Nature, in the broadest sense, refers to the physical world or universe. It can refer to the phenomena of the physical world, and also to life in general. The study of nature is a large part of science. Nature ranges in scale from the subatomic to the cosmic. The term "nature" may refer to living plants and animals, geological processes, weather, and physics, such as matter and energy. It is often taken to mean the "natural environment" or wilderness—wild animals, rocks, forest, beaches, and in general areas that have not been substantially altered by humans, or which persist despite human intervention. For example, manufactured objects and human interaction are generally not considered part of nature, unless qualified as, for example, "human nature" or "the whole of nature". The term "nature" has been used to name more and more diverse things, as well as their opposite, at the risk of becoming another meaningless panchreston. The concept of nature has been used in public policies, conservation science, or environmental ethics, but it has never been really theorized during all this time. The word "nature" is derived from the Latin word "natura," which means "essential qualities, innate disposition," and literally means "birth".