Question- There is a product on the market called a "Wall O' Water". It is a doubly thick cylinder made of polyethylene which is often colored green, blue, or red. This cylinder is about 1 foot in diameter and has cells that are to be filled with water. The directions say to set these out in the garden before the last frost; after about 4 days, you can plant frost sensitive plants without worrying about them freezing to death. What are the physical principles behind how they might work? (Hint: there are both thermodynamic and light absorption considerations.
Please explain above problem in step by step manner so I can easily understand it