Harbor

A harbor or harbour (see spelling differences), or haven, is a body of water where ships, boats and barges seek shelter from stormy weather, or are stored for future use. Harbors and ports are often confused with each other. A port is a facility for loading and unloading vessels; ports are often located in harbors.

Harbors can be natural or artificial. An artificial harbor can have deliberately constructed breakwaters, sea walls, or jettys, or they can be constructed by dredging, which requires maintenance by further periodic dredging. An example of an artificial harbor is Long Beach Harbor, California, which was an array of salt marshes and tidal flats too shallow for modern merchant ships before it was first dredged in the early 20th century.

In contrast, a natural harbor is surrounded on several sides by prominences of land. Examples of natural harbors include Sydney Harbour, Australia and San Francisco Bay, California.

Artificial harbors

Artificial harbors are frequently built for use as ports. The oldest artificial harbor known is the Ancient Egyptian site at Wadi al-Jarf, on the Red Sea coast, which is at least 4500 years old (ca. 2600-2550 BC, reign of King Khufu). The largest artificially created harbor is Jebel Ali in Dubai. Other large and busy artificial harbors include:

System

A system is a set of interacting or interdependent component parts forming a complex/intricate whole. Every system is delineated by its spatial and temporal boundaries, surrounded and influenced by its environment, described by its structure and purpose and expressed in its functioning.

The term system may also refer to a set of rules that governs structure and/or behavior. Alternatively, and usually in the context of complex social systems, the term is used to describe the set of rules that govern structure and/or behavior.

Etymology

The term "system" comes from the Latin word systēma, in turn from Greek σύστημα systēma: "whole compounded of several parts or members, system", literary "composition".

History

According to Marshall McLuhan,

"System" means "something to look at". You must have a very high visual gradient to have systematization. In philosophy, before Descartes, there was no "system". Plato had no "system". Aristotle had no "system".

In the 19th century the French physicist Nicolas Léonard Sadi Carnot, who studied thermodynamics, pioneered the development of the concept of a "system" in the natural sciences. In 1824 he studied the system which he called the working substance (typically a body of water vapor) in steam engines, in regards to the system's ability to do work when heat is applied to it. The working substance could be put in contact with either a boiler, a cold reservoir (a stream of cold water), or a piston (to which the working body could do work by pushing on it). In 1850, the German physicist Rudolf Clausius generalized this picture to include the concept of the surroundings and began to use the term "working body" when referring to the system.