Lasko 18″ Remote Control Large Room Pedestal 4-Speed Fan, Model S18605

Eighteen or 18 may refer to:

• 18 (number), the natural number following 17 and preceding 19
• one of the years 18 BC, AD 18, 1918, 2018 1818

4 (four) is a number, numeral and digit. It is the natural number following 3 and preceding 5. It is a square number, the smallest semiprime and composite number, and is considered unlucky in many East Asian cultures.

Fan commonly refers to:

• Fan (machine), a machine for producing airflow, often used for cooling
• Hand fan, an implement held and waved by hand to move air for cooling
• Fan (person), short for fanatic; an enthusiast or supporter, especially with regard to entertainment

Fan, FAN or fans may also refer to:

A model is an informative representation of an object, person, or system. The term originally denoted the plans of a building in late 16th-century English, and derived via French and Italian ultimately from Latin modulus, a measure.

Models can be divided into physical models (e.g. a ship model or a fashion model) and abstract models (e.g. a set of mathematical equations describing the workings of the atmosphere for the purpose of weather forecasting). Abstract or conceptual models are central to philosophy of science.

In scholarly research and applied science, a model should not be confused with a theory: while a model seeks only to represent reality with the purpose of better understanding or predicting the world, a theory is more ambitious in that it claims to be an explanation of reality.

A pedestal (from French piédestal, from Italian piedistallo 'foot of a stall') or plinth is a support at the bottom of a statue, vase, column, or certain altars. Smaller pedestals, especially if round in shape, may be called socles. In civil engineering, it is also called basement. The minimum height of the plinth is usually kept as 45 cm (for buildings). It transmits loads from superstructure to the substructure and acts as the retaining wall for the filling inside the plinth or raised floor.

In sculpting, the terms base, plinth, and pedestal are defined according to their subtle differences. A base is defined as a large mass that supports the sculpture from below. A plinth is defined as a flat and planar support which separates the sculpture from the environment. A pedestal, on the other hand, is defined as a shaft-like form that raises the sculpture and separates it from the base.

An elevated pedestal or plinth that bears a statue, and which is raised from the substructure supporting it (typically roofs or corniches), is sometimes called an acropodium. The term is from Greek ἄκρος ákros 'topmost' and πούς poús (root ποδ- pod-) 'foot'.

In a building or a ship, a room is any enclosed space within a number of walls to which entry is possible only via a door or other dividing structure. The entrance connects it to either a passageway, another room, or the outdoors. The space is typically large enough for several people to move about. The size, fixtures, furnishings, and sometimes placement of the room within the building or ship (or sometimes a train) support the activity to be conducted in it.

In kinematics, the speed (commonly referred to as v) of an object is the magnitude of the change of its position over time or the magnitude of the change of its position per unit of time; it is thus a non-negative scalar quantity. The average speed of an object in an interval of time is the distance travelled by the object divided by the duration of the interval; the instantaneous speed is the limit of the average speed as the duration of the time interval approaches zero. Speed is the magnitude of velocity (a vector), which indicates additionally the direction of motion.

Speed has the dimensions of distance divided by time. The SI unit of speed is the metre per second (m/s), but the most common unit of speed in everyday usage is the kilometre per hour (km/h) or, in the US and the UK, miles per hour (mph). For air and marine travel, the knot is commonly used.

The fastest possible speed at which energy or information can travel, according to special relativity, is the speed of light in vacuum c = 299792458 metres per second (approximately 1079000000 km/h or 671000000 mph). Matter cannot quite reach the speed of light, as this would require an infinite amount of energy. In relativity physics, the concept of rapidity replaces the classical idea of speed.