Gigantic images, 3D thrills, 360-degree views and mixed reality thrill visitors to Aichi exhibition A trip to the 2005 World Exposition in Aichi prefecture, Japan, takes visitors to another world altogether. Call it 'Planet of the Screens'. This is the first World Exposition of the 21st century, and many of the exhibiting countries, corporations and groups are using the latest imaging technologies to their advantage. There are screens everywhere, from a giant outdoor display to its even bigger 52-metre wide sibling inside, not to mention screens so small they can only be seen through binocular-style viewers. The most innovative presentation belonged to Hitachi, which is showcasing 'mixed reality' technology in its 'Nature Contact' show. The mixed reality show puts visitors into virtual safari trucks, kits them out with binoculars and hand sensors, and assigns them a wise cartoon owl as guide. The binoculars give you a 3D version of the show, while the hand sensor brings you into the picture, quite literally. Put out your hand and you receive a bunch of virtual bananas, which you can then throw to a monkey who dashes to pick them up. In the virtual aquarium, you can put your hand under the hawksbill turtle and tilt it left or right. It looks obligingly confused as you do so. If you make the animal turn turtle, it starts waving its flippers around frantically until you put it right way up. In the savannah section, you come eyeball to eyeball with a giraffe, who puffs into your face with his virtual nostrils. The project's special technical adviser, Hideyuki Tamura of the Ritsumeikan University, described mixed reality as a form of virtual reality in which a virtual world is imposed on real-life scenes. 'The technological challenge is capturing the real world with the internal camera of the scope and synthesising these images with computer graphic images, fusing them geometrically and optically without any sense of incompatibility,' he said. He believes mixed reality will become ubiquitous in the future, finding its way into mobile phones as well as museum showrooms. Hitachi, however, did not play a direct role in the development of mixed reality. The production was put together by Canon and a government research institute. Hitachi was using the show as a way to publicise another innovation, the methanol fuel cell. The cells power the small hand-held guides that visitors receive when going through the first part of the exhibition. The company plans to put these fuel cells into mobile phones that will be on the market from 2007. For sheer scope of display, it is hard to beat Japan's national pavilion, which provides a screen that gives 360-degree viewing in the horizontal as well as vertical. You stand on a bridge inside a sphere and the show is screened all around you. Initially, you are in the upper atmosphere but gradually descend trough layers of cloud into the sea. Canada's pavilion starts with the small and goes on to the large. Visitors waiting to enter are entertained by teku-jin (technical people) who stroll next to the queue with power-packs on their backs, a bright flat-screen above their heads and a webcam at their side. The screen carries information on Canada and the teku-jin answer questions or snap pictures for visitors. Inside the pavilion, the screen is large but otherwise seems unremarkable, until the viewers watching the presentation realise that the next set of viewers waiting in the wings has been co-opted to be part of the show, appearing to stand underneath the maple trees on the translucent screen - just as these viewers themselves had a few minutes before.