WRP-1: What a warp drive is

The class definition.

Kind: constraint · Family: WRP (The warp drive class) · Last reviewed: 2026-09-12

The result

What a warp drive is. Alcubierre: contract spacetime ahead of a ship and expand it behind, and motion faster than light as seen by outside observers is possible, but, as with wormholes, exotic matter is needed. Natário: the expansion and contraction are a marginal consequence of Alcubierre's choice; a warp drive with zero expansion exists, and the general class is any metric with unit lapse, flat spatial slices and a shift vector carrying the ship. Every warp proposal in this catalogue lives in that class and is priced by ENE-5

What it forbids or costs

The class definition. A proposal outside it is not a warp drive and must say what it is instead

Escape hatches

None needed; this entry defines the object

Who it bites

Physics proposals

• DODGES: Fuchs et al. 2024: the constant-velocity physical warp shell. Steps outside the class by design (non-unit lapse, curved slices) and gives its own three-part definition of a warp drive: geodesic transport, an empty passenger region and a comoving bounded bubble. Whether that is a warp drive or a spaceship with frame dragging is the WRP-2 question
• SATISFIES: Alcubierre 1994: the warp drive metric. This is the entry's first citation: the class-defining example, with unit lapse, flat slices and shift $-v_s f(r_s)$ along the direction of travel.
• SATISFIES: Bobrick and Martire 2021: physical warp drives. Places Alcubierre and Natário inside its scheme as Classes I and III and says what its own objects are, shells; Santiago, Schuster and Visser note that two of its metrics (non-unit lapse, conformally flat slices) lie outside the Natário class and must be judged separately
• SATISFIES: Fell and Heisenberg 2021: positive energy from hidden geometric structure. Unit lapse, flat slices, shift vector: the zero-vorticity subclass of the Natário class, as Santiago, Schuster and Visser label it
• SATISFIES: Lentz 2021: hyper-fast positive-energy solitons. Unit lapse, flat slices, a shift vector: a Natário-class metric, as the conference reply itself says
• SATISFIES: NASA Eagleworks warp field interferometer. The Alcubierre metric verbatim, plus White's canonical rewriting of it
• SATISFIES: Natário 2002: warp drive with zero expansion. This paper is the class definition WRP-1 cites: unit lapse, flat slices, a shift vector field carrying the ship, and the demonstration that expansion is incidental.
• SATISFIES: Van Den Broeck 1999: the pocket geometry. Unit lapse and Alcubierre shift, with a conformally flat rather than flat slice; the paper says it "can still be written in the 3 + 1 formalism" and the register's ENE-4 entry treats it as a warp drive. The departure from strictly flat slices is noted in the text above.
• SATISFIES: Warp drives in modified gravity. The metrics studied are Alcubierre's and Van Den Broeck's; the class definition is unchanged by the choice of field equations.
• SATISFIES: White et al. 2021: the worldline-numerics Casimir pattern. The Alcubierre metric verbatim, with its shape function, York time and energy density

Fictional drives

• SILENT: Death's End: curvature propulsion (Liu Cixin, 2010). Curvature ahead pulling, flattened space behind, a ship carried without local acceleration: the description is warp-shaped, and the novel never says whether the metric is of the Natário class or something else.
• ENGAGES: Campbell's Islands of Space (1931): where the word came from. The novel describes, in words, a region of changed curvature carrying a ship at rest inside it past light speed; this is the class WRP-1 defines, stated in 1931 or 1957 depending on which sentences survived revision, and Gardiner (2008) credits the text with the warp drive on that basis.
• ENGAGES: Futurama: the Planet Express ship's dark matter engines (1999 onward). Cubert's line is the class definition in plain words: the ship stays where it is and the space moves. Stated on screen and animated in the take-off sequence.
• ENGAGES: Star Citizen: quantum drive and jump points. The developer describes the quantum drive as contraction ahead and expansion behind, "essentially an Alcubierre drive", which is the entry's class definition adopted by name; the "essentially an Alcubierre drive" wording found on the Star Citizen Wiki is that wiki's paraphrase, and the forum copy of Roberts's post (2 April 2019) has the softer "somewhat inspired by" and calls the rest "hand wavium" [MED] S3.
• RULE: Elite Dangerous: the frame shift drive (Frontier Developments, 2014). A ship carried at rest inside a region of moved space, throttled by its environment, matches the class definition as a stated rule of the flight model.
• RULE: EVE Online: the warp drive (CCP Games, 2003). A ship at rest inside a bubble of altered vacuum that carries it matches the class definition as a stated mechanism.
• RULE: Star Trek: warp drive (1966 onward). The show's own description, a field that distorts space and carries the ship without local motion, matches the class definition; the rule is stated in the manual and on screen without the mathematics.
• RULE: Stellaris: warp, hyperlane and wormhole (Paradox Development Studio, 2016). The warp mode, a drive on the ship that moves the fleet without a lane or a gate, is the class as a menu item; stated, never described.
• RULE: The Orville: quantum drive (2017 onward). Quantum bubbles that carry the ship, per LaMarr on screen, match the class definition as a stated rule; the production says Alcubierre by name.

Sources

• Alcubierre, Class. Quantum Grav. 11, L73 (1994), arXiv:gr-qc/0009013; Natário, Class. Quantum Grav. 19, 1157 (2002), arXiv:gr-qc/0110086 ✓