Nature,
in the broadest sense, is equivalent to the natural world, physical
world or material world. "Nature" refers to the phenomena of the
physical world, and also to life in general. Manufactured objects and
human interaction generally are not considered part of nature, and are
referred to as artificial or man-made. Nature is generally
distinguished from the supernatural. It ranges in scale from the
subatomic to the cosmic.
The word nature is
derived from the Latin word natura, or "essential qualities,
innate disposition," but literally meaning "birth."
*
BTU - British
Thermal Unit, now replaced by SI unit of energy, the joule (J)