Here's a report from the fringes of science: researchers at the Fraunhofer Institute for Industrial Engineering in Germany have created a luminous ceiling that re-creates the fluctuating lighting conditions that occur naturally out of doors on a cloudy day.

It's not cheap. Fraunhofer says installing a virtual sky would probably cost approximately 1000 euros ($1249) per square yard (per 0.91 metre). But in a study, the researchers found that 80 per cent of workers preferred working under a dynamic virtual sky. And in a release about the project, Fraunhofer reports it has already had inquiries about the new type of lighting, mostly from companies hoping to use it in conference rooms.

The dynamic luminous ceiling, created by researchers at the Fraunhofer Institute for Industrial Engineering in Germany, in action.

The luminous ceiling is made of 20-inch-by-20-inch (50.8-cm-by-50.8cm) tiles, each loaded with a board containing 288 light emitting diodes (LEDs). The lights are covered with a matt white diffuser film so the individual points of light meld together. The researchers used a combination of red, blue, green and white LEDs to create the full light spectrum.

The trick to simulating outdoor light is to simulate the dynamic changes in the light in such a way that is not obvious to the naked eye. The researchers did not want to distract people from their work, but found that gentle fluctuations improved concentration and heightened alertness.

The researchers at Fraunhofer say they are optimistic that the price of their virtual sky will come down eventually. "The more units are produced, the more cost-effective each luminous ceiling will be," they said.

LA Times