Solaris: Experimental Solar Holography

Solans: Experimental Solar Holography Mane-Christiane Mathieu Holography deals with the relationship between certain material and non-mate­ rial phenomena, between the recording of light waves and their virtual image. It involves a type of artificial light cap­ tured in silver halide grain on holo­ graphic film. The silver halide absorbs and secures the light energy emanating from a laser source. At the same time, holography involves restructuring the captured mass of light. In order to re­ construct and reproduce the image, a light source is necessary, preferably a white light whose position has been carefully pre-determined. Halogenous light is excellent, but the sun is even better. While the plethora of mythical, religious and ritualistic symbols associ­ ated with this star might stimulate the intellect, when all is said and done the sun is our basic source of light and heat and accounts for the fact that we live on an oxygenated planet. Compared to all Marie-Christiane Mathieu (artist, holographer, research­ er), 5470 St. Urbain, Montreal H2T 2X1, Quebec, Canada. Received 17January 1995. Manuscript solicited by Jürgen Claus. The edited text was translated from the French by Stuart Anthony Stilitz. other natural and artificial methods, it is the sun that enables us to calculate time most effectively. At the same time, the sun leaves its imprint on holographic film. It is also the sun which imbues the weather, the sky and all earthly objects with color. Its white light is simply the sum of its many colors, colors reproduced by hologra­ phy. The hologram may thus be viewed as a prism that decomposes white light into its spectrum. By studying the gyration of the earth, one can determine the angle of the sun with respect to a specific point. At noon­ time on 21 June in Montreal, the sun is at 69 degrees, its highest point. It reaches its lowest point, 22 degrees, on 21 December. During the spring and au­ tumn equinoxes, which occur on 21 March and 21 September, respectively, the angle is 45 degrees. These transfor­ mations determine the seasons. When combined with the daily east-west move­ ment of the sun, they influence the con­ stantly metamorphosing quality of the light. In recording a hologram, it is of critical importance to take all of these factors into account. Every change has a particular effect. Fig. 5. Marie-Christiane Mathieu, Solaris, sketch of solar hologram installation, conception 1994, to be erected in spring 1995. This hologram will be lit by the sun and will project different images in perpetual motion depending on the season and the sun's inclinations. In a project such as Solaris, the sun provides a unique method for integrat­ ing holograms with external structures. As the various lighting angles change during the daytime over the course of the year, the sun creates different im­ ages. This results in constantly chang­ ing colors and virtual forms. But there are also dangers involved. Little con­ crete data is available on the reaction of holographic emulsions to ultraviolet light. Sooner or later, constant expo­ sure to direct sunlight will almost inevi­ tably darken the film. To what extent is such an effect acceptable and what can be done about it? Many solutions have been proposed, including chemical treatments, lamination and even solarization . Then again, does the darken­ ing effect actually constitute a problem? Though the image has been darkened, is it not still present? These are but a few of the many questions that will be resolved only through in­ tensive research. Once the film has been developed, a holographic emulsion, which is compa­ rable to a photographic emulsion, con­ tains silver particles in suspension. It is these non-developed particles that, upon exposure to sunlight, darken and create what are known as "print-outs." I therefore set out to find ways of elimi­ nating, as much as possible, the effects of ultraviolet rays on the film, as well as ways to control all other possible reac­ tions related to the humidity, intense heat and minus-40-degree (C) weather that we experience so frequently in our country. The upshot of these efforts was the creation in August 1994 of Project Solaris (Fig...