BERLIN (Reuters) - Shimmering giant bubbles carpeted with exotic plants are suspended within the vaulted hallway of a former Berlin railway station, in a new exhibition of the artworks of Tomas Saraceno.
Visitors can enter the soap-like bubbles and experience a sense of floating in a futuristic galaxy at Berlin's contemporary art museum and former station, Hamburger Bahnhof.
The "Cloud Cities" exhibition, which runs until January 15, aims to offer a utopian vision of architecture and to stimulate contemplation on space and the earth's fragile ecology.
Saraceno, 38, says he wants to bring people who can no longer see the stars due to light pollution to a better awareness of the way the earth is floating in a galaxy.
"We are flying at the very moment, the question is: are you aware of it?" said Saraceno, who is something of a renaissance man bridging science and art in his works.
"These bubbles are biospheres, like the earth which is flying around the sun at a very high speed."
The Argentine artist, who prefers to describe himself as a "citizen of planet earth," studied architecture and art in Buenos Aires and Frankfurt, as well as completing a NASA space program in Silicon Valley.
Ultimately he aims to create a flying city of his biosphere-bubbles, which he says would lift skywards as the sun heated up the interior and the air pressure changed within. He uses plants with no roots, as earth would weigh the bubbles down.
"You feel like you are in another realm, like an astronaut," said nine-year old museum visitor Jan Benno, excitedly bouncing around in one of the bubbles suspended above the ground. "Or like a fly caught in a spider's web."
Saraceno has exhibited works worldwide including at the 2009 Venice Biennale but this is the first exhibition to show 20 of his bubbles in one go.
Saraceno, who is wary of explaining his work too directly, wants museum-goers' physical interaction with the artworks to stimulate their own imagination and thought processes.
Twenty plastic bubbles of varying sizes, some covered with plants, are strung from a wire spider web sprawling within the massive Hamburger Bahnhof, which served as the terminus for trains from Hamburg in the 19th century.
Saraceno has long been fascinated by the strength and flexibility of spider webs, creating giant webs for his Biennale show "Galaxies Forming along Filaments, like Droplets along the Strands of a Spider's Web."
"Scientists and journalists try to explain the geometry of the universe as a three-dimensional spider web," said Saraceno, who, with arachnologists, scanned Black Widow webs into a computer in order to conceive how to construct one himself.
Steep, rickety ladders lead up to the two largest bubbles, with diameters of 7 and 12 meters. Inside, the exhibition appears from another, muted, perspective. It feels like a bouncy castle and when you move, the web of wires stretches.
Saraceno says he wants to reflect on social and environmental interconnectedness: "By moving one, the whole system reverberates through space conveying a sense of responsibility."
He added: "By building a flying city, we may learn how to live better and more sustainably on a flying earth."
Visitors must carefully close flaps behind them on entering the bubbles to sustain an adequate level of air pressure. If one bubble deflates, it impacts the whole constellation. The plants, inside or covering the bubbles, are carefully kept humid.
"It is a very delicate equilibrium when you are trying to build up an ecosystem," he said. "You have to have the right temperature, the right amount of air."
Saraceno says he was exciting about using the space of the former station, built in neoclassical style in the mid 19th century. The station was turned into a traffic museum in the early 20th century, and finally into an art museum in 1996.
"It's like nothing I've ever seen before," said 80-year old museum-goer Lorna Mattison, from Britain, gazing up at the bubbles. "And very Berlin: enterprising and forward-looking."
Saraceno, who caused some consternation among his architect colleagues when he said he wanted to create a floating city, says he is now working with engineers on a floating museum.
While he likes Berlin, he also misses the sun of his native Argentina, and a floating museum would enable him to get above the city's grey cloud-cover.
"People talk about traveling exhibitions, but what if the museum itself was traveling?" asked Saraceno. "At the moment, it is just in my mind, but hopefully it will catalyze someday!"
Reporting by Sarah Marsh, editing by Paul Casciato