Anti-gravity machine

{{pseudoscience}}
An '''anti-gravity machine''' is a machine that allows one to conquer the force of [[gravity]] and fly. In common use, the term refers to devices that operate ''contra'' the known laws of [[physics]], require less [[energy]] than is physically possible, or utilise strange phenomena far outside the realm of [[Newton]]ian physics, rather than well-known technologies such as [[aircraft]] and hot air/[[helium]] balloons. Hypothetical power plants that might drive [[flying saucer]]s often rely on some kind of anti-gravity. Many anti-gravity machines would also qualify as [[perpetual motion]] machines: if you can genuinely shield something from gravity, this allows one to generate perpetual motion (raise something "for free" using anti-gravity, then drop it, doing work as it falls, and repeat).<ref name=nature2005/>

Research in anti-gravity has often been spurred by new scientific discoveries, such as general relativity and superconductors. It is unclear whether an anti-gravity device would necessarily violate the laws of physics, and physicists debate the extent to which [[quantum mechanics]] and general relativity allow exotic forms of locomotion such as wormholes and {{wpl|Alcubierre drive|Alcubierre drives}} for [[faster-than-light travel]]. But as yet, there is no practical way of shielding an object from gravity or [[Levitation|levitating]] an object without inputting a much greater amount of [[energy]] than the object gains in gravitational potential.

There is evidence that the [[United States|US]] government, the US military, and agencies including [[NASA]] have occasionally investigated unorthodox antigravity machines.<ref name=warzone>[https://www.thedrive.com/the-war-zone/30499/the-truth-is-the-military-has-been-researching-anti-gravity-for-nearly-70-years The Truth Is The Military Has Been Researching "Anti-Gravity" For Nearly 70 Years], Brett Tingly, The Warzone, Oct 29, 2019</ref><ref name=nature2005/> However, there is no evidence that they've found anything.

The US [[patent]] office is supposed to automatically reject anti-gravity machines, perpetual motion machines, and other inventions that are obviously contrary to the laws of physics, but occasionally things slip through their net.<ref name=nature2005>[https://www.nature.com/articles/438139a Antigravity craft slips past patent officers], Nature volume 438, page 139 (2005), 9 Nov 2005</ref> This invariably adds to the suspicion of [[conspiracy theorists]] who think the government already has secret technology powering its [[UFO]]s and [[black helicopters]].

==Proposed technologies==
===Gravity shields===
This is one of the simplest ideas: what if there was a material that blocks gravity? Anything behind or above the shield would float!

This has featured in [[science fiction]], such as H.G. Wells's "The First Men in the Moon".<ref>[http://adsabs.harvard.edu/full/1943PA.....51...76L Marvelous voyages - V, H. G. Wells' The first Men in the Moon - Part I], Lafleur, L. J., Popular Astronomy, Vol. 51, p.76, 1943</ref> But there are no obvious candidates in the [[real world]]. Today, most interest (at least from eccentric home researchers) is on shields with some kind of electrical property. Some people have proposed {{wpl|electret|electrets}} (materials with a permanent electrostatic charge), or capacitors, and there is also interest in superconductors; these are discussed below.

===Superconductivity===
Eugene Podkletnov (a [[Russian]] physicist) and Boris Volfson (of Huntington, [[Indiana]]) have both suggested that superconductors can somehow shield an object from gravity and allow it to fly.<ref name=nature2005/> Superconductors are clever things, and appear to offer a kind of perpetual motion machine in that they allow motion without resistance, but that does not include flight.

In 1992, Podkletnov proposed blocking gravity with a spinning superconducting disk, claiming a reduction of 0.5-2% in weight, in a paper published in ''Physica C''.<ref>Podkletnov E. and Nieminen R. A possibility of gravitational force shielding by bulk YBa<sub>2</sub>Cu<sub>3</sub>O<sub>7-x</sub> superconductor. Physica C, v. 203, 1992, 441– 444.</ref><ref>Rabounski, & Borissova, Larissa. (2007). [https://www.researchgate.net/publication/26460495_A_Theory_of_the_Podkletnov_Effect_based_on_General_Relativity_Anti-Gravity_Force_due_to_the_Perturbed_Non-Holonomic_Background_of_Space A Theory of the Podkletnov Effect based on General Relativity: Anti-Gravity Force due to the Perturbed Non-Holonomic Background of Space]. Progress in Physics. 3. </ref> He wrote a more substantial paper that was initially accepted by ''Journal of Physics-D'' and due for publication in 1996, but when [[journalist]]s leaked the story ahead of publication, Podkletnov was rejected both by his employer, the Institute of Materials Science in the University of Tampere, [[Finland]], and his credited co-author, and as a result he withdrew the paper.<ref>[https://www.wired.com/1998/03/antigravity/ Breaking the Law of Gravity], Charles Platt, ''Wired'', March 1998</ref> There were nonetheless various attempts to develop his research, and in 1999, NASA engaged a Columbus, [[Ohio]] company Superconductive Components Inc to try and produce a prototype, despite most scientists feeling that it was nonsense.<ref>"Weighty Implications: NASA Funds Controversial Gravity Shield", Space.com, 28 Sept 2000, via [https://web.archive.org/web/20060210065536/http://www.space.com/businesstechnology/technology/anti_grav_000928.html archive.org]</ref> Boeing also conducted research, according to press reports in 2014.<ref>[https://www.independent.co.uk/news/science/boeing-investigates-possibility-that-planes-can-be-set-free-from-the-pull-of-gravity-186448.html Boeing investigates possibility that planes can be set free from the pull of gravity], The Independent, Jan 6, 2014</ref> In 2020, it was announced that Podkletnov was still working in the same area.<ref>[https://medium.com/predict/eugene-podkletnovs-new-gravity-modification-experimental-video-b7813b04c6f8 Eugene Podkletnov’s New Gravity Modification Experiment & Video], Tim Ventura, Medium, Feb 5, 2020</ref>

===Other electric solutions===
An "electric rocket" using capacitors has also been proposed, but is considered implausible (as well as risking fatal electric shocks).<ref>[http://amasci.com/caps/capwarp.html "Electric Rocket": capacitor array gravity warp drive], Bill Beaty, 2005</ref>

===Gyroscopes===
Gyroscopes are clever little things that spin and always point in the same direction, resisting attempts to turn them; if a force is applied, it produces a highly unintuitive movement at a 90 degree angle, which suggests magic to the naive. They also appear to exhibit an upward "anti-gravity" force: if supported on one side, they appear to hover in space. This is not a mysterious force or method of anti-gravity; all their behavior is a consequence of torque around the vertical axis and can be explained perfectly well by Newtonian physics.<ref>[http://www2.eng.cam.ac.uk/~hemh1/gyroscopes.htm Gyroscopes and Boomerangs], Hugh Hunt, University of Cambridge Department of Physics, accessed May 21, 2021</ref><ref>[https://www.hindawi.com/journals/amp/2019/4197863/ Physics of Gyroscope’s “Antigravity Effect”], Ryspek Usubamatov, Advances in Mathematical Physics, Volume 2019 |Article ID 4197863 | https://doi.org/10.1155/2019/4197863</ref>

Nonetheless, a number of people have claimed that a spinning gyroscope reduces its weight somehow, in a way not explained by current physics. The [[engineer]] Eric Laithwaite claimed to have discovered strange behavior in gyroscopes, and Hideo Hayasaka and Sakae Takeuchi of Tokohu University reported a weight loss of 0.005% in a 1989 paper.

Laithwaite was Professor of Electrical Engineering at the distinguished Imperial College, London, Professor of Applied Electricity at the Royal Institution, and a pioneer in the development of the {{wpl|linear motor}} and maglev [[Rail transportation|trains]]. But he had unorthodox views on gyroscopes, claiming to detect a weight loss in experiments. He set out his views to British children in the televised ''Royal Institution Christmas Lectures'' in 1974, despite the Royal Institute refusing to publish his reports. It later emerged that he had used engineering approximations in his calculations, and a more accurate calculation revealed there was no discrepancy in his measurements and no weight loss. His continuing defence of his ideas reportedly harmed his career: he left the Royal Institution in 1975 and was refused a Fellowship of the Royal Society.<ref>[https://www.rigb.org/blog/2013/december/eric-laithwaite The gyroscope, an engineer and the CHRISTMAS LECTURES], Royal Institution blog, Dec 10, 2013</ref>

Likewise, scientists suggested that errors in Hayasaka and Takeuchi's experimental procedure were probably to blame, and attempts by others to repeat it did not find anything.<ref name=ns1990>[https://www.newscientist.com/article/mg12517042-700-science-does-a-spinning-mass-really-lose-weight/#ixzz6vUVEzggF Science: Does a spinning mass really lose weight?], New Scientist, Feb 17, 1990</ref> As yet, there is no evidence that gyroscopes can fly.

===Unequal pressure===
It has been suggested that the atomic nature of gas can be exploited, similar to in [[Maxwell's demon]] or the {{wpl|Brownian ratchet||.}} If one could let air [[molecule]]s travel downwards through a membrane but prevent them from going upwards, this would naturally lead to the membrane and anything attached to it rising.

A similar mechanism has been advanced using variations in quantum energy density, particularly the [[zero-point energy]] of empty space. It is well known that the {{wpl|Casimir effect}} can force two plates together, but this doesn't get you far. A variation on this, the dynamical Casimir effect, produces a force by accelerating a mirror through empty space. This has been suggested as a form of propulsion, and it appears theoretically possible, but in practice would provide a tiny amount of thrust.<ref>[https://arxiv.org/abs/physics/0303108 A Gedanken Spacecraft that Operates Using the Quantum Vacuum (Dynamic Casimir Effect)], G. Jordan Maclay & Robert L. Forward, Foundations of Physics volume 34, pages477–500 (2004)</ref>

The [[EmDrive]], partly developed by NASA's Eagleworks, uses differing pressures from electromagnetism in a shaped cavity, where the pressure in one direction is supposedly different to that in the other direction, to supposedly provide a method of propulsion that seems to go against the laws of physics. There have been demonstrations, although [[skepticism]] is still strong.<ref>[https://www.wired.com/story/nasas-emdrive-leader-has-a-new-interstellar-project/ NASA's EmDrive Leader Has a New Interstellar Project], Wired, May 8, 2020</ref><ref>[http://large.stanford.edu/courses/2017/ph240/blakemore1/ Harnessing Zero-Point Energy], Chas Blakemore, December 10, 2017</ref> Such a device would emit no matter, not even photons: this is in contrast to a range of drives that emit electrically-charged ions or [[subatomic particle]]s and are well within the bounds of physics.

===Fifth force===
A force in addition to strong nuclear, weak nuclear, [[electromagnetism]], and gravity has been postulated; it may be attractive or repulsive.<ref>[https://www.epj.org/images/stories/news/2015/10.1140--epjh--e2015-60044-5.pdf The fifth force: A personal history], Ephraim Fischbach, The European Physical Journal H volume 40, pages385–467 (2015)</ref> It's not terribly clear how such a force could be used, unless it could be turned on and off — and if one can control the fifth force, why not gravity?

==Research efforts==
===US government===
The US military and government agencies have pursued a lot of crazy ideas ([[MKULTRA]], [[Project Stargate]], etc), often in conjunction with private contractors. In the 1950s, there seemed to be particular interest in anti-gravity, with physicist Louis Witten conducting research at the Research Institute for Advanced Studies<ref group="note">Not to be confused with the {{wpl|Institute for Advanced Study|Institute for Advanced Study}}, sometime academic home of preeminent scholars [[Einstein]], [[Oppenheimer]] and John von Neumann ''et al''.</ref> for aviation firm Glenn L. Martin Company (later part of Lockheed Martin).<ref name=warzone/>

NASA's {{wpl|Breakthrough Propulsion Physics Program}} from 1996-2002 investigated a variety of outlandish ideas for space travel.

===Gravity Research Foundation===
{{main|Gravity Research Foundation}}
Founded by Roger Babson in 1948, this was one of the most serious attempts at defying gravity, although it later moved into more conventional scientific research.

===Rumors===
There are rumors of other research efforts. A secret base at [[Area 51]] was allegedly disassembling UFOs for the US government and figuring out how they flew; we can safely assume that is nonsense.

There is talk about Edward Teller, the slightly sinister physicist best known for the [[hydrogen bomb]] and considered one of the influences for Stanley Kubrick's [[Dr Strangelove]].<ref>[https://www.theguardian.com/science/2004/apr/01/science.research1 Meet the real Dr Strangelove], Peter Goodchild, The Guardian, 1 April 2004</ref> He published a paper on the electrical fields in rapidly rotating insulators, and their relationship to gravity via general relativity.<ref>[https://www.pnas.org/content/pnas/74/7/2664.full.pdf Electromagnetism and gravitation], Edward Teller, Proc. Nati. Acad. Sci. USA, Vol. 74, No. 7, pp. 2664-2666, July 1977</ref> Because of this (which sounds like some of the anti-gravity devices already mentioned) and because of his status as a prominent figure in [[Cold War]] physics, it is rumored he was involved in anti-gravity research, although discussion seems restricted to more [[fringe]] sites such as ExoPolitics, so it might be taken with a pinch of salt.<ref>[https://exopolitics.org/secret-australian-antigravity-program-linked-to-1966-flying-saucer-landing/ Secret Australian Antigravity Program Linked to 1966 Flying Saucer Landing], ExoPolitics, July 11, 2016</ref>

==Tricks and mistakes==
Inventors of anti-gravity machines often fall into two categories: [[crank]]s who deceive themselves and fraudsters who deceive others. It is easy to convince oneself that one is changing the weight of an object, particularly since demonstrated effects tend to be very small: things like vibration or magnetic fields can affect the performance of scales, leading to incorrect readings even if great care is taken. This is often suggested as an explanation in anomalous gyroscope experiments.<ref name=ns1990/> In theory, even slightly reducing an object's weight would be impressive, but in practice, small changes in measurement make it more difficult to control for sources of error that affect the result. As with perpetual motion machines, energy can be added to a system either surreptitiously or accidentally.

==In fiction==
* HG Wells invented Cavorite, which blocks gravity in ''The First Men in the Moon''
* James Blish wrote about the {{wpl|Spindizzy (Cities in Flight)|Spindizzy}} in several science fiction books

==See also==
*[[Otis T. Carr]]
*[[John Hutchison]]
*[[Levitation]]
*[[Moscovium]]
*[[Nazi UFOs]]

==External links==

*{{wpl|Salvatore Pais}}
*{{wpl|United States gravity control propulsion research}}

==Notes==
{{reflist|group=note}}

==References==
{{reflist|2|80%}}

[[Category:Aircraft]]
[[Category:Pseudophysics]]
[[Category:Transport]]

Categories: Aircraft, Pseudophysics, Transport