Science and inventions of Leonardo da Vinci

Infobox Artist
name = Leonardo da Vinci

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imagesize = 200px
caption = "The Vitruvian Man" by Leonardo is possibly the best known drawing in the world.
birthname = Leonardo di Ser Piero
birthdate = birth date|1452|4|15|mf=y flagicon|ITA Anchiano, Florence, Italy
deathdate = death date and age|1519|5|2|1452|4|15|mf=y
deathplace = Flagicon|FRA Amboise, Indre-et-Loire, France
nationality = Italian
field = Many and diverse fields of arts and sciences
movement = High Renaissance
works = Paintings including Mona Lisa and The Last Supper. Many scientific drawings including The Vitruvian Man

Leonardo da Vinci (1452–1519) was an Italian polymath, regarded as the epitome of the "Renaissance Man", displaying skills in many and diverse areas. Whilst most famous for his paintings such as the "Mona Lisa" and the "Last Supper", Leonardo is also renowned as a scientist, engineer and inventor. The areas of his scientific study included aeronautics, anatomy, astronomy, botany, civil engineering, chemistry, geology, geometry, hydrodynamics, mathematics, mechanical engineering, optics, physics, pyrotechnics and zoology.

Whilst the full extent of his scientific studies has only become recognized in the last 150 years, he was, during his lifetime, employed for his engineering and skill of invention. Many of his designs, such as the movable dykes to protect Venice from invasion, proved too costly or impractical. Some of his smaller inventions entered the world of manufacturing unheralded. As an engineer, Leonardo conceived ideas vastly ahead of his own time, conceptually inventing a helicopter, a tank, the use of concentrated solar power, a calculator, a rudimentary theory of plate tectonics and the double hull. In practice, he greatly advanced the state of knowledge in the fields of anatomy, astronomy, civil engineering, optics, and the study of water (hydrodynamics).

Leonardo's most famous drawing, the "Vitruvian Man", is a study of the proportions of the human body, linking art and science in a single work that has come to represent Renaissance Humanism.

Condensed biography

"This is a brief summary of Leonardo's early life and journals with particular emphasis on his introduction to science."

Leonardo di ser Piero da Vinci (April 15, 1452 – May 2, 1519) was born the illegitimate son of Messer Piero, a notary, and Caterina, a peasant woman. His early life was spent in the region of Vinci, in the valley of the Arno River in near Florence, firstly with his mother and in later childhood in the household of his father, grandfather and uncle Francesco.

His curiosity and interest in scientific observation were stimulated by his uncle Francesco, while his grandfather's keeping of journals set an example which he was to follow for most of his life, diligently recording in his own journals both the events of the day, his visual observations, his plans and his projects. The journals of Leonardo contain matters as mundane as grocery lists and as remarkable as diagrams for the construction of a flying machine.

In 1466, Leonardo was sent to Florence to the workshop of the artist Verrocchio, in order to learn the skills of an artist. At the workshop, as well as painting and drawing, he learnt the study of "topographical anatomy". ["Topographical anatomy" is the anatomy that is visible on the surface of the body.] He was also exposed to a very wide range of technical skills such as drafting, set construction, plasterworking, paint, chemistry, and metallurgy.

Among the older artists whose work stimulated Leonardo's scientific interest was Piero della Francesca, then a man in his 60s, who was one of the earliest artists to systematically employ linear perspective in his paintings, and who had a greater understanding of the science of light than any other artist of his date. While Leonardo's teacher, Verrocchio, largely ignored Piero's scientifically disciplined approach to painting, Leonardo and Ghirlandaio, who also worked at Verrocchio's workshop, did not. Two of Leonardo's earliest paintings, both scenes of the "Annunciation" show his competent understanding of the linear perspective.

Leonardo was profoundly observant of nature, his curiosity having been stimulated in early childhood by his discovery of a deep cave in the mountains and his intense desire to know what lay inside. His earliest dated drawing, 1473, is of the valley of the Arno River, where he lived. It displays some of the many scientific interests that were to obsess him all his life, in particular geology and hydrology. References:BortolonLiana Bortolon, "The Life and Times of Leonardo", Paul Hamlyn, 1967]

Approach to scientific investigation

During the Renaissance, the study of Art and Science was not perceived as mutually exclusive; on the contrary, the one was seen as informing upon the other. Although Leonardo's training was primarily as an artist, it was largely through his scientific approach to the art of painting, and his development of a style that coupled his scientific knowledge with his unique ability to render what he saw that created the outstanding masterpieces of art for which he is famous.

As a scientist, Leonardo had no formal education in Latin and mathematics and did not attend a university. Because of these factors, his scientific studies were largely ignored by other scholars. Leonardo's approach to science was one of intense observation and detailed recording, his tools of investigation being almost exclusively his eyes. His journals give insight into his investigative processes.

Leonardo's journals

Leonardo kept a series of journals in which he wrote almost daily, as well as separate notes and sheets of observations, comments and plans which were left to various pupils and were later bound. Many of the journals have survived to illustrate Leonardo's studies, discoveries and inventions. Most of the journals were written backwards in mirror script. His journals were later published 165 years after his death.

Publication

Leonardo illustrated a book on mathematical proportion in art written by his friend Luca Pacioli and called "De divina proportione", published in 1509. He was also preparing a major treatise on his scientific observations and mechanical inventions. It was to be divided into a number of sections or "Books", Leonardo leaving some instructions as to how they were to be ordered. Many sections for it appear in his notebooks.

These pages deal with scientific subjects generally but also specifically as they touch upon the creation of artworks. In relating to art, this is not science that is dependent upon experimentation or the testing of theories. It deals with detailed observation, particularly the observation of the natural world, and includes a great deal about the visual effects of light on different natural substances such as foliage.Jean Paul Richter editor 1880, "The Notebooks of Leonardo da Vinci" Dover, 1970, ISBN 0-486-22572-0. [http://www.fromoldbooks.org/Richter-NotebooksOfLeonardo] (accessed 2007-02-04)]

Leonardo writes:

Natural science

Light

For an artist working in the 15th century, some study of the nature of light was essential. It was by the effective painting of light falling on a surface that "modelling", or a three dimensional appearance was to be achieved in a two-dimensional medium. It was also well understood by artists like Leonardo's teacher, Verrocchio, that an appearance of space and distance could be achieved in a background landscape by painting in tones that were less in contrast and colours that were less bright than in the foreground of the painting. The effects of light on solids were achieved by trial and error, few artists except Piero della Francesca, having accurate scientific knowledge of the subject.

At the time when Leonardo commenced painting, it was unusual for figures to be painted with extreme contrast of light and shade. Faces, in particular, were shadowed in a manner that was bland and maintained all the features and contours clearly visible. Leonardo broke with this. In the painting generally titled "The Lady with an Ermine" (about 1483) he sets the figure diagonally to the picture space and turns her head so that her face is almost parallel to her nearer shoulder. The back of her head and the further shoulder are deeply shadowed. Around the ovoid solid of her head and across her breast and hand the light is diffused in such a way that the distance and position of the light in relation to the figure can be calculated.

Leonardo's treatment of light in paintings such as The Virgin of the Rocks and the Mona Lisa was to change forever the way in which artists perceived light and used it in their paintings. Of all Leonardo's scientific legacies, this is probably the one that had the most immediate and noticeable effect.

Human anatomy

Topographic anatomy

Leonardo began the formal study of the topographical anatomy of the human body when apprenticed to Andrea del Verrocchio. As a student he would have been taught to draw the human body from life, to memorise the muscles, tendons and visible subcutaneous structure and to familiarise himself with the mechanics of the various parts of the skeletal and muscular structure. It was common workshop practice to have plaster casts of parts of the human anatomy available for students to study and draw.If, as is thought to be the case, Leonardo painted the torso and arms of Christ in "The Baptism of Christ" on which he famously collaborated with his master Verrocchio, then his understanding of topographical anatomy had surpassed that of his master at an early age as can be seen by a comparison of the arms of Christ with those of John the Baptist in the same painting.

In the 1490s he wrote about demonstrating muscles and sinews to students:

His continued investigations in this field are demonstrated by many fine drawings in his journals. In conjunction with studies of aspects of the body are drawings of faces displaying different emotions and many drawings of people suffering facial deformity, either congenital or through illness. Some of these drawings, generally referred to as "caricatures", on analysis of the skeletal proportions, appear to be based on anatomical studies.

Dissection

As Leonardo became successful as an artist, he was given permission to dissect human corpses at the hospital Santa Maria Nuova in Florence. Later he dissected in Milan at the hospital Maggiore and in Rome at the hospital Santo Spirito (the first mainland Italian hospital). From 1510 to 1511 he collaborated in his studies with the doctor Marcantonio della Torre.

In 30 years, Leonardo dissected 30 male and female corpses of different ages. Together with Marcantonio, he prepared to publish a theoretical work on anatomy and made more than 200 drawings. However, his book was published only in 1680 (161 years after his death) under the heading "Treatise on painting". Among the detailed images that Leonardo drew are many studies of the human skeleton. He was the first to describe the double S form of the backbone. He also studied the inclination of pelvis and sacrum and stressed that sacrum was not uniform, but composed of five fused vertebrae. He dissected and drew the human skull and cross-sections of the brain, transversal, sagittal, and frontal.

Not only interested in structure but also in function, Leonardo was a physiologist in addition to being an anatomist. He studied internal organs, being the first to draw the human appendix and also drawing detailed images of the lungs, mesentery, urinary tract, sex organs, the muscles of the cervix and a detailed cross-section of coitus.

Leonardo was one of the first to draw a scientific representation of the fetus in the intrautero. He studied the vascular system and drew a dissected heart in detail. He correctly worked out how heart valves ebb the flow of blood yet he did not fully understand circulation as he believed that blood was pumped to the muscles where it was consumed. Leonardo's drawing inspired a British heart surgeon to pioneer a new way to repair damaged hearts in 2005. [http://news.bbc.co.uk/2/hi/health/4289204.stm]

His study of human anatomy led also to the design of the first known robot in recorded history. The design, which has come to be called Leonardo's robot, was probably made around the year 1495 but was rediscovered only in the 1950s. It is not known if an attempt was made to build the device.

Comparative anatomy

Leonardo not only studied human anatomy, but the anatomy of many other animals as well. He dissected cows, birds, monkeys and frogs, comparing in his drawings their anatomical structure with that of humans. On one page of his journal Leonardo drew five profile studies of a horse with its teeth bared in anger and, for comparison, a snarling lion and a snarling man.

In the early 1490s Leonardo was commissioned to create a monument in honour of Francesco Sforza. In his notebooks are a series of plans for an equestrian monument. There are also a large number of related anatomical studies of horses. They include several diagrams of a standing horse with the angles and proportions anotated, anatomical studies of horses' heads, a dozen detailed drawings of hooves and numerous studies and sketches of horses rearing.

He studied the topographical anatomy of a bear in detail, making many drawings of its paws. There is also a drawing of the muscles and tendons of the bear's hind feet. Other drawings of particular interest include the uterus of a pregnant cow, the hindquarters of a decrepit mule and studies of the musculature of a little dog.

Botany

The science of Botany was long established by Leonardo's time, a treatise on the subject having been written as early as 300 BCE [eg. 'Theophrastus, "On the History of Plants".] Leonardo's study of plants, resulting in many beautiful drawings in his notebooks, was not to record in diagramatic form the parts of the plant, but rather, as an artist and observer to record the precise appearance of plants, the manner of growth and the way that individual plants and flowers of a single variety differed from one another. One such study shows a page with several species of flower of which ten drawings are of wild violets. Along with a drawing of the growing plant and a detail of a leaf, Leonardo has repeatedly drawn single flowers from different angles, with their heads set different on the stem.

Apart from flowers the notebooks contain many drawings of crop plants including several types of grain and a variety of berries including a detailed study of bramble. There are also water plants such as irises, bullrushes and sedge. His notebooks also direct the artist to observe how light reflects from foliage at different distances and under different atmospheric conditions.

A number of the drawings have their equivalents in Leonardo's painting. An elegant study of a stem of lilies may have been for one of Leonardo's early Annunciation paintings, carried in the hand of the Archangel Gabriel. In both the Annunciation pictures the grass is dotted with blossoming plants.

The plants which appear in both the versions of The Virgin of the Rocks demonstrate the results of Leonardo's studies in a meticulous realism that makes each plant readily identifiable to the botanist.

Geology

As an adult, Leonardo had only two childhood memories, one of which was the finding of a cave in the Apennines. Although fearing that he might be attacked by a wild beast, he ventured in driven "by the burning desire to see whether there might be any marvelous thing within."

Leonardo's earliest dated drawing is a study of the Arno Valley, strongly emphasizing its geological features. His note books contain landscapes with a wealth of geological observation from the regions of both Florence and Milan, often including atmospheric effects such as a heavy rainstorm pouring down on a town at the foot of a mountain range.

It had been observed for many years that strata in mountains often contained bands of sea shells. Conservative science said that these could be explained by the "Great Flood" described in the Bible. Leonardo's observations convinced him that this could not possibly be the case.

This quotation makes clear the breadth of Leonardo's understanding of Geology, including the action of water in creating sedimentary rock, the tectonic action of the earth in raising the sea bed and the action of erosion in the creation of geographical features.

In Leonardo's earliest paintings we see the remarkable attention given to the small landscapes of the background, with lakes and water, swathed in a misty light. In the larger of the Annunciation paintings is a town on the edge of a lake. Although distant, the mountains can be seen to be scored by vertical strata. This characteristic can be observed in other paintings by Leonardo, and closely resembles the mountains around Lago di Garda and Lago d'Iseo in Northern Italy. It is a particular feature of both the paintings of The Virgin of the Rocks, which also include caverns of fractured, tumbled and water eroded limestone. [The London painting of the Virgin of the Rocks is denounced by the geologist Anne C. Pizzorusso, of New York, as largely by the hand of someone other than Leonardo, because the rocks appear incongruous and the lake looks like a fjord. Pizzorusso says "Fjords do not exist in Italy and it is highly unlikely the glacial lakes of the Lombard region would have such steep relief surrounding them." In fact, the glacial lake, Garda, has just such steep geological formations. The sedimentary red limestone which appears in the picture is also typical of Italy.]

Hydrodynamics

Among Leonardo's drawings are many that are studies of the motion of water, in particular the forms taken by fast-flowing water on striking different surfaces.

Many of these drawings depict the spiralling nature of water. The spiral form had been studied in the art of the Classical era and strict mathematical proportion had been applied to its use in art and architecture. An awareness of these rules of proportion had been revived in the early Renaissance. In Leonardo's drawings can be seen the investigation of the spiral as it occurs in water.

There are several elaborate drawings of water curling over an object placed at a diagonal to its course. There are several drawings of water dropping from a height and curling upwards in spiral forms. One such drawing, as well as curling waves, shows splashes and details of spray and bubbles.

Leonardo's interest manifested itself in the drawing of streams and rivers, the action of water in eroding rocks, and the cataclysmic action of water in floods and tidal waves. The knowledge that he gained from his studies was employed in devising a range of projects, particularly in relation to the Arno River. None of the major works was brought to completion.

See below

Astronomy

Alchemy

Claims have sometimes been made that Leonardo da Vinci was an alchemist. However, his scientific process was based mainly upon observation. His practical experiments are also founded in observation rather than belief. Leonardo, who questioned the order of the solar system and the deposit of fossils by the Great Flood, had little time for the notion that a lead could be turned into gold or that a potion could be created that gave eternal life.

Leonardo said about alchemists:-

Mathematical studies

Perspective

During the early 15th century, both Brunelleschi and Alberti made studies of linear perspective. In 1436 Alberti published "della Pittura" ("On Painting"), which includes his findings on linear perspective. Piero della Francesca carried his work forward and by the 1470s a number of artists were able to produce works of art that demonstrated a full understanding of the principles of linear perspective.

Leonardo studied linear perspective and employed it in his earlier paintings. His use of perspective in the two Annunciations is daring, as he uses various features such as the corner of a building, a walled garden and a path to contrast enclosure and spaciousness.

The unfinished Adoration of the Magi was intended to be a masterpiece revealing much of Leonardo's knowledge of figure drawing and perspective. There exists a number of studies that he made, including a detailed study of the perspective, showing the complex background of ruined Classical buildings that he planned for the left of the picture. In addition, Leonardo is credited with the first use of anamorphosis, the use of a "perspective" to produce an image that is intelligible only with a curved mirror or from a specific vantage point. [ [http://www.illusionworks.com/mod/anamorph.htm# Animations of anamorphosis of Leonardo and other artists] ]

Leonardo wrote:

Geometry

While in Milan in 1496 Leonardo met a traveling monk and academic, Luca Pacioli. Under him, Leonardo studied mathematics. Pacioli, who devised the double entry system of bookkeeping, had already published a major treatise on Mathematical knowledge, collaborated with Leonardo in the production of a book called "De divina proportione" about mathematical and artistic proportion. Leonardo prepared a series of drawings of regular solids in a skeletal form to be engraved as plates. "De divina proportione" was published in 1509.

Engineering and invention

Vasari in "Lives of the Artists" says of Leonardo:

See:fulling

Practical inventions and projects

Leonardo was a master of mechanical principles. He utilised leverage and cantilevering, pulleys, cranks, gears, including angle gears and rack and pinion gears; parallel linkage, momentum, centripetal force and the aerofoil.

Because Leonardo's inventions date from an era before the issue of patents, it is impossible to say with any certainty how many or even which of his inventions passed into general and practical use, and thereby had impact over the lives of many people. Among those inventions that are credited with passing into general practical use are the strut bridge, the automated bobbin winder, the machine for testing the tensile strength of wire and the lens-grinding machine pictured at right.

In the lens-grinding machine, the hand rotation of the grinding wheel operates an angle-gear, which rotates a shaft, turning a geared dish in which sits the glass or crystal to be ground. A single action rotates both surfaces at a fixed speed ratio determined by the gear.

As an inventor, Leonardo was not prepared to tell all that he knew:

Bridges and hydraulics

Leonardo's study of the motion of water led him to design machinery that utilised its force. Much of his work on hydraulics was for Ludovico il Moro. Leonardo wrote to Ludovico describing his skills and what he could build:

Among his projects in Florence was one to divert the course of the Arno, in order to flood Pisa. Fortunately, this was too costly to be carried out. He also surveyed Venice and came up with a plan to create a movable dyke for the city's protection against invaders.

In 1502, Leonardo produced a drawing of a single span 240 m (720 ft) bridge as part of a civil engineering project for Ottoman Sultan Beyazid II of Istanbul. The bridge was intended to span an inlet at the mouth of the Bosphorus known as the Golden Horn. Beyazid did not pursue the project, because he believed that such a construction was impossible. Leonardo's vision was resurrected in 2001 when a smaller bridge based on his design was constructed in Norway. On 17 May 2006, the Turkish government decided to construct Leonardo's bridge to span the Golden Horn. [Daniel S. Levy, "Dream of the Master", Time Life, 4 October 1999, [http://www.vebjorn-sand.com/dreamsofthemaster.html] ]

War machines

Leonardo's letter to Ludovico il Moro assured him:

In Leonardo's notebooks there is an array of war machines which includes a tank to be propelled by two men powering crank shafts. Although the drawing itself looks quite finished, the mechanics were apparently not fully developed because, if built as drawn, the tank, with a lot of effort, might be made to rotate on the spot, but would never progress in a forward direction. In a BBC documentary, a military team built the machine and found it not working, until they changed only one of the gears. It is believed that Da Vinci deliberately left this error in the design, in order to prevent it from being put to practice by unauthorized people. [ [http://www.theage.com.au/articles/2002/12/13/1039656218782.html Da Vinci war machines "designed to fail" - theage.com.au ] ] Another machine, propelled by horses with a pillion rider, carries in front of it four scythes mounted on a revolving gear, turned by a shaft driven by the wheels of a cart behind the horses.

Leonardo's notebooks also show cannons which he claimed "to hurl small stones like a storm with the smoke of these causing great terror to the enemy, and great loss and confusion."

He also designed an enormous crossbow. Following his detailed drawing, one was constructed by the British Army, but could not be made to fire successfully.

Leonardo was the first to sketch the wheel-lock musket c. 1500 AD (the precedent of the flintlock musket which first appeared in Europe by 1547), although the Chinese of the earlier 14th century had used a flintlock 'steel wheel' in order to detonate land mines.Needham, Volume 5, Part 7, 199.]

Flight

In Leonardo's infancy a hawk had once hovered over his cradle. Recalling this incident, Leonardo saw it as prophetic.

The desire to fly is expressed in the many studies and drawings. His later journals contain a detailed study of the flight of birds and several different designs for wings based in structure upon those of bats which he described as being less heavy because of the impenetrable nature of the membrane. There is a legend that Leonardo tested the flying machine with one of his apprentices, and that the apprentice fell and broke his leg. [Liana Bortolon, "Leonardo", Paul Hamlyn, (1967)] Experts Martin Kemp and Liana Bortolon agree that there is no evidence of such a test, which is not mentioned in his journals.

One design that he produced shows a helicopter to be lifted by a rotor powered by four men. It would not have worked since the body of the craft itself would have rotated in the opposite direction to the rotor. [ see Helicopter for detailed description of solutions and types of functional helicopter.]

While he designed a number of man powered flying machines with mechanical wings that flapped, he also designed a parachute and a light hang glider which could have flown. [U.S. Public Broadcasting Service (PBS), "Leonardo's Dream Machine", October 2005 ]

Leonardo's inventions made reality

In the late 20th century, interest in Leonardo's inventions has escalated. There have been many projects which have sought to turn diagrams on paper into working models. One of the factors is the awareness that, although in the 15th and 16th centuries Leonardo had available a limited range of materials, modern technological advancements have made available a number of robust materials of light-weight which might turn Leonardo's dreams into reality. This is particularly the case with his designs for flying machines.

A difficulty encountered in the creation of models is that often Leonardo had not entirely thought through the mechanics of a machine before he drew it, or else he used a sort of graphic shorthand, simply not bothering to draw a gear or a lever at a point where one is absolutely essential in order to make a machine function. Matters like this were probably so obvious to a person of Leonardo's skills that he didn't need to record them, but to a technical college student, creating a model for a display, this lack of refinement of mechanical details can cause considerable confusion. Thus many models that are created, such as some of those on display at Clos Luce, Leonardo's home in France, do not work, but would work, with a little mechanical tweaking.

Exhibitions

* Models of Leonardo's designs are on permanent display at Clos Luce.
* The Victoria and Albert Museum, London, held an exhibition called "Leonardo da Vinci: Experience, Experiment and Design" in 2006

Television programs

* The U.S. Public Broadcasting Service (PBS), aired in October 2005, a television programme called "Leonardo's Dream Machines", about the building and successful flight of a glider based on Leonardo's design.

Leonardo's projects

Models based on Leonardo's drawings

ee also

* Leonardo da Vinci
* Luca Pacioli
* Leonardo da Vinci's personal life
* Cultural depictions of Leonardo da Vinci

References

External links

* [http://www.sacred-texts.com/aor/dv/index.htm Complete text & images of Richter's translation of the Notebooks]
* [http://www.studio-international.co.uk/reports/da_vinci.asp Leonardo da Vinci: Experience, Experiment, Design (review)]
* [http://www.bl.uk/onlinegallery/ttp/ttpbooks.html Some digitized notebook pages with explanations] from the British Library (Macromedia Shockwave format)
* [http://leonardodavinci.stanford.edu/projects/anatomy/index.html Digital and animated compendium of anatomy notebook pages]
* [http://www.bbc.co.uk/science/leonardo BBC Leonardo homepage]
* [http://www.odranoel.de/index.php?lang=eng&menu=start&area=0&page=0 Leonardo da Vinci: The Leicester Codex]
* [http://www.leonardo-history.com/life.htm?Section=S5 Leonardo's Letter to Ludovico Sforza]
* [http://www.illusionworks.com/mod/anamorph.htm# Animations of anamorphosis of Leonardo and other artists]
* [http://www.juliantrubin.com/bigten/davinciparachute.html The Invention of the Parachute]