patentNumber: "US-IMP-3,887,201" title: "Faster-than-Light Communicator" titleRu: "Сверхсветовой коммуникатор" filingDate: "August 30, 1971" issueDate: "April 14, 1976" inventor: "Dr. Eleanor M. Vaszquez & Dr. Konstantin V. Mirsky" inventorRu: "д-р Э. М. Васкес и д-р К. В. Мирский" inventorSlug: "vaszquez-mirsky" classification: "Relativistic Impossibilities" status: "Provisionally Impossible" abstract: "An apparatus for the transmission of arbitrary classical messages between two stations at velocity exceeding that of light in vacuo, comprising a paired-station entanglement bench (1) at which is generated a continuous stream of Einstein-Podolsky-Rosen pairs, one member of each pair being conveyed by conventional means to the remote station (2), and the corresponding member retained at the local station (3). A keyed measurement console (4) permits the operator to select, for each pair, either a position or momentum measurement; the remote operator, performing a measurement of his own choosing, may by statistical analysis of his received string discern which measurement protocol was employed at the originating station, the protocol thereby encoding a binary message. Said message is decoded at the remote terminal by a synchronized receiving register (5) and printed on a paper tape (6) of standard telegraphic configuration." abstractRu: "Аппарат для передачи произвольных классических сообщений между двумя станциями со скоростью, превышающей скорость света в вакууме, состоящий из стенда парной запутанности (1), на котором генерируется непрерывный поток пар Эйнштейна–Подольского–Розена; один член каждой пары обычными средствами доставляется на удалённую станцию (2), а соответствующий ему член удерживается на местной станции (3). Ключевая измерительная консоль (4) позволяет оператору выбирать для каждой пары измерение либо координаты, либо импульса; удалённый оператор, выполняя измерение по своему выбору, может посредством статистического анализа полученной им строки определить, какой именно протокол измерения применялся на станции-отправителе, кодируя тем самым бинарное сообщение. Указанное сообщение декодируется на удалённом терминале синхронизированным приёмным регистром (5) и печатается на бумажной ленте (6) стандартной телеграфной конфигурации." citations:

• "US-IMP-3,144,902"
• "US-IMP-4,221,008"
• "US-IMP-3,447,772"

Field of InventionОбласть изобретенияField of Invention

The present invention relates to apparatus for the transmission of information between distant stations at speeds exceeding that of light, and more particularly to such transmission by means of quantum-mechanical correlations between entangled particle pairs. The invention is intended for application to interplanetary and interstellar communication, where the conventional limitation upon signal velocity introduces delays incompatible with continuous dialogue, and to such terrestrial applications as may benefit from the elimination of propagation latency (e.g., commodity arbitrage between geographically separated exchanges).

BackgroundПредпосылкиBackground

The conventional means of long-distance communication — by mail packet, by submarine cable, by wireless telegraphy, and most recently by satellite relay — share the property that they convey information at velocities not exceeding that of light in vacuo. While this velocity is high in absolute terms, it produces, over interplanetary distances, delays of inconvenient magnitude: a round-trip exchange between Earth and Mars at conjunction requires not less than forty-four minutes, while the corresponding delay to the nearest stellar neighbor is approximately eight-and-a-half years. Conversational dialogue, by the standards of contemporary diplomatic and commercial practice, is impracticable under these conditions.

The instant invention proposes to circumvent this limitation by exploitation of the non-local correlations exhibited by entangled quantum-mechanical systems, as first identified by Einstein, Podolsky, and Rosen (1935) and subsequently formalized in the experimental program initiated by Bell (1964). The Bureau acknowledges that the use of entangled states for the transmission of classical information has been the subject of considerable theoretical analysis since 1935, the prevailing view among the relativistic physicists being that such transmission is not in fact possible; the Bureau notes, however, that the inventors are of contrary opinion, and that the present application has been prosecuted by them in good faith and at considerable personal expense.

Summary of the InventionКраткое изложение изобретенияSummary of the Invention

The apparatus comprises:

• A paired-station entanglement bench (1) at the originating terminus, comprising a parametric down-conversion crystal of beta-barium-borate composition, pumped continuously by a single-mode argon-ion laser at 351 nanometers, configured to generate a stream of polarization-entangled photon pairs at a rate of approximately 10⁶ pairs per second;
• A remote optical channel consisting of a single-mode optical fiber or, in alternative embodiments, a free-space line-of-sight propagation path, conveying one photon of each pair from the bench (1) to the remote station (2) located at the receiving terminus;
• A local detection bench at the local station (3) located at the originating terminus, comprising a beam-splitter, a pair of polarization analyzers, and a pair of photomultiplier tubes of conventional construction;
• A keyed measurement console (4) accessible to the local operator, configured to direct each incoming local photon to one of two measurement protocols (designated by the inventors as the X protocol and the Z protocol);
• A synchronized receiving register (5) at the remote station, accumulating the outcomes of remote measurements in real time and applying a statistical-analysis algorithm to detect the changing distribution corresponding to the local operator's protocol selection;
• A paper tape (6) of telegraphic-standard width, printed at the remote terminus by an electromagnetic platen with the decoded message in International Morse Code.

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 to FIG. 6A, the apparatus is shown as a block diagram. The originating station (Station A, at left) contains the entanglement bench (1), the local detection bench (3), and the keyed measurement console (4). The receiving station (Station B, at right) contains the remote detection bench (2), the receiving register (5), and the paper-tape printer (6). The two stations are coupled by an optical channel of indefinite length, said channel conveying one photon of each entangled pair from Station A to Station B.

In operation, the originating operator wishes to convey a binary message to the receiving operator. The operator selects, for each successive entangled pair, either the X protocol (corresponding to a binary 0) or the Z protocol (corresponding to a binary 1), by means of the keyed measurement console (4). The local detection bench (3) thereupon measures the local photon under the selected protocol and records the outcome.

Concurrently, at Station B, the remote detection bench (2) is configured to perform a fixed measurement (the inventors' specification calls for a polarization analysis along the +45° axis throughout), and the outcomes of these measurements are accumulated by the receiving register (5). The inventors assert that the statistical distribution of these outcomes, taken in aggregate over a large number of pairs, reflects the protocol selected at Station A, and that the receiving register may therefore infer the originating operator's selection — and accordingly decode the binary message — without the need for any classical channel between the two stations.

The message is printed in real time upon the paper tape (6) and may be read by the remote operator with negligible delay relative to its transmission at Station A. As the entangled correlations are instantaneous in the rest frame of the originating laboratory, the apparatus is asserted to convey information at superluminal velocity — and indeed, in the limit of perfect entanglement, at infinite velocity.

The inventors have, for the avoidance of doubt, identified the no-signaling theorem as the principal theoretical objection to their invention and have submitted a separate brief addressing this objection. The brief is appended to this application as Exhibit A and is summarized in the section following.

ClaimsФормула изобретенияClaims

1. An apparatus for the transmission of classical information between two stations, comprising: an entanglement bench at a first of said stations configured to generate pairs of entangled particles; an optical channel conveying one particle of each pair to the second of said stations; a local detection bench at said first station; a keyed measurement console at said first station; and a receiving register at said second station configured to infer, by statistical analysis, the measurement protocol employed at said first station.

2. The apparatus of claim 1, wherein said entanglement bench comprises a parametric down-conversion crystal of beta-barium-borate composition pumped by an argon-ion laser at 351 nanometers.

3. The apparatus of claim 1, wherein said keyed measurement console is configured to alternate between an X protocol and a Z protocol corresponding to binary 0 and binary 1 respectively.

4. The apparatus of claim 1, wherein said receiving register applies a maximum-likelihood detector to the accumulated remote measurement outcomes.

5. The apparatus of claim 1, further comprising a paper-tape printer of telegraphic standard configuration, coupled to said receiving register and configured to print the decoded message in International Morse Code.

6. A method for the transmission of a binary message between two stations separated by an arbitrary distance, comprising: (a) generating a stream of entangled photon pairs at said first station; (b) conveying one photon of each pair to said second station; (c) selecting, for each pair at said first station, one of two measurement protocols in accordance with the bit of said message to be transmitted; (d) at said second station, performing fixed measurements upon the received photons; and (e) inferring said message from the statistical distribution of said fixed measurement outcomes.

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

The invention as claimed is, in the unanimous view of the relativistic physics community, provisionally impossible — and the Bureau is constrained to concur, notwithstanding the inventors' submitted brief at Exhibit A.

First, the invention contradicts the no-signaling theorem of relativistic quantum mechanics, established by Eberhard (1978) and Ghirardi et al. (1980). The theorem holds that the marginal probability distribution of measurement outcomes at one station, taken without reference to outcomes at the other station, is invariant under any choice of measurement performed at the other station. That is to say: the receiving operator, examining his accumulated string of outcomes in isolation, cannot determine what measurement protocol was employed at the originating station, because the marginal statistics of his outcomes are identical under all such protocols. The receiving register of claim 4 will, however sophisticated its maximum-likelihood detector, find no statistical signal to distinguish the X protocol from the Z protocol, because there is none to be found.

Second, the inventors' Exhibit A asserts that the marginal-invariance result is inapplicable to the present invention because the originating operator performs his measurements prior in absolute time to those performed at the receiving station, the absolute simultaneity of the entangled pair being broken by this temporal asymmetry. The Bureau notes that the invocation of absolute simultaneity in 1971 is, at best, anachronistic; the Lorentz covariance of the laws of physics, established by Einstein (1905) and confirmed by every experiment since, holds that no absolute time can be defined, and the asserted asymmetry cannot exist. The Bureau notes further that the inventors' position is approximately that taken by Bohm and Vigier (1954), and that the position has been substantively refuted by Bell (1964) and by the experiments of Aspect (1982).

Third, the invention as claimed, if operative, would permit the transmission of information into the past light cone of the originating station by appropriate choice of reference frame, leading to the closed timelike curves contemplated in U.S.-IMP-3,091,447 and to the corresponding violations of causality. The chronology protection conjecture of Hawking (1992), if correct, forbids the invention on the same grounds as it forbids the temporal locomotion apparatus.

Fourth, the entangled state produced by the parametric down-conversion bench is degraded by transmission losses in the optical channel. The state degrades at an exponential rate with respect to channel length, and for any distance significant on the interplanetary scale the degradation reduces the entanglement to a level indistinguishable from a classically-correlated mixed state. The inventors' specification calls for entanglement purification by a procedure described in U.S.-IMP-3,447,772, but the said procedure is itself provisionally impossible for reasons stated in that filing.

The Bureau accordingly holds the invention to be provisionally impossible, and the application is held On File in the customary manner. The Bureau notes that the inventors have appealed the determination and that the appeal is now in its eleventh year of consideration. Citations: Einstein, A., Podolsky, B., Rosen, N., Phys. Rev. 47, 777 (1935); Eberhard, P. H., Il Nuovo Cimento B 46, 392 (1978); Bell, J. S., Physics 1, 195 (1964); Aspect, A., Grangier, P., Roger, G., Phys. Rev. Lett. 49, 91 (1982).