|
|
|
|
Tractor beam
|
| |
|
| |
A tractor beam is a hypothetical device with the ability to attract one object to another from a distance. Tractor beams are frequently used in science fiction. Less commonly, a similar beam that repels is called a pressor beam or repulsor beam. No mainstream science equivalents of these beams exist outside of the microscopic level (see optical tweezers). The exact specifics vary, but there are generalities.
Discussion
Ask a question about 'Tractor beam' Start a new discussion about 'Tractor beam' Answer questions from other users |
Encyclopedia
A tractor beam is a hypothetical device with the ability to attract one object to another from a distance. Tractor beams are frequently used in science fiction. Less commonly, a similar beam that repels is called a pressor beam or repulsor beam. No mainstream science equivalents of these beams exist outside of the microscopic level (see optical tweezers). The exact specifics vary, but there are generalities. Gravity impulse and gravity propulsion beams are areas of research from fringe physics that coincide with the concepts of tractor and repulsor beams. A few UFO reports, that have been thoroughly investigated and formally classified as inexplicable, in terms of conventional science, feature tractor and repulsor beam characteristics.
Usage in 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:
- As a device for securing or retrieving cargo, passengers, shuttlecraft, etc. This is analogous to cranes on modern ships.
- 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 center 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 work slightly differently. The target is placed in the focus of a subspace/graviton interference pattern created by two beams from the 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.
Appearances
Works containing well-known appearances of tractor beams include:
Literature
- The Skylark of Space books by E. E. Smith (possibly the original appearance: 1929). The protagonist invents "attractor beams" and "repellor beams." Repellors can also be emitted isotropically as a sort of defensive force field against material projectiles.
- In Buck Rogers first book, Armageddon 2419, (1928), by Philip Francis Nowlan the enemy ships used "repellor beams" for support and propulsion.
- The Lensman books by E. E. Smith
- Tom Swift - In the The New Tom Swift Jr. book Tom Swift and The Deep-Sea Hydrodome (1958), Tom invents the "repellatron." The device can be set to repel specific chemical elements. It was used to create a bubble habitat on the ocean floor, and as the propulsion system for his spacecraft Challenger.
- The Honor Harrington books by David Weber
- The Sector General books by James White The 1963 novel Star Surgeon is the source of the combined tractor/pressor beam weapon, the so called "Rattler." These weapons attract then repel the target (entire ship or a segment of the ship's hull) at 80 gs, several times a minute. The novel also featured a type of Force field called a "repulsion screen."
- Starfire series - the combined tractor/pressor beam weapon
- Starplex by Robert J. Sawyer
- The Trigger by Arthur C. Clark involves the development of tractor beams in the early part of the novel.
Comics
- Buck Rogers comic strip - originally just repulsor beams; tractors appeared by 1970s
- Archie Comics, where it is caricatured as a literal "tractor"
Movies and television series
- Star Trek (TV series, movies, books, games)- However the USS Enterprise in the prequel series Enterprise does not employ tractor beams in favor of grappling lines.
- Star Wars (TV series, movies, books, games)
- Babylon 5 (TV series). The Minbari Federation is known to use "gravity nets" which wrap a bubble around its target allowing the ship creating the net to "grapple" the target. They also have some sort of "levitation beams" seen in the TV movie "In the Beginning" wherein Lennon and a group of Minbari emissaries from the Grey Council are levitated from a platform on the ground up to ship high above them.
- The seaQuest DSV episode "Splashdown."
- in Spaceballs, Spaceball 1 uses a tractor beam - referred to as a "magnetic beam" in the film - to intercept Princess Vespa's Mercedes space cruiser.
- The Taelon mothership on Earth: Final Conflict used tractor beams on several occasions.
- In The Incredibles, Syndrome uses zero-point energy.
- In Recess: School's Out, the film's main antagonist attempted to use a tractor beam to move the moon to create a new ice age.
- The anime Uchuu Senkan Yamato (known as Star Blazers outside Japan). In one episode, multiple magnetic beam projectors on planet Gamilon were used to drag the Yamato into a trap.
- Pixar's 2006 short movie Lifted is based on an alien character who is in a tractor beam usage test.
- In Austin Powers in Goldmember, Dr. Evil's evil plan involved using a tractor beam to crash a golden asteroid into the Earth, causing a torrential flood.
- In the animated series Aqua Teen Hunger Force, one of Dr. Weird's inventions is a rainbow shooting machine, which actually turns out to be a tractor beam, but the doc simply calls it "this thing".
- In Dumb n Dumber, Lloyd (Jim Carey) described meeting Mary 'Swimmy, Swimey' Swanson (Lauren Holly) for the first time being like a; "tractor beam - sucked me right in".
- In This Island Earth (1955), a small airplane was drawn into a Metalunan flying saucer by a visible and audible tractor beam that engulfed the entire aircraft.
- In the movie Wayne's World, Garth says "Stacy alert. We've been spotted and are being pulled in by her tractor beam" when Wayne's obsessed ex-girlfriend approaches them at a bar.
Games
- Galaga - used by the Galagas to steal the player's ship.
- The "Grabber" in Doom 3: Resurrection of Evil
- The Salvage Corvette's "Salvage Field" in Homeworld
- The Grapple Beam from the Metroid series
- One Crystal Eres (magic spell) in Tales of Legendia and a magic spell in Tales of Phantasia is named Tractor Beam, that launches the enemy in the air.
- In Time Crisis 4, Wild Dog uses a Tractor Beam at one point to direct crates and other heavy objects at the players.
- Ratchet and Clank: Going Commando, It is used as a Gadget to move marked objects from one place to another, often presenting a plot advance.
- In Half-Life 2, Gordon Freeman is armed with a device called the "Zero-Point Energy Field Manipulator" or simply the "Gravity Gun", which can pick up, throw, and "punt" heavy or sharp objects with little or no effort. In the last mission, it is accidentally modified to manipulate heavier objects, and can throw Combine soldiers to their deaths.
- A similar gun to the one in Half-Life 2, called the "Uplink", appears in TimeSplitters: Future Perfect, available to the player beginning with the second mission. In addition to a "gravity gun", the item also serves as a map and a time machine for the player's character, Sergeant Cortez.
- In Freelancer, each ship is fitted with a tractor beam, with which it salvages cargo, weapons and mission items from destroyed ships.
- In the video game Portal, yet another similar gun to Half-Life 2's, which is titled the "Aperture Science Handheld Portal Device", can create a weaker zero-point energy field by simply lifting objects and carrying them, but cannot throw or pull in from a distance. These items can also be dropped through the portals it can create.
- In the Metroid prime series, the charged beam has a tractor beam effect.
- In the MMORPG EVE Online tractor, tractor beams can be used to retrieve wrecks of enemy ships and cargo containers in space.
- Another similar gun to Half-Life 2's gravity gun called the "Capture gun" appears as the primary tool in the Wii video game Elebits, where it is used to manipulate objects and capture the titular creatures.
- In the MMORPG Star Sonata, tractor beams can be used to push and pull enemy ships, collect debris from space, and are also a valid form of transportation.
Fringe physics
A force field confined to a well-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. 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. 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.
Mainstream scientists typically regard reported repulsor beam concepts and experiments as highly speculative and/or controversial forms of fringe physics. Subsequently, such lines of research are rarely pursued. 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. Neither comments nor criticism of the report appeared in subsequent articles. Five years earlier, a photograph of Kaplan had appeared with the front-page newspaper article that was published near the beginning of the intensified period of United States gravity control propulsion research (1955 - 1974).
In 1964, Copenhagen physicists, L. Halpern, Universitetets Institut fur Teoretisk Fysik, and B. Laurent, Nordisk Institut fur Teoretisk Atomfysik, indicated general relativity theory and quantum theory allowed the generation and amplification of gravitons in a manner like the LASER. 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. 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. Three years later, Podkletnov reported the results of additional experiments with a toroidal disk superconductor. 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.
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. 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. 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. 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. 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. Woods summarized 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 organized 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. 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. 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. Their paper indicated a high voltage discharge device had been constructed that emitted a horizontal, well-collimated beam, with clean 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 and Wu. Chris Taylor, Jupiter Research Corporation, Houston, Texas, and Modanese conducted an analysis of the suitability of impulse gravity generators for Earth-to-orbit, interplanetary, and interstellar applications. In general, mainstream scientific community have treated the impulse gravity generator reports as extremely speculative and controversial. No other groups have attempted to replicate Podkletnov's gravity impulse generator experiment.
UFO Reports
The following is a summary of two thoroughly researched UFO cases that could not be attributed conventional science that had featured behavior resembling tractor beam activity of science fiction. These cases may serve as a form of proof of concept for tractor and/or repulsor beams.
Mansfield, Ohio
According to Peter Sturrock’s report of findings by the panel of scientists assembled to review the physical evidence of UFO’s, one of the “quite interesting” and “better documented reports” of apparent gravitational and/or inertial effects was the Mansfield, Ohio, Case of October 18, 1973. 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. 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. The Mansfield, Ohio, Case has been described as one of the most amazing UFO reports.
Jenny Randles’ summary of the Mansfield, Ohio, Case concluded a tractor beam had been used to cause the rapid ascension of the helicopter. 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 Leed train.
Jemgum, Germany
The compilation of best 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. 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).
External links
|
| |
|
|
