Warp drive

The Original Series: Establishing a background

Warp drive is one of the fundamental features of the Star Trek franchise; in the first pilot episode of Star Trek: The Original Series, "The Cage", it is referred to as a "hyperdrive"/"time warp" drive combination, and it is stated that the "time barrier" has been broken, allowing a group of stranded interstellar travelers to return to Earth far sooner than would have otherwise been possible. The light speed time barrier shouldn't be confused with time dilation which occurs when approaching very fast speeds. Warp drive technology avoids time dilation.

The episode "Metamorphosis", also from The Original Series, establishes a backstory for the invention of warp drive on Earth, in which Zefram Cochrane discovered the "space warp". Cochrane is repeatedly referred to afterwards, but the exact details of the first warp trials were not shown until the second Star Trek: The Next Generation movie, Star Trek: First Contact. The movie depicts Cochrane as having first operated warp drive on Earth in 2063 (two years after the date speculated by the first edition of the Star Trek Chronology). By using a matter/antimatter reactor to create plasma, and by sending this plasma through warp coils, he created a warp bubble which he could use to move a craft into subspace, thus allowing it to exceed the speed of light. This successful first trial led directly to first contact with the Vulcans.

Enterprise: Leading up to The Original Series

Later on, a prequel series titled Star Trek: Enterprise describes the warp engine technology as a "Gravimetric Field Displacement Manifold" (Commander Tucker's tour, "Cold Front"), and describes the device as being powered by a matter/anti-matter reaction which powers the two separate nacelles (one on each side of the ship) to create a displacement field.

The episode also firmly establishes that many other civilizations had warp drive before humans; First Contact co-writer Ronald D. Moore suggested Cochrane's drive was in some way superior to forms which existed beforehand, and was gradually adopted by the galaxy at large.

Enterprise, set in 2151 and onwards, follows the voyages of the first human ship capable of traveling at warp factor 5.2, which under the old warp table formula (the cube of the warp factor times the speed of light), is about 140 times the speed of light (i.e., 5.2 cubed). In the series pilot episode "Broken Bow", Capt. Archer equates warp 4.5 to "Neptune and back [from Earth] in six minutes" (which would correspond to a distance of 547 light-minutes or 66 au, consistent with Neptune being a minimum of 29 au distant from Earth).

The Next Generation onwards

Only three stories in the original Star Trek series involved the Enterprise traveling beyond Warp 10 ( Warp 11, briefly, as a result of Nomad's "correction of inefficiencies" in the antimatter control system in "The Changeling"; Warp 11 again in "By Any Other Name" after the Kelvans modify the Enterprise's engines for greater sustained speed to make the trip from the Milky Way Galaxy to the Andromeda Galaxy; and Warp 14.1 in "That Which Survives" after the ship was put through a Kalandan transporter, beamed parsecs away from where it had been, and reassembled slightly out of phase). In The Next Generation, such stories were rare, and usually involved a malfunction in (or alien interference with) a starship's engines. A new warp scale was drawn up, with Warp Factor 10 set as an unattainable maximum (according to the new scale, reaching or exceeding Warp 10 required an infinite amount of energy). This is described in some technical manuals as "Eugene's limit", in homage to creator/producer Gene Roddenberry. Warp 8 in the original series was the "Never Exceed" speed for the hulls and engines of Constitution-class starships, equivalent to the aircraft V_NE V-speed. Warp 6 was the V_NO "Normal Operation" maximum safe cruising speed for that vessel class. The Warp 14.1 incident was the result of runaway engines which brought the hull within seconds of structural failure before power was disengaged.

The limit of 10 did not entirely stop warp inflation. By the mid-24th century, the Enterprise-D could travel at Warp 9.8 at "extreme risk", while normal maximum operating speed was Warp 9.6 and the maximum rated cruise was Warp 9.2. According to the Deep Space Nine Tech Manual, during the Dominion War, Galaxy-class starships were refitted with newer technology including modifications which increased their maximum speed to Warp 9.9.

In the episode "Where No One Has Gone Before" the Enterprise-D was shown to exceed Warp 10, traveling 2.7 million light-years from their home galaxy in a matter of minutes (though the ship's extreme velocity was due to the influence of an alien being and could not be achieved by starship engines). The Intrepid-class starship Voyager has a maximum sustainable cruising speed of Warp 9.975; the Enterprise-E can go even faster, with a maximum velocity of Warp 9.999. In the alternative future depicted in "All Good Things...", the series finale of The Next Generation, the "future" Enterprise-D travels at Warp 13, although it is never established whether this is truly "above" Warp 10, or simply the result of another reconfiguration of the warp scale.

Warp velocities

Warp drive velocity in Star Trek is generally expressed in "warp factor" units, which—according to the Star Trek Technical Manuals—correspond to the magnitude of the warp field. Achieving warp factor 1 is equal to breaking the light barrier, while the actual velocity corresponding to higher factors is determined using an ambiguous formula. Several episodes of the original series placed the Enterprise in peril by having it travel at high warp factors; at one point in "That Which Survives" the Enterprise traveled at a warp factor of 14.1. In the Star Trek: The Next Generation episode "The Most Toys" the crew of Enterprise-D discovers that the android Data may have been stolen while on board another ship, Jovis. At this point the Jovis, which has a maximum warp factor of 3, has had a 23-hour head start, which the Enterprise-D figures puts her anywhere within a 0.102 light year radius of her last known position. However, the velocity (in present dimensional units) of any given warp factor is rarely the subject of explicit expression, and travel times for specific interstellar distances are not consistent through the various series.

According to the Star Trek episode writer's guide for The Original Series, warp factors are converted to multiples of c with the cubic function v = w³c, where w is the warp factor, v is the velocity, and c is the speed of light. Accordingly, "warp 1" is equivalent to the speed of light, "warp 2" is 8 times the speed of light, "warp 3" is 27 times the speed of light, etc.

For Star Trek: The Next Generation and the subsequent series, Star Trek artist Michael Okuda devised a formula based on the original one but with important differences; for warp factors 1 through 9, v = w^10/3c. In the half-open interval from warp 9 to warp 10, the exponent of w increases toward infinity. Thus, in the Okuda scale, warp velocities approach warp 10 asymptotically.

There is no exact formula for this interval because the quoted velocities are based on a hand-drawn curve; what can be said is that at velocities greater than warp 9, the form of the warp function changes because of an increase in the exponent of the warp factor w. Due to the resultant increase in the derivative, even minor changes in the warp factor eventually correspond to a greater than exponential change in velocity. In the episode "Threshold", Tom Paris breaks the warp 10 threshold, but travel beyond the threshold is later discovered to be unacceptably hazardous to biological life.

Exact velocities were given in a few episodes, one being "Relativity", where Kathryn Janeway describes Voyager's velocity at warp factor 9.975. Voyager was about 70,000 light-years away from home, and crew would often use "75 years" as the time it would take to get back home at top speed. This means the Voyager series used the old method of Warp calculation. 70,000/9.975³ is roughly 70.5 years. If delays for refueling, repair, restocking, and downtime are considered, 75 years is a logical rounding.

Slingshot effect

A curious extension of warp travel, shown throughout Star Trek, is the "slingshot effect".

It was first discovered accidentally in "Tomorrow Is Yesterday" (1967), one of the earlier episodes of the original Star Trek series, as a method of time travel. While the actual procedure is intentionally obscure, it involved traveling at a high warp velocity (depicted in Star Trek IV: The Voyage Home as more than warp 9.8) in the direction of a star, on a precisely calculated "slingshot" path; if successful, the ship is caused to travel to a desired point, past or future. The same technique was used later in the episode "Assignment: Earth" (1968) for historic research — in this episode, the warp factor required for "time warp" is given the name "light speed breakaway factor". The term "time warp" was first used in "The Naked Time" (1966) when a previously untried cold-start intermix of matter and antimatter threw the Enterprise back three days in time. The term was later used in Star Trek IV in describing the slingshot effect. The technique was mentioned as a viable method of time travel in the TNG episode "Time Squared" (1989).

This "slingshot" effect has been explored in theoretical physics: it is hypothetically possible to slingshot oneself "around" the event horizon of a black hole. As a result of the black hole's extreme gravitation, time would pass at a slower rate near the event horizon, relative to the outside universe; the traveler would experience the passage of only several minutes or hours, while hundreds of years would pass in 'normal' space.

Warp core

A primary component of the warp drive method of propulsion in the Star Trek universe is the "gravimetric field displacement manifold", more commonly referred to as a warp core. It is a fictional reactor that taps the energy released in a matter-antimatter annihilation to provide the energy necessary to power a starship's warp drive, allowing faster-than-light travel. Starship warp cores generally also serve as powerplants for other primary ship systems.

When matter and antimatter come into contact, they annihilate—both matter and antimatter are converted directly and entirely into enormous quantities of energy, in the form of subnuclear particles and electromagnetic radiation (specifically, mesons and gamma rays). In the Star Trek universe, fictional "dilithium crystals" are used to regulate this reaction. These crystals are described as being non-reactive to anti-matter when bombarded with high levels of radiation.

Usually, the reactants are deuterium, which is an isotope of hydrogen, and antideuterium (its antimatter counterpart). In The Original Series and in-universe chronologically subsequent series, the warp core reaction chamber is often referred to as the "dilithium intermix chamber" or the "matter/antimatter reaction chamber", depending upon the ship's intermix type. The reaction chamber is surrounded by powerful magnetic fields to contain the anti-matter. If the containment fields ever fail, the subsequent interaction of the antimatter fuel with the container walls would result in a catastrophic release of energy, with the resultant explosion capable of utterly destroying the ship. Such "warp core breaches" are used as plot devices in many Star Trek episodes. An intentional warp core breach can also be deliberately created, as one of the methods by which a starship can be made to self-destruct.

The mechanisms that provide a starship's propulsive force are the "warp nacelles", one (or more) cylindrical pods that are offset from the hull of the ship by large pylons; the nacelles generate the actual 'warp bubble' that surrounds the ship, and destruction of one or both nacelles will cripple the ship, and possibly cause a warp-core breach.

Real-world theories and science

In 1994, physicist Miguel Alcubierre formulated a theoretical solution, called the Alcubierre drive, for faster-than-light travel which models the warp drive concept. Subsequent calculations found that such a model would require prohibitive amounts of negative energy or mass.

In 2012, NASA researcher Harold White hypothesized that by changing the shape of the warp drive, much less negative mass and energy could be used, though the energy required ranges from the mass of Voyager 1 to the mass of the observable universe, or many orders of magnitude greater than anything currently possible by modern technology. NASA engineers have begun preliminary research into such technology.