Terminology

Leonardo, Vol. 16, No, 2, p. 138. 1983 Printed in Great Britain 0024-094X/83%3.00+0.00 Pergamon Press Ltd. TERMINOLOGY The terms defined below were selected from artists’ Articles and Notes published in the previous issue of Leonardo. Each definition is followed by an indication of the volume and page ofLeonard0 on which the term first appears. The terms were not found in the art dictionariesamong the dictionaries listed in Leonardo 16, 60 (1983) or they are used in a new sense. Some are terms that have been carried over into the field of art from the natural and social sciences, from mathematics and from technology. Numbers in brackets, e.g. [ 11, 171,refer to the dictionaries mentioned above. The definitions are not presumed to be unassailable. The editors would, therefore, welcome the comments of readers on the definitions presented. 1178. Acoustic image (in physics)-A 2-dimensional amplitude distribution of a sound field of any frequency, but not necessarily made visible. If the frequency is above 17kHz (17,000 cycles per sec). it is called an ultrasonic image. (16, 38; [P. Gregus, Ultrasonic Imaging: Seeing by Sound (London, New York: Focal Press, 1980)l) (Cf. Terminology, Leonardo 7, 66 (1974):frequency) 1179. Artificial intelligence, A.I. (in computer science)-The study of computer techniques to supplement the intellectual capacities of humans. It is concerned with the more effective use ofdigitalcomputers through improved programming methods. (16, 15: [ 141) 1180. Chladny pattern (in physics)-A pattern produced usually by fine sand dusted on a thin regularly shaped metal plate (a Chladny plate) when the plate is caused to vibrate. The sand collectsalong nodal linesof the standing waves. Different patterns can be produced by causing vibration at different frequencies. (16, 40; [R. E. Berg and D. G. Stock, The Physicso f Sound (Englewood Cliffs,N.J.: Prentice-Hall. 1982)])(Cf. Terminology. Leonardo 6, 355 (1973): node and standing waves: 7, 66 (1974):frequency) 1181. Diapason (in music)-The interval or consonance of the octave in ancient Greek music, (16, 36; [Websrer’s Third New International Dictionary (Springfield, Mass.: G. & C. Merriam, 1971)]) Diapente (in music)-The interval or consonance of the fifth in ancient Greek music. (16, 36; [ Webster’s Third New International Dictionary (Springfield, Mass.: G. & C. Merriam, 1971)]) 1182. 1183. Diatessaron (in music)-The interval of a fourth in ancient Greek music. (16. 36; [Webster’s Third New International Dictionary (Springfield, Mass.: G. & C. Merriam, 1971)]) 1184. Flat-sphere perspective (in visual art)-The geometrical organization produced by the three spatial dimensions of spherical perspective when it is flattened (mapped) on a finite 2-dimensional surface. (16, I ) (Cf. Term 1188: spherical perspective) 1185. Polar perspective (in visual art)-The geometrical organization produced by the three spatial dimensions of two or more flat-sphere perspective images when these dimensions are integrated (mapped)with a fourth, or higher, representational dimension. (16, 1) (Cf. Term 1184: flut-sphere perspective) 1186. Sonosensitized photographic plate or film (in physics)-A photographic plate or film made sensitive to sound and ultrasound waves by fogging with diffused light. (16, 38; [P, Greguss, Ultrasonic Imaging: Seeing by Sound(London. New York: Focal Press, 1980)])(Cf. Term 1191: ultrasound) 1187. Sound paintings (in visual art)-Term used by P. Greguss for ultrasonic images which are produced by moving an ultrasonic transducer as a painter’s brush and combining with techniques employing ultrasound reflection from, and/or transmission through, an object. (16, 39)(Cf. Terms 1178: acoustic image: 1191: ultrasound; 1190: ultrasonic transducer) 1188. Spherical perspective (in visual art)-The geometric organization produced by the three spatial dimensions of the visual world surrounding an observer when they are projected (mapped) onto a spherical surface with the observer at the center of the sphere. (16, 3) 1189. Ultrasonic image (rn phtrrc ,)-(Cf Term 1178: acoustfc /mare) 1190. Ultrasonic transducer (in physics)-A device actuated by electric power, that supplies a beam of ultrasound to the surrounding medium. (16, 38; [P. Greguss. Ultrasonic Imaging: Seeing by Sound (London, New York: Focal Press, 1980)])(Cf. Term 1191: ultrasound) 1191. Ultrasound (in physics)-Vibration of the same physical nature as sound, but with frequencies above the range of human hearing. generally above 17...