Why doesn't stomach acid dissolve the stomach itself? Why are most plants green? Why are there more tornados in the Midwest than on the coast? This volume answers these and more than 200 other questions, shedding light on the science behind them. The book addresses every major branch of science, including physics, chemistry, biology, geology, meteorology, astronomy, and cosmology. It highlights some of the big ideas that helped shape science as we know it and discusses the future of science with regards to nanotechnology, genetic modification, molecular medicine, and string theory.