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.
A glass of water left in the freezer eventually becomes a glass of ice. Most people know what happens at 0Âº Celsius (or 32 Âº Fahrenheit): Water freezes. When the temperature outside is below freezing, for example, a rain storm may become a blizzard of snow. A glass of water left in the freezer eventually becomes a glass of ice. The freezing point of water may seem like a simple fact, but the story of how water freezes is a little more complicated. In water at the freezing temperature, ice crystals usually form around a dust particle in the water. Without dust particles, the temperature can get even lower before the water turns to ice. In the laboratory, for example, researchers have shown that itâs possible to cool water down to -40Âº C â without producing a single ice cube.