da Vinci

“When I see a white piece of paper, I feel I’ve got to draw”*…



The Nuremberg paper mill, the building complex at the lower right corner, in 1493


Paper made its first appearance in Europe in the 11th century, but was expensive and suffered from poor quality.  By the 15th century, it was inexpensive and of good quality– and that dramatically boosted the level of Renaissance art:

Paper created a monumental shift in European art. … Drawing is a primal urge, … but drawing only became a standard art form when paper became available. In the case of Europe, this occurred dur­ing the Renaissance, when paper was still a new idea on the Continent. Previously, there had been very little informal use of parchment for art because it was too expensive and too difficult to erase. At first, European paper was also too expensive to be used to dash off a quick sketch and had too low a standing to be used for serious art. But by the late fifteenth century, this had all changed. Paper opened up the possibility of the sketch. Renaissance artists sketched out their work before they drew, painted, or sculpted it — or, in the case of Albrecht Dürer’s woodcuts, carved it. This new ability to not only plan but toy with ideas raised their art to a level not known in the Middle Ages…

Sixteenth-century artist and historian Giorgio Vasari, whose Lives of the Most Eminent Painters, Sculptors, and Architects is the leading source of biographical information on the Italian Renaissance artists [see here], tells the story of a sketch by Michelangelo that was displayed in the Palazzo Medici for art students to copy. Since the sheet, like most of Michelan­gelo’s sheets, had a variety of sketches on it, students started tearing off pieces of it, and they became ‘scattered over many places.’ According to Vasari, those fortunate students who ended up with a remnant treasured it and regarded it as something ‘more divine than human.’

Michelangelo used a great deal of paper, [and] … almost any piece of paper he used contained a few sketches. A few are finished drawings. A stunning drawing of the resurrection of Christ is also marked with a shopping list. Masterful drawings were folded up, with notes about the banal ephemera of everyday life jotted on the reverse side. …

Michelangelo may have been among the first to jot down quick ideas for himself. Some 2,000 letters from and to Michelangelo have also been collected. Letter writing is another practice that blossomed with the widespread use of paper…

Leonardo da Vinci was notorious in his lifetime for his inability to complete projects. … Fortunately, there was paper, on which Leonardo could capture his genius. Though he is usually thought of as a painter, only fifteen paintings, some unfinished, have been found, along with two damaged murals. He also attempted some sculpture, though he never finished one piece. But he left behind thirty bound notebooks. Unlike Michel­angelo, he did want people to see this work on paper, including the notes he made in his mirror-image script — a curious response to being left-handed. He left drawings depicting all kind of inventions, and notes on literature, arts, mythology, anatomy, engineering, and, most of all nature….

Leonardo also left behind four thousand sheets of drawings of stag­gering beauty. He was the first artist to be recognized for his drawings on paper. Leonardo’s work became the standard for art in Renaissance Florence. Studying art now meant working on paper, learning to draw. Leonardo had learned art that way himself, in the workshop taught by Andrea del Verrocchio. Artists have been trained on paper ever since.”

More at “Leonardo, Michelangelo, and Paper,” an excerpt from Mark Kurlansky’s Paper: Paging Through History, via the ever-illuminating Delanceyplace.com.

For more on the enabling technologies of art, see “Primary Sources: A Natural History of the Artist’s Palette.”

* Ellsworth Kelly


As we sketch, we might spare a thought for Joseph Severn; he died on this date in 1879.  A painter of portraits and literary and biblical subjects, he was a close friend and traveling companion of John Keats.  His works hang in museums including The (British) National Portrait Gallery, the Victoria and Albert Museum, and Tate Britain.


Severn’s portrait of Keats







Written by LW

August 3, 2020 at 1:01 am

“There is no business like show business. There is also no business like certified public accounting, but that doesn’t rhyme as well.”*…



Portrait of Luca Bartolomeo de Pacioli, attributed to Jacopo de’ Barbari


Modern capitalism began among the European merchant families of the early Renaissance—the Fuggers of Augsburg, Medicis of Florence and, in Venice, one Antonio de Rompiasi, who in 1464 hired a tutor in mathematics for his three sons. Like any sensible teacher, young Luca Pacioli aimed to make his lessons memorable and clear. Good humanist that he was, 30 years later he gathered all the world’s knowledge of the subject into a single massive volume.

His “Summa de Arithmetica, Geometria, Proportioni et Proportionalita” was the 615-page work of a mature professor who had spent decades working across northern Italy. The book was revolutionary on more than one count. It integrated computation using Hindu-Arabic numerals with the logic of classic Greek geometry; it was written in the Italian of the marketplace rather than Latin; and it was circulated in large numbers thanks to the new technology of printing. Yet its greatest significance lay in a slim ‘how to’ chapter that described the double-entry accounting system used by Venetian merchants.

With examples from dealers in butter to lemons to silk, Pacioli set out the method for tracking income and expenditure and the calculation of net profit or loss, which for the first time allowed an immediate snapshot of a firm’s financial position. This slim section would facilitate the birth of the modern corporation.

“Without order there is chaos,” Pacioli observed in a breezy style that is still in vogue in business books today. His manual is stuffed with quotes from scripture and Dante and pithy advice such as “Don’t learn from ignoramuses who have more leaves than grapes.” He wrote the accounting chapter to help would-be traders in Venice, then the capital of the financial world, “sleep easily at night”. Without double-entry book-keeping, “their minds would keep them awake with worry”. He could not suspect that what might be called “Book-keeping for Dummies” would become the backbone of business for centuries.

Like many monumental works of 15th-century printing, Pacioli’s treatise has survived in its original form. Some 120 copies still exist, from an initial run of about 1,000. Now today’s moguls have a chance to own this first folio of finance. Christie’s, the auction house, is offering a first edition in its original vellum binding for sale in New York on June 12th. The starting price is $1m for what it unabashedly calls “the most influential work in the history of capitalism.”

Pacioli’s later life augments the glamour of the first printed use of ‘plus’ and ‘minus’ signs. Impressed by the book, Leonardo da Vinci convinced his patron Lodovico Sforza to hire Pacioli to teach at the court of Milan. Pacioli and Leonardo collaborated on the treatise “Divina Proportione,” which married maths with art through the study of perspective. Not one, but two Renaissance masters were thus responsible for the exquisite harmony of “The Last Supper”…

The 15th-century guide to book-keeping enabled the rise of modern corporations: “A revolutionary treatise goes on the block.”

* Craig Shaw Gardner


As we count carefully, we might recall that it was on this date in 1902 that a US patent (#701,839) was issued to Americus F. Callahan of Chicago, Ill., which he called the outlook envelope– what we call the window envelope.

300px-USPatent701839-CallahanAmericus-WindowedEnvelope source


“The karma of humans is AI”*…


The black box… penetrable?

Already, mathematical models are being used to help determine who makes parole, who’s approved for a loan, and who gets hired for a job. If you could get access to these mathematical models, it would be possible to understand their reasoning. But banks, the military, employers, and others are now turning their attention to more complex machine-learning approaches that could make automated decision-making altogether inscrutable. Deep learning, the most common of these approaches, represents a fundamentally different way to program computers. “It is a problem that is already relevant, and it’s going to be much more relevant in the future,” says Tommi Jaakkola, a professor at MIT who works on applications of machine learning. “Whether it’s an investment decision, a medical decision, or maybe a military decision, you don’t want to just rely on a ‘black box’ method.”

There’s already an argument that being able to interrogate an AI system about how it reached its conclusions is a fundamental legal right. Starting in the summer of 2018, the European Union may require that companies be able to give users an explanation for decisions that automated systems reach. This might be impossible, even for systems that seem relatively simple on the surface, such as the apps and websites that use deep learning to serve ads or recommend songs. The computers that run those services have programmed themselves, and they have done it in ways we cannot understand. Even the engineers who build these apps cannot fully explain their behavior…

No one really knows how the most advanced algorithms do what they do. That could be a problem: “The Dark Secret at the Heart of AI.”

* Raghu Venkatesh


As we get to know our new overlords, we might spare a thought for the painter, sculptor, architect, musician, mathematician, engineer, inventor, physicist, chemist, anatomist, botanist, geologist, cartographer, and writer– the archetypical Renaissance Man– Leonardo da Vinci.  Quite possibly the greatest genius of the last Millennium, he died on this date in 1519.

Self-portrait in red chalk, circa 1512-15


Written by LW

May 2, 2017 at 1:01 am

“Time flies over us, but leaves its shadow behind”*…


A lot of photographers aim to capture one, perfect moment in time. Richard Silver might argue that’s aiming low. His surreal productions are multilayered temporal sandwiches, showing how world landmarks morph in appearance from dawn to sunset.

The Manhattan-based photographer has deployed his “time-slice” technique during extensive travels around the globe (he has reportedly visited “more than 200 cities in his life, traveling to 13 countries last year alone”). Silver must have a superhuman tolerance to jet lag, because his process requires torturous amounts of labor and alertness…

See more of Silver’s time-conflated photos, and read more of his method, at “Behold, Famous Landmarks Shot in the Fourth Dimension of Time.”

* Nathaniel Hawthorne, The Marble Faun


As we watch the clock, we might send beautiful birthday greetings to Michelangelo di Lodovico Buonarroti Simoni; he was born on this date in 1475.  A sculptor, painter, architect, poet, and engineer in the High Renaissance, Michelangelo was considered one of the greatest artists of his time.  And given his profound influence on the development of Western art, he has subsequently been considered one of the greatest artists of all time.  Indeed, he is widely held to be (with Leonardo da Vinci) the archetypal Renaissance man.

Daniele da Volterra’s portrait of Michelangelo



Written by LW

March 6, 2015 at 1:01 am

A Matter of Some Gravity…


I’ve been noticing gravity since I was very young.
-Cameron Diaz

Isaac Newton first proposed a universal law of gravitation, where every massive body in the universe was attracted to every other one. This simple law proved extremely powerful, able to explain the orbits of planets and the reason the apocryphal apple fell on his head. However, Newton was never able to explain why gravity worked or what exactly it was. Two hundred plus years later, Albert Einstein was able to offer a more complete description of gravity—one where Newton’s laws are a limited case. According to Einstein, gravity was due to the warpage of spacetime by mass and energy; all objects followed straight paths, just on curved spaces.

With the advent of quantum theory over the past 100 years, scientists have been able to develop an elegant mathematical framework capable of uniting three of the four fundamental forces that are thought to exist in the universe. The fourth, gravity, still remains the fly in the ointment, and has resisted unification to this point. Early last year, Dutch theoretical physicist Erik Verlinde published a manuscript to the arXiv that purports to explain why science cannot reconcile all four fundamental forces. According to him, it is simple: “gravity doesn’t exist.”

Read the full story (SPOILER ALERT: it relates to Leonard Susskind‘s “holographic principle,” suggesting in effect that gravity isn’t a fundamental force, but an “entropic” result of information imbalances between the bodies/regions in question) in Ars Technica (recapping Physical Review D, 2011. DOI: 10.1103/PhysRevD.83.021502).

As we sit more confidently beneath apple trees, we might wish a polymathic Happy Birthday to the painter, sculptor, architect, musician, scientist, mathematician, engineer, inventor, anatomist, geologist, cartographer, botanist and writer– the archetypical Renaissance Man– Leonardo da Vinci; he was born on this date in 1452.

Self-portrait in Red Chalk (source)

%d bloggers like this: