Once again the temporary's so contemporary

SOME curious news, with images to match, began bouncing around the Internet last month: A Paris firm called Serero Architects had been chosen to design a temporary viewing platform for the Eiffel Tower, to mark the landmark's 120th birthday next year. Online, a few commentators complained that the mushroom-shaped platform would ruin the tower's tapered profile. Others pointed out that the original structure was never meant to be permanent anyway.

That back-and-forth soon came to a quick halt: Word came from Eiffel Tower officials announced that they'd be building no such addition, temporary or otherwise. It was less a hoax than a Web-fueled misunderstanding. Serero Architects, it turned out, had decided on its own to produce the design for a platform; after the firm posted images on its website, bloggers and news outlets began re-posting them, suggesting that the project was actually in the works. It was a story about temporary architecture that was itself temporary, written in the HTML version of invisible ink.

If nothing else, the timing was perfect. Architecture has entered another of its periodic bouts of fascination with impermanence. Maybe it's the anxiety produced by doomsday predictions about the state of the environment and, lately, the economy. Maybe it's the quicksilver quality of digital culture, closer in character to sand or water than bricks and mortar. Whatever the source, architects are playing up the idea of temporariness, and even finding solace in it, to a degree not seen since the 1960s and '70s, when several experimental design teams explored what Peter Cook, a member of London's Archigram, called "expendability" and "throwaway architecture."

Japan's Shigeru Ban has made a career out of the ephemeral, crafting emergency shelters from cardboard tubes and movable art galleries from stacked shipping containers. Architecture students, inspired by advances in biotechnology, are dreaming up buildings with the ability to change shape or even regenerate themselves, adding a room the way a starfish grows a new arm. The Chinese architect Qingyun Ma, dean of the architecture school at USC, has even argued that cities themselves should have "expiration dates."