Faster-than-light

Faster-than-light (also superluminal or FTL) communication and travel refer to the propagation of information or matter faster than the speed of light. Under the special theory of relativity, a particle (that has rest mass) with subluminal velocity needs infinite energy to accelerate to the speed of light, although special relativity does not forbid the existence of particles that travel faster than light at all times (tachyons).

On the other hand, what some physicists refer to as "apparent" or "effective" FTL depends on the hypothesis that unusually distorted regions of spacetime might permit matter to reach distant locations in less time than light could in normal or undistorted spacetime. Although according to current theories matter is still required to travel subluminally with respect to the locally distorted spacetime region, apparent FTL is not excluded by general relativity. Examples of apparent FTL proposals are the Alcubierre drive and the traversable wormhole, although their physical plausibility is uncertain.

Explorer (disambiguation)

An explorer is a person involved in exploration; see also list of explorers.

Explorer, explore, exploring or exploration may also refer to:

Aircraft and spacecraft

Automobiles

Companies

Computing

FTL

FTL may stand for:

Games

Science and technology

Other uses

Battle

Generally, a battle "is a conceptual component in the hierarchy of combat in warfare between two or more armed forces, or combatants. A war sometimes consists of many battles. Battles generally are well defined in duration, area, and force commitment.

Wars and military campaigns are guided by strategy, whereas battles take place on a level of planning and execution known as operational mobility. German strategist Carl von Clausewitz stated that "the employment of battles ... to achieve the object of war" was the essence of strategy.

Etymology

The definition of a battle cannot be arrived at solely through the names of historical battles, many of which are misnomers. The word battle is a loanword in English from the Old French bataille, first attested in 1297, from Late Latin battualia, meaning "exercise of soldiers and gladiators in fighting and fencing", from Late Latin (taken from Germanic) battuere "beat", from which the English word battery is also derived via Middle English batri, and comes from the staged battles in the Colosseum in Rome that may have numbered 10,000 individuals.