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,
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.
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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
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
William P
SHEEHAN, MN, USA