Guess what this bottle (2 photos)

In the Philippines, people have found a primitive, but still a smart way to light their homes without electricity. The idea came from students at MIT, and is already used to light homes in the Philippines in the poor neighborhoods. Using liter plastic bottle, water and disinfectant, they managed to create a lamp "Illuminated bottle." The concept is very simple, but it is a miracle for those poor people who lived in the dark or in the light of kerosene lamps. Such bulbs bottles were installed in the roof, when the sunlight falls on the water in the bottle, it is distributed in the room. A few teaspoons of bleach and water in the bottle is clean, the device can be operated up to five years.