Tractor beam

A tractor beam is a device with the ability to attract one object to another from a distance.[1] The term was coined by E. E. Smith (an update of his earlier "attractor beam") in his novel Spacehounds of IPC (1931). Since the 1990s, technology and research has laboured to make it a reality, and have had some success on a microscopic level.[2] Another method to realize tractor beams is based on the use of biaxial birefringent media.[3] Less commonly, a similar beam that repels is called a pressor beam or repulsor beam. Gravity impulse and gravity propulsion beams are traditionally areas of research from fringe physics that coincide with the concepts of tractor and repulsor beams.

Physics

One well-accepted approach to attracting an asteroid towards a spacecraft is the gravity tractor. Essentially, a spacecraft approaches a small asteroid, and then the spacecraft's own gravity pulls the asteroid. The effect is tiny, but over a very long time, provided the asteroid isn't too big, the spacecraft can change the direction of the asteroid by a very small degree. This has been proposed as a way to prevent an asteroid from colliding with the Earth where a several decades long warning is raised as to a future collision.

A force field confined to a collimated beam with clean borders, is one of the principal characteristics of tractor and repulsor beams. Several theories that have predicted repulsive effects, do not fall within the category of tractor and repulsor beams because of the absence of field collimation. For example, Robert L. Forward, Hughes Research Laboratories, Malibu, California, showed general relativity theory allowed the generation of a very brief impulse of a gravity-like repulsive force along the axis of a helical torus containing accelerated condensed matter.[4][5] The mainstream scientific community has accepted Forward’s work. A variant of Burkhard Heim’s theory by Walter Dröscher, Institut für Grenzgebiete der Wissenschaft (IGW), Innsbruck, Austria, and Jocham Häuser, University of Applied Sciences and CLE GmbH, Salzgitter, Germany, predicted a repulsive force field of gravitophotons could be produced by a ring rotating above a very strong magnetic field.[6] Heim’s theory, and its variants, have been treated by the mainstream scientific community as fringe physics. But, the works by Forward, Dröscher, and Häuser could not be considered as a form of repulsor or tractor beam because the predicted impulses and field effects were not confined to a well defined, collimated region.

The following are a summary of experiments and theories that resemble repulsor and tractor beam concepts:

1960s

In July 1960, Missiles and Rockets reported Martin N. Kaplan, Senior Research Engineer, Electronics Division, Ryan Aeronautical Company, San Diego, had conducted experiments that justified planning for a more comprehensive research program. The article indicated such a program, if successful, would yield either “restricted” or “general” results. It described the “restricted” results as an ability to direct an anti-gravitational force towards or away from a second body.[7]

In 1964, Copenhagen physicists, L. Halpern, Universitetets Institut fűr Teoretisk Fysik, and B. Laurent, Nordisk Institut fűr Teoretisk Atomfysik, indicated general relativity theory and quantum theory allowed the generation and amplification of gravitons in a manner like the LASER.[8] They showed, in principle, gravitational radiation in the form of a beam of gravitons could be generated and amplified by using induced, resonant emissions.

1980s

According to Paul LaViolette, Starburst Foundation, Schenectady, New York, Eric Dollard, and Guy Obolensky had independently conducted gravity-like beam experiments during the 1980s that had been inspired by observations reported by Nikola Tesla.[9] Those experiments were not reported in peer reviewed journals.

1990s

In 1992, Russian Professor of Chemistry, Yevgeny Podkletnov, and Nieminen, Tampere University of Technology, Tampere, Finland, discovered weight fluctuations in objects above an electromagnetically levitated, massive, composite superconducting disk.[10] Three years later, Podkletnov reported the results of additional experiments with a toroidal disk superconductor.[11] They reported the weight of the samples would fluctuate between -2.5% and +5.4% as the angular speed of the superconductor increased. Certain combinations of disk angular speeds and electromagnetic frequencies caused the fluctuations to stabilize at a 0.3% reduction. The experiments with the toroidal disk yielded reductions that reached a maximum of 1.9-2.1%. Reports about both sets of experiments stated the weight loss region was cylindrical, extending vertically for at least three meters above the disk. Qualitative observations of an expulsive force at the border of the shielded zone were reported in the Fall of 1995.[12]

Italian physicist Giovanni Modanese, while a Von Humboldt Fellow at the Max Planck Institute for Physics, made the first attempt to provide a theoretical explanation of Podkletnov’s observations.[12][13] He argued the shielding effect and slight expulsive force at the border of the shielded zone could be explained in terms of induced changes in the local cosmological constant. Modanese described several effects in terms of responses to modifications to the local cosmological constant within the superconductor.[14] Ning Wu, Institute of High Energy Physics, Beijing, China, used the theory of quantum gauge theory of gravity he had developed in 2001 to explain Podkletnov’s observations.[15] Wu’s theory approximated the relative gravity loss as 0.03% (an order of magnitude smaller than the reported range of 0.3 – 0.5%).

Several groups around the world tried to replicate Podkletnov’s gravity shielding observations.[16] According to R. Clive Woods, Department of Electrical and Computer Engineering, Iowa State University, those groups were not able to overcome the extremely challenging technical problems of replicating all aspects of the 1992 experimental conditions.[17] Woods summarised those shortcomings in the following list:

  • Use of a superconductor disk with a diameter greater than 100 mm;
  • A disk containing ~30% non-superconducting YBCO, preferable organised into two layers;
  • A disk capable of self-levitation, but still containing large numbers of inter-grain junctions;
  • An AC levitation field with a frequency of ~10 kHz;
  • A second excitation field with a frequency of ~1 MHz, for disk rotation; and
  • Disk rotation speeds of 3,000 rpm or greater for large (>0.05%) gravitational effects.

C. S. Unnikrishan, Tata Institute of Fundamental Research, Bombay, India, showed that if the effect had been caused by gravitational shielding, the shape of the shielded region would be similar to a shadow from the gravitational shield. For example, the shape of the shielded region above a disk would be conical. The height of the cone's apex above the disk would vary directly with the height of the shielding disk above the earth.[18] Podkeltnov and Nieminen described the shape of the weight loss region as a cylinder that extended through the ceiling above the cryostat. That factor and others precipitated a recommendation to reclassify the effect as gravitational modification instead of gravitational shielding.[17] Such a reclassification means the region causing the weight modifications can be directed and is not limited to the space above the superconductor.

2000s

In 2001, Podkeltnov and Modanese reported the generation of a beam of gravity-like impulses.[19][20] Their paper indicated a high voltage discharge device had been constructed that emitted a horizontal, collimated beam, with sharp borders, of short impulses of a repulsive force field that could penetrate different bodies without any noticeable loss of energy. Subsequently, the apparatus was dubbed an impulse gravity generator. Measurements of the impulses taken three to six meters beyond the emitter and in a building 150 meters away yielded identical results. Analyses of the measurements indicated the impulses briefly caused accelerations one thousand times the rate of gravity.

The gravity impulse generator received further theoretical support from David Maker and Glen A. Robertson, Gravi Atomic Research, Madison, Alabama[21][22] and Wu.[23] Chris Taylor, Jupiter Research Corporation, Houston, Texas, along with a private individual Robert Hendry and the original theorist Modanese conducted an analysis of the suitability of impulse gravity generators for Earth-to-orbit, interplanetary, and interstellar applications, this was repeated again in 2008 and a United States and European patent was received.[24] In general, mainstream scientific community have treated the impulse gravity generator reports as extremely speculative and controversial.[16] At least one other group based in central Europe has attempted to replicate Podkletnov's gravity impulse generator experiment, but they have elected not to publish their results.

2010s

A team of scientists at the Australian National University led by Professor Andrei Rode created a device similar to a tractor beam to move small particles 1.5 meters through the air.[25] Rather than create a new gravitational field, however, the device utilizes a doughnut-shaped Laguerre-Gaussian laser beam, which has a high intensity ring of light that surrounds a dark core along the beam axis. This method confines particles to the centre of the beam using photophoresis, whereby illuminated sections of the particle have a higher temperature and thus impart more momentum to air molecules incident on the surface. Owing to this method, it is impossible for such a device to work in space due to lack of air, but Professor Rode states that there are practical applications for the device on Earth such as, for example, the transportation of microscopic hazardous materials and other microscopic objects.[26][27]

Prof. John Sinko and Dr. Clifford Schlecht researched a form of reversed-thrust laser propulsion as a macroscopic laser tractor beam. Intended applications include remotely manipulating space objects at distances up to about 100 km,[28] removal of space debris,[29] and retrieval of adrift astronauts or tools on-orbit.[30]

In March 2011, Chinese scientists posited that a specific type of Bessel beam (a special kind of laser that that does not diffract at the centre) is capable of creating a pull-like effect on a given microscopic particle, forcing it towards the beam source.[31][32] The underlining physics is the maximization of forward scattering via interference of the radiation multipoles. They show explicitly that the necessary condition to realize a negative (pulling) optical force is the simultaneous excitation of multipoles in the particle and if the projection of the total photon momentum along the propagation direction is small, attractive optical force is possible.[33] The Chinese scientists suggest this possibility may be implemented for optical micromanipulation.

Functioning tractor beams based on solenoidal modes of light were demonstrated in 2010 by physicists at New York University. [34] The spiraling intensity distribution in these non-diffracting beams tends to trap illuminated objects and thus helps to overcome the radiation pressure that ordinarily would drive them down the optical axis. Orbital angular momentum transferred from the solenoid beam's helical wavefronts then drives the trapped objects upstream along the spiral. Both Bessel-beam and solenoidal tractor beams are being considered for applications in space exploration by NASA.[35]

In 2013, scientists at the Institute of Scientific Instruments (ISI) and the university of St Andrews succeeded in creating a tractor beam that pulls objects on a microscopic level.[36] The new study states that while this technique is new, it may have potential for bio-medical research. Professor Zemanek said: “The whole team have spent a number of years investigating various configurations of particles delivery by light. Dr Brzobohaty said: “These methods are opening new opportunities for fundamental phonics as well as applications for life-sciences.” Dr Cizmar said: “Because of the similarities between optical and acoustic particle manipulation we anticipate that this concept will provide inspiration for exciting future studies in areas outside the field of photonics.”

Physicist from the Australian National University successfully built a reversible tractor beam, capable of transporting particles "one fifth of a millimetre in diameter a distance of up to 20 centimetres, around 100 times further than previous experiments." According to Professor Wieslaw Krolikowski, of the Research School of Physics and Engineering, “demonstration of a large scale laser beam like this is a kind of holy grail for laser physicists.”[37] The work was published in Nature in 2014.[38]

Fiction

Science fiction movies and telecasts normally depict tractor and repulsor beams as audible, narrow rays of visible light that cover a small area of a target. Tractor beams are most commonly used on spaceships and space stations. They are generally used in two ways:

  1. As a device for securing or retrieving cargo, passengers, shuttlecraft, etc. This is analogous to cranes on modern ships.
  2. As a means of preventing an enemy from escaping, analogous to grappling hooks.

In the latter case, there are usually countermeasures that can be employed against tractor beams. These may include pressor beams (a stronger pressor beam will counteract a weaker tractor beam) or plane shears aka shearing planes (a device to "cut" the tractor beam and render it ineffective). In some fictional realities, shields can block tractor beams, or the generators can be disabled by sending a large amount of energy back up the beam to its source.

Tractor beams and pressor beams can be used together as a weapon: by attracting one side of an enemy spaceship while repelling the other, one can create severely damaging shear effects in its hull. Another mode of destructive use of such beams is rapid alternating between pressing and pulling force in order to cause structural damage to the ship as well as inflicting lethal forces on its crew.

Two objects being brought together by a tractor beam are usually attracted toward their common centre of gravity. This means that if a small spaceship applies a tractor beam to a large object such as a planet, the ship will be drawn towards the planet, rather than vice versa.

In Star Trek, tractor beams are imagined to work by placing a target in the focus of a subspace/graviton interference pattern created by two beams from an emitter. When the beams are manipulated correctly the target is drawn along with the interference pattern. The target may be moved toward or away from the emitter by changing the polarity of the beams. Range of the beam affects the maximum mass that can be moved by the emitter, and the emitter subjects its anchoring structure to significant force.[39]

Literature

Comics

Movies and television series

The Original Series used the tractor beam several times. In "Space Seed", it was used to tow Khan Noonien Singh's ship, the SS Botany Bay. In "Tomorrow Is Yesterday", the Starship Enterprise attempts to capture Captain John Christopher's 20th century F-104 Starfighter jet, "Bluejay 4", using a tractor beam.

Games

UFO reports

Mansfield, Ohio

According to Peter Sturrock’s report of findings by the panel of scientists assembled to review the physical evidence of UFOs, one of the reports of apparent gravitational and/or inertial effects was the Mansfield, Ohio, Case of October 18, 1973.[41] Chapter 29 of Sturrock’s report included the entire investigative report by Jennie Zeidman, former Project Blue Book secretary for J. Allen Hynek. Zeidman’s reports had been prepared for the Center for UFO Studies.[42][43] Michael D. Swords presented the Mansfield, Ohio, Case to Sturrock’s panel of scientists. According to the testimony of the flight crew and independent ground witnesses, a green light beam from a cigar-shaped UFO had caused an U.S. Army Reserve helicopter to ascend 2,000 feet while its flight controls were in the descend position. Attempts to debunk the early reports of the incident were effectively refuted by researchers.[44] The Mansfield, Ohio, Case has been described as one of the most amazing UFO reports.[45]

Jenny Randles’ summary of the Mansfield, Ohio, Case concluded a tractor beam had been used to cause the rapid ascension of the helicopter.[46] She compared that case with a February 12, 1979, incident that had been investigated by the Yorkshire UFO Society. According to that account, a British Rail worker was transported six feet into the air by a green light beam to avoid potential harm from a passing Harrogate to Leeds train.

Jemgum, Germany

The compilation of European cases by Illobrand von Ludwiger, Director, Mutual UFO Network – Central European Section, Incorporated (MUFON-CES), included the sightings of two cigar-shaped UFO’s emitting light beams, that seemed to guide the behavior of smaller UFOs.[47] Witnesses in Jemgum, a small village in the northeast corner of Germany, saw the objects through binoculars on March 7, 1977. MUFON-CES investigated the reports and assessed the case with a 99.99% reliability index (a definition of Olsen’s reliability index was given in Appendix A of Ludwiger’s book).

See also

References

  1. ↑ "Nasa examines 'tractor beams' for sample gathering". BBC News. November 1, 2011.
  2. ↑ "Star Trek style 'tractor beam' created by scientists". BBC. 25 January 2013. Retrieved 1 October 2014.
  3. ↑ Nemirovsky, Jonathan; Rechtsman Mikael and Segev Mordechai (9 April 2012). "Negative radiation pressure and negative effective refractive index via dielectric birefringence". Optics Express 20 (8): 8907–8914. doi:10.1364/oe.20.008907. PMID 22513601.
  4. ↑ Forward, R. L.. (1961, September 11). Practical anti-gravity still far off. Missiles and Rockets, 9(11), 28-31, 35.
  5. ↑ Forward, Robert L. (1963). "March). Guidelines to antigravity". American Journal of Physics 31 (3): 166–170. Bibcode:1963AmJPh..31..166F. doi:10.1119/1.1969340.
  6. ↑ Dröscher, W., & Häuser, J. (2004, July). Guidelines for a space propulsion device based on Heim's quantum theory (AIAA 2004-3700). Paper presented at the meeting of the 40th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit, Fort Lauderdale, Florida. This work was named the 2004 AIAA Best Paper by the AIAA Nuclear and Future Flight Technical Committee.
  7. ↑ Force (1960). "July 11)". Missiles and Rockets 7 (2): 27.
  8. ↑ Halpern, L.; Laurent, B. (1964). "Agosto). On the gravitational radiation of microscopic systems". IL Nuovo Cimento. XXXIII (3): 728–751. doi:10.1007/bf02749891.
  9. ↑ LaViolette, P. A. (2008). Secrets of Antigravity Propulsion [pp. 178-189]. Rochester, VT: Bear & Company. ISBN 978-1-59143-078-0
  10. ↑ Podkletnov, E.; Nieminen, R. (1992). "A possibility of gravitational force shielding by bulk YBa2Cu3O7-x superconductor". Physica C 203 (3–4): 441–444. Bibcode:1992PhyC..203..441P. doi:10.1016/0921-4534(92)90055-H.
  11. ↑ Podkletnov, E. E. (1995, January). Weak gravitational shielding properties of composite bulk YBa2Cu3O7-x superconductor below 70 K under e.m. field [Report MSU-chem 95]. Moscow, Russia: Moscow Chemical Scientific Research Centre. Also, LANL Physics Preprint Server, arXiv: cond-mat/9701074v3.
  12. ↑ 12.0 12.1 Modanese, G. (1997). Updating the theoretical analysis of the weak gravitational shielding experiments. Proceedings of the 1997 IAF Congress, nr. IAA-97-4.107.
  13. ↑ Modanese, G. (1996, August 20). Theoretical analysis of a reported weak-gravitational-shielding effect. Europhysics Letters, 35(6), 413-418. Also, LANL Physics Preprint Server, arXiv: hep-th/9505094v2.
  14. ↑ Modanese, G. (1996). Role of a “local” cosmological constant in Euclidean quantum gravity. Physical Review D, 54(8), 5002-5009. Also, LANL Physics Preprint Server, arXiv: hep-th/9601160v1.
  15. ↑ Wu, N. (2004). Gravitational shielding effects in gauge theory of gravity. Communications in Theoretical Physics, 41, 567-572. Also, LANL Physics Preprint Server, arXiv: hep-th/0307225v1.
  16. ↑ 16.0 16.1 Allen, J. E. (2003). "Quest for novel force: a possible revolution in aerospace". Progress in Aerospace Sciences 39: 1–60. Bibcode:2003PrAeS..39....1A. doi:10.1016/S0376-0421(02)00049-0.
  17. ↑ 17.0 17.1 Woods, R. C. (2004). "February 4). Review of claims of interaction between gravitation and high-temperature superconductors". AIP Conference Proceedings 669 (1): 1085–1092.
  18. ↑ Unnikrishan, C. S. (1996). "Does a superconductor shield gravity?". Physica C 266: 133–137. Bibcode:1996PhyC..266..133U. doi:10.1016/0921-4534(96)00340-1.
  19. ↑ Podkletnov, E., & Modanese, G. (2001, August 3). Impulse gravity generator based on charged YBa2Cu3O7-y superconductor with composite crystal structure. LANL Physics Preprint Server, arXiv: physics/0108005.
  20. ↑ Podkletnov, E., & Modanese, G. (2003, August). Investigation of high voltage discharges in low pressure gases through large ceramic superconducting electrodes. Journal of Low Temperature Physics, 132(3-4), 239-259. Also, LANL Physics Preprint Server, arXiv: physics/0209051.
  21. ↑ Maker, D. (2002). "January). A new kind of electrostatic propulsion from fractal space-time physics. AIP Conference Proceedings, 608, 633-642. Maker, D., & Robertson, G. A. (2003). Very large propulsive effects predicted for a 512 kV rotator. AIP Conference Proceedings, 654, 958-967. Maker. D. (2007, January). Electrostatic 512 kV rotator/oscillator propulsion system". AIP Conference Proceedings 880: 1216–1224.
  22. ↑ Robertson, G. A.; Murad, P. A.; Davis, E. (2008). "New frontiers in space propulsion sciences". Energy and Conversion Management 49 (3): 436–452. doi:10.1016/j.enconman.2007.10.013.
  23. ↑ Wu, N. (2006). Mechanism for gravity impulse. Communications in Theoretical Physics, 46, 639-642. Also, LANL Physics Preprint Server, arXiv: gr-qc/0510010v1.
  24. ↑ Taylor, C. Y., & Modanese, G. (2002, July 10). Evaluation of an impulse gravity generator based beamed propulsion concept [AIAA-2002-4095]. Presented by Taylor at the 38th AIAA/ASME/SAE/ASEE Joint Propulsion Conference, Indianapolis, IN. Also, LANL Physics Preprint Server, arXiv: physics/0209023.
  25. ↑ Shvedov, Vladlen; A. V. Rode; Ya. V. Izdebskaya; A. S. Desyatnikov; W. Z. Krolikowski; and Yu.S. Kivshar (10 September 2010). "Giant optical manipulation". Physical Review Letters 105 (11): 118103. Bibcode:2010PhRvL.105k8103S. doi:10.1103/PhysRevLett.105.118103. PMID 20867612.
  26. ↑ Smart, Ashley (November 2010). "Optical manipulation of light – absorbing particles takes to the air". Physics Today 63 (11): 13–14. Bibcode:2010PhT....63k..13S. doi:10.1063/1.3518265.
  27. ↑ McDaniel, Tracie (September 9, 2010). "Aussie Scientists Have New "Pull" as Tractor Beam Goes the Distance". Daily Tech. Retrieved 2010-09-09.
  28. ↑ Sinko, John (September 17, 2010). "Laser Ablation Propulsion Tractor Beam System" (PDF). Journal of Propulsion and Power. Retrieved 2010-09-17.
  29. ↑ Shane (September 17, 2010). "Laser Beams to Clean Up Space Junk". GoArticles.com. Retrieved 2010-09-17.
  30. ↑ brian wang (17 October 2011). "Laser activated ablation propulsion could rescue astronauts and move space junk". Nextbigfuture.com. Retrieved 17 September 2013.
  31. ↑ "Tractor Beam Lasers? Possible, Say Scientists". Time. March 3, 2011. Retrieved 2011-03-04. |first1= missing |last1= in Authors list (help)
  32. ↑ "How To Turn A Laser Into A Tractor Beam". The Physics arXiv Blog (MIT). 28 February 2011. Retrieved 2011-03-04.
  33. ↑ Jun Chen; Jack Ng, Zhifang Lin, C. T. Chan (24 February 2011). "Backward Pulling Force from a Forward Propagating Beam". Nature Photonics 5 (9): 531. arXiv:1102.4905. doi:10.1038/nphoton.2011.153.
  34. ↑ Lee, Sang-Hyuk; Roichman, Yohai; Grier, David G. (2010). "Optical solenoid beams". Optics Express 18 (7): 6988. doi:10.1364/OE.18.006988. ISSN 1094-4087.
  35. ↑ "Nasa examines 'tractor beams' for sample gathering". 1 November 2011. Retrieved 2012-09-21.
  36. ↑ "Star-Trek style tractor beam created by scientists". 25 January 2013.
  37. ↑ http://news.anu.edu.au/2014/10/20/physicists-build-reversible-tractor-beam/
  38. ↑ http://www.nature.com/nphoton/journal/vaop/ncurrent/full/nphoton.2014.242.html
  39. ↑ Startrek Reference Manual, Rick Sternbach and Michael Okuda, pages 89 - 90
  40. ↑ Nowlan, P. F. (1962). Armageddon 2419 A. D. [pp. 37-41]. New York, NY: Ace Books, Inc.
  41. ↑ Sturrock, P. A. (Study Director)(1999). The UFO Enigma [pp. 89-92]. New York, NY: Warner Books, Inc. ISBN 0-446-67709-4.
  42. ↑ Zeidman, J. (1979). A Helicopter-UFO Encounter Over Ohio. Evanston, IL: Center for UFO Studies.
  43. ↑ Zeidman, J. (1988). "November/December). Green light over Mansfield". International UFO Reporter 13 (6): 13–14.
  44. ↑ Birnes, W. J. (Ed.)(2004). The UFO Magazine UFO Encyclopedia [pp. 200-201, 299-301]. New York, NY: Pocket Books, a division of Simon & Schuster, Inc. ISBN 0-7434-6674-8.
  45. ↑ Dolan, R. M. (2002). UFOs and the National Security State (Revised Edition) [p. 383]. Charlottesville, VA: Hampton Roads Publishing Company, Inc. ISBN 1-57174-317-0
  46. ↑ Randles, J. (1987). The UFO Conspiracy [p. 105]. New York, NY: Barnes & Noble, Inc. ISBN 1-56619-195-5.
  47. ↑ v. Ludwiger, I. (1998). Best UFO Cases - Europe [pp. 23-25, 28, 159]. Las Vegas, NV: The National Institute for Discovery Science. ISBN 0-9666077-0-8. This is registered under MUFON-CES Case ID: 654.

External links

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