Remko Scha
Course "Algorithmic Art
& A.I."
Op Art, Moiré
& Emergence
Emergentie.
Bij algoritmische kunst in de
smallere betekenis des woords is het eigenlijke kunstwerk het algoritme.
En dan kan men het interessant vinden als er een verrassende relatie
bestaat tussen het algoritme en de output – als bijvoorbeeld
een eenvoudig principe een zeer complex eindresultaat oplevert,
of als een willekeurig lijkend proces volstrekt regelmatige structuren
blijkt op te leveren. Het "vanzelf" ontstaan van structuren
die niet expliciet voorgeprogrammeerd zijn, wordt "emergentie"
genoemd. Interessante algoritmes in deze categorie komen we tegen
in sommige nieuwe wetenschappelijke disciplines zoals Computational
Mathematics en Artificial Life.
Early Algorithmic Art. Iteratie-loopjes
met transformaties: translatie, rotatie, scaling.
Moiré patterns
'Moiré' is a French word meaning
'watery' or 'watered silk' and has now been adopted in English.
Watered silk and mohair fabric have an appearance that is both
shimmery and like the grain of wood. That such patterns could
be produced with a pair of diffraction gratings was pointed out
by Lord Rayleigh in 1874, who also mentioned that the principle
could be useful in making accurate measurements. (. . .)
A diffraction grating is a transparency with ruled parallel lines
so close they cannot be seen with the naked eye. But if two such
gratings are superimposed, with slightly different rulings, a
pattern analogous to the beats of sound becomes entirely visible,
in fact a good alternative name for moiré patterns would
be 'visible beats'. One is provoked to conjecture that the fundamental
nature of matter is based on such a principle. Perhaps all we
can observe in nature are moiré fringes produced by something
analogous to diffraction gratings in which the distances between
adjacent lines are so small that there is no method known for
their direct observation, even with an electron microscope. This
suggestion would fit in well with the theory of 'winding space',
where space is assumed not to close in on itself but to just miss,
that is, instead of being a hypersphere it is a sort of hyper-helix.
Irving John Good:
Science in the Flesh. In: Jasia Reichardt (ed.): Cybernetics,
Art and Ideas (London: Studio Vista, 1971), pp. 104-106.
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This applet uses a grid of balls which
continuously change colour in a cyclic way. There are
small frequency differences between the balls: they
cycle slightly faster if they are closer to the center
of the image. The applet demonstrates how patterns and
apparent motion emerge out of the increasing phase differences.
Click on the image to go the page with the full
details.
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Bibliography
I. Amidror: The
Theory of the Moiré Phenomenon, Kluwer Academic Publishers
(1999).
Gregory Bateson: "The Case
of Beats and Moiré Phenomena." In: Mind and Nature.
J. Guild: Interference Systems of Crossed Diffraction Gratings:
Theory of Moiré Fringes. London: Oxford University Press,
1956.
J. Guild: Diffraction Gratings as Measuring Scales. London:
Oxford University Press, 1960.
G. Oster and Yasunovi Nishijama: "Moiré Patterns."
Scientific American May 1963, pp. 54-63.
Lord Rayleigh: "On the manufacture and theory of diffraction
gratings." Scientific Papers 1, p. 209; Philosophical
Magazine 47 (1874), pp. 81-93, 193-204.
Online examples
and applets.
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Table
of Contents "Algorithmic Art & A.I."