(Roughly) Daily

Posts Tagged ‘Leonardo da Vinci

“The most important things are paper airplanes and dreams”*…

The paper airplane has a long history of contributions to our understanding of flight…

… Our obsession with testing the boundaries of folded flight is relatively recent, but our desire to explore and explain the complex world of aerodynamics goes back much further.

Chinese engineers are thought to have invented what could be considered the earliest paper planes around 2,000 years ago. But these ancient gliders, usually crafted from bamboo and paper or linen, resembled kites more than the dart-shaped fliers that have earned numerous Guinness World Records in recent years.

Leonardo da Vinci would take a step closer to the modern paper airplane in the late 14th and early 15th centuries by building paper models of his aircraft designs to assess how they might sustain flight. But da Vinci’s knowledge of aerodynamics was fairly limited. He was more inspired by animal flight and, as a result, his design for craft like the ornithopter—a hang-glider-​size set of bat wings that used mechanical systems powered by human movement—never left the ground.

Paper airplanes helped early engineers and scientists learn about the mechanics of flight. The British engineer and aviator Sir George Cayley reportedly crafted the first folded paper plane to approach modern specifications in the early 1800s as part of his personal experimentation with aerodynamics. “He was one of the early people to link together the idea that the lift from the wings picking up the aircraft for stable flight must be greater than or equal to the weight of the aircraft,” says Jonathan Ridley, PhD, the head of engineering and a scholar of early aviation at Solent University in the U.K.

More than a century later, before their famous 1903 flight in Kitty Hawk, North Carolina, the Wright Brothers built paper models of wings to better understand how their glider would sustain flight, explains Ridley. They then tested these models in a rudimentary, refrigerator-size wind tunnel—only the second to be built in the U.S. Paper planes are still illuminating the hidden wonders of flight. Today, these lightweight aircraft serve as a source of inspiration not only for aviation enthusiasts but also for fluid dynamicists and engineers studying the complex effects of air on small aircraft like drones…

For centuries, paper airplanes have unlocked the science of flight—now they could inspire drone technology: “A Living History of The Humble Paper Airplane,” from @PopMech.

* Christopher Morley


As we fold ’em and fly ’em, we might spare a thought for Wiley Post. A famed aviator of the interwar period, he was the first the first pilot to fly solo around the world. Post was also known for his work in high-altitude flying; he helped develop one of the first pressure suits and discovered the jet stream.

Today is also the anniversary of the death of famed humorist Will Rogers. On this date in 1935, Post and Rogers were killed when Post’s aircraft crashed on takeoff from a lagoon near Point Barrow in the Territory of Alaska.


“These are the forgeries of jealousy”*…

Analysis of Leonardo da Vinci’s Salvator Mundi required dividing a high-resolution image of the complete painting into a set of overlapping square tiles. But only those tiles that contained sufficient visual information, such as the ones outlined here, were input to the author’s neural-network classifier.

Is it authentic? Attorney and AI practitioner Steven J. Frank, working with his wife, art historian and curator Andrea Frank (together, Art Eye-D Associates), brings machine learning to bear…

The sound must have been deafening—all those champagne corks popping at Christie’s, the British auction house, on 15 November 2017. A portrait of Jesus, known as Salvator Mundi (Latin for “savior of the world”), had just sold at Christie’s in New York for US $450.3 million, making it by far the most expensive painting ever to change hands.

But even as the gavel fell, a persistent chorus of doubters voiced skepticism. Was it really painted by Leonardo da Vinci, the towering Renaissance master, as a panel of experts had determined six years earlier? A little over 50 years before that, a Louisiana man had purchased the painting in London for a mere £45. And prior to the rediscovery of Salvator Mundi, no Leonardo painting had been uncovered since 1909.

Some of the doubting experts questioned the work’s provenance—the historical record of sales and transfers—and noted that the heavily damaged painting had undergone extensive restoration. Others saw the hand of one of Leonardo’s many protégés rather than the work of the master himself.

Is it possible to establish the authenticity of a work of art amid conflicting expert opinions and incomplete evidence? Scientific measurements can establish a painting’s age and reveal subsurface detail, but they can’t directly identify its creator. That reLeonardo da quires subtle judgments of style and technique, which, it might seem, only art experts could provide. In fact, this task is well suited to computer analysis, particularly by neural networks—computer algorithms that excel at examining patterns. Convolutional neural networks (CNNs), designed to analyze images, have been used to good advantage in a wide range of applications, including recognizing faces and helping to pilot self-driving cars. Why not also use them to authenticate art?

That’s what I asked my wife, Andrea M. Frank, a professional curator of art images, in 2018. Although I have spent most of my career working as an intellectual-property attorney, my addiction to online education had recently culminated in a graduate certificate in artificial intelligence from Columbia University. Andrea was contemplating retirement. So together we took on this new challenge…

With millions at stake, deep learning enters the art world. The fascinating story: “This AI Can Spot an Art Forgery,” @ArtAEye in @IEEESpectrum.

* Shakespeare (Titania, A Midsummer Night’s Dream, Act II, Scene 1)


As we honor authenticity, we might spare a thought for a champion of authenticity in a different sense, Joris Hoefnagel; he died on this date in 1601. A Flemish painter, printmaker, miniaturist, draftsman, and merchant, he is noted for his illustrations of natural history subjects, topographical views, illuminations (he was one of the last manuscript illuminators), and mythological works.

Hoefnagel made a major contribution to the development of topographical drawing. But perhaps more impactfully, his manuscript illuminations and ornamental designs played an important role in the emergence of floral still-life painting as an independent genre in northern Europe at the end of the 16th century. The almost scientific naturalism of his botanical and animal drawings served as a model for a later generation of Netherlandish artists.  Through these nature studies he also contributed to the development of natural history and he was thus a founder of proto-scientific inquiry.

Portrait of Joris Hoefnagel, engraving by Jan Sadeler, 1592 (source)

“I don’t believe in astrology; I’m a Sagittarius and we’re skeptical.”*…

(Roughly) Daily has looked at almanacs before (e.g., here and here), but never with an eye to their astrological underpinnings. Livia Gershon plugs that gap…

Some Christians today see astrology as a clear affront to their beliefs, and possibly a dangerous manifestation of the occult. And yet, as historian T.J. Tomlin writes, through the eighteenth century, it was a central aspect of the almanacs that were ubiquitous in Protestant American homes.

By 1800, Tomlin writes, U.S. printers produced enough almanacs to provide one to every household in the country. People turned to the books for a clear, simple idea of how the universe worked. Their astrological calculations helped readers gain practical know-how about agricultural management, weather, and personal health.

Like the study of the natural world in general in that time and place, almanacs were rooted in Protestantism. They presented simple, widely held religious ideas—God’s power, redemption through Christ, the promise of heaven—to an increasingly literate public. “This was the liturgy of early American popular culture,” Tomlin writes.

But there were debates about what sort of astrology was compatible with this religious belief. “Natural astrology,” using the movements of heavenly bodies to draw conclusions about agriculture, medicine, and the weather, was widely regarded as “a way to illuminate God’s creative impulse in the universe,” Tomlin writes. But “judicial astrology,” predicting the events of individual lives or political affairs, might be seen as blasphemous…

Wildly popular, almanacs helped people understand farming and health through the movement of the planets, in a way compatible with their faith: “The Protestant Astrology of Early American Almanacs,” from @LiviaGershon in @JSTOR_Daily.

* Arthur C. Clarke


As we study the stars, we might send multi-faceted birthday greetings to 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 was born on this date in 1452.

While Leonardo’s attention (and thus his notebooks) extended to astronomy, there’s no evidence that he believed in astrology. That said, his chart has been cast myriad times (e.g., here).

 Self-portrait in red chalk, circa 1512-15 [source]

Written by (Roughly) Daily

April 15, 2023 at 1:00 am

“What beauty is, I know not, though it adheres to many things”*…

Albrecht Dürer (German, 1471 – 1528 ), Saint Eustace, c. 1500/1501, engraving

Renaissance artist Albrecht Dürer was on a constant hunt for inspiration– and found novelty everywhere on his travels…

In 1520 Albrecht Dürer was in Brussels when the contents of a treasure ship sent back from the Americas by Hernán Cortés were put on display to celebrate the coronation of Charles V. The cache contained, among other items, obsidian weapons, jaguar pelts, feathered shields, gemstones and mosaic pieces, and gold wrought in innumerable inventive ways. Dürer, the son of a Nuremberg goldsmith, was flabbergasted. “All the days of my life I have seen nothing that rejoiced my heart so much as these things,” he wrote, “for I saw amongst them wonderful works of art.” But then, for him, everything was a work of art – either God-made or man-made. His well-known watercolours of a piece of turf and the iridescent wing of a blue roller bird are themselves marvels of creation that show marvels of creation.

For Dürer, even more than for most artists, the world was a place of wonder. If Leonardo da Vinci, his senior by 19 years, looked longest and deepest at natural phenomena – from the flow of water to the action of veins and sinews – Dürer (1471-1528) was in thrall to materiality, where sight became an extension of touch…

How a Renaissance master and inveterate traveler journeyed in a permanent state of fascination: “The wonders of Albrecht Dürer’s world,” from Michael Prodger in @NewStatesman.

* Albrecht Dürer


As we wonder, we might spare a thought for Ludwig Emil Grimm; he died on this date in 1863. A painter, art professor, etcher, and copper engraver, his subjects included his two brothers, the folklorists Jacob and Wilhelm Grimm.

self-portrait, 1813


“Inanimate objects sometimes appear endowed with a strange power of sight. A statue notices”*…

Scan the World is an ambitious initiative that gives you the possibility to enjoy 3D printable representations of cultural artifacts in a remarkably tangible way. The community led project enables everyone with access to the internet to experience material culture in an emotionally impactful manner, one which digital images cannot otherwise offer. The collaborative, living network removes the barriers of geographic location and socioeconomic backgrounds by empowering you to engage, behold, scan or own a copy of 3d printable artifacts that hold significance for you. The collective effort is as much about renowned historical artifacts as it is about household antiques with deep culturally significant roots.

Your contributions work to bridge the gap between technology and the arts. The web of diverse sharers range from educators, scanners, storytellers, artists, makers, historians, art lovers, globe trotters and all passionate individuals, eager to share a piece of their unique culture. Scan the world is about adding dimension to your cultural identity by sharing your views, roots, artifacts and narratives with the world. Providing you with space to deepen your understanding of your personal heritage while giving you the freedom to enrich the otherwise untold story of your ancestors. This initiative was born to put culture back on the map; to connect you to your roots and sense of belonging, and give you a chance to share and strengthen your understanding of yourself. You are the result of the generations that came before you. This network in its truest form is a shared, open access, museum of the future, built by and for you…

Cultural heritage is important for historical research and education as well as establishing a sense of identity amongst communities. Through documenting the past, cultural heritage comes in both physical and intangible forms which include objects, monuments, beliefs, rituals and traditions. 

Scan the World collects stories from people and museums alike, to share various views on the importance and impact of culture, helping diversify our personal approach to art. As different individuals will have very different experiences and values within their own culture, this network provides a safe space for culture to be shared and discovered, no matter where in the world it comes from… 

Access to heritage: Scan the World collects and shares 3-D printable files of cultural artifacts (since it’s inception in 2014, over 17,000, by over 1800 artists/artisans, from over 800 places around the world).

* Victor Hugo


As we peruse our past, we might spare a thought for someone whose work is in STW– 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 [source]

%d bloggers like this: