Sector (Star Trek)
Encyclopedia
In Star Trek, a sector is a cubic region of space, 20 light-year
Light-year
A light-year, also light year or lightyear is a unit of length, equal to just under 10 trillion kilometres...

s on each edge. In the region of galaxy around earth, which comprises the Star Trek Universe, a sector contains 6-10 star systems. (This number would increase closer to the galactic center, where there are more stars per volume.)

Sectors are primarily used as the smallest volume of space, or basic unit, in galactic mapping. Sectors are often named after the star system of interest they contain, such as the Risa Sector. (Risa is the popular vacation planet in the Federation.)

Inconsistency in the representation of travel times in the Star Trek dramas compared to canon
Canon (fiction)
In the context of a work of fiction, the term canon denotes the material accepted as "official" in a fictional universe's fan base. It is often contrasted with, or used as the basis for, works of fan fiction, which are not considered canonical...

 descriptions of Warp speed
Warp drive (Star Trek)
Warp drive is a faster-than-light propulsion system in the setting of many science fiction works, most notably Star Trek. A spacecraft equipped with a warp drive may travel at velocities greater than that of light by many orders of magnitude, while circumventing the relativistic problem of time...

 make it tenuous to describe a sector in terms of time required to travel through it.

A good estimate to use, based on Star Trek drama and not canonized tech details, is that a sector can be crossed in 1 day at Warp 6. (See discussion below).

Cartesian Mapping of Galaxy

A Circular sector
Circular sector
A circular sector or circle sector, is the portion of a disk enclosed by two radii and an arc, where the smaller area is known as the minor sector and the larger being the major sector. In the diagram, θ is the central angle in radians, r the radius of the circle, and L is the arc length of the...

 and Circular segment
Circular segment
In geometry, a circular segment is an area of a circle informally defined as an area which is "cut off" from the rest of the circle by a secant or a chord. The circle segment constitutes the part between the secant and an arc, excluding the circle's center...

 are geometric concepts of how to subsect a circle. However, this meaning of sector is unrelated to the Star Trek sector. Sector is used in Star Trek for its English meaning, which is similar in meaning to the word section. A mathematically preferred method to map the galaxy might be to use a Cylindrical coordinate system
Cylindrical coordinate system
A cylindrical coordinate system is a three-dimensional coordinate systemthat specifies point positions by the distance from a chosen reference axis, the direction from the axis relative to a chosen reference direction, and the distance from a chosen reference plane perpendicular to the axis...

 or Spherical coordinate system
Spherical coordinate system
In mathematics, a spherical coordinate system is a coordinate system for three-dimensional space where the position of a point is specified by three numbers: the radial distance of that point from a fixed origin, its inclination angle measured from a fixed zenith direction, and the azimuth angle of...

, such as used for astrogation at the Star Trek helm.

Star Tek has however, adopted a Cartesian coordiante system for mapping the galaxy. Consequently, the galaxy can be subdivided into cubes, and these cubes are called sectors. While this arguably makes poor science fiction, this was likely adopted to make it easier for the audience and writers to relate. Because the surface of the earth is experienced as roughly flat, three dimensional travel is foreign to the audience. A two dimensional paradigm makes crossing the Federation like travelling on a road trip. For example, the galaxy is divided into quadrants
Galactic quadrant
A galactic quadrant, or quadrant of the galaxy, refers to one of four circular sectors in the division of the Milky Way galaxy.-Quadrants in the galactic coordinate system:...

, which largely serves to help the audience understand large distances.

Some Star Trek pictographic representations of sectors have given them curved edges, implying sectors are only roughly cubes. (One easily recognized example is the map of the galaxy used in the Deep Space Nine conference room.) This is misleading and can cause confusion. However, official Star Trek maps use square sectors.

Two dimensional Mapping in Star Trek

A common simplification used in Star Trek dramas is to simplify space in two dimensions. Ships meet each other in space as two ships sailing on the ocean, using the same direction as up. All Star Trek maps are two-dimensional, using squares to represent sectors.

The Star Trek Universe is thus mapped as if it were one sector thick, i.e. 20 light years high. The treatment of a third dimension is totally neglected. The Federation core has a circular XY cross-section of the galaxy of about 150 light years in diameter, but spans 300-400 light-years at its most remote locations. Modern science estimates the galaxy is 1000 light years in height at the Sol system. (See Milky Way
Milky Way
The Milky Way is the galaxy that contains the Solar System. This name derives from its appearance as a dim un-resolved "milky" glowing band arching across the night sky...

 for discussion of galactic thickness.) It is never addressed how thick the Federation terriotry is, and this could have significant impact on plot. The Romulans threaten Federation from the east, but does the Federation face threats from above or below?

Because a galaxy is truly a three dimensional space, and not two dimensional, this oversimplification can distort distances potentially 100 times or more.

This simplification is known to cause some disagreement regarding Star Trek facts. Official, 2-D maps would lead one to believe that Vulcan is 14 light years from Sol, yet is often cited as 18 light years away in Star Trek writing.

Sectors Mapped Relative to Earth

In one form of mapping, the galaxy is mapped using 3-dimensional Cartesian Coordinates
Cartesian coordinate system
A Cartesian coordinate system specifies each point uniquely in a plane by a pair of numerical coordinates, which are the signed distances from the point to two fixed perpendicular directed lines, measured in the same unit of length...

 to enumerate the sectors, centered on earth. This referenced in Star Trek: tNG, episode "The Best of Both Worlds" when the Borg direct the Enterprise to escort them to "sector zero-zero-one", presumably (0, 0, 1).

This method of mapping space relative to earth is arguably egocentric of mankind. However, mapping relative to a known star has several advantages over more advanced methods, such as using the center of the galaxy as the map center. For example, defining the center of the galaxy is not entirely a trivial task.

Speed of Galactic travel: Canonized details

Original concepts by Gene Roddenberry for the Original Star Trek TV series indicated Warp Drive was incredibly fast, ".73 of one light year per hour". This would equivalent to around 9.96 on the next generation warp factor scale. At this speed, crossing the core of the Federation would take a little over a week.

However, technical manuals for writers indicate Warp Drive is much slower than this. Taking the Warp Power to the power of three indicates speed as a multiplier of the Speed of Light. Thus, at Warp Six, one travels 216 light years per year, and it would take approximately 1 month to cross a sector.

Canon vs. portrayal in TV/film

Inconsistencies among special effects, oversimplification in mapping, canon technical manual, and the evolution of plot during the teleplay are largely irreconcilable.

A good way to describe distance is to be consistent with the manner in which the audience most experiences it: as represented in the teleplay. A good estimate is that a sector can be crossed in 1 day at Warp 6 (7,300 light years per year). Warp 1 would then be 33.8 light years / year, or 1 light year in 10.8 days. This roughly matches Roddenberry's vision; warp 6 travel is 0.83 light years/hour vs. Roddenberry's 0.73.

Special effects

An iconic image for Star Trek is the view out the Starship window at warp. Stars stream by the ship, appearing as short lines of light. This visual image leads us to believe that ships at medium warp factors are passing by many stars (over several light years) in a matter of seconds. This is clearly in conflict with the canonized speeds of warp engines, and even faster than Gene Roddenberry's original concepts by several orders of magnitude (10^5 - 10^6). This cool visual effect simply cannot be reconciled with the rest of Star Trek, and so we should simply appreciate it as art.

Notable inconsistencies between canon tech manual and teleplay

  • The Original Enterprise travelled both to the edge of the Galaxy and the Center of the Galaxy in the same lifetime.
  • The plotline of Voyager TV series was based on the canon speed calculations that Voyager would take 70 years to travel home, despite being the fastest ship in the fleet. (By the recommended estimate, Warp 6 = 20 light year/day, this trip would take 2 years.)
  • The Enterprise-D was often diverted from routine duty to the Neutral zone, and expected to arrive in a matter of days, when the distance to do so could easily be 100 light years or more (by a 2-dimensional mapping), or 1000 light years by a 3-dimensional mapping.
  • When searching for the lost ship, the Pegasus, the Enterprise-D was able to beat Romulan ships (which are slower) to the suspected location. This claim is not credible considering the Federation is 150 light years across (400 light years across at its remotest portions), while the Romulan Star Empire is at most 40 light years across. It is highly unlikely the Enterprise was close enough to have any chance of winning such a race.
  • After crossing into the Gamma-quadrant, the combined Romulan and Cardassian fleet allegedly traveled one thousand light years to reach the believe Founder's homeworld for an attack. In the television program, only 1–3 days passes during this trip.
  • During Star Trek: tNG Season 6 episode "Face of the Enemy", the Romulan defector specifically states a slower (vs. Enterprise-D) freighter could travel 15 light years in 24 hours. (Generously assuming warp 7, this is 16x as fast as canon. By the recommended estimate, the freighter's max speed would be warp 5.5.)
  • In the film "Star Trek: Nemesis", it is implied that the Praetor's flagship can travel 100 light years from Romulus to Earth during one action sequence. As if there would not be enough time for Enterprise to warn Star Fleet.

External links

  • Memory Alpha, fan wiki containing only official canon Star Trek discussion, http://memory-alpha.org
  • Memory Beta, fan wiki containing non-canon discussion http://memory-beta.wikia.com/wiki/Main_Page
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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