By the time you read this the city will probably have grown far beyond the few roads and houses that appeared on Monday afternoon. By the end of the month, when building ceases, the place could be an urban utopia or a disaster area. Building materials are free, there is plenty of space and no planning regulations. Cyberspace offers opportunities for experiments in urban geography that cannot be performed anywhere on the earth's surface.
"I want to look at how somewhere like London grew," explains Andy Smith, who launched the experiment as part of his PhD research at University College London's centre for advanced spatial analysis. He is already seeing the first results on his screen: "It was a completely blank world. I have got roads, houses, trees. Why roads, with no cars?" The obsessive road building is puzzling, in a world where people can fly and buildings can float in the air.
In a world with so few rules, some bad behaviour is to be expected. "I'm having to delete vandalism from my lot already," one first-day builder complained during an online conversation.
Visitors and would-be builders must first download a 3D browser program from Active Worlds (www.activeworlds.com). Once inside, visitors can move around, meet other people and converse with them by keyboard. All the conversations during the 30-day trial will be logged, and the virtual city's growth will be mapped daily.
It is part of a bigger programme of research on the use of virtual reality to involve the public in planning decisions.
Notable buildings erected during the trial will be preserved. The designer of the best building will win a prize of free citizenship in Active Worlds, a club where members can meet and chat in any of 432 virtual worlds.