By Jonathan Thar – Research Program Coordinator, Pacific Ocean Shelf Tracking Program (POST)
How much do we know about life in the ocean? A lot, you might say. But how much do we reallyknow about life in the ocean? A lot less than you might think, I say.
Take a look at the map below. It was prepared in late 2010 to summarize the current state of our knowledge at the end of the groundbreaking decade-long Census of Marine Life. The coloured dots are half-degree squares where we do have data on life in the ocean. White areas are where we have not studied ocean life – an unexplored majority of the 71 watery percent of the Earth’s surface.
A map of the nearly 30 million records of 120,000 species from over 800 datasets collected in the Census of Marine Life’s legacy database, the Ocean Biogeographic Information System (OBIS). Coloured dots represent half-degree areas where there is data on ocean life; white areas are where we lack data. Much of the uncatalogued ocean lies in the Arctic and waters south of the equator. Credit: OBIS.
If that does not convince you, think in the third dimension: depth. The diagram below is a cross section of the various depths of the global ocean. Reds and oranges show where in the water column we have a good amount of information about ocean life. Blues and yellows, on the other hand, show where we have little or no information.
A scaled cross section of the depth of the global oceans shows where we have much (reds and oranges) and little (blues and yellows) data on ocean life. The data, aggregated from OBIS, reveal a vast volume of deep water, far from the world’s shores, where we have little or no information on what lives there. Credit: Webb et al 2010, PLoS ONE 5(8): e10223.
The moral: despite the valuable knowledge gained from the tireless efforts of thousands of marine biologists and ecologists who have and continue to dedicate themselves to learning about life in the ocean, we still have much to learn.
So what is the benefit to knowing more about ocean life? The more we know, the more we will be able to effectively protect and conserve ocean life. And why is it important to conserve ocean life? For a multitude of reasons, particularly considering the threats that many marine animals face; but ultimately because the ocean brought life to and is the great regulator of our earth. The health of marine life is a key indicator of the health of the ocean. The health of the ocean is hugely important to the health of the planet.
Some marine animal or plant could give us answers to secrets about curing deadly diseases, or how to more efficiently feed a growing world population. We, land dwellers, are inextricably linked to life in the ocean. If something goes awry under the sea, the more we know about ocean life, the more ready we will be to interpret what is happening, face the challenges and mitigate the results.
But because so much of the uncatalogued ocean lies so deep and so far from shore, learning about what lives there poses a real challenge. About 40 years ago, we sent 12 astronauts on six different missions to the surface of the moon, 400,000 kilometres away. Ten years prior, in 1960, two aquanauts dove 11 kilometres below the surface in a submarine, to the deepest part of the ocean in the Marianas Trench. In the 50 years since, not one person has been that deep, only two unmanned remotely operated vehicles (ROVs).
We need to take advantage of recent technological advances and shift the focus of human exploration away from the skies and to our oceans. It does not make sense that we know more about the surface of the moon than we do about the depths of our oceans.
The program that I work for, the Vancouver Aquarium’s Pacific Ocean Shelf Tracking Program (POST), spent its time as a partner of the Census of Marine Life applying the underwater equivalent of cell phone technology to migrating ocean animals. In ten years, we have gained a more detailed picture of where marine animals travel under the ocean’s surface. As POSTmoves into its next decade of exploration, we are experimenting with using autonomous ocean gliders, capable of transiting an entire ocean basin, to track these tagged animals far from shore and deeper than ever before.
Perhaps we are starting to see a shift in curiosity towards what is left to explore on our own planet. The Census of Marine Life garnered significant international attention and real interest when it released its results last October. But the interest cannot end there.
Starting this 2011 World Oceans Day, get curious. Learn more about what we do and do not know about life in the ocean. Let your imagination soar with the amazing things you learn and think about what else might possibly live beneath the surface, and how we can learn even more. Your novel ideas and innovations can revolutionize our understanding of our world. Run with those ideas and make a difference.
World Oceans Day was first proposed by Canada in 1992, and officially recognized by the UN in 2008. It is celebrated annually on June 8, and organized by The Ocean Project and World Ocean Network.
Florentinepainter, sculptor, architect, engineer, and scholar, and one of the greatest minds of the Renaissance; born at Vinci, near Florence, in 1452; died at Cloux, near Amboise, France, 2 May, 1519, natural son of Ser Piero, a notary, and a peasantwoman. He was reared carefully by his father, and was remarkably gifted and precocious. Few artists owed so little to circumstances and teachers. He was quite self-made. His work was small in bulk, and what remains may be counted on fingers of both hands. Few men had such varied talent and amassed such encyclopedic knowledge; his method as an artist was original with him, science was the measure of beauty, he combined fact with poetry and made use of both to carry on wide investigations in nature and to reproduce life according to the very laws of life. There are three periods in Leonardo's biography: The Florentine period (1469-82); the Milanese period (1483-99); the Nomadic period (1500-19).
The artist
Florentine period (1469-82)
At an early age, doubtless about his fifteenth year, Leonardo entered Verrocchio's studio which about 1465 was the foremost in the city. Among his associates was Pietro Vanucci called Perugino. A sculptor and painter, Verrocchio was not an artist of the highest genius, but he played an important part in the history of art. The contemporary of Castagno and Pollaiulo, he centralized their labours, codified their efforts, and circulated the results of their studies; in a certain sense Florentinenaturalism was organized in his studio. The work of both generations was summed up in a work common to master and pupil, Verrocchio's"Baptism of Christ", in the Academy of Florence, wherein Leonardo painted the face of one of the angels who hold the garments of Jesus. In the midst of a work which, although a conscientious study, is dull and prosaic this ravishing countenance shines with a divine life. Under these conditions young Leonardo acquired the technique of his craft, all the progress attained by theFlorentine School about the middle of the fifteenth century, but he gave to it a new value and incomparable beauty. AsVerrocchio's collaborator in all branches of art he assisted in the preliminary studies and the preparatory researches for the famous equestrian statue of the condottiere Colleone. He was also admitted to the celebrated garden of the Medicis, where they had gathered a collection of antiquities, then the foremost in the world, and which they had, moreover, made a museum and aschool, or academy, of fine arts. The young artist nevertheless almost entirely escaped the superstition of antiquity, and this is a clear proof of his wonderful independence. The artists of the next generation, especially Michelangelo, scarcely beheld life savethrough the marble veil of Graeco-Roman sculpture; Leonardo, on the other hand, borrowed almost nothing from the past; a few details in a candelabrum in the small "Annunciation" of the Louvre, rare sketches such as the "Dancers" of the Academy of Venice, a warrior's head at London (British Museum), these constitute nearly the whole of his debt to antiquity. In this sense Leonardo is the first of the "moderns".
We possess very few of the works of his youth. Apart from the face of the angel in the "Baptism of Christ" spoken of above, we can ascribe to him with certainty only the delicate miniature "Annunciation" of the Louvre, the portrait of a young woman in the Liechtenstein Gallery at Vienna, and two small terra-cottas in the South Kensington Museum, London; a "Madonna and Child", and a bust of St. John the Baptist. Drawings have preserved for us the traces of other projects, e.g., in "Adoration of the Shepherds" (drawing at the Louvre), but we have almost no information concerning this period. A landscape drawing dated 1573 and another study dated 1578 (Uffizi) are the first certain dates we encounter in his life. The following note has also been found: ". . . bre 1578 cominciai le due Madonne"; but no one knows what became of these Madonnas, nor even if they were executed. However, a great many studies, leaves covered with sketches, heads of young women, children playing with cats, etc., show the direction of his researches. He had already conceived this type of mother and child in which the divine expression results only from human race and the poetry of life carried to its highest degree. This was the formula of the Renaissance, of the Madonnas of Raphaeland Andrea del Sarto, and which Leonardo himself soon applied in the immortal masterpieces, the "Virgin of the Rocks" and "St. Anne and the Blessed Virgin".
Milanese period (1483-99)
In 1481 Ludovico il Moro assumed in the name of his nephew, Gian Galeazzo, the regency of the Duchy of Milan. He was one of the most remarkable princes in that age of tyrants of genius: clever, magnificent, ambitious, and cruel. A letter of which a copy forms part of the celebrated "Codex Atlanticus", in the Ambrosian Library, Milan, has preserved the terms in which Leonardo offered his services to this formidable lord; among other terms were read:
(1) I have a process for constructing very light, portable bridges, for the pursuit of the enemy; others more solid, which will resist fire and assault and may be easily set in place and taken to pieces. I also know ways of burning and destroying those of the enemy. . . (4) I can also construct a very manageable piece of artillery which projects inflammable materials, causing great damage to the enemy and also great terror because of the smoke . . . (8) Where the used of cannon is impracticable I can replace them with catapults and engines for casting shafts with wonderful and hitherto unknown effect; briefly, whatever the circumstances I can contrive countless methods of attack. (9) In the event of a naval battle I have numerous engines of great power both for attack and defense: vessels which are proof against the hottest fire, powder or steam. (10) In times of peace I believe that I can equal anyone in architecture, whether for the building of public or private monuments. I sculpture in marble, bronze and terra cotta; in painting I can do what another can do, it matters not who he may be. Moreover I pledge myself toexecute a bronze horse to the eternal memory of your father and the very illustrious House of Sforza, and if any of the above things seem impracticable or impossible I offer to give a test of it in your Excellency's park or in any other place pleasing to your lordship, to whom I commend myself in all humility.
Leonardo was at this time thirty years of age and very handsome. He was an accomplished gentleman, and had a keen mind for the invention of fables. His contemporaries, for example the storyteller Bandello, relate the charms of his conversation. He was a musician, being given to improvising verses while accompanying himself on a lute of his own invention, shaped like a bucranium and possessing wonderful sonorousness. For the fêtes, ballets, and amusements, and interludes of which the Renaissance was so fond, Leonardo was unequalled. At the time of Louis XII's entry into Milan a mechanical lion crossed the banquet hall, halted before him a shower of lilies. This machine Leonardo had invented. Such was Leonardo when towards the end of 1482 he entered the service of Ludovico il Moro. One of his earliest Milanese works was the delightful "Woman with a Marten", which is believed to be the portrait of Cecilia Gallerani, Ludovico's mistress, and which is now at Cracow, in the collection of Count Czartorisky. Unfortunately, the work has been much injured by restorations, but it is the first truly modern work of its kind, wherein femininegrace, subtlety of analysis, refinement of the moral personality, and not merely resemblance of features, constitute the subject of the picture. The pretty profile of "Beatrice d'Este" at the Ambrosian and the so-called "Lucrezia Crivelli" (also called "La Belle Ferroniere") of the Louvre have nothing in common with Leonardo.
At Milan, also, in the early years of his sojourn there, he completed his first large picture, the wonderful "Virgin of the Rocks". Besides copies there are two of these pictures in existence, differing somewhat in details, one at the Louvre and the other at the National Gallery. There have been endless discussions with regard to their authenticity. The truth is that they are both originals, the first in point of time being that of the Louvre, the execution of which, extremely minute in detail, still shows something of the somewhat dry methods of Verrocchio's studio. The other and somewhat later one repeats the same motif for the convent of San Francesco, Milan. On the side panels Ambrogio da Predis paintedangels playing on musical instruments. These side panels are with the central picture at the National Gallery. But Leonardo did not finish the picture he had begun, its Madonna and the landscape are the work of a pupil and a mediocre pupil. On the other hand the angel kneeling behind the Infant Jesus whose attitude differs from that of the Paris Angel, is one of the artist's most perfect creations. Both pictures are poetical. The fantastic landscape, the dolomite grotto of prismatic rocks, the ineffable art of the "pyramidal" grouping, the often copied triangle of which the base is formed by two beautiful children, and the summit of the head of a smiling virgin; the grace and life of themotif, the selection of the moment, the perfection of the model, the depth of the atmosphere, and even the smallest details of the herbs, the stones, the slight ripples in a surface of transparent water — all this endows the "Virgin of the Rocks" with an imperishable charm, making it one of the works which open a new world to the imagination and fixing eternally the poetry of the subject. Without Leonardo Raphael's "Madonna", his "Belle Jardinière" and "Madonna of the Goldfinch" would not exist and even their charm does not equal that of their sublime model.
Leonardo's most important work at Milan is his "Last Supper" which he painted in the refectory of the Dominicanconvent of StaMaria delle Grazie. This masterpiece is now little more than a ruin, the disaster being largely due to the painter's methods. Frescoseemed to him too summary and hurried a process and he painted in oil on the wall. Dampness soon soaked into and ruined the work, and as early as the middle of the sixteenth century the damage was irreparable. Vandalism did the rest. In 1652 a door was opened in the wall mutilating the feet of Christ and two Apostles. In 1726 and 1770 daubers wrought a masterpiece of injury with their restorations, and finally in 1797 a French army occupied the convent and made a stable of the refectory; evenBonaparte's orders could not prevent the men from mutilating the "Last Supper"; such was the long martyrdom of the masterpiece. Only in recent years have precautions been taken to preserve the remains; the wall has been separated and the hall dried but this tardy care threatens to complete the destruction of the picture. It is to be feared that it will scale and crumble to dust. However there exist memorials and copies of it. Few works have exercised a similar fascination and been as often reproduced from the beginning. Some of these copies have been collected in the refectory of Sta Maria delle Grazie; among them the best of all, which was formerly at Castellazzonear Milan, is believed to be by Solari. An excellent copy is preserved at Ponte Capriasca, a neighbouring parish of Lugano. The Academy of London has one, which was formerly at the Certosa of Pavia and attributed to Oggionno or to Gianpietrino. There are two at Paris, one at the Louvre, and the other at St. Germain l'Auxerrois. All there copies, which are fairly correct as regards the composition, vary in detail and especially show great difference of colouring.
Still more valuable are the separate studies of heads, although the most of them may be originals; the most important series are at Strasburg and Weimar. The famous head of Christ in crayon at the Brera seems to be a study of Sodoma or of Cesare da Sesto and to have no relation to the "Last Supper". None of these helps to the study of the masterpiece should be neglected, but despite its ruinous condition there are impressions which can only be given by the picture itself, which still preserves the atmosphere, the moving tonality, a peculiar pathos which seems the sorcery or presence of genius. Its extraordinary superiority is apparent when we compare it with all the extant "Last Supper" with those of Giotto, Castagno, or Ghirlandajo. The old representations become antiquated and obsolete and a new order of ideas is inaugurated. With regard to its subject the theme of the "Last Supper" may be divided into two distinct movements: the institution of the Sacrament and the "Unus vestrum". Leonardo has chosen the moment at which Christ declares that there is a traitor in the company. We are shown the effect of a speech on twelve persons, on twelve different temperaments: a single ray and twelve reflections (Burckhardt). The subject has been well analyzed by Goethe. It is clear that in a drama of this class, a kind of "seated" drama, of which the subject is interior disquiet, surprise, anguish, it suffices to show the persons at half length; busts, face, and hands suffice to manifest the moralemotion; the table with its damask cloth by almost completely concealing the lower limbs offered the ingenious artist a resource which he knew how to use. The difficulty under these conditions was to succeed in constituting a whole with these thirteen figures seated side by side; the greatest weakness of the old painters was composition; each table companion seemed isolated from his neighbour.
With an instinct of genius Leonardo divided his actors into two groups, two on each side of Christ, and he linked these groups so as to imbue the general outline with a certain continuity, animated by a single movement. The whole is like the successiveundulations of a vast wave of emotions. The fatal word uttered by Christ seated at the middle of the table produces tumult which symmetrically repels and agitates the two nearest groups and which lapses as it is communicated to the two groups farther removed. The intimate composition of each group is no less wonderful. Stupefaction, sorrow, indignation, denial, vengeance, the variety of expression which the painter has gathered together in this picture, the depth of the analysis, theveracity of the types and physiognomies, the power and the accumulation of contrasts are without parallel in all previous art; the countless studies made for each piece denote in the author a world of new preoccupations. Each head is the "monograph" of a human passion, a plate of moral anatomy. It will be readily understood how such a work cost the artist ten years of preparation. None ever summarized in a single picture a similar total of life. The hands possess incomparable beauty and eloquence. Here for the first time and for the whole future was created the definitive formula of historic painting.
On the wall opposite the "Last Supper" Leonardo had painted (1495), in the great Montorfano Crucifixion, portraits of Ludovico il Moro, his wife Beatrice d'Este, and their sons Maximillian and Francesco. Only whitish traces and uncertain lineaments of these portraits remain. Finally in 1893 Professor Müller Walde discovered in the castle of Milan under a rough cast of the hall of the Torre delle Asse a whole decoration painted by Leonardo in 1498; it is a trellis of laurel, vines, and foliage. The artist conveyed the illusion of a hall of verdure. To this period likewise belong the studies of St. Anne. Together with the cult of the Immaculate Conception the end of the fifteenth century saw the rise of that of the mother of the Blessed Virgin. The work of the learnedTrithemius, "De laudibus sanctissimæ matris Annæ", dates from 1494 (cf. Shankell, "Der Kultus der heilige Annas am susgange Mittelalters", Freiburg, 1893). Leonardo composed two different versions of this subject, one of them being now at the Louvre, the other at the London Academy. That of the Louvre is unfinished. The Virgin is only sketched, the head of St. Anne alone showing that modelling in which Leonardo is unrivalled. Art possesses few groups more charming than that of these two women, one seated on the other's knees. Together with the "Last Supper" Leonardo's greatest Milanese work must have been the equestrian statue of Ludovico il Moro, the famous "bronze horse" which he pledged himself to cast in the letter quoted above. He worked on this constantly for more than fifteen years (1483-99). A plaster model was cast in 1489, but the artist was dissatisfied within and made another which was moulded in 1493. He then turned his attention to preparations for casting. But the French came in 1499 and besides driving out the duke they broke the plaster model of his statue. We have only countless sketches, studies, and drawings of this masterpiece and Leonardo's books dealing with the anatomy and science of the horse.
Nomadic period (1500-19)
By Ludovico's fall Leonardo was left unemployed, and he was in no hast to seek another position and there began for him a period of wandering. Completed works grow more and more rare, each of them showing traces of more complicated ambitions. From this period date most of his scientific works. After fifty he began to gather the elements of a new synthesis which was never completed. The last twenty years of his life were given to this activity and these experiences. From Milan, Leonardo went toMantua where he sketched (1500) the portrait of the Marchesa Isabella d'Este, the cartoon of which is one of the wonders of the Louvre. Then he went to Venice (1501) and thence to Florence; from there he entered the service of Cæsar Borgia as military engineer and head of the corps of engineers in his Romagna campaign. After Cæsar's fall he returned to Florence and seems to have stayed there for three or four years. Then he began see-sawing between Florence and Milan, finally taking up his residence in the latter city where he was called by a law-suit concerning the property left by his father. In 1514 we find him atRome, but at the end of the year he returned to Florence; in 1515 came journeys to Pavia, Bologna, and a last stay for some months at Milan. Finally in 1516 he accepted the invitation of King Francis I to come to France and left Italy, never to return.
During these wandering years there are only two places where we find undoubted proofs of his activity, at Florence (1501-06) and Milan (1506-13). At Florence he executed two of his most famous works, now unfortunately lost or destroyed. The Seignioryof Florence had for the decoration of its council hall opened a contest for the portrayal of two patriotic subjects drawn from the annals of the Republic. One was an occurrence of the war against Pisa in 1304 and was confided to Michelangelo; the other commemorated the victory of Anghiari Maria Visconti. This was the subject treated by Leonardo. The rival cartoons were exhibited in 1505 and were an event in the history of the school. All the youth of the artist world hastened to copy them, but in the midst of all this Michelangelo was called to Rome and abandoned his work. Warned by his experience with the "Last Supper" Leonardo refrained from painting in oil, but would not be satisfied with fresco; he fancied some process of encaustic (one of the rare instances in him of the influence of the ancients). The attempt was unfortunate. The coat did not dry and the colours flowed together. But the artist was not discouraged and continued his work. The cartoon still existed in the eighteenth century; it is not known when it or that of Michelangelo disappeared. The latter is known only through a famous engraving by Marcantoni Raimondi. Leonardo did not fare so well. Apart from countless sketches there exists only a single group of his work, that of theknights of the "Battle of the Standard" which has been preserved by a drawing of Rubens (Louvre) and an engraving of Edelinck. Nevertheless there are few more important battle pieces in the art work of the sixteenth and seventeenth centuries. All theclasses of Rubens and the Flemishschool are but variations and repetitions of this furious melée. The Adoration of the Magi in the Uffizi is unfortunately only a sketch, a rough cartoon, chiefly interesting for the information it gives concerning the basis of Leonardo's painting and his manner of preparing a picture. It belongs to the same period (about 1505) as that work of the artistswhich is most popular, most complete, and most closely associated with his name as that which best sums up in a woman's face all the research, grace, and seductiveness of his genius. This is the portrait of Madonna (Monna) Lisa, wife of Ser Giocondo, and universally known as Jaconde (La Gioconda), and which, acquired directly from the artist by Francis I, and preserved for three centuries at Fontainebleau, disappeared, 21 August, 1911, under mysterious circumstances, from the Louvre, where it had been since 1793.
The numerous copies of this enchanting face, those of the museums of Madrid, Munich, Quimper, and St. Petersburg, the Torlonia Gallery at Rome, and the Mozzi Gallery, Florence, of the Villa Sommariva on Lake Lugano, of the Hume and Woodburncollections at London, can scarcely console us for the loss of the masterpiece. Leonardo never painted anything with more love. He devoted four years to this single face. Vasari relates what delicate care he took to amuse his graceful model during the sittings and to bring to her lips that imperceptible smile, which has been taken to mean such depth and perfidy and which is merely the serene expression of a harmonious soul, of moral peace and health, with a slight tinge of Florentine irony. Its place in the Louvre is occupied by another of Leonardo's works, one of the last really authentic of his productions, the enigmatic St. JohnBaptist. Here the depth and complexity of his intentions, above all the systematic use of chiaroscuro, lead to odd and equivocal results. But the spoiled work formulated the whole language of chiaroscuro, and fixed its laws with a clearness which has never been surpassed.
The following pictures preserve the memory of others of Leonardo's works of which the originals are lost. The St. John the Baptist or Bacchus full length, seated, amid a landscape; the picture belongs to a date previous to 1505 and is contemporary with the Giaconda. Ancient copies are at the Louvre and at Sant'Eustorgio, Milan. The Leda; same period; copy (by Bacchiacca?) at the Casino Borghese; others in the Ruble collection, Paris, and the Oppler collection, Cologne; drawing by Raphael at Windsor. The Resurrection at the Museum of Berlin is apocryphal. The famous wax bust required in 1909 by the same museum is the work of an Englishforger who worked about 1840. Finally the charming wax Head of the Wicar Museum, at Lille, belongs probably to the school of Canova, which robs it of none of its exquisite grace. The last picture of Leonardo's which we possess is the splendid sketch of St. Jerome in the desert in the collection at the Vatican. It dates from 1514. Leonardo spent the last three years of his unquiet life in France. The king gave him a pension of 7000 crowns and had given him a dwelling in the Château ofCloux near Amboise. At this period the master was very tired, and his faculties were declining. He was still engaged with the question of canalization and studied ways of regulating the course of the Loire and making it navigable. He died amid these occupations at the age of 67. A legend, popularized by Ingres's picture, relates that he passed away in the arms of Francis I; but on that day the king was at Saint-Germain-en-Laye.
The scholar
Art represents only a small part of Leonardo's activity. Always and especially at Milan from 1506 his genius was absorbed inscientific matters, but these researches had begun in Verrocchio's studio, as is shown by the letter of 1482 to Ludovico il Moro. It is impossible to give here a detailed analysis even of his principal works, for his studies included all branches of knowledge. On the other hand their strictly personal nature, the secret and deliberately cabbalistic practices with which he loved to surround them, the methods of abbreviation and cryptography of which he made use in order to conceal his discourse (he wrote from rightto left, in an inverted hand which could probably only be read with the aid of a mirror), all this mystery removes a great deal ofinterest from the treasures of observation which Leonardo consigned to countless manuscripts. In fact by refusing to disclose his discoveries, by wishing to retain the monopoly of his processes and secrets, he condemned this portion of his work to oblivion and sterility. However, his art is in so many ways connected with his science that the former cannot be known without an acquaintance with the latter. In his drawings of flowers, plants, landscapes, and in his studies of persons, it is impossible to say whether it is the botanist, the geologist, the anatomist or the artist who interests us most. In Leonardo, knowledge and art are never separate. The characteristics frequently seen in the men of the Renaissance, the encyclopedic turn of mind so striking in aLeone Battista Alberti, a Bramante, or a Dürer, is never more brilliantly evident than in Leonardo da Vinci. His method is based exclusively on observation and experiment. He recognized no mistress save nature. Neither in science nor in art did he admit the authority of either the ancients or the scholastics.
Furthermore he clearly understood: (1) that science should be subject to formulation in mathematical laws; (2) that science has power over nature, and ability to foresee phenomena and at need to reproduce or imitate them. This granted, there were few questions which this tireless mind did not study, and to which he did not bring ingenious views and new solutions. Often he perceived truths established by modern science. Long before Bacon and with a far different range of application he invented the positive sciences. As a geologist, for example, he discerned that there was a "history of the earth", that the outside of the globe was not formed at a single stroke, and in this history, guided by studies of hydraulics, he successfully saw through the function of water. He divined the true nature of fossils. In botany he formulated the laws of the alternation of leaves, that of the eccentricity of trunks, and that of solar attraction. As an anatomist (he had dissected nine bodies) he gave figures concerning the insertion of the muscles and their movements which specialists still admire for their accuracy. He devised the earliest theories concerning the muscular movements of the cardiac valves. By his studies in embryology he laid the foundations for comparativeanatomy. In mechanics he understood the power of steam and if he did not invent any action machines he at least made it an agent of propulsion, for he invented a steam cannon. He composed explosives and shells. But perhaps his most "modern" title to fame lies in his having laid down the principle of aviation, devoting years to this task. He foresaw nearly all the forms, parachute and montgolfier, but by boldly adhering to the "heavier than air" principle he constructed the first artificial bird. Long series of studies analyze with astonishing clearness the flight of the bird, the form and movement of the wing Leonardo distinguishes between the soaring flight and that made by successive flappings, in each case defining the action of the air and the part played by it; he understands that the bird rises obliquely on an aerial inclined plane, forming under it a kind of angle and that currentsform in the concavity of the wing which serve it as momentary supports to recover its equilibrium, like the waves on which the car is rested to propel the boat.
Leonardo was more a scholar than a philosopher, nevertheless his wholly naturalistic science implies a certain philosophy, which if it is neither the kind of paganism nor the materialism in which the Renaissance so often resulted cannot be called truly Christian. Either through prudence or through scorn of abstract ideas Leonardo seems to have avoided declaring himself on this subject. Nevertheless it is easy to see that the idea of miracles is repugnant to his imagination. He admits or would logically admit only animmanent Providence, a God who refrains from intervention in the universe like to God of Lucretius or the Stoics. It is alsocertain, and he does not conceal it, that he did not like the monks. However, as an artist, he accommodated himself perfectly to the Christian tradition. His art, though not at all mystic, is in its forms certainly less pagan than that of Raphael or evenMichelangelo. He died a very Christian death.
His manuscripts are now divided among several depositories. The most important are (1) the gigantic collection in the Ambrosian Library of Milan called the Codex Atlanticus consisting of 393 folio pages on which are pasted more than 1600 leaves of notes; (2) at Paris in the library of the Institut twelve manuscripts numbered from A to M; (3) at London three volumes at South Kensington, a manuscript of 566 pages at the British Museum, and at Windsor splendid anatomical plates and drawings. Other books are in the possession of Count Manzoni and the Earl of Leicester. The treatise on painting is his first work. It was printed at Paris in folio in 1651 in the Italian text by Raphael du Fresne and almost immediately translated into French by Fréart de Chambray. More correct editions have since been issued, notably that of Manzi (1817), and that of Ludwig made according to aVaticanmanuscript (3 vols., at Vienna, 1883). Ventura compiled a memoir on Leonardo's scientific works properly so called which he presented to the Institute in 1797. He announced that this would soon be followed by the publication of original documents, but this promise was not kept. In 1872 the Italian Government issued a limited number of copies of a de luxe work, "Saggio dell' opere di L. da V.", containing extracts from the Codex Atlanticus with twenty-four facsimiles. In 1889 J.P. Richter issued atLondon, under the title "The Literary Works of Lenoardo da Vinci", two quarto volumes comprising more than 1500 extracts and fragments of manuscripts. Systematically classified, with beautiful reproductions.
However, Ravaisson-Mollier had undertaken the entire publication of the manuscripts of the Institut in a model edition with facsimiles of the original text, transcription in ordinary characters and French translation (6 vols. for., Paris, 1881-92). The example at Milan a manuscript of Leonardo's belonging to Prince Trivulzio. And since 1892 the Accademia dei Lincei has published completely the Codex Atlanticus. If the Londonmanuscript were published we should have as complete knowledge as possible of this extraordinary man who united in himself the triple or quadruple genius of an Apelles, an Aristides, a Euclid, and an Archimedes. Mention must be made of Leonardo's artistic influence. His influence on painting was supreme; it has been shown above what paths his genius opened to historical painting, to portraiture, to scenes of sanctity, landscapes, and the art of chiaroscuro. But this general action, profound as it was, did not give rise to a school at Florence. Leonardo's pupils and imitators properly so called must be sought for at Milan. There were very numerous, and nothing enables us to judge better of his ascendency than the revolution of taste which his appearance determined in Milanesepainting. The national school of Foppa,Zenale, Borgognone was suddenly cast into the shade, eclipsed by a host of disciples, among them Solario, Ambrogio da Predis, Cesare de Sesto, Marco d'Oggione, Boltraffio, some of them very gifted and talented men. To them we owe the multitude of copies which often take the place of lost works of the master; but only two or three pupils attained an absolute independent expression, and were other than reflections of Leonardo: these included the gentle and prolific Bernardino Luini and the troubled, passionate, and very unequal Sodoma.
Surfer waves -- initiated in the sun, as they are in the water, by a process called a Kelvin-Helmholtz instability -- have been found in the sun's atmosphere. (Credit: NASA/SDO/Astrophysical Journal Letters)
Science Daily — Cue the surfing music. Scientists have spotted the iconic surfer's wave rolling through the atmosphere of the sun. This makes for more than just a nice photo-op: the waves hold clues as to how energy moves through that atmosphere, known as the corona.
"One of the biggest questions about the solar corona is the heating mechanism," says solar physicist Leon Ofman of NASA's Goddard Space Flight Center, Greenbelt, Md. and Catholic University, Washington. "The corona is a thousand times hotter than the sun's visible surface, but what heats it up is not well-understood. People have suggested that waves like this might cause turbulence which cause heating, but now we have direct evidence of Kelvin-Helmholtz waves."Since scientists know how these kinds of waves -- initiated by a Kelvin-Helmholtz instability if you're being technical -- disperse energy in the water, they can use this information to better understand the corona. This in turn, may help solve an enduring mystery of why the corona is thousands of times hotter than originally expected.
Ofman and his Goddard colleague, Barbara Thompson, spotted these waves in images taken on April 8, 2010. These were some of the first images caught on camera by the Solar Dynamics Observatory (SDO), a solar telescope with outstanding resolution that launched on February 11, 2010 and began capturing data on March 24 of that year. The team's results appeared online in Astrophysical Journal Letters on May 19, 2011 and will be published in the journal on June 10.
That these "surfer" waves exist in the sun at all is not necessarily a surprise, since they do appear in so many places in nature including, for example, clouds on Earth and between the bands of Saturn. But observing the sun from almost 93 million miles away means it's not easy to physically see details like this. That's why the resolution available with SDO gets researchers excited.
"The waves we're seeing in these images are so small," says Thompson who in addition to being a co-author on this paper is the deputy project scientist for SDO. "They're only the size of the United States," she laughs.
Kelvin-Helmholtz instabilities occur when two fluids of different densities or different speeds flow by each other. In the case of ocean waves, that's the dense water and the lighter air. As they flow past each other, slight ripples can be quickly amplified into the giant waves loved by surfers. In the case of the solar atmosphere, which is made of a very hot and electrically charged gas called plasma, the two flows come from an expanse of plasma erupting off the sun's surface as it passes by plasma that is not erupting. The difference in flow speeds and densities across this boundary sparks the instability that builds into the waves.
In order to confirm this description, the team developed a computer model to see what takes place in the region. Their model showed that these conditions could indeed lead to giant surfing waves rolling through the corona.
Ofman says that despite the fact that Kelvin-Helmholtz instabilities have been spotted in other places, there was no guarantee they'd be spotted in the sun's corona, which is permeated with magnetic fields. "I wasn't sure that this instability could evolve on the sun, since magnetic fields can have a stabilizing effect," he says. "Now we know that this instability can appear even though the solar plasma is magnetized."
Seeing the big waves suggests they can cascade down to smaller forms of turbulence too. Scientists believe that the friction created by turbulence -- the simple rolling of material over and around itself -- could help add heating energy to the corona. The analogy is the way froth at the top of a surfing wave provides friction that will heat up the wave. (Surfers of course don't ever notice this, as any extra heat quickly dissipates into the rest of the water.)
Hammering out the exact mechanism for heating the corona will continue to intrigue researchers for some time but, says Thompson, SDO's ability to capture images of the entire sun every 12 seconds with such precise detail will be a great boon. "SDO is not the first solar observatory with high enough visual resolution to be able to see something like this," she says. "But for some reason Kelvin-Helmholtz features are rare. The fact that we spotted something so interesting in some of the first images really shows the strength of SDO."
ScienceDaily — Biology researchers discover that bacteria living in mosses on tree branches twice as effective at 'fixing' nitrogen as those on the ground.
These findings highlight the importance of maintaining the large old-growth trees in the coastal temperate rainforests that stretch from Southern Alaska to Northern California. Lindo's findings suggest that it is the interactions between old trees, mosses and cyanobacteria, which contribute to nutrient dynamics in a way that may actually sustain the long-term productivity of these forests.A new study by Dr. Zoë Lindo, a post-doctoral fellow in the Department of Biology at McGill University, and Jonathan Whiteley, a doctoral student in the same department, shows that large, ancient trees may be very important in helping forests grow.
"What we're doing is putting large old trees into a context where they're an integral part of what a forest is," says Dr. Lindo. "These large old trees are doing something: they're providing habitat for something that provides habitat for something else that's fertilizing the forest. It's like a domino effect; it's indirect but without the first step, without the trees, none of it could happen."
There are three players in this story: 1) large, old trees; 2) mosses that grow along their branches; and 3) a group of bacteria called cyanobacteria associated with the mosses. The cyanobacteria take nitrogen from the atmosphere and make it available to plants-a process called "nitrogen fixation" that very few organisms can do.
The growth and development of many forests is thought to be limited by the availability of nitrogen. Cyanobacteria in mosses on the ground were recently shown to supply nitrogen to the Boreal forest, but until now cyanobacteria have not been studied in coastal forests or in canopies (tree-tops). By collecting mosses on the forest floor and then at 15 and 30 metres up into the forest canopy, Lindo was able to show both that the cyanobacteria are more abundant in mosses high above the ground, and that they "fix" twice as much nitrogen as those associated with mosses on the forest floor.
Moss is the crucial element. The amount of nitrogen coming from the canopy depends on trees having mosses.
"You need trees that are large enough and old enough to start accumulating mosses before you can have the cyanobacteria that are associated with the mosses," Lindo said. "Many trees don't start to accumulate mosses until they're more than 100 years old. So it's really the density of very large old trees that are draped in moss that is important at a forest stand level. We surveyed trees that are estimated as being between 500 and 800 years old."
The research was funded by the Natural Sciences and Engineering Research Council of Canada (NSERC)
ScienceDaily — If a person's blood becomes too thick it can damage blood vessels and increase the risk of heart attacks. But a Temple University physicist has discovered that he can thin the human blood by subjecting it to a magnetic field.
Rongjia Tao, professor and chair of physics at Temple University, has pioneered the use of electric or magnetic fields to decrease the viscosity of oil in engines and pipelines. Now, he is using the same magnetic fields to thin human blood in the circulation system.
Because red blood cells contain iron, Tao has been able to reduce a person's blood viscosity by 20-30 percent by subjecting it to a magnetic field of 1.3 Telsa (about the same as an MRI) for about one minute.
Tao and his collaborator tested numerous blood samples in a Temple lab and found that the magnetic field polarizes the red blood cells causing them to link together in short chains, streamlining the movement of the blood. Because these chains are larger than the single blood cells, they flow down the center, reducing the friction against the walls of the blood vessels. The combined effects reduce the viscosity of the blood, helping it to flow more freely.
When the magnetic field was taken away, the blood's original viscosity state slowly returned, but over a period of several hours.
"By selecting a suitable magnetic field strength and pulse duration, we will be able to control the size of the aggregated red-cell chains, hence to control the blood's viscosity," said Tao. "This method of magneto-rheology provides an effective way to control the blood viscosity within a selected range."
Currently, the only method for thinning blood is through drugs such as aspirin; however, these drugs often produce unwanted side effects. Tao said that the magnetic field method is not only safer, it is repeatable. The magnetic fields may be reapplied and the viscosity reduced again. He also added that the viscosity reduction does not affect the red blood cells' normal function.
Tao said that further studies are needed and that he hopes to ultimately develop this technology into an acceptable therapy to prevent heart disease.
Tao and his former graduate student, Ke "Colin" Huang, now a medical physics resident in the Department of Radiation Oncology at the University of Michigan, are publishing their findings in the journal Physical Review E
