Placing a plastic bottle full of water in the house window: what it's for and why it's recommended

In the 1980s, the medium Chico Xavier met mechanic Alfredo Moser and said: "Moser, you will have a light in your life, but this light will not be only yours." Some years later, during the Power Outage Crisis, which lasted between late 2001 and early 2002, Moser invented his "lamp." The invention consists of a pet bottle filled with water, pushed halfway outside and halfway inside the roof. This way, homes without electricity could have some kind of lighting, using the concept of water refraction that, when hit by sun rays, causes the light to spread throughout the room. The article also mentions how to make the "Moser Lamp" in apartments.