Solid, liquid, and gas—these are the three states of matter presented in the homeschooling science curriculum I was preparing to review with our 7-year-old daughter. The best example to learn these states is water in its different forms: moisture vapor in a cloud, liquid rain, and solid ice. I couldn’t stop there though, not when the intersection of biology and physics tells of a truly amazing fourth state of water that may be the key to life in the animal kingdom. The fourth state, or phase, of water is gel. With a love of all things cooking and baking, our daughter immediately thought of an example of a gel. Gelatin, a nutrient-dense snack when prepared with pure fruit juice and quality gelatin, is a favorite in our home. The cooking process is amazing to watch. Gelatin is slowly stirred into hot fruit juice until it dissolves. Upon cooling, the proteins …