This time, we will deal with an optical experiment easy to do, but which, in spite of its simplicity, is able to give you a continuous marvel. What you have to do is simply mount a lens on the bedroom window. In this way, when you wake up in the morning, you will admire the outside scene projected on a wall of your bedroom (figure 1).

If your window is turned to East, you will be able to enjoy the spectacle of dawn and the sunrise. This show changes every day, according to the seasons and the weather conditions, and you will never become tired of observing it. During a storm, lighting will seem to fall in your room. If you live in a City, during the night, you will see car lights to chase each other; the building in front of your house, open one eye or the other; you will see street lamps far away. Some nights, if you have the window facing the favorable direction, you will see the Moon run among the clouds.

http://www.funsci.com/fun3_en/sky/sky.htm