How did the first peoples know which foods were safe to eat? Excellent question! Food historians make educated guesses based on ancient records and modern practices.
When water freezes its entropy decreases. This does not violate the second law of thermodynamics. The second law does not say that entropy can never decrease anywhere. It just says that the total entropy of the universe can never decrease.he entropy increases whenever heat flows from a hot object to a cold object. It increases when ice melts, water is heated, water boils, water evaporates. The entropy increases when a gas flows from a container under high pressure into a region of lower pressure.
This is due to ice's density being less than liquid water's density. Upon freezing, the density of ice decreases by about 9 percent. The best way to visualize how water can have different densities is to look at the frozen form of water. Ice actually has a very different structure than liquid water, in that the molecules align themselves in a regular lattice rather than more randomly as in the liquid form.