Antimatter 1317 226179955 2008-07-17T05:06:47Z 72.219.203.145 /* Fuel */ {{otheruses}} {{Antimatter}} In [[particle physics]] and [[quantum chemistry]], '''antimatter''' is the extension of the concept of the [[antiparticle]] to [[matter]], where antimatter is composed of antiparticles in the same way that normal matter is composed of particles. For example, an antielectron (a [[positron]], an electron with a positive charge) and an antiproton (a proton with a negative charge) could form an antihydrogen atom in the same way that an electron and a proton form a ''normal matter'' hydrogen atom. Furthermore, mixing matter and antimatter would lead to the annihilation of both in the same way that mixing antiparticles and particles does, thus giving rise to high-energy [[photon]]s ([[gamma ray]]s) or other particle–antiparticle pairs. The particles resulting from matter-antimatter annihilation are endowed with energy equal to the difference between the [[rest mass]] of the products of the annihilation and the rest mass of the original matter-antimatter pair, which is 50% anti-matter (Other 50% are Neutrinos) to energy efficient. Which means that for instance if you had 500 grams of anti-matter and 500 grams of matter it would perfectly make the energy of E=MC<sup>2</sup>(mass in kilograms equaling 1 in this situation). There is considerable speculation both in [[science]] and [[science fiction]] as to why the observable universe is apparently almost entirely matter, whether other places are almost entirely antimatter instead, and what might be possible if antimatter could be harnessed, but at this time the apparent [[asymmetry]] of matter and antimatter in the visible universe is one of the greatest [[unsolved problems in physics]]. The process of developing particles and antiparticles is called [[baryogenesis]]. ==Notation== One way to denote an antiparticle is by adding a bar (or [[macron]]) over the particle's symbol. For example, the proton and antiproton are denoted as p and <span style="text-decoration: overline">p</span>, respectively. The same rule applies if you were to address a particle by its constituent components. A proton is made up of u&thinsp;u&thinsp;d [[quark]]s, so an antiproton must therefore be formed from <span style="text-decoration: overline">u</span>&thinsp;<span style="text-decoration: overline">u</span>&thinsp;<span style="text-decoration: overline">d</span> [[quark#Antiquarks|antiquark]]s. Another convention is to distinguish particles by their [[electric charge]]. Thus, the electron and positron are denoted simply as e<sup>−</sup> and e<sup>+</sup> respectively. ==Origin (Naturally occurring production)== ===Asymmetry=== Most objects observable from the Earth seem to be built of matter rather than antimatter. There is no current reasoning over why matter prevailed over antimatter, but many believe it was the result of asymmetry, and some scientists believe that the ratio of this asymmetry was a billion antimatter particles to a billion and one matter particles<ref>{{cite web |last=Sather |first=Eric |year=1999 |title=The Mystery of the Matter Asymmetry | url=http://www.slac.stanford.edu/pubs/beamline/26/1/26-1-sather.pdf }}</ref>. Antiparticles are created everywhere in the [[universe]] where high-energy particle collisions take place. High-energy [[cosmic ray]]s impacting Earth's atmosphere (or any other matter in the [[solar system]]) produce minute quantities of antimatter in the resulting [[particle jet]]s, which are immediately annihilated by contact with nearby matter. It may similarly be produced in regions like the center of the [[Milky Way Galaxy]] and other galaxies, where very energetic celestial events occur (principally the interaction of [[relativistic jet]]s with the interstellar medium). The presence of the resulting antimatter is detectable by the [[gamma ray]]s produced when [[positron]]s annihilate with nearby matter. The gamma rays' frequency and wavelength indicate that each carries 511 [[electronvolt|keV]] of energy (i.e. the [[rest mass]] of an [[electron]] or positron multiplied by [[speed of light|c]]<sup>2</sup>). Recent observations by the European Space Agency’s INTEGRAL (International Gamma-Ray Astrophysics Laboratory) satellite may explain the origin of a giant cloud of antimatter surrounding the galactic center. The observations show that the cloud is asymmetrical and matches the pattern of [[X-ray binaries]], [[binary star]] systems containing black holes or neutron stars, mostly on one side of the galactic center. While the mechanism is not fully understood, it is likely to involve the production of electron-positron pairs, as ordinary matter gains tremendous energy while falling into a stellar remnant.<ref>{{cite web|accessdate=2008-05-24|url=http://www.esa.int/esaCP/SEMKTX2MDAF_index_0.html|title=Integral discovers the galaxy’s antimatter cloud is lopsided|publisher=[[European Space Agency]]}}</ref><ref>{{cite journal |last=Weidenspointner |first=Georg |year=2008 |title=An asymmetric distribution of positrons in the Galactic disk revealed by &gamma;-rays |journal=[[Nature (journal)|Nature]] |volume=451 |pages=159–162 |doi=10.1038/nature06490 }}</ref> ==Artificial production== Antiparticles are also produced in any environment with a sufficiently high temperature (mean particle energy greater than the [[pair production]] threshold). During the period of [[baryogenesis]], when the universe was extremely hot and dense, matter and antimatter were continually produced and annihilated. The presence of remaining matter, and absence of detectable remaining antimatter,<ref>{{cite web|accessdate=2008-05-24|url=http://science.nasa.gov/headlines/y2000/ast29may_1m.htm|title=What's the Matter with Antimatter?|publisher=[[NASA]]}}</ref> also called [[baryon asymmetry]], is attributed to [[CP-violation|violation]] of the [[CP-symmetry]] relating matter and antimatter. The exact mechanism of this violation during baryogenesis remains a mystery. Positrons are also produced via the radioactive [[Beta decay|beta<sup>+</sup> decay]], but this mechanism can be considered as "natural" as well as "artificial". ===Antihydrogen=== In 1995 [[CERN]] announced that it had successfully created nine antihydrogen atoms by implementing the SLAC/[[Fermilab]] concept during the [[PS210 experiment]]. The experiment was performed using the Low Energy Antiproton Ring (LEAR), and was led by Walter Oelert and Mario Macri. Fermilab soon confirmed the [[CERN]] findings by producing approximately 100 antihydrogen atoms at their facilities. The antihydrogen atoms created during PS210, and subsequent experiments (at both [[CERN]] and Fermilab) were extremely energetic ("hot") and were not well suited to study. To resolve this hurdle, and to gain a better understanding of antihydrogen, two collaborations were formed in the late 1990s — [[ATHENA]] and [[ATRAP]]. In 2005, ATHENA disbanded and some of the former members (along with others) formed the [[ALPHA Collaboration]], which is also situated at CERN. The primary goal of these collaborations is the creation of less energetic ("cold") antihydrogen, better suited to study. In 1999 [[CERN]] activated the [[Antiproton Decelerator]], a device capable of decelerating antiprotons from 3.5&nbsp;[[GeV]] to 5.3&nbsp;[[MeV]] — still too "hot" to produce study-effective antihydrogen, but a huge leap forward. In late 2002 the ATHENA project announced that they had created the world's first "cold" antihydrogen. The antiprotons used in the experiment were cooled sufficiently by decelerating them (using the Antiproton Decelerator), passing them through a thin sheet of foil, and finally capturing them in a [[Penning trap]]. The antiprotons also underwent [[stochastic cooling]] at several stages during the process. The ATHENA team's antiproton cooling process is effective, but highly inefficient. Approximately 25 million antiprotons leave the Antiproton Decelerator; roughly 10 thousand make it to the Penning trap. In early 2004 ATHENA researchers released data on a new method of creating low-energy antihydrogen. The technique involves slowing antiprotons using the Antiproton Decelerator, and injecting them into a [[Penning trap]] (specifically a Penning-Malmberg trap{{Fact|date=May 2008}}). Once trapped the antiprotons are mixed with electrons that have been cooled to an energy potential significantly less than the antiprotons; the resulting [[Coulomb potential|Coulomb]] collisions cool the antiprotons while warming the electrons until the particles reach an equilibrium of approximately 4&nbsp;K. While the antiprotons are being cooled in the first trap, a small cloud of positron [[plasma (physics)|plasma]] is injected into a second trap (the mixing trap). Exciting the [[resonance]] of the mixing trap’s confinement fields can control the temperature of the positron plasma; but the procedure is more effective when the plasma is in thermal equilibrium with the trap’s environment. The positron plasma cloud is generated in a positron accumulator prior to injection; the source of the positrons is usually radioactive sodium. Once the antiprotons are sufficiently cooled, the antiproton-electron mixture is transferred into the mixing trap (containing the positrons). The electrons are subsequently removed by a series of fast pulses in the mixing trap's electrical field. When the antiprotons reach the positron plasma further Coulomb collisions occur, resulting in further cooling of the antiprotons. When the positrons and antiprotons approach thermal equilibrium antihydrogen atoms begin to form. Being electrically neutral the antihydrogen atoms are not affected by the trap and can leave the confinement fields. Using this method ATHENA researchers predict they will be able to create up to 100 antihydrogen atoms per operational second. ATHENA and ATRAP are now seeking to further cool the antihydrogen atoms by subjecting them to an inhomogeneous field. While antihydrogen atoms are electrically neutral, their spin produces [[magnetic moment]]s. These magnetic moments vary depending on the spin direction of the atom, and can be deflected by inhomogeneous fields regardless of electrical charge. The biggest limiting factor in the production of antimatter is the availability of antiprotons. Recent data released by [[CERN]] states that when fully operational their facilities are capable of producing 10<sup>7</sup> antiprotons per second.{{Fact|date=May 2008}} Assuming an optimal conversion of antiprotons to antihydrogen, it would take two billion years to produce 1 gram of antihydrogen (approximately 6.02×10<sup>23</sup> atoms of antihydrogen.) Another limiting factor to antimatter production is storage. As stated above there is no known way to effectively store antihydrogen. The ATHENA project has managed to keep antihydrogen atoms from annihilation for tens of seconds — just enough time to briefly study their behaviour. Hydrogen atoms are simplest objects, that can be considered as "matter" rather than as just particles. Simultaneous trapping of antiprotons and antielectrons was reported<ref name="both">{{cite journal|title=The ingredients of cold antihydrogen: Simultaneous confinement of antiprotons and positrons at 4 K|author= Gabrielse, G.|coauthors= Hall, D. S.; Roach, T.; Yesley, P.; Khabbaz, A.; Estrada, J.; Heimann, C.; Kalinowsky, H.|journal=Physics Letters B|volume=455|issue= 1–4|year=1999|pages = 311–315|doi=10.1016/S0370-2693(99)00453-0 |url=http://www.freepatentsonline.com/6163587.html}}</ref> and the cooling is achieved;<ref name="cool-H">{{cite journal|author= Andresen, G.|title=Antimatter Plasmas in a Multipole Trap for Antihydrogen|journal=[[Physical Review Letters|PRL]]|volume= 98|pages= 023402 |year=2007 |url=http://scitation.aip.org/error/cookies.jsp?url=http%3a//scitation.aip.org/getabs/servlet/GetabsServlet%3fprog=normal%26id=PRLTAO000098000002023402000001%26idtype=cvips%26gifs=yes|doi=10.1103/PhysRevLett.98.023402}}</ref> there are patents on the way of production of antihydrogen.<ref name="US6163587">{{cite journal|title = Process for the production of antihydrogen|journal=[[United States Patent and Trademark Office]]|volume= 6163587|author = Arthur, Hessels Eric|date = December 2000|url =http://www.freepatentsonline.com/6163587.html}}</ref> ===Antihelium=== A small number of nuclei of the antihelium isotope, <math>\overline{\mathrm{^3He}}</math> have been created in collision experiments.<ref>{{cite journal |last=Arsenescu |first=R. |year=2003 |title=Antihelium-3 production in lead-lead collisions at 158 ''A'' GeV/''c'' |journal=[[New Journal of Physics]] |volume=5 |pages=1 |doi=10.1088/1367–2630/5/1/301 |doi_brokendate=2008-06-24 }}</ref> ===Preservation=== <!--===Antimatter trap===!--> Antimatter cannot be stored in a container made of ordinary matter because antimatter reacts with any matter it touches, annihilating itself and the container. Antimatter that is composed of [[charged particle]]s can be contained by a combination of an [[electric field]] and a [[magnetic field]] in a device known as a [[Penning trap]]. This device cannot, however, contain antimatter that consists of uncharged particles, and [[atomic trap]]s are used. In particular, such a trap may use the [[dipole]] moment ([[Electric dipole moment|electrical]] or [[Magnetic moment|magnetic]]) of the trapped particles; at high vacuum, the matter or anti-matter particles can be trapped (suspended) and cooled with slightly off-resonant laser radiation (see, for, example, [[magneto-optical trap]] and [[Magnetic trap (atoms)|Magnetic trap]]). Small particles can be also suspended by just intensive optical beam in the [[optical tweezers]]. ===Cost=== Antimatter is said to be the most expensive substance in existence, with an estimated cost of $300 billion per milligram. This is because production is difficult (only a few atoms are produced in reactions in particle accelerators), and because there is higher demand for the other uses of particle accelerators. According to CERN, it has cost a few hundred million Swiss Francs to produce about 1 billionth of a gram.<ref>{{cite web|accessdate=2008-05-24|url=http://livefromcern.web.cern.ch/livefromcern/antimatter/FAQ1.html|title=Questions & Answers|publisher=[[CERN]]}}</ref> Several [[NASA Institute for Advanced Concepts]]-funded studies are exploring whether it might be possible to use magnetic scoops to collect the antimatter that occurs naturally in the [[Van Allen belt]]s of Earth, and ultimately, the belts of gas giants like [[Jupiter]], hopefully at a lower cost per gram.<ref>{{cite web|accessdate=2008-05-24|url=http://www.niac.usra.edu/files/studies/abstracts/1071Bickford.pdf|title=Extraction of Antiparticles Concentrated in Planetary Magnetic Fields|publisher=[[NASA]]}}</ref> ==Uses== ===Medical=== Antimatter-matter reactions have practical applications in medical imaging, such as [[positron emission tomography]] (PET). In positive [[beta decay]], a [[nuclide]] loses surplus positive charge by emitting a positron (in the same event, a proton becomes a neutron, and [[neutrino]]s are also given off). Nuclides with surplus positive charge are easily made in a [[cyclotron]] and are widely generated for medical use. ===Fuel===<!-- This section is linked from [[Deuterium]] --> In antimatter-matter collisions resulting in [[photon]] emission, the entire [[rest mass]] of the particles is converted to [[kinetic energy]]. The [[energy density|energy per unit mass]] (9×10<sup>16</sup> J/kg) is about 10 [[order of magnitude|orders of magnitude]] greater than [[chemical energy]] (compared to [[trinitrotoluene|TNT]] at 4.2×10<sup>6</sup> J/kg, and [[heat of formation|formation]] of [[water]] at 1.56×10<sup>7</sup> J/kg), about 4 orders of magnitude greater than [[nuclear energy]] that can be liberated today using [[nuclear fission]] (about 40 [[MeV]] per [[Uranium|<sup>238</sup>U]] nucleus transmuted to [[Lead]], or 1.5×10<sup>13</sup> J/kg), and about 2 orders of magnitude greater than the best possible from [[nuclear fusion|fusion]] (about 6.3×10<sup>14</sup> J/kg for the [[proton-proton chain reaction|proton-proton chain]]). The reaction of 1&nbsp;[[kilogram|kg]] of antimatter with 1&nbsp;kg of matter would produce 1.8×10<sup>17</sup>&nbsp;[[joule|J]] (180 petajoules) of energy (by the [[mass-energy equivalence]] formula ''E'' = ''mc''²), or the rough equivalent of 47 megatons of TNT. For comparison, [[Tsar Bomba]], the largest [[nuclear weapon]] ever detonated produced an estimated 57 Mt and was capable of over 100Mt, but utilized hundreds of kgs of fissile material. Not all of that energy can be utilized by any realistic technology, because as much as 50% of energy produced in reactions between nucleons and antinucleons is carried away by [[neutrino]]s, so, for all intents and purposes, it can be considered lost.<ref>{{cite web|accessdate=2008-05-24|url=http://gltrs.grc.nasa.gov/reports/1996/TM-107030.pdf|title=Comparison of Fusion/Antiproton Propulsion systems|publisher=[[NASA]]}}</ref> The scarcity of antimatter means that it is not readily available to be used as fuel, although it could be used in [[antimatter catalyzed nuclear pulse propulsion]]. Generating a single antiproton is immensely difficult and requires particle accelerators and vast amounts of energy—millions of times more than is released after it is annihilated with ordinary matter, due to inefficiencies in the process. Known methods of producing antimatter from energy also produce an equal amount of normal matter, so the theoretical limit is that half of the input energy is converted to antimatter. Counterbalancing this, when antimatter annihilates with ordinary matter, energy equal to twice the mass of the antimatter is liberated—so energy storage in the form of antimatter could (in theory) be 100% efficient. Antimatter production is currently very limited, but has been growing at a nearly geometric rate since the discovery of the first antiproton in 1955 by Segrè and Chamberlain.{{Fact|date=July 2007}} The current antimatter production rate is between 1 and 10 nanograms per year, and this is expected to increase to between 3 and 30 nanograms per year by 2015 or 2020 with new superconducting linear accelerator facilities at [[CERN]] and [[Fermilab]]. Some researchers claim that with current technology, it is possible to obtain antimatter for [[United States dollar|US$]]25 million per gram by optimizing the collision and collection parameters (given current electricity generation costs). Antimatter production costs, in mass production, are almost linearly tied in with electricity costs, so economical pure-antimatter thrust applications are unlikely to come online without the advent of such technologies as [[deuterium]]-tritium [[fusion power]] (assuming that such a power source actually would prove to be cheap). Many experts, however, dispute these claims as being far too optimistic by many orders of magnitude. They point out that in 2004; the annual production of antiprotons at [[CERN]] was several picograms at a cost of $20 million. This means to produce 1 gram of antimatter, [[CERN]] would need to spend 100 quadrillion dollars and run the antimatter factory for 100 billion years. Storage is another problem, as antiprotons are negatively charged and repel against each other, so that they cannot be concentrated in a small volume. [[Plasma oscillation]]s in the charged cloud of antiprotons can cause instabilities that drive antiprotons out of the storage trap. For these reasons, to date only a few million antiprotons have been stored simultaneously in a magnetic trap, which corresponds to much less than a femtogram. Antihydrogen atoms or molecules are neutral so in principle they do not suffer the plasma problems of antiprotons described above. But cold antihydrogen is far more difficult to produce than antiprotons, and so far not a single antihydrogen atom has been trapped in a magnetic field. Since the energy density is vastly higher than these other forms, the thrust to weight equation used in [[antimatter rocket]]ry and [[spacecraft]] would be very different. In fact, the energy in a few grams of antimatter is enough to transport an unmanned spacecraft to [[Mars]] in a few minutes. In comparison, the [[Mars Global Surveyor]] took eleven months to reach Mars using conventional means. It is hoped that antimatter could be used as [[fuel]] for [[interplanetary travel]] or possibly [[interstellar travel]], but it is also feared that, as a side-effect of antimatter propulsion, the design of [[antimatter weapon]]s might become an equal reality. One researcher of the [[CERN]] laboratories, which produces antimatter on a regular basis, said: {{cquote|If we could assemble all of the antimatter we've ever made at [[CERN]] and annihilate it with matter, we would have enough energy to light a single electric light bulb for a few minutes.<ref>{{cite web|accessdate=2008-05-24|url=http://public.web.cern.ch/public/en/Spotlight/SpotlightAandD-en.html|title=Angels and Demons|publisher=[[CERN]]}}</ref>}} ==Antimatter in fiction== {{Trivia|date=June 2008}} Existence of anti-particles is more "sci-" than "fiction" .<ref>{{cite journal |author= Overbye, D. |title= Physicists' Antimatter Recipe Is More Sci- Than Fi |journal=[[The New York Times]] |date=[[2008-05-07]] |url=http://query.nytimes.com/gst/fullpage.html?res=9B0CE1D71330F93AA2575AC0A9649C8B63 }} </ref> However, until now, the ''anti-world'', or even macroscopic amounts of antimatter exist rather in jokes and sci-fi novels, than in laboratories. One of these novels is Dan Brown's "Angels and Demons" in which the whole story centers around production of antimatter at the CERN facility and its possible use in terrorism because of the awesome power of an annihilation. ===Pop culture=== The 1960s hit television show [[The Man from U.N.C.L.E.]] dealt with the potential of antimatter in an episode called The Suburbia Affair. Pianist and comedian [[Victor Borge]] played a pianist and scientist who had come up with a formula for antimatter and, fearing its destructive potential, hid in a bizarre suburban development populated by single adults and couples who hate children. Borge's character, Dr. Rutter, disguised his formula in a dissonant piece of music until forced to reveal it to the evil organization, ''THRUSH'' (Technological Hierarchy for the Removal of Undesirables and Subjugation of Humanity). The good guys, Illya Kuryakin and Napoleon Solo, arrive to save the day and, after a plea from the wounded Rutter, destroy the computer where the antimatter formula has been stored. In another 20 years, Rutter warns, someone else will come up with the formula. ===Military=== Because of its potential to release immense amounts of energy in contact with normal matter, there has been interest in various [[antimatter weapon|weapon uses]], potentially enabling miniature warheads of pinhead-size to be more destructive than modern-day [[nuclear weapon]]s. An antimatter particle colliding with a matter particle releases 100% of the energy contained within the particles, while a hydrogen bomb only releases about 0.7% of this energy. This gives a clue to how effective and powerful this force is. However, this development is still in early planning stages, though antimatter weapons are popular in [[science fiction]] such as in [[Peter F. Hamilton]]'s ''[[Night's Dawn Trilogy]]'' , [[Dan Brown]]'s ''[[Angels and Demons]]'' and [[Star Trek]] where the production of antimatter leads to the possibility of use as both a fuel and highly effective weapon. At the moment, the traps are not very efficient, and <!-- the technology permits us to store only a few particles at a time, making 10^6 particles in atomic tap - it is not "few" !--> it is more constructive to just create all the antimatter at the moment it would be used. ===Cartoons=== In the Scott Adams's Dilbert cartoon strip from June 30 2008, Dilbert creates an anti Dilbert using a particle accelerator. However, Alice throws a cup of coffee on to him, thus destroying his "matterscreen," and he is destroyed.<ref name="Dilbert">{{cite web|accessdate=2008-06-30|url=http://dilbert.com/strips/comic/2008-06-30/|title=Dilbert Strip from June 30 2008}}</ref> ===Stanisław Lem=== [[Image:St Lem resize.jpg|100px|right|thumb|[[Stanisław Lem]]]] In the novel [[The Cyberiad]], [[Stanisław Lem]] describes the building up the antimatter in the following way:<ref name="Cyberiad">{{cite web|accessdate=2008-05-24|url=http://www.lem.pl/cyberiadinfo/english/dziela/cyberiada/cyberiadapl.htm|title=How The World Was Saved|publisher=[[The Cyberiad]]}}</ref> *The machine, however, had already begun. First it manufactured antiprotons, then antielectrons, antineutrons, antineutrinos, and labored on, until from out of all this antimatter an antiworld took shape, .. In another novel, [[The Invincible]] ,<ref name="invincible"> {{cite book |author= Lem, Stanisław |title=Invincible |publisher=[[Penguin Books]] |isbn=0140038531 |url=http://www.rpi.edu/~sofkam/lem/ |year=1976 }}</ref> the researchers fail to fight the self-organizing microrobots, even though they use antimatter as a weapon.<br /> In the novel [[Eden (novel)|Eden]] ,<ref name="eden"> {{cite book |author= Lem, Stanisław |title=Eden |year=1959 |location=[[Kraków]] |publisher= Wydawn. Literackie |isbn=8308029973 |url=http://lccn.loc.gov/%20%20%2000270136 }}</ref> humans use antimatter as a weapon, but it does not help them to understand anything about the civilization they met. ==See also== *[[Ambiplasma]] *[[Particle accelerator]] *[[Antiparticle]] *[[antihydrogen]] ==References== {{reflist|2}} ==External links== * [http://www.anti-matter.org/ Links to top sites on AntiMatter] * [http://www.vega.org.uk/video/programme/14 Freeview Video 'Antimatter' by the Vega Science Trust and the BBC/OU] * [http://livefromcern.web.cern.ch/livefromcern/antimatter/webcast/AM-webcast06.html CERN Webcasts (Realplayer required)] * [http://www.positron.edu.au/faq.html What is Antimatter?] (from the Frequently Asked Questions at the Center for Antimatter-Matter Studies) * [http://public.web.cern.ch/public/en/Spotlight/SpotlightAandD-en.html FAQ from CERN] with lots of information about antimatter aimed at the general reader, posted in response to antimatter's fictional portrayal in [[Angels and Demons]] *[http://www2.slac.stanford.edu/tip/special/cp.htm What is direct CP-violation?]'' * [http://www.exploratorium.edu/origins/cern/tools/animation.html Animated illustration of antihydrogen production at CERN] from the [[Exploratorium]]. * [http://blog.wired.com/wiredscience/2008/01/mystery-of-anti.html Mystery of antimatter source solved - Maybe] [[Category:Antimatter]] [[Category:Duality theories]] [[Category:Matter]] [[Category:Particle physics]] [[Category:Physics in fiction]] [[Category:Quantum field theory]] [[ar:مادة مضادة]] [[az:Antimaddə]] [[bn:প্রতিপদার্থ]] [[bs:Antimaterija]] [[bg:Антиматерия]] [[ca:Antimatèria]] [[cs:Antihmota]] [[da:Antistof (fysik)]] [[de:Antimaterie]] [[el:Αντιύλη]] [[es:Antimateria]] [[eo:Antimaterio]] [[fa:ضدماده]] [[fr:Antimatière]] [[gl:Antimateria]] [[ko:반물질]] [[hr:Antimaterija]] [[id:Antimateri]] [[it:Antimateria]] [[he:אנטי-חומר]] [[lt:Antimedžiaga]] [[hu:Antianyag]] [[nl:Antimaterie]] [[ja:反物質]] [[no:Antimaterie]] [[oc:Antimatèria]] [[pl:Antymateria]] [[pt:Antimatéria]] [[ro:Antimaterie]] [[ru:Антивещество]] [[sq:Kundërlënda]] [[simple:Antimatter]] [[sk:Antihmota]] [[sl:Antimaterija]] [[sr:Антиматерија]] [[sh:Antimaterija]] [[fi:Antimateria]] [[sv:Antimateria]] [[vi:Phản vật chất]] [[tr:Antimadde]] [[uk:Антиматерія]] [[ur:ضد مادہ]] [[zh:反物质]]