London

The idea was to “unite all nations by the enlightening power of physics”. But with eight months to go, Max Lippitsch's plans have succeeded only in dividing his colleagues.

Lippitsch, a physicist at the Karl-Franzens University in Graz, Austria, wants to shine a relay of lights around the Earth to celebrate the World Year of Physics 2005. But astronomers say the scheme sanctions light pollution, the needless illumination of the night sky that increasingly interferes with their observations.

Britain's Institute of Physics pulled out of the project late last month. “Astronomers were very concerned,” says Caitlin Watson, who is managing the institute's contribution to the year's celebrations. “Even though this won't produce much light pollution, it sets a very bad precedent.”

The World Year of Physics celebrates the centenary of Albert Einstein's “miraculous year”, which saw him lay the foundations for the theory of relativity, quantum theory and the theory of brownian motion. The goal is to boost the public awareness of physics.

The light relay is set to begin on 18 April next year in Princeton, New Jersey, the 50th anniversary of Einstein's death. Participants will shine torches to neighbouring groups up to 10 kilometres away, who will then switch on their lights. This domino effect should ripple around the Earth, with undersea fibre-optic cables linking continents. Lippitsch says that the light pollution will be tiny because high-powered searchlights and lasers are banned.

But Vinaya Sathyasheelappa, the World Year of Physics project coordinator for the American Physical Society, says there are “mixed emotions” about the project in the United States. He adds that the society is nonetheless likely to back it: “Without the United States the light would have to go through Canada, and Canada's physics society just doesn't have the resources to make this work.”