A plan to celebrate the "Year of Physics" by shining lights into the night sky has upset some astronomers.
Dubbed a "grand optical relay", the proposal involves people switching on lights in a relay around the world on 18 April next year.
It would start in the United States with the lighting of a single light, commemorating the 50th anniversary of Albert Einstein's death.
Leicester-based astronomer Darren Baskill, from the Campaign for Dark Skies, described the plan as "irresponsible".
He said the project was "educating people that generating light pollution is okay".
"It is ironic that they plan to celebrate physics by destroying the view for astronomers."
Since he raised the matter with fellow light pollution campaigners, they have contacted organisers pleading with them to reconsider.
However the event's planners downplayed the concerns.
Max Lippitsch, from the University of Graz in Austria, told the BBC that there would be very little light pollution.
He said: "What we want is to unite as many people as possible in a demonstration that science is, like sports or music, an international language that is understood across all kinds of political or ideological borders.
"That we chose light as our symbol has the obvious reason that, despite the well-justified objections of dark sky promoters, light has a positive connotation in human thinking.
"What they will do is switch on moderate light sources, such as torches and car headlights, for less than a minute each.
"This will result in a tiny flash of light compared to the enormous light pollution produced steadily by our civilization."
In a bid to appease dark sky campaigners, the event may include a "flash of darkness" preceding the light signal, "to strengthen the awareness of the light pollution problem", Dr Lippitsch said.