Tug of war

Tug of war (also known as war of tug, tug o' war, tug war, rope war, rope pulling, or tugging war) is a sport that directly puts two teams against each other in a test of strength: teams pull on opposite ends of a rope, with the goal being to bring the rope a certain distance in one direction against the force of the opposing team's pull.

Terminology

The Oxford English Dictionary says that the phrase "tug of war" originally meant "the decisive contest; the real struggle or tussle; a severe contest for supremacy". Only in the 19th century was it used as a term for an athletic contest between two teams who haul at the opposite ends of a rope.

Origins

The origins of tug of war are uncertain, but this sport was practised in ancient Egypt, Greece and China, where it was held in legend that the Sun and Moon played Tug of War over the light and darkness.

According to a Tang dynasty book, The Notes of Feng, tug of war, under the name "hook pulling" (牽鉤), was used by the military commander of the State of Chu during the Spring and Autumn Period (8th century BC to 5th century BC) to train warriors. During the Tang dynasty, Emperor Xuanzong of Tang promoted large-scale tug of war games, using ropes of up to 167 metres (548 ft) with shorter ropes attached, and more than 500 people on each end of the rope. Each side also had its own team of drummers to encourage the participants.

Tug of war (astronomy)

The tug of war in astronomy is the ratio of planetary and solar attractions on a natural satellite. The term was coined by Isaac Asimov in The Magazine of Fantasy and Science Fiction in 1963.

Law of universal gravitation

According to Isaac Newton's law of universal gravitation

In this equation

The two main attraction forces on a satellite are the attraction of the Sun and the satellite's primary (the planet the satellite orbits). Therefore, the two forces are

where the subscripts p and s represent the primary and the sun respectively, and m is the mass of the satellite.

The ratio of the two is

Example

Callisto is a satellite of Jupiter. The parameters in the equation are

The table of planets

Asimov lists tug-of-war ratio for 32 satellites (then known in 1963) of the Solar System. The list below shows one example from each planet.

Tug of war (disambiguation)

Tug of war is a sport that directly puts two teams against each other in a test of strength and stamina.

Tug of war may also refer to:

Film and television

Astronomy

Music

Albums

Songs