[illegible] understand how holographic images are produced, but are excited at the prospect of three dimensional reproduction. Hilary Driver reviews the current state of holographic technology revealed in an exhibition currently showing at the Science Museum in London.
'Gradually Connie had aroused her curiosity and managed to get her to peep at the sparkling night sky of the ceiling. This ceiling too became a night sky with more purple in its black than the night they had just abandoned, with a pale moth-green moon rising in the south over one of the entrances. Slowly as people came wandering in to their seats, a different colour moon rose majestically over each of the doors ...
'As the moons reached the zenith, the four of them began a stately dance to music welling up. Their shapes began to shift from round to oblong to crescent to wing-shaped like birds, in images of dignified flight ...
'The cranes came down from the ceiling and became flesh — although she had learned that these vivid three-dimensional images were a mere trick of projectors and lights. The image broadened. One enormous crane filled it and then its head spread into clouds and its feet turned to water ...'
Marge Piercy's novel, Woman on the Edge of Time, portrays a vivid and striking view of the possible future of the hologram. The word hologram conjures up images of being able to view something from all directions which looks real, but is in fact a projected image. Indeed, the word itself is derived from the Greek holo meaning whole, and graphis meaning image.
But imagination and technology are still many years apart and, in spite of the theory of holography being developed as long ago as 1947 by the Hungarian scientist Dennis Gabor, holography today can be compared to the early developments of photography or film. Production of a hologram requires comparably as much investment in specialised equipment and technical know-how.
At the risk of infuriating the more scientifically-inclined readers, here's a simplified description of how a holographic image is produced. A [laser is used to] emit a coherent light — that is a narrow beam of light all of one wavelength (or colour), unlike 'normal' light which is made up of a spectrum of wave lengths or colours. Any perceptible vibration will interfere with an eventual image, so the equipment and subject matter of the hologram are placed on a vibration-free table. The light is then split into two parts. One beam passes through a deflecting mirror and a lens onto the subject matter which is in front of a holographic plate (similar to the early, heavy photographic plates). The second beam, also deflected by a mirror, passes through a lens directly onto the plate. Since this second beam hasn't had an object in its path, it reaches the plate in the same undisturbed pattern as it originally left the laser. A shutter in front of the laser controls the two beams. When opened, both beams meet at the holographic plate and the interaction of these produces an interference pattern on the light-sensitive plate which creates the hologram.
[illegible] the viewing of the finished object. It can require the plate to be illuminated by laser light before the image can be seen. Even where no special light is necessary, at present it is difficult for more than one or two people to fully view a hologram at the same time.
The exhibition at the Science Museum was at the same time disappointing and fascinating. Disappointing because it was on the whole artistically prehistoric with many of the works heavy abstract images that wouldn't have been given wall space if they were on display in a self-respecting gallery. The exhibition was also dominated by capitalist enterprises, the military and [illegible] on displaying how they use the technology of holography for such socially useful works as advertising checking out groceries in supermarkets, or for forcing everyone to use a 'fraud-proof' credit card in call boxes.
But it wasn't all bad. Some of the scientific applications of holography are valuable. For instance, the fact that minute vibrations can be detected by holographic analysis means that the efficiency of machinery or components can be scrutinised in tremendous detail. Holograms have also been used to open an entirely new area of medical research from body scans to locating tumours, improving the design of artificial limbs and even keeping holographic records of dental work.
In the Soviet Union the holographic reproduction of precious art objects had resulted in what amounts to a travelling museum. The work is of such amazing quality that it is hard to believe that the object is not actually there in the glass case. People in remote areas of the country would otherwise be unlikely to be able to see these cultural treasures in such a lifelike form.
For me, it was these 'real' as opposed to 'abstract' images that held the true fascination of holography. In particular, holography comes into its own in the art of portraiture. The Portrait of Nicole by Nicole Aebischer is undoubtedly the most stunning of the exhibits. Impossible to reproduce in flat black and white, it is an animated hologram that really takes your breath away. The face looks real enough to touch, but as you view the image from different angles the eyes appear to naturally open, look directly at you and then close — a very disconcerting experience!
As a technology, holography can be like any other, developed for profit or for the benefit of the majority of people. As an art or entertainment there is a long way to go before we can look forward to holographic theatre or cinema, with the biggest obstacle being the tremendous resources needed to enable someone to produce holograms and the limitations existing at present on the numbers who can appreciate the end result.
Whatever the drawbacks, holography is here to stay and, alongside other new technologies, will have to be wrested from the control of the ruling class if it is to be developed as genuinely socially useful.
The Light Dimensions exhibition is running until 29 April at the Science Museum, London SW7 (01-581 4308).
HILARY DRIVER is a member of the International Editorial Board.