My guide Claudine Buehler, whose husband, father, uncle, aunt and grandfather all work or worked in the watchmaking business, explained that the buildings were laid out this way in the early 19th Century to maximize the amount of sunlight that could flood into the first-floor workshop windows.

BBC: Where the world��s most expensive watches are made

The first is to make sure that most of the sunlight which falls on it is absorbed, rather than being reflected.

ECONOMIST: Solar power

Conversely, the algae -- and therefore the coral -- rely on CO2 for their very survival as the algae soak up the CO2 and sunlight to produce carbohydrates for the corals to eat in the first place.

CNN: All About: Coral Reefs

This was when it was first pointed out that, because sunlight near the lunar poles comes in at a shallow angle, the floors of the deeper craters there might be in permanent shadow.

ECONOMIST: Creative destruction

First, simply by absorbing sunlight, algae floating on the surface warm the water.

ECONOMIST: Aerobiology

Scientists have known for a long time that aerosols cool climate by reflecting sunlight and making clouds brighter, but the new study is the first to use a global model to estimate the net effects on plant carbon intake resulting from this type of atmospheric pollution.

CNN: Study: Pollution helps plants absorb C02

Here on Earth, Natcore Technology has created the world's first commercially viable absolute black silicon cell, which can make virtually 100 percent of received sunlight available for conversion into electricity.

ENGADGET: Inhabitat's Week in Green: Dyson Spheres, bladeless wind turbines and airless bike tires