Water: An Absolute Requirement for Life

Abstract

The characteristic of life and the situation of the Earth are analyzed from the viewpoint of entropy. Living being is an open system, which takes low-entropy materials from and puts out high-entropy ones into the environment; for living beings to be able to maintain their lives, the environment itself has to be kept in a low-entropy state. As the environment of the living beings, the Earth has a mechanism of entropy elimination, the circulation of water. Living beings have two kinds of low-entropy materials, clean liquid water of low energy, and carbohydrate of high energy. For all living beings, the ``low-energy and low-entropy'' material is liquid water. Water is absolutely important for life not only as the place where the elementary bio-process proceed, but also as the low-energy and low-entropy material indispensable for entropy elimination from the concerned living system.