- Force field
A force field, sometimes known as an energy shield, force shield, or deflector shield is a concept of a field tightly bounded and of significant magnitude so that objects affected by the particular force relating to the field are unable to pass through the central axis of the field and reach the other side. Commonly depicted as an impenetrable wall of energy.
A University of Washington group in Seattle has been experimenting with using a bubble of charged plasma to surround a spacecraft, contained by a fine mesh of superconducting wire. This would protect the spacecraft from interstellar radiation and some particles without needing physical shielding.
Plasma windows have some similarities to force fields, being difficult for matter to pass through.
Diamagnetic levitation has been demonstrated to produce a force field strong enough to enable a frog to hover in mid-air.
Workers at a 3M factory in South Carolina in August 1980 encountered an "invisible electrostatic wall" in an area under a fast-moving sheet of polypropylene film that had become electrically charged to a voltage that "had to be in the Megavolt range". This phenomenon was a result of Coulomb's law.
Television and film
Science fiction and fantasy venues postulate a number of potential uses for force fields:
- A barrier to allow workers to work in areas that can be exposed to the vacuum of space, keeping the atmosphere inside while allowing certain other objects to pass through.
- Emergency quarantine of an area afflicted by a harmful biological or chemical agent or occupied by enemy forces.
- The extinguishing of a fire by forcing the reaction to use up all the available oxygen in the confined space.
- As a shield from damage by natural forces or enemy attack.
- To create a temporary habitable space in a place not usually suited to sustaining life.
- As a security method to direct someone in a particular direction for capture, or to confine a captive in a particular area.
The concept goes back at least as far as the 1920s, in the works of E.E. 'Doc' Smith and others; and William Hope Hodgson's The Night Land (1912) has the Last Redoubt, in which the remnants of humanity shelter, protected by something very like a force field[original research?].
The abilities and exact functionality of energy shields vary; in some works (such as in the Star Trek universe), energy shields can stop, or mitigate the effects of, both energy and particle weapons (e.g. phasers) and normal projectiles, both natural and artificial. In the various series, shields function primarily as a defensive measure against weapons fire from other ships; these shields also generally block the use of transporters while active. Also, inside ships, force field generators can seal off ship atmosphere from the vacuum of space, as in the case of a hull breach caused by an attack or explosion. Within the Stargate franchise universe, force fields function in much the same way.
In the Star Wars universe, deflector shields are standard issue on most ships and perform a function similar to that of their Star Trek counterparts. Unlike Star Trek, multiple kinds of shielding are required to guard against different weapons and interstellar debris.
While the explanations of how force fields were developed, how they are powered or their precise function are as varied as there are computer video games that use them, the concept of force fields as a defensive measure from enemy attack or as a form of attack in and of itself is a popular one. By no means a complete listing, some video games that employ the concept of force fields include the Command & Conquer franchise, the Mass Effect trilogy, StarCraft (series), Haegemonia, Earth 2150 (and its sequel, Earth 2160) and the Halo franchise.
Literature and graphic media
In Frank Herbert's Dune series, set in speculative fiction setting, personal shields have been deployed that can stop objects with high kinetic energy. As well, when struck by an energy weapon, the subsequent violent reaction makes both the shield and emitter explode. In response to this, many have returned to using melee weapons, slowed before strike to penetrate the shield. On Arrakis shield technology is avoided, as it tends to attract the local fauna (sandworms) and drive them into a killing frenzy.
In Isaac Asimov's Foundation universe, personal shields have been developed by scientists specializing in the miniaturization of planet-based shields. As they are primarily used by Foundation Traders, most other inhabitants in the Galactic Empire do not know about this technology.
The ability to create a force field is a popular superpower in comic books and associated media. While only a few characters have the explicit ability to create force fields (for example, the Invisible Woman and Violet Parr), many can emulate it with other powers, such as Green Lantern's energy constructs, Jean Grey's telekinesis, and Magneto's manipulation of electromagnetic fields.
- ^ Shiga, David (2006-07-17). "Plasma bubble could protect astronauts on Mars trip". New Scientist. Reed Business Information Ltd.. http://www.newscientist.com/article/dn9567. Retrieved 2008-12-13.
- ^ Shiga, David (2007-04-18). "'Deflector' shields could protect future astronauts". New Scientist. Reed Business Information Ltd.. http://www.newscientist.com/article/dn11623. Retrieved 2008-12-13.
- ^ Rincon, Paul (2007-04-18). "Space shield to block radiation". BBC News Online (BBC). http://news.bbc.co.uk/2/hi/science/nature/6567709.stm. Retrieved 2008-12-13.
- ^ "esdjournal.com/articles/final/final.htm". http://www.esdjournal.com/articles/final/final.htm. Retrieved March 19, 2010. issue of the ESD Journal discussing report in Session 7: Special session, 17th Annual EOS/ESD Symposium, Sept 14, 1995. See also amasci.com/weird/unusual/e-wall.html
- ^ http://virginia.cc.vt.edu/files/books/235/ComputationalDynamicsbuk157p.pdf
- Andrews, Dana G. (2004-07-13). "Things to do While Coasting Through Interstellar Space" (PDF). 40th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit. Fort Lauderdale, Florida. AIAA 2004-3706. http://pdf.aiaa.org/preview/CDReadyMJPC2004_946/PV2004_3706.pdf. Retrieved 2008-12-13.
- Martin, A.R. (1978). "Bombardment by Interstellar Material and Its Effects on the Vehicle, Project Daedalus Final Report". Journal of the British Interplanetary Society: S116–S121.
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