2 0 0 9 P a r i s / M e u d o n

IWCMO Conference

William SHEEHAN: 鄭 Pretty Picture, Signor Schiaparelli, but you mustn稚 call it Mars; or, the art of Mars: views of the planet in the era of pencil, sketchpad, brush and paint.


Talk at the IWCMO conference, Paris, 18th September 2009

的t will concern us particularly to take note of those cases in which men not only solved a problem but had to alter their mentality in the process, or at least discovered afterwards that the solution involved a change in their mental approach Little progress can be made if we think of the older studies as merely a case of bad science or if we imagine that only the achievements of the scientists in very recent times are worthy of serious attention at the present day.

  Herbert Butterfield, The Origins of Modern Science, 1300-1800 (Bell & Sons, 1950), pp. viii-x.            

典he spots and streaks on the globe of Mars are always changing, even from hour to hour.  But that they are the same regions is shown by the fact that the same shapes and positions develop and pass away again, as one would expect of the variable atmospheric appearances occurring above a solid surface.

  Johann Hieronymus Schrter; quoted in William Sheehan, The Planet Mars (University of Arizona Press, 1996), p. 37.


 典he drawings were executed immediately at the telescope. Ordinarily some time elapsed before the indefinite mass of light resolved into an image with recognizable features.

  Johann Heinrich M臈ler; quoted in ibid., p. 47.


  鄭 blooming, buzzing confusion.

   William James, The Principles of Psychology (Henry Holt & Co., 1890), vol. I, p. 488.


e are now seriously discussing sending humans by means of rockets to Mars.  But for centuries our Mars-faring ancestors had only one appliance to ferry them across the millions of miles of intervening void: the telescope. Their bodies tied hopelessly to the Earth, they could nevertheless steer their minds across space by means of these marvelous tubes, these magician痴 wands.  They faced dangers enough, dangers of mind more than body. For the planet that entranced them at the eyepieces of their telescopes was a master of illusion and often preyed on observers tendency to shape it into the image of their own desires. Those who partly escaped the snares預nd none did so altogether幼ame little by little to acquire true knowledge of another world.

  Francis Bacon, in his Novum Organum, prescribed an expurgation of the intellect, based on washing the mind of its prejudices and preconceptions謡hat he called the Idols of the mind.  As he used the word, an idol was a picture of reality: a thought mistaken for a thing.  He went on to analyze the idols, such as idols of the tribe, idols of the cave, idols of the market-place; an analysis which is still worth reading, for its antiseptic quality, even today. His Idols of the Tribe were fallacies natural to humanity in general: 鄭ll the perceptions, both of the senses and the mind, bear reference to man and not to the universe; and the human mind resembles those uneven mirrors which impart their own properties to different objects and distort and disfigure them.  His Idols of the Cave were errors peculiar to the individual man, while the Idols of the Market-place arose 吐rom the commerce and association of men with one another.  

  The whole history of Mars observation might well be discussed in terms of these successive idols or sources of error.

  Mars in the telescope is, after all, as Laurie Hatch has evocatively described it, 都o subtle ethereal, delicate, floating, at times seemingly without mass or obvious three-dimensionality容ven when the seeing was exceptional. That image was reflected in妖istorted by預nd ultimately captured by the eye and mind of the observer; it was subject to distortion and disfiguring by the equally 砥neven mirrors of optics and cognition.  Filippo Brunelleschi, the great Florentine architect, showed as early as 1425 how susceptible to illusion was an observer who looked at things under special and severely restricted conditions as when the eye痴 view is restricted by means of a hole.  Brunelleschi used his discovery, which contains the germ of the theory of linear perspective, to create a skillfully composed picture of the Baptisterium in Florence in which the observer could not distinguish his picture from a mirror image of the thing itself.  Though Leonardo later would insist that the artist does not paint for one-eyed observers with their eyes in a fixed positions, astronomers peering through telescopes necessarily observed under the special and severely restricted conditions realized by Brunelleschi with his one-hole contraption.  To put it another way, the astronomer痴 view of a planet is, in a sense, 都taged.  One sees what one is allowed to see; and that is determined as much by opportunity and convention as by instrumentation and capacity. (According to Paul A. Feyerabend, 渡atives who have never seen pictures in black and white cannot at first see them; if one tells the natives 奏his is the picture of an ox or a dog, they will look at you and say that you are a liar.  In the same way perspective熔r the images seen in a microscope or telescope擁nitially create difficulties and have to be learned and stabilized.)  In the case of Mars, it is only by learning to apply conventions that this 都ubtle ethereal, delicate, floating image in the telescope is transformed into a set of consistent and coherent projections that we can refer to as a 努orld.  

   The 努orld of Mars has obviously evolved over three hundred and fifty years as a function of modifications of equipment and techniques. If the reality of Mars is what we now know熔r think we know預bout it as a result of the extensive in situ investigations of space probes, the views of the series of leading students of the planet幽uygens and Cassini, Herschel and Schrter, Beer and M臈ler, Secchi, Philips, Dawes, Lockyer, Green, Schiaparelli, Trouvelot, Barnard, Lowell, Antoniadi and the rest預re a series of successive approximations; representations; to be approached, in sequence, rather like a series of works in a standard history of art.  Each attempted to convey what he was able to make of the planet under special and severely restricted conditions.  Each had a trained eye, knowledge of optics and observational technique; each in some sense thought to represent or imitate things as he saw them.  But each also faced the problem which was noted by the seventeenth-century noble French art theorist and agent Roland Fr饌rt: 展henever the painter claims that he imitates things as he sees them he is sure to see them wrongly.  He will represent them according to his faulty imagination and produce a bad painting.  (There were certainly 吐aulty imaginations and 澱ad paintings aplenty in the history of Mars observation.)

   Fr饌rt goes on say:

  釘efore he takes up his pencil or brush he must, therefore, adjust his eye to reasoning according to the principles of art which teach how to see things not only as they are in themselves, but also how they should be represented.  For it would often be a grave mistake to paint them exactly as the eye sees them, however this may look like a paradox.

 Stylistically, some followed the methods of the Florentine masters (to whose school Brunelleschi was assigned) who had devised a method by which nature could be represented in a picture with almost scientific accuracy, beginning with the framework of perspective lines and building up their representations through a knowledge of shapes and the laws of foreshortening. Others, following Van Eyck and the Flemish school, took the opposite way, achieving the illusion of nature by patiently adding detail upon detail until the picture became like a mirror-image of that which it was supposed to represent. Still others moved away from naturalistic representation altogether, and adopted the mixed mode of map-making, combining diagram-like conventions and pictorial icons, following Mercator and Bayer. In each case預s Fr饌rt realized葉he representations were grounded on systems which the particular artist had learned to use, and these formulae and were dependent on traditions of art, not on an unmediated visual reality. That being the case, observers were not in any case 渡ave tabulae rasae, possessed of an 妬nnocent eye ready to register exactly what they perceived.  The paradox is well expressed by historian E. H. Gombrich who writes, the drawing accounts for the picture seen as much as the picture seen accounts for the drawing.  What he goes on to say applies with particular force to the representation of something as ambiguous as the 都ubtle ethereal, delicate image of a planet never less than a hundred and forty times farther from us than the Moon, as captured in a telescope (which if its nature can never be perfect) and seen through an always more or less quavering and tremulous atmosphere: The achievement of the innocent eye, what modern authorities call stimulus concentration, turned out to be not only psychologically difficult but logically impossible. The stimulus, as we know, is of infinite ambiguity and ambiguity cannot be seen擁t can only be inferred by trying different readings that fit the same configuration. The artist has learned to probe his perceptions by trying alternative representations.

  The artist starts from a schema蓉sually the point his predecessors had reached in the task of representation預nd he strives for corrections which approximate ever closer to the real world.

  You must have a starting point, a standard of comparison, in order to begin that process of making and matching and remaking. The artist cannot start from scratch but he can criticize his forerunners. The evidence of history suggests that all artistic innovation involves the systematic comparison of past achievements and present motifs.

  Thus, each observer痴 drawing captured not only the image before him in the eyepiece but something of other drawings熔f Mars or scenes of the terrestrial landscape謡hich served as starting points and standards of comparison, illustrating Gombrich痴 conclusion that 殿ll paintings owe more to other paintings than they owe to direct observation.  In terms of the history of Mars observations, each observer was thus indebted to the one before; each observer could 砥se previous examples from other artists of the spatial relationships, the way the visual elements of the Martian globe interacted with one another, to stand on 鍍he difficult path of adjusting. Herschel and Schrter 殿djusted Huygens痴 view; Beer and M臈ler adjusted Herschel痴 and Schrter痴, and so on. The sequence continues more or less linearly through the naturalistic landscapes depicted by gifted astronomer-artists like Nathaniel Green and ノtienne L駮pold Trouvelot in 1877. Then預nd this is where the story heads off orthogonally from its course thus far預 very different model is introduced: Giovanni Schiaparelli痴 trigonometrically-inspired map which is produced largely independently of the hitherto dominant tradition of naturalistic representation and instead draws on other traditions, mapmaking as a branch of surveying  and geometry. Mars is now seen (and rendered) as a strongly schematic form, instead of a naturalistic landscape. It is recast as a design. The successive observers of Mars now bring a very different beholder痴 share with them to the eyepiece耀o the era of the celebrated Martian canals, which essentially grew out of a stylistic aberration of an influential but idiosyncratic astronomer, is born.

  Thus the history of Mars observations, which has become one of the most extensively documented chapters in the history of astronomy謡ith good reason傭ecomes a unique case-study in the intricate process by which we come to know anything. Even within astronomy, the problem has not gone away with the introduction of remote observing預s is necessary of course in all space observatories謡here the question remains, as Felix J. Lockman suggested at a workshop on remote observing in 1993, 展hat is good observing? What is the output of a successful observing run? What is meant by 蘇igh quality data? and so on. Eliminating the presence of the astronomer at the eyepiece has not removed the astronomer from assessing, molding, and interpreting the data揺e or she has only moved down the line of the data train; it still ends with the astronomer. We want our telescopes to produce good science, and good data are a part, but only a part, of good science. Lockman continues: 展hen scientists present the results of an experiment [or a set of observations] they take responsibility for those results by attaching to them the most precious coin of the scientific realm: the individual scientist痴 pledge to speak the truth.  The word 途esponsibility makes it clear that this involves something peculiar to humans; a CCD or a computer is not responsible for its behavior. The person who is in the best position to take responsibility is the one who 殿ctively plays with the equipment, tries out various combinations of things, and constantly iterates on technique. Here he is speaking of an observer in the modern sense耀omeone who is assigned to the acquisition of data using equipment that no longer involves looking through an eyepiece at all (Lockman is a radio astronomer). But the process is the same which Gombrich and others have identified in the history of art; a process of 都chema and correction, of taking a starting point, a standard of comparison, and 杜aking and matching and remaking.
      In the history of art, it is the artists who were 途esponsible for this 殿ctively playing with the equipment, trying out various combinations of things, constantly iterating on technique.  Now it is quite possible to write the history of art without knowing much about the individual artists at all (and in some cases, such as Giotto and Masaccio, very little can be known; the biographies are sketchy or lacking). But can see that the whole experimental method葉he relationship of results to technique, the process of playing with equipment and materials謡as created not by the Theoreticians and the Schoolmen but by the artists who were (at least until Alberti published his Della Pittura and made picture-painting into a geometrical problem and a painter into a producer of cross-sections of optical pyramids) manual laborers.  Thus, when guilds were founded in Italy in the thirteenth and fourteenth centuries, sculptors and architects were classified with stonemasons and bricklayers, while in England 吐ace painters, coach painters, and house painters continued to belong to the Painters-Stainers Company until the seventeenth century. The modern-day observatory or laboratory is descended not from the scholar痴 *******



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