HAZ-2: The crew is cooked

The crew problem as well as the bubble problem, if ENE-3 holds.

Kind: constraint · Family: HAZ (Hazards) · Last reviewed: 2026-09-12

The result

The crew problem. An observer at the centre of a superluminal bubble sees a thermal flux of Hawking particles from the horizons. Its temperature is fixed by the wall thickness: if the exotic matter obeys the quantum inequalities the wall is Planck-thin and the temperature is a sizeable fraction of the Planck temperature; a metre-thick wall would give millikelvin. Under the inequalities the interior is a Planck-scale bath

What it forbids or costs

The crew problem as well as the bubble problem, if ENE-3 holds

Escape hatches

Subluminal speeds; a thick wall, which ENE-3 forbids

Who it bites

Physics proposals

• VIOLATES: Alcubierre 1994: the warp drive metric. Finazzi, Liberati and Barceló find that an observer at the centre of a superluminal bubble sees Hawking radiation from the horizons at a temperature set by the wall thickness; with the ENE-3 wall the interior is a Planck-temperature bath. The ship sits at the centre.
• SILENT: Bobrick and Martire 2021: physical warp drives. Horizon flux on the crew is not discussed; the subluminal class has no horizons
• SILENT: Fell and Heisenberg 2021: positive energy from hidden geometric structure. Crew flux never discussed
• SILENT: Lentz 2021: hyper-fast positive-energy solitons. "Bombardment of the inside observers by Hawking radiation" is listed as a known concern in the introduction and not addressed
• SILENT: NASA Eagleworks warp field interferometer. Never discussed
• SILENT: Natário 2002: warp drive with zero expansion. The horizon is present and its infinite blueshift is Natário's own result, so a Hawking flux to the centre is expected; the temperature calculation exists only for Alcubierre-type walls.
• SILENT: Van Den Broeck 1999: the pocket geometry. The wall is Planck-thin so the horizon temperature of Finazzi, Liberati and Barceló would be Planckian, but the crew sit deep inside a pocket where $B = 1 + 10^{17}$; how the flux reaches them through the neck has not been computed.
• SILENT: Warp drives in modified gravity. The Hawking flux temperature is set by the wall thickness; with a classical spin-fluid source the ENE-3 wall bound need not hold, so the wall could be thick and the temperature low, but no calculation exists.
• SILENT: White et al. 2021: the worldline-numerics Casimir pattern. Never discussed

Fictional drives

• SILENT: Andromeda: the slipstream. The crew are never harmed by the stream itself; the hazard is a wrong turn. Nothing says what the stream does to a body, so the row is silent rather than excluded.
• SILENT: Campbell's Islands of Space (1931): where the word came from. A superluminal bubble bathes its crew in horizon radiation; Arcot's crew see violet and green star images and are otherwise untouched, with no rule stated.
• SILENT: Elite Dangerous: the frame shift drive (Frontier Developments, 2014). The pilot sits at the centre of a superluminal bubble with no Hawking flux; wall thickness is never a concept.
• SILENT: EVE Online: the warp drive (CCP Games, 2003). The pilot sits at the centre of a superluminal bubble with no Hawking flux; wall thickness is never a concept.
• SILENT: Futurama: the Planet Express ship's dark matter engines (1999 onward). The crew sit at the centre of a moving-universe bubble with no Hawking flux; wall thickness is not a concept.
• SILENT: No Man's Sky: the hyperdrive, warp cells and range. The tunnel does nothing to the pilot; the mid-warp ambushes of later updates are the only thing that happens in it, and nothing says what the tunnel is to a body.
• SILENT: Star Trek: warp drive (1966 onward). The crew at the centre of a superluminal bubble see no Hawking flux; the show has no wall thickness to set a temperature and does not ask.
• SILENT: Stargate: the ships' hyperdrives. The crew are never affected by hyperspace itself; nothing says what the corridor does to a body, so the row is silent rather than excluded.
• SILENT: Stellaris: warp, hyperlane and wormhole (Paradox Development Studio, 2016). Crews at the centre of a warp bubble see no Hawking flux; wall thickness is not a concept.
• SILENT: The Orville: quantum drive (2017 onward). The crew sit at the centre of a superluminal bubble with no Hawking flux; the show has no wall thickness and does not ask.
• ENGAGES: Cordwainer Smith: planoforming, Space² and Space³. The crew problem is the subject of "The Game of Rat and Dragon": the space the ship enters kills or maddens the unprotected, and the story quantifies the losses and the defence. The mechanism is not Hawking flux, but the row's question, what the transit does to the people inside, is the story.
• ENGAGES: Doctor Who: the TARDIS and the time vortex. The crew problem exists in story form: exposure to the vortex is lethal (Rose in 2005, Jack Harkness clinging to the exterior in "Utopia", 2007) and the ship's interior is the only safe place. The mechanism is not Hawking flux, but the row's question, what the medium does to a traveller, is answered.
• ENGAGES: Space Battleship Yamato: warp by wave motion engine. The crew problem is shown, in the series' way: episode 4 has the crew disoriented and seeing visions during the first warp, and later warps keep the convention. Not a Hawking flux, but the row's question, what the transit does to the people inside, is put on screen.
• ENGAGES: Xenocide: travel through the Outside. The crew problem is the plot: the transit acts on the passengers' minds and returns what they hold, giving Miro a body and Ender two people ("Voyage"). Not Hawking flux, but the row's question of what the medium does to the crew is answered at length.
• RULE: Death's End: curvature propulsion (Liu Cixin, 2010). No horizon forms below c, so no Hawking flux reaches the crew; a consequence of the stated ceiling.
• RULE: Halo: slipspace and the Shaw-Fujikawa translight engine (2001 onward). The crew problem is answered by a stated rule: raw slipspace destroys ordinary matter and the drive's quantum field is what keeps the crew alive (Ghosts of Onyx ch. 3; Halsey's journal). The hazard is not the register's Hawking flux, but the rule answers the question the entry asks.
• RULE: Star Citizen: quantum drive and jump points. No horizon, no Hawking flux; the subluminal rule again. The game's interior hazard is heat from the drive, not radiation from a wall.

Sources

• Finazzi, Liberati and Barceló, Phys. Rev. D 79, 124017 (2009), arXiv:0904.0141 ✓