patentNumber: "US-IMP-4,221,008" title: "Alcubierre Warp Drive, Mark II" titleRu: "Варп-двигатель Алькубьерре, тип II" filingDate: "May 9, 1989" issueDate: "November 22, 1994" inventor: "Capt. Ada R. Hartwell, USN (Ret.)" inventorRu: "кап. 1 ранга в отст. Ада Р. Хартвелл, ВМС США" inventorSlug: "ada-hartwell" classification: "Relativistic Impossibilities" status: "Theoretically Plausible by ~3001" abstract: "An apparatus for the apparent superluminal conveyance of a vessel through interstellar distances without violation of the local invariance of the speed of light, comprising a flat-bottomed habitat module (1) of conventional naval construction surrounded by an annular field generator (2) configured to establish, upon energization, a bubble of locally Minkowskian spacetime (3) within which the vessel resides at rest. Said bubble is propelled forward by a region of contracted spacetime ahead (4) and a region of expanded spacetime astern (5), the differential contraction-expansion driving the bubble across the surrounding manifold at an effective velocity determined by the magnitude of the supplied negative-energy density. The Mark II is an improvement upon the configuration of Alcubierre (1994), reducing the required negative-energy budget by a factor of approximately 10⁴⁸ through the introduction of a thin-shell field geometry." abstractRu: "Аппарат для кажущейся сверхсветовой перевозки судна на межзвёздные расстояния без нарушения локальной инвариантности скорости света, состоящий из плоскодонного жилого модуля (1) обычной военно-морской постройки, окружённого кольцевым генератором поля (2), конфигурированным так, что при подаче питания устанавливается пузырь локально минковского пространства-времени (3), внутри которого судно покоится. Указанный пузырь движется вперёд за счёт области сжатого пространства-времени впереди (4) и области расширенного пространства-времени позади (5); дифференциальное сжатие-расширение прогоняет пузырь через окружающее многообразие с эффективной скоростью, определяемой величиной подаваемой плотности отрицательной энергии. Тип II представляет собой усовершенствование конфигурации Алькубьерре (1994), снижающее требуемый бюджет отрицательной энергии примерно в 10⁴⁸ раз за счёт введения тонкостенной геометрии поля." citations:

• "US-IMP-3,091,447"
• "US-IMP-3,887,201"
• "US-IMP-3,302,991"

Field of InventionОбласть изобретенияField of Invention

The present invention relates to apparatus for the apparent superluminal conveyance of vessels across interstellar distances, and more particularly to the propulsion of such vessels by means of the local deformation of the surrounding spacetime metric, rather than by the conventional expedients of chemical, nuclear, or photonic reaction propulsion. The invention is intended for application to deep-space exploration, for the conveyance of personnel and cargo between heliocentric and exoheliocentric stations, and for such military, scientific, and commercial purposes as may from time to time arise.

BackgroundПредпосылкиBackground

The conveyance of vessels across interstellar distances has been a subject of speculation since at least the work of Tsiolkovsky (1903), and of serious engineering proposals since the Project Orion studies of the late 1950s. All such proposals to date, however, are constrained by the special-relativistic prohibition against the conveyance of material bodies at velocities equal to or exceeding the speed of light in vacuo. The nearest stellar neighbor of the Sun, Proxima Centauri, lies at a distance of approximately 4.24 light-years; transit by any sub-luminal craft would therefore require not less than 4.24 years of proper time on the part of the crew, and considerably longer of coordinate time on the part of observers at the point of departure. The intervening period is judged inconvenient by all interested parties.

Prior art has attempted to circumvent this difficulty by various means. The relativistic-rocket proposals of Sänger (1953) and others contemplate transit at velocities asymptotic to that of light, with attendant time-dilation reducing the proper-time duration of the voyage at the cost of catastrophic energetic and engineering requirements. The wormhole proposals of Morris and Thorne (1988) contemplate the establishment of a non-trivial spacetime topology, but require the support of negative-energy density on a global scale and present manifold difficulties of stability. The instant Mark II modification of the proposal of Alcubierre (1994) is distinguished from each prior art by its requirement of negative-energy density on a local scale only, confined to the immediate vicinity of the vessel, and by its compliance with the local invariance of light-speed throughout the volume occupied by the crew.

Summary of the InventionКраткое изложение изобретенияSummary of the Invention

The apparatus comprises:

• A habitat module (1) of conventional flat-bottomed naval construction, dimensioned to accommodate a crew of not less than fifty and a payload of not less than five metric tonnes, fitted with such life-support, navigational, and recreational facilities as customary in long-duration spaceborne assignments;
• An annular field generator (2) of toroidal geometry surrounding the habitat module, comprising a continuous superconducting winding of exotic-matter-stabilized construction, energized in operation to a negative-energy density of approximately −10⁴⁵ joules per cubic meter, this figure representing the reduction by approximately forty-eight orders of magnitude from the Alcubierre Mark I specification;
• A bubble of locally Minkowskian spacetime (3) established by the energization of said field generator, within which the habitat module resides at rest in its own inertial frame;
• A forward contraction region (4) located ahead of the bubble in the direction of intended travel, within which the spacetime manifold is compressed by a factor of up to 10³;
• A rearward expansion region (5) located astern of the bubble, within which the manifold is expanded by an equal factor;
• A navigational system (6) comprising a stellar-reference attitude indicator, a chronometric station-keeper, and a steerage console operatively coupled to the asymmetric pole of the field generator;
• A safety bulkhead (7) at the leading edge of the bubble, to deflect any massive particles encountered in transit and to mitigate the blueshift-induced thermal load described in the following section.

U.S.B.I.P. Drawing №Чертёж У.С.Б.И.П. №U.S.B.I.P. Drawing №

Sheet 1 of 1Лист 1 из 1Sheet 1 of 1

Detailed DescriptionПодробное описаниеDetailed Description

Referring now to FIG. 3A, the warp drive of the present invention is shown in plan view. The habitat module (1) is of conventional construction and is of substantially rectangular geometry, the rectangular form being preferred over the spherical for reasons of crew morale, the seated population of a flat-bottomed vessel being demonstrably more contented than that of a spherical one.

The annular field generator (2) is mounted upon a separable framework surrounding the habitat module at a clearance of not less than five meters at any point, the clearance being required to prevent the energization fields from intruding upon the inertial frame of the crew. The winding is fabricated of a superconducting composite of yet-undisclosed composition (see U.S.-IMP-3,887,201 for description of suitable materials), maintained at a temperature not exceeding 1.7 kelvin by means of a circumambient bath of superfluid helium.

Upon engagement of the warp cycle, the field generator is energized to its operating density. The geometry of the resulting metric perturbation is given by

ds² = −dt² + (dx − v_s(t) f(r_s) dt)² + dy² + dz²,

where v_s(t) is the desired velocity of the bubble, r_s is the radial distance from the center of the bubble, and f(r_s) is a thin-shell form function of compact support, vanishing identically outside a thin shell of radius R and thickness δR. The Mark II specification differs from the original Alcubierre configuration in the thinness of the shell, the present invention prescribing δR/R = 10⁻³, whereas the original prescribed δR/R = 1; this reduction has been shown by Van Den Broeck (1999) to permit a corresponding reduction in the integrated negative-energy budget.

The asymmetric pole of the field generator, located forward, is energized to produce the forward contraction region (4), and the corresponding aft pole produces the rearward expansion region (5). The differential between the two regions drives the bubble — and therefore the habitat module — across the surrounding manifold at an effective coordinate velocity which may, by suitable choice of v_s(t), substantially exceed unity in natural units. Within the bubble, however, the habitat module remains at rest in a locally Minkowskian frame; the crew detect no acceleration, and no local measurement reveals a violation of the local invariance of light-speed.

The navigational system (6) is operated by a duty officer of the deck and is coupled, by mechanical linkage, to the asymmetric pole of the field generator. Course corrections are effected by adjustment of the relative magnitudes of the forward and rearward distortions; emergency reversal is effected by interchange of the two.

ClaimsФормула изобретенияClaims

1. An apparatus for the conveyance of a vessel between two points in space, comprising: a habitat module; an annular field generator surrounding said habitat module; and means for energizing said field generator to a negative-energy density sufficient to establish, in the volume surrounding said habitat module, a bubble of locally Minkowskian spacetime.

2. The apparatus of claim 1, wherein said means for energizing comprises a superconducting winding cooled to a temperature not exceeding 1.7 kelvin.

3. The apparatus of claim 1, wherein said field generator is configured to establish a region of contracted spacetime forward of said bubble and a region of expanded spacetime rearward of said bubble.

4. The apparatus of claim 3, wherein the differential between said forward and rearward regions drives said bubble across the surrounding manifold at an effective coordinate velocity exceeding unity in natural units.

5. The apparatus of claim 1, wherein said field generator establishes said bubble in a thin-shell configuration of fractional thickness δR/R not exceeding 10⁻³.

6. The apparatus of claim 5, wherein the integrated negative-energy density supported by said winding is not more than 10⁻⁴⁸ times that required by the configuration of Alcubierre (1994).

7. The apparatus of claim 1, further comprising a safety bulkhead disposed at the leading edge of said bubble.

8. A method for the conveyance of a crew between two points separated by an interstellar distance, comprising the steps of: embarking said crew within said habitat module; energizing said field generator; engaging the asymmetric pole of said generator in the direction of intended travel; and, upon arrival at the destination, de-energizing said generator.

Why This Violates Physics (For Now)Почему это нарушает физику (пока)Why This Violates Physics (For Now)

The invention as claimed is, at the date of issuance, classified as theoretically plausible by approximately 3001 — that is, the Bureau acknowledges that the metric solution upon which the invention is grounded is a valid solution of the Einstein field equations, but is unable to certify that the requisite engineering can be performed within the foreseeable future.

First, the apparatus requires a global negative-energy density of approximately −10⁴⁵ joules per cubic meter, distributed over a thin toroidal shell of radius approximately one hundred meters and thickness approximately ten centimeters. This figure represents the Mark II improvement over the original Alcubierre estimate of approximately the negative mass of Jupiter, and is now estimated at approximately the negative mass of a small mammal — a remarkable reduction by some forty-eight orders of magnitude, but one which remains beyond any presently demonstrated source of negative-energy density. The Casimir effect, the squeezed vacuum, and the Hawking radiation of an evaporating black hole are each known to admit localized regions of negative-energy density, but in magnitudes insufficient by many orders of magnitude and over volumes incompatible with the thin-shell geometry.

Second, the apparatus appears to violate the averaged null energy condition (ANEC), which requires that the integral of the stress-energy tensor along any complete null geodesic be non-negative. While quantum-field-theoretic violations of the pointwise null energy condition are well documented, violations of the averaged condition over arbitrary geodesics remain conjectural and have not been demonstrated experimentally. The conjecture, formulated by Penrose, Sorkin, and Woolgar (1993), holds that ANEC violations of the magnitude required by the present invention are forbidden by self-consistent quantum gravity. The Bureau notes that this conjecture has neither been proven nor disproven.

Third, the apparatus is subject to the horizon problem of warp-drive theory, viz., that an observer within the bubble cannot causally influence the leading face of the bubble during travel, with the consequence that the bubble cannot be steered, decelerated, or returned to a sub-luminal configuration by any action of the crew. The navigational system of claim (6) is, on this account, inoperative. The Bureau notes that the use of remote tachyonic relays to circumvent the horizon problem is contemplated by certain extensions of the invention, but that such relays would themselves require the prior solution of the problem of superluminal signaling, which problem is the subject of U.S.-IMP-3,887,201 and is itself provisionally impossible.

Fourth, the Hadamard divergence at the bubble surface, predicted by Hiscock (1997), implies that the vacuum state of the quantum fields seen by the bubble at relativistic velocities is non-renormalizable, with the result that any blueshifted particle encountered by the bubble during travel is amplified to arbitrarily large energy and radiated upon arrival. The safety bulkhead of claim 7 is, in the Bureau's estimation, inadequate to this hazard. Citations: Alcubierre, M., "The Warp Drive: Hyper-Fast Travel within General Relativity," Class. Quantum Grav. 11, L73 (1994); Van Den Broeck, C., Class. Quantum Grav. 16, 3973 (1999); Hiscock, W. A., Class. Quantum Grav. 14, L183 (1997).