Summer sunlight can change my mood, and I don't suffer from seasonal affective disorder. It's hard to ignore the positive feeling one gets from sunlight streaming through a window. Soon you'll be able to bring sunshine to any cloudy day and even into a dark windowless cave. Or even better, you'll be able to have a "sky light" on the ceiling of a non-top-floor space of a building.

Researchers in Italy have created a lighting panel that uses nanoparticles to create nearly natural daylight. This is much better than fluorescents; think about daylight coming into dark subways or windowless offices.

It starts with white LEDs. But the magic comes from a clear plastic panel filled with titanium oxide nanoparticles that can mimic the way Earth's atmosphere scatters sunlight. Different panels can offer different kinds of sunlight—from super bright to twilight.The team created this clear polymer that can exactly mimic the phenomenon of Rayleigh scattering—this is how air molecules scatter the sun's radiation. In this case, white light is scattered into a so-called "sky light." This results in mostly blue wavelengths with a specific source spot of warm yellow light (this is supposed to be the direct sunlight).

The prototype is almost 6 feet by 3 feet, and was first presented at a lighting show in Germany this past March.

The researchers hope it will transform road tunnels, malls, hotels, and hospital rooms. Because LEDs are so cheap, there are a lot of new lighting options coming to the market.

Philips recently launched a very attractive, textile-based luminous ceiling called OneSpace. And I am sure there is a lot more to come especially as the incandescent bulbs continue to be phased out.