The creation of a huge, artificial cloud in Yverdon-les-Bains has presented organisers of the Swiss national exhibition with one of their greatest challenges.
Suspended over the lakeside at the end of a long, metal walkway the cloud is created by spraying lake water through more than 30,000 jets evenly spread over a 78-ton structure.
While the final product is impressive, its creation has given the Expo organisers headaches-a-plenty. After running into early problems when micro-organisms from the lake clogged the cloud's filters, the installation fell foul of local health authorities.
Regional government doctors feared that bacteria in the lake could put the public at risk of contracting Legionnaire's disease. However, engineers set up a system to filter out potentially harmful bacteria, and cantonal authorities have approved use of the lake water. The cloud system will operate with pure tap water until June.
Currently, the problem is dealing with the plankton that has clogged the filters. Engineers are creating a system to suck the plankton out as lake water enters. The system will be installed at the end of the month, and will require approval from cantonal authorities again.
Even running at subsequently lower power levels, the cloud still makes for an astonishing sight which visitors can choose to admire from a distance or, at the risk of getting soaked, from within the cloud itself - raincoats are provided!
The interaction of the artificial cloud with the 'real' weather that surrounds it offers an introduction to Yverdon's theme of "Me and the Universe", says the site's artistic director, Sergio Cavero.
"Me and the Universe"
"We didn't particularly want to concentrate on the 'Me' or on 'the Universe'", Cavero says, "but rather on the 'and' - the actual nature of the relationships we have with ourselves, those around us and our whole environment."
In keeping with this aim, the Yverdon organisers have created four installations addressing the relationships individuals have with their own bodies and minds.
"Who am I" is a soothing but also thought-provoking exhibit in which visitors lie cocooned in cushioned pods while watching a giant kaleidoscopic projection show. Speakers in the side of the individual pods pose a series of questions, ranging from the frivolous to the deadly serious.
Our relationship to our bodies is then examined in exhibits such as the "Garden of Eden" which informs and educates visitors about healthy (and unhealthy) living, the "Circuit" cinema show taking the public inside the head of top athletes and "Signalpain" - a brave examination of how sensations of pain affect different people's lives.
A somewhat lighter touch is then taken in the three installations dedicated to the relationships we have with those nearest to us.
"Le Premier Regard" examines the mystery of human attractions and seductions, a theme which is subsequently acted out in the interactive comedy film, "SwissLove".
Romantic feelings then come to a head in "Oui", an exhibit which offers couples the chance to marry - for 24 hours.
"There are no boundaries of age, gender or nationality," Cavero explains. "The only limitation is that you must come as a couple and be prepared to make a commitment to each other for at least 24 hours.
"Some will use the exhibit to reveal their love for someone for the very first time, and perhaps risk rejection. Or it might be a married couple wanting to reconfirm your love. Someone might be already married and decide to enter into a 24-hour marriage with someone else - but that's their business, we make no judgement."
If bigamy, even for just 24 hours, isn't your thing, there's always the less controversial "Onoma" project which widens the relationship theme to encompass people's involvement with the villages or towns in which they live.
The exhibit's creators have shot video films in locations all over Switzerland and linked them together using common roots in the place names. For example, visitors can go on a virtual journey from Yverdon to Rhäzuns via Kloten - all three of which derive their names from the Celtic word for castle.
With its combination of education and entertainment, Yverdon can offer the public plenty of bright spells this summer - even if there's bound to be at least one cloud permanently in the sky.
by Mark Ledsom
Expo.02 runs until October 20. Adult tickets cost between SFr48 ($30) for a single day and SFr240 for a season pass. A comprehensive English guide to Expo.02 can be purchased, and most of the individual exhibitions have English captions, where necessary. Many of the Expo.02 staff speak English. Improved rail and boat links between the Expo towns should ensure few traffic problems and the region also boasts an excellent network of bicycle and in line skate routes. Bikes and skates can be hired at the Expo sites and railway stations, and one-way hires for no extra charge are also possible.