3. Solar pump
We heat the first bottle which is
empty with a lamp which
represents the sun during 15min.
The pression in the first bottle
dicreases and when we switch off
the lamp, the water in the second
bottle goes in the first.
4. Water Fountain
The water in the first bottle goes into
the second bottle. The air in the
second bottle goes into the third
bottle. And the water in the third
bottle goes into the first bottle.
5. Water lamp
The light of the sun reflects inside the water and the bottle illuminates the box.