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Annales school

The Annales school is a group of historians associated with a style of historiography developed by French historians in the 20th century to stress long-term social history. It is named after its scholarly journal Annales. Histoire, Sciences Sociales, which remains the main source of scholarship, along with many books and monographs. The school has been influential in setting the agenda for historiography in France and numerous other countries, especially regarding the use of social scientific methods by historians, emphasizing social and economic rather than political or diplomatic themes.

The school deals primarily with late medieval and early modern Europe (before the French Revolution), with little interest in later topics. It has dominated French social history and heavily influenced historiography in Europe and Latin America. Prominent leaders include co-founders Lucien Febvre (1878–1956), Henri Hauser (1866–1946) and Marc Bloch (1886–1944). The second generation was led by Fernand Braudel (1902–1985) and included Georges Duby (1919–1996), Pierre Goubert (1915–2012), Robert Mandrou (1921–1984), Pierre Chaunu (1923–2009), Jacques Le Goff (1924–2014), and Ernest Labrousse (1895–1988). Institutionally it is based on the Annales journal, the SEVPEN publishing house, the Fondation Maison des sciences de l'homme (FMSH), and especially the 6th Section of the École pratique des hautes études, all based in Paris. A third generation was led by Emmanuel Le Roy Ladurie (1929–2023) and includes Jacques Revel, and Philippe Ariès (1914–1984), who joined the group in 1978. The third generation stressed history from the point of view of mentalities, or mentalités. The fourth generation of Annales historians, led by Roger Chartier (born 1945), clearly distanced itself from the mentalités approach, replaced by the cultural and linguistic turn, which emphasizes the social history of cultural practices.

The main scholarly outlet has been the journal Annales d'Histoire Economique et Sociale ("Annals of Economic and Social History"), founded in 1929 by Lucien Febvre and Marc Bloch, which broke radically with traditional historiography by insisting on the importance of taking all levels of society into consideration and emphasized the collective nature of mentalities. Its contributors viewed events as less fundamental than the mental frameworks that shaped decisions and practices. However, informal successor as head of the school was Le Roy Ladurie. Multiple responses were attempted by the school. Scholars moved in multiple directions, covering in disconnected fashion the social, economic, and cultural history of different eras and different parts of the globe. By the time of crisis the school was building a vast publishing and research network reaching across France, Europe, and the rest of the world. Influence indeed spread out from Paris, but few new ideas came in. Much emphasis was given to quantitative data, seen as the key to unlocking all of social history. However, the Annales ignored the developments in quantitative studies underway in the U.S. and Britain, which reshaped economic, political, and demographic research. An attempt to require an Annales-written textbook for French schools was rejected by the government. By 1980 postmodern sensibilities undercut confidence in overarching metanarratives. As Jacques Revel notes, the success of the Annales school, especially its use of social structures as explanatory forces, contained the seeds of its own downfall, for there is "no longer any implicit consensus on which to base the unity of the social, identified with the real". The Annales school kept its infrastructure, but lost its mentalités.

The journal
The journal began in Strasbourg as Annales d'histoire économique et sociale; it moved to Paris and kept the same name from 1929 to 1939. It was successively renamed Annales d'histoire sociale (1939–1942, 1945), Mélanges d'histoire sociale (1942–1944), Annales. Economies, sociétés, civilisations (1946–1994), and Annales. Histoire, Sciences Sociales (1994– ).

In 1962, Braudel and Gaston Berger used Ford Foundation money and government funds to create a new independent foundation, the Fondation Maison des sciences de l'homme (FMSH), which Braudel directed from 1970 until his death. In 1970, the 6th Section and the Annales relocated to the FMSH building. FMSH set up elaborate international networks to spread the Annales gospel across Europe and the world. In 2013, it began publication of an English language edition, with all the articles translated.

The scope of topics covered by the journal is vast and experimental—there is a search for total history and new approaches. The emphasis is on social history, and very long-term trends, often using quantification and paying special attention to geography and to the intellectual world view of common people, or "mentality" (mentalité). Little attention is paid to political, diplomatic, or military history, or to biographies of famous men. Instead the Annales focused attention on the synthesizing of historical patterns identified from social, economic, and cultural history, statistics, medical reports, family studies, and even psychoanalysis.

Origins
The Annales was founded and edited by Marc Bloch and Lucien Febvre in 1929, while they were teaching at the University of Strasbourg and later in Paris. These authors, the former a medieval historian and the latter an early modernist, quickly became associated with the distinctive Annales approach, which combined geography, history, and the sociological approaches of the Année Sociologique (many members of which were their colleagues at Strasbourg) to produce an approach which rejected the predominant emphasis on politics, diplomacy and war of many 19th and early 20th-century historians as spearheaded by historians whom Febvre called Les Sorbonnistes. Instead, they pioneered an approach to a study of long-term historical structures (la longue durée) over events and political transformations. Geography, material culture, and what later Annalistes called mentalités, or the psychology of the epoch, are also characteristic areas of study. The goal of the Annales was to undo the work of the Sorbonnistes, to turn French historians away from the narrowly political and diplomatic toward the new vistas in social and economic history.

Co-founder Marc Bloch (1886–1944) was a quintessential modernist who studied at the elite École Normale Supérieure, and in Germany, serving as a professor at the University of Strasbourg until he was called to the Sorbonne in Paris in 1936 as professor of economic history. Bloch's interests were highly interdisciplinary, influenced by the geography of Paul Vidal de la Blache (1845–1918) and the sociology of Émile Durkheim (1858–1917). His own ideas, especially those expressed in his masterworks, French Rural History (Les caractères originaux de l'histoire rurale française, 1931) and Feudal Society, were incorporated by the second-generation Annalistes, led by Fernand Braudel.

Precepts
Georges Duby, a leader of the school, wrote that the history he taught:
 * relegated the sensational to the sidelines and was reluctant to give a simple accounting of events, but strove on the contrary to pose and solve problems and, neglecting surface disturbances, to observe the long and medium-term evolution of economy, society and civilisation.

The Annalistes, especially Lucien Febvre, advocated a histoire totale, or histoire tout court, a complete study of a historic problem.

Postwar
Bloch was shot by the Gestapo during the German occupation of France in World War II for his active membership of the French Resistance, and Febvre carried on the Annales approach in the 1940s and 1950s. It was during this time that he mentored Braudel, who would become one of the best-known exponents of this school. Braudel's work came to define a "second" era of Annales historiography and was influential throughout the 1960s and 1970s, especially for his work on the Mediterranean region in the era of Philip II of Spain. Braudel developed the idea, often associated with Annalistes, of different modes of historical time: l'histoire quasi immobile (the quasi motionless history) of historical geography, the history of social, political and economic structures (la longue durée), and the history of men and events, in the context of their structures.

While authors such as Emmanuel Le Roy Ladurie, Marc Ferro and Jacques Le Goff continue to carry the Annales banner, today the Annales approach has been less distinctive as more and more historians do work in cultural history, political history and economic history.

Mentalités
Bloch's Les Rois thaumaturges (1924) looked at the long-standing folk belief that the king could cure scrofula by his thaumaturgic touch. The kings of France and England indeed regularly practiced the ritual. Bloch was not concerned with the effectiveness of the royal touch—he acted instead like an anthropologist in asking why people believed it and how it shaped relations between king and commoner. The book was highly influential in introducing comparative studies (in this case France and England), as well as long durations ("longue durée") studies spanning several centuries, even up to a thousand years, downplaying short-term events. Bloch's revolutionary charting of mentalities, or mentalités, resonated with scholars who were reading Freud and Proust. In the 1960s, Robert Mandrou and Georges Duby harmonized the concept of mentalité history with Fernand Braudel's structures of historical time and linked mentalities with changing social conditions. A flood of mentalité studies based on these approaches appeared during the 1970s and 1980s. By the 1990s, however, mentalité history had become interdisciplinary to the point of fragmentation, but still lacked a solid theoretical basis. While not explicitly rejecting mentalité history, younger historians increasingly turned to other approaches.

Braudel
Fernand Braudel became the leader of the second generation after 1945. He obtained funding from the Rockefeller Foundation in New York and founded the 6th Section of the Ecole Pratique des Hautes Etudes, which was devoted to the study of history and the social sciences. It became an independent degree-granting institution in 1975 under the name École des Hautes Études en Sciences Sociales (EHESS). Braudel's followers admired his use of the longue durée approach to stress slow, and often imperceptible effects of space, climate and technology on the actions of human beings in the past. The Annales historians, after living through two world wars and incredible political upheavals in France, were deeply uncomfortable with the notion that multiple ruptures and discontinuities created history. They preferred to stress inertia and the longue durée. Special attention was paid to geography, climate, and demography as long-term factors. They believed the continuities of the deepest structures were central to history, beside which upheavals in institutions or the superstructure of social life were of little significance, for history lies beyond the reach of conscious actors, especially the will of revolutionaries. They rejected the Marxist idea that history should be used as a tool to foment and foster revolutions. In turn the Marxists called them conservatives.

Braudel's first book, La Méditerranée et le Monde Méditerranéen à l'Epoque de Philippe II (1949) (The Mediterranean and the Mediterranean World in the Age of Philip II) was his most influential. This vast panoramic view used ideas from other social sciences, employed effectively the technique of the longue durée, and downplayed the importance of specific events and individuals. It stressed geography but not mentalité. It was widely admired, but most historians did not try to replicate it and instead focused on their specialized monographs. The book dramatically raised the worldwide profile of the Annales School.

In 1951, historian Bernard Bailyn published a critique of La Méditerranée et le Monde Méditerranéen à l'Epoque de Philippe II, which he framed as dichotomizing politics and society.

Regionalism
Before Annales, French history supposedly happened in Paris. Febvre broke decisively with this paradigm in 1912, with his sweeping doctoral thesis on Philippe II et la Franche-Comté. The geography and social structure of this region overwhelmed and shaped the king's policies.

The Annales historians did not try to replicate Braudel's vast geographical scope in La Méditerranée. Instead they focused on regions in France over long stretches of time. The most important was the study of the Peasants of Languedoc by Braudel's star pupil and successor Emmanuel Le Roy Ladurie. The regionalist tradition flourished especially in the 1960s and 1970s in the work of Pierre Goubert in 1960 on Beauvais and René Baehrel on Basse-Provence. Annales historians in the 1970s and 1980s turned to urban regions, including Pierre Deyon (Amiens), Maurice Garden (Lyon), Jean-Pierre Bardet (Rouen), Georges Freche (Toulouse), Gregory Hanlon (Agen and Layrac ), and Jean-Claude Perrot (Caen). By the 1970s the shift was underway from the earlier economic history to cultural history and the history of mentalities.

Impact outside France
The Annales school systematically reached out to create an impact on other countries. Its success varied widely. The Annales approach was especially well received in Italy and Poland. Franciszek Bujak (1875–1953) and Jan Rutkowski (1886–1949), the founders of modern economic history in Poland and of the journal Roczniki Dziejów Spolecznych i Gospodarczych (1931– ), were attracted to the innovations of the Annales school. Rutkowski was in contact with Bloch and others, and published in the Annales. After the Communists took control in the 1940s Polish scholars were safer working on the Middle Ages and the early modern era rather than contemporary history. After the "Polish October" of 1956 the Sixth Section in Paris welcomed Polish historians and exchanges between the circle of the Annales and Polish scholars continued until the early 1980s. The reciprocal influence between the French school and Polish historiography was particularly evident in studies on the Middle Ages and the early modern era studied by Braudel.

In South America the Annales approach became popular. From the 1950s Federico Brito Figueroa was the founder of a new Venezuelan historiography based largely on the ideas of the Annales School. Brito Figueroa carried his conception of the field to all levels of university study, emphasizing a systematic and scientific approach to history and placing it squarely in the social sciences. Spanish historiography was influenced by the "Annales School" starting in 1950 with Jaume Vicens Vives (1910–1960). In Mexico, exiled Republican intellectuals extended the Annales approach, particularly from the Center for Historical Studies of El Colegio de México, the leading graduate studies institution of Latin America.

British historians, apart from a few Marxists, were generally hostile. Academic historians decidedly sided with Geoffrey Elton's The Practice of History against Edward Hallett Carr's What Is History? One of the few British historians who were sympathetic towards the work of the Annales school was Hugh Trevor-Roper. American, German, Indian, Russian and Japanese scholars generally ignored the school. The Americans developed their own form of "new social history" from entirely different roots. Both the American and the Annales historians picked up important family reconstitution techniques from French demographer Louis Henry.

The Wageningen school centered on Bernard Slicher van Bath was viewed internationally as a Dutch counterpart of the Annales school, although Slicher van Bath himself vehemently rejected the idea of a quantitative "school" of historiography.

Has been cited as a key influence in the development of World Systems Theory by sociologist Immanuel Wallerstein.

Current
The current leader is Roger Chartier, who is Directeur d'Études at the École des Hautes Études en Sciences Sociales in Paris, Professeur in the Collège de France, and Annenberg Visiting Professor of History at the University of Pennsylvania. He frequently lectures and teaches in the United States, Spain, Mexico, Brazil and Argentina. His work in Early Modern European History focuses on the history of education, the history of the book and the history of reading. Recently, he has been concerned with the relationship between written culture as a whole and literature (particularly theatrical plays) for France, England and Spain. His work in this specific field (based on the criss-crossing between literary criticism, bibliography, and sociocultural history) is connected to broader historiographical and methodological interests which deal with the relation between history and other disciplines: philosophy, sociology, anthropology.

Chartier's typical undergraduate course focuses upon the making, remaking, dissemination, and reading of texts in early modern Europe and America. Under the heading of "practices", his class considers how readers read and marked up their books, forms of note-taking, and the interrelation between reading and writing from copying and translating to composing new texts. Under the heading of "materials", his class examines the relations between different kinds of writing surfaces (including stone, wax, parchment, paper, walls, textiles, the body, and the heart), writing implements (including styluses, pens, pencils, needles, and brushes), and material forms (including scrolls, erasable tables, codices, broadsides and printed forms and books). Under the heading of "places", his class explores where texts were made, read, and listened to, including monasteries, schools and universities, offices of the state, the shops of merchants and booksellers, printing houses, theaters, libraries, studies, and closets. The texts for his course include the Bible, translations of Ovid, Hamlet, Don Quixote, Montaigne's essays, Pepys's diary, Richardson's Pamela, and Franklin's autobiography.

About the School

 * Aurell i Cardona, Jaume. "Autobiographical Texts as Historiographical Sources: Rereading Fernand Braudel and Annie Kriegel", Biography, Volume 29, Number 3, Summer 2006, pp. 425–445 in Project Muse
 * Bintliff, John L. (ed.), The Annales School and archaeology, Leicester : Leicester University Press (1991), ISBN 978-0-7185-1758-8
 * Burguière, André. L'École des Annales: Une histoire intellectuelle. Paris: Odile Jacob. 2006. Pp. 366. (English edition) Annales School: An Intellectual History. Ithaca NY: Cornell University Press. 2009. Pp. 309
 * Burke, Peter. The French Historical Revolution: The Annales School 1929–89, (1990), the major study in English excerpt and text search
 * Carrard, Philippe. "Figuring France: The Numbers and Tropes of Fernand Braudel", Diacritics, Vol. 18, No. 3 (Autumn, 1988), pp. 2–19 in JSTOR
 * Carrard, Philippe. Poetics of the New History: French Historical Discourse from Braudel to Chartier, (1992)
 * Clark, Stuart, ed. The Annales School: Critical Assessments (4 vol, 1999)
 * Crifò, Giuliano. "Scuola delle Annales e storia del diritto: la situazione italiana", Mélanges de l'École française de Rome, antiquité, vol. No. 93, (1981), pp. 483-494 in Persée
 * Dewald, Jonathan. Lost Worlds: The Emergence of French Social History, 1815–1970 (2006) 250pp excerpt and text search
 * Dosse, Francois. New History in France: The Triumph of the Annales, (1994, first French edition, 1987) excerpt and text search
 * Fink, Carole. Marc Bloch: A Life in History, (1989) excerpt and text search
 * Forster, Robert. "Achievements of the Annales School", The Journal of Economic History, Vol. 38, No. 1, (Mar., 1978), pp. 58–76 in JSTOR
 * Friedman, Susan W. Marc Bloch, Sociology and Geography: Encountering Changing Disciplines (1996) excerpt and text search
 * Harris, Olivia. "Braudel: Historical Time and the Horror of Discontinuity", History Workshop Journal, Issue 57, Spring 2004, pp. 161–174 in Project Muse
 * Herubel, Jean-Pierre V. M. "Historiography's Horizon and Imperative: Febvrian Annales Legacy and Library History as Cultural History", Libraries & Culture, 39#3 (2004), pp. 293–312 in Project Muse
 * Hexter, J. H. "Fernand Braudel and the Monde Braudellien", Journal of Modern History, 1972, vol. 44, pp. 480–539 in JSTOR
 * Hufton, Olwen. "Fernand Braudel", Past and Present, No. 112. (Aug., 1986), pp. 208–213. in JSTOR
 * Hunt, Lynn. "French History in the Last Twenty Years: the Rise and Fall of the Annales Paradigm". Journal of Contemporary History 1986 21(2): 209–224. Fulltext: in Jstor
 * Huppert, George. "Lucien Febvre and Marc Bloch: The Creation of the Annales". The French Review 55#4 (1982), pp. 510–513 in JSTOR
 * Iggers, G.G. Historiography in the Twentieth Century: From Scientific Objectivity to the Postmodern Challenge (1997), ch.5
 * Leroux, Robert, Histoire et sociologie en France: de l'histoire-science à la sociologie durkheimienne, Paris, Presses universitaires de France, 1998.
 * Long, Pamela O. "The Annales and the History of Technology", Technology and Culture, 46#1 (2005), pp. 177–186 in Project Muse
 * Megill, Allan. "Coherence and Incoherence in Historical Studies: From the Annales School to the New Cultural History", New Literary History, 35#2 (2004), pp. 207–231 in Project Muse
 * Rubin, Miri. The Work of Jacques Le Goff and the Challenges of Medieval History (1997) 272 pages excerpts and text search
 * Moon, David. "Fernand Braudel and the Annales School" online edition
 * Poirrier, Philippe. Aborder l'histoire, Paris, Seuil, 2000.
 * Roberts, Michael. "The Annales school and historical writing". in Peter Lambert and Phillipp Schofield, eds. Making History: An Introduction to the History and Practices of a Discipline. (2004), pp 78–92 online edition
 * Schilling, Derek. "Everyday Life and the Challenge to History in Postwar France: Braudel, Lefebvre, Certeau", Diacritics, Volume 33, Number 1, Spring 2003, pp. 23–40 in Project Muse
 * Steiner, Frederick. "Material Life: Human Ecology and the Annales School", Landscape Architecture Volume 76, Number 1, pp. 69–75.
 * Stirling, Katherine. "Rereading Marc Bloch: the Life and Works of a Visionary Modernist". History Compass 2007 5#2: 525–538. in History Compass
 * Stoianovich, Traian. French Historical Method: The Annales Paradigm, (1976)
 * Trevor-Roper, H. R. "Fernand Braudel, the Annales, and the Mediterranean", The Journal of Modern History, 44#4 (1972), pp. 468–479 in JSTOR

Major books and essays from the school

 * Ariès, Philippe et al. eds, A History of Private Life (5 vols. 1987–94)
 * Bloch, Marc. Les Rois Thaumaturges (1924), translated as The Royal Touch: Monarchy and Miracles in France and England (1990)
 * Bloch, Marc. Feudal Society: Vol 1: The Growth and Ties of Dependence (1989); Feudal Society: Vol 2: Social Classes and Political Organisation(1989) excerpt and text search
 * Bloch, Marc. French Rural History: An Essay on Its Basic Characteristics (1972)
 * Braudel, Fernand. La Méditerranée et le Monde Méditerranéen à l'Epoque de Philippe II (1949) (translated as The Mediterranean and the Mediterranean World in the Age of Philip II excerpt and text search vol. 1)
 * Braudel, Fernand. Civilisation Matérielle, Economie et Capitalisme XVe–XVIIIe Siècle (3 vol. 1979) (translated as Capitalism and Material Life; excerpt and text search vol. 1; excerpt and text search vol 3)
 * Burguière, André, and Jacques Revel. Histoire de la France (1989), textbook
 * Chartier, Roger. Inscription and Erasure: Literature and Written Culture from the Eleventh to the Eighteenth Century (2007) excerpt and text search
 * Earle, P., ed. Essays in European Economic History, 1500–1800, (1974), translated articles from Annales
 * Ferro, Marc, ed. Social Historians in Contemporary France: Essays from "Annales", (1972)
 * Goubert, Pierre. The French Peasantry in the Seventeenth Century (1986) excerpt and text search
 * Goubert, Pierre. The Ancien Régime, 1600–1750 (1974)
 * Le Roy Ladurie, Emmanuel. Montaillou: Cathars and Catholics in a French Village, 1294–1324 (1978) excerpt and text search
 * Le Roy Ladurie, Emmanuel. The Peasants of Languedoc (1966; English translation 1974) search
 * Hunt, Lynn, and Jacques Revel (eds). Histories: French Constructions of the Past. The New Press. 1994. (A collection of 64 essays with many pieces from the Annales).

Historiography from the school

 * Bloch, Marc. Méthodologie Historique (1988); originally conceived in 1906 but not published until 1988; revised in 1996
 * Bloch, Marc. Apologie pour l'histoire ou Métier d'historien (1949), translated as The Historian's Craft (1953) excerpt of 1992 introduction by Peter Burke (historian), and text search
 * Braudel, Fernand. Ecrits sur l'histoire (1969), reprinted essays; translated as On History, (1980) excerpt and text search
 * includes Braudel, Fernand. "Histoire et Science Sociale: La Longue Durée" (1958) Annales E.S.C., 13:4 October–December 1958, 725–753
 * Braudel, Fernand. "Personal Testimony". Journal of Modern History 1972 44(4): 448–467. in JSTOR
 * Burke, Peter, ed. A New Kind of History From the Writings of Lucien Febvre, (1973)
 * Duby, Georges. History Continues, (1991, translated 1994)
 * Febvre, Lucien. A New Kind of History: From the Writings of Lucien Febvre ed. by Peter Burke (1973) translated articles from Annales
 * Le Roy Ladurie, Emmanuel. The Mind and Method of the Historian (1981)
 * Le Roy Ladurie, Emmanuel. The Territory of the Historian (1979)
 * Le Goff, Jacques and Paul Archambault. "An Interview with Jacques Le Goff". Historical Reflections 1995 21(1): 155–185.
 * Le Goff, Jacques, History and Memory (1996) excerpt and text search
 * Revel, Jacques, and Lynn Hunt, eds. Histories: French Constructions of the Past, (1995). 654pp
 * Revel, Jacques, ed. Political Uses of the Past: The Recent Mediterranean Experiences (2002) excerpt and text search
 * Vovelle, M. Ideologies and Mentalities (1990)

title: Annales school


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Antimatter

In modern physics, antimatter is defined as matter composed of the antiparticles (or "partners") of the corresponding particles in "ordinary" matter, and can be thought of as matter with reversed charge, parity, and time, known as CPT reversal. Antimatter occurs in natural processes like cosmic ray collisions and some types of radioactive decay, but only a tiny fraction of these have successfully been bound together in experiments to form antiatoms. Minuscule numbers of antiparticles can be generated at particle accelerators; however, total artificial production has been only a few nanograms. No macroscopic amount of antimatter has ever been assembled due to the extreme cost and difficulty of production and handling. Nonetheless, antimatter is an essential component of widely available applications related to beta decay, such as positron emission tomography, radiation therapy, and industrial imaging.

In theory, a particle and its antiparticle (for example, a proton and an antiproton) have the same mass, but opposite electric charge, and other differences in quantum numbers.

A collision between any particle and its anti-particle partner leads to their mutual annihilation, giving rise to various proportions of intense photons (gamma rays), neutrinos, and sometimes less-massive particle–antiparticle pairs. The majority of the total energy of annihilation emerges in the form of ionizing radiation. If surrounding matter is present, the energy content of this radiation will be absorbed and converted into other forms of energy, such as heat or light. The amount of energy released is usually proportional to the total mass of the collided matter and antimatter, in accordance with the notable mass–energy equivalence equation, $E=mc^{2}$.

Antiparticles bind with each other to form antimatter, just as ordinary particles bind to form normal matter. For example, a positron (the antiparticle of the electron) and an antiproton (the antiparticle of the proton) can form an antihydrogen atom. The nuclei of antihelium have been artificially produced, albeit with difficulty, and are the most complex anti-nuclei so far observed. Physical principles indicate that complex antimatter atomic nuclei are possible, as well as anti-atoms corresponding to the known chemical elements.

There is strong evidence that the observable universe is composed almost entirely of ordinary matter, as opposed to an equal mixture of matter and antimatter. This asymmetry of matter and antimatter in the visible universe is one of the great unsolved problems in physics. The process by which this inequality between matter and antimatter particles developed is called baryogenesis.

Definitions
Antimatter particles carry the same charge as matter particles, but of opposite sign. That is, an antiproton is negatively charged and an antielectron (positron) is positively charged. Neutrons do not carry a net charge, but their constituent quarks do. Protons and neutrons have a baryon number of +1, while antiprotons and antineutrons have a baryon number of –1. Similarly, electrons have a lepton number of +1, while that of positrons is –1. When a particle and its corresponding antiparticle collide, they are both converted into energy.

The French term led to the initialism "C.T." and the science fiction term, as used in such novels as Seetee Ship.

Conceptual history
The idea of negative matter appears in past theories of matter that have now been abandoned. Using the once popular vortex theory of gravity, the possibility of matter with negative gravity was discussed by William Hicks in the 1880s. Between the 1880s and the 1890s, Karl Pearson proposed the existence of "squirts" and sinks of the flow of aether. The squirts represented normal matter and the sinks represented negative matter. Pearson's theory required a fourth dimension for the aether to flow from and into.

The term antimatter was first used by Arthur Schuster in two rather whimsical letters to Nature in 1898, in which he coined the term. He hypothesized antiatoms, as well as whole antimatter solar systems, and discussed the possibility of matter and antimatter annihilating each other. Schuster's ideas were not a serious theoretical proposal, merely speculation, and like the previous ideas, differed from the modern concept of antimatter in that it possessed negative gravity.

The modern theory of antimatter began in 1928, with a paper by Paul Dirac. Dirac realised that his relativistic version of the Schrödinger wave equation for electrons predicted the possibility of antielectrons. Although Dirac had laid the groundwork for the existence of these “antielectrons” he initially failed to pick up on the implications contained within his own equation. He freely gave the credit for that insight to J. Robert Oppenheimer, whose seminal paper “On the Theory of Electrons and Protons” (Feb 14th 1930) drew on Dirac's equation and argued for the existence of a positively charged electron (a positron), which as a counterpart to the electron should have the same mass as the electron itself. This meant that it could not be, as Dirac had in fact suggested, a proton. Dirac further postulated the existence of antimatter in a 1931 paper which referred to the positron as an "anti-electron". These were discovered by Carl D. Anderson in 1932 and named positrons from "positive electron". Although Dirac did not himself use the term antimatter, its use follows on naturally enough from antielectrons, antiprotons, etc. A complete periodic table of antimatter was envisaged by Charles Janet in 1929.

The Feynman–Stueckelberg interpretation states that antimatter and antiparticles behave exactly identical to regular particles, but traveling backward in time. This concept is nowadays used in modern particle physics, in Feynman diagrams.

Notation
One way to denote an antiparticle is by adding a bar over the particle's symbol. For example, the proton and antiproton are denoted as proton and antiproton, respectively. The same rule applies if one were to address a particle by its constituent components. A proton is made up of Up quark Up quark Down quark quarks, so an antiproton must therefore be formed from Up antiquark Up antiquark Down antiquark antiquarks. Another convention is to distinguish particles by positive and negative electric charge. Thus, the electron and positron are denoted simply as Electron and Positron respectively. To prevent confusion, however, the two conventions are never mixed.

Properties
There is no difference in the gravitational behavior of matter and antimatter. In other words, antimatter falls down when dropped, not up. This was confirmed with the thin, very cold gas of thousands of antihydrogen atoms that were confined in a vertical shaft surrounded by superconducting electromagnetic coils. These can create a magnetic bottle to keep the antimatter from coming into contact with matter and annihilating. The researchers then gradually weakened the magnetic fields and detected the antiatoms using two sensors as they escaped and annihilated. Most of the anti-atoms came out of the bottom opening, and only one-quarter out of the top.

There are compelling theoretical reasons to believe that, aside from the fact that antiparticles have different signs on all charges (such as electric and baryon charges), matter and antimatter have exactly the same properties. This means a particle and its corresponding antiparticle must have identical masses and decay lifetimes (if unstable). It also implies that, for example, a star made up of antimatter (an "antistar") will shine just like an ordinary star. This idea was tested experimentally in 2016 by the ALPHA experiment, which measured the transition between the two lowest energy states of antihydrogen. The results, which are identical to that of hydrogen, confirmed the validity of quantum mechanics for antimatter.

Origin and asymmetry
Most matter observable from the Earth seems to be made of matter rather than antimatter. If antimatter-dominated regions of space existed, the gamma rays produced in annihilation reactions along the boundary between matter and antimatter regions would be detectable.

Antiparticles are created everywhere in the universe where high-energy particle collisions take place. High-energy cosmic rays striking Earth's atmosphere (or any other matter in the Solar System) produce minute quantities of antiparticles in the resulting particle jets, which are immediately annihilated by contact with nearby matter. They may similarly be produced in regions like the center of the Milky Way and other galaxies, where very energetic celestial events occur (principally the interaction of relativistic jets with the interstellar medium). The presence of the resulting antimatter is detectable by the two gamma rays produced every time positrons annihilate with nearby matter. The frequency and wavelength of the gamma rays indicate that each carries 511 keV of energy (that is, the rest mass of an electron multiplied by c2).

Observations by the European Space Agency's INTEGRAL satellite may explain the origin of a giant antimatter cloud 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 kinetic energy while falling into a stellar remnant.

Antimatter may exist in relatively large amounts in far-away galaxies due to cosmic inflation in the primordial time of the universe. Antimatter galaxies, if they exist, are expected to have the same chemistry and absorption and emission spectra as normal-matter galaxies, and their astronomical objects would be observationally identical, making them difficult to distinguish. NASA is trying to determine if such galaxies exist by looking for X-ray and gamma ray signatures of annihilation events in colliding superclusters.

In October 2017, scientists working on the BASE experiment at CERN reported a measurement of the antiproton magnetic moment to a precision of 1.5 parts per billion. It is consistent with the most precise measurement of the proton magnetic moment (also made by BASE in 2014), which supports the hypothesis of CPT symmetry. This measurement represents the first time that a property of antimatter is known more precisely than the equivalent property in matter.

Antimatter quantum interferometry has been first demonstrated in 2018 in the Positron Laboratory (L-NESS) of Rafael Ferragut in Como (Italy), by a group led by Marco Giammarchi.

Natural production
Positrons are produced naturally in β+ decays of naturally occurring radioactive isotopes (for example, potassium-40) and in interactions of gamma quanta (emitted by radioactive nuclei) with matter. Antineutrinos are another kind of antiparticle created by natural radioactivity (β− decay). Many different kinds of antiparticles are also produced by (and contained in) cosmic rays. In January 2011, research by the American Astronomical Society discovered antimatter (positrons) originating above thunderstorm clouds; positrons are produced in terrestrial gamma ray flashes created by electrons accelerated by strong electric fields in the clouds. Antiprotons have also been found to exist in the Van Allen Belts around the Earth by the PAMELA module.

Antiparticles are also produced in any environment with a sufficiently high temperature (mean particle energy greater than the pair production threshold). It is hypothesized that 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, is called baryon asymmetry. The exact mechanism that produced this asymmetry during baryogenesis remains an unsolved problem. One of the necessary conditions for this asymmetry is the violation of CP symmetry, which has been experimentally observed in the weak interaction.

Recent observations indicate black holes and neutron stars produce vast amounts of positron-electron plasma via the jets.

Observation in cosmic rays
Satellite experiments have found evidence of positrons and a few antiprotons in primary cosmic rays, amounting to less than 1% of the particles in primary cosmic rays. This antimatter cannot all have been created in the Big Bang, but is instead attributed to have been produced by cyclic processes at high energies. For instance, electron-positron pairs may be formed in pulsars, as a magnetized neutron star rotation cycle shears electron-positron pairs from the star surface. Therein the antimatter forms a wind that crashes upon the ejecta of the progenitor supernovae. This weathering takes place as "the cold, magnetized relativistic wind launched by the star hits the non-relativistically expanding ejecta, a shock wave system forms in the impact: the outer one propagates in the ejecta, while a reverse shock propagates back towards the star." The former ejection of matter in the outer shock wave and the latter production of antimatter in the reverse shock wave are steps in a space weather cycle.

Preliminary results from the presently operating Alpha Magnetic Spectrometer (AMS-02) on board the International Space Station show that positrons in the cosmic rays arrive with no directionality, and with energies that range from 10 GeV to 250 GeV. In September, 2014, new results with almost twice as much data were presented in a talk at CERN and published in Physical Review Letters. A new measurement of positron fraction up to 500 GeV was reported, showing that positron fraction peaks at a maximum of about 16% of total electron+positron events, around an energy of 275 ± 32 GeV. At higher energies, up to 500 GeV, the ratio of positrons to electrons begins to fall again. The absolute flux of positrons also begins to fall before 500 GeV, but peaks at energies far higher than electron energies, which peak about 10 GeV. These results on interpretation have been suggested to be due to positron production in annihilation events of massive dark matter particles.

Cosmic ray antiprotons also have a much higher energy than their normal-matter counterparts (protons). They arrive at Earth with a characteristic energy maximum of 2 GeV, indicating their production in a fundamentally different process from cosmic ray protons, which on average have only one-sixth of the energy.

There is an ongoing search for larger antimatter nuclei, such as antihelium nuclei (that is, anti-alpha particles), in cosmic rays. The detection of natural antihelium could imply the existence of large antimatter structures such as an antistar. A prototype of the AMS-02 designated AMS-01, was flown into space aboard the on STS-91 in June 1998. By not detecting any antihelium at all, the AMS-01 established an upper limit of 1.1×10−6 for the antihelium to helium flux ratio. AMS-02 revealed in December 2016 that it had discovered a few signals consistent with antihelium nuclei amidst several billion helium nuclei. The result remains to be verified, and the team is currently trying to rule out contamination.

Positrons
Positrons were reported in November 2008 to have been generated by Lawrence Livermore National Laboratory in large numbers. A laser drove electrons through a gold target's nuclei, which caused the incoming electrons to emit energy quanta that decayed into both matter and antimatter. Positrons were detected at a higher rate and in greater density than ever previously detected in a laboratory. Previous experiments made smaller quantities of positrons using lasers and paper-thin targets; newer simulations showed that short bursts of ultra-intense lasers and millimeter-thick gold are a far more effective source.

In 2023, the production of the first electron-positron beam-plasma was reported by a collaboration led by researchers at University of Oxford working with the High-Radiation to Materials (HRMT) facility at CERN. The beam demonstrated the highest positron yield achieved so far in a laboratory setting. The experiment employed the 440 GeV proton beam, with $$3\times 10^{11}$$ protons, from the Super Proton Synchrotron, and irradiated a particle converter composed of Carbon and Tantalum. This yielded a total $$1.5\times 10^{13}$$ electron-positron pairs via a particle shower process. The produced pair beams have a volume that fills multiple Debye spheres and are thus able to sustain collective plasma oscillations.

Antiprotons, antineutrons, and antinuclei
The existence of the antiproton was experimentally confirmed in 1955 by University of California, Berkeley physicists Emilio Segrè and Owen Chamberlain, for which they were awarded the 1959 Nobel Prize in Physics. An antiproton consists of two up antiquarks and one down antiquark (Up antiquarkUp antiquarkDown antiquark). The properties of the antiproton that have been measured all match the corresponding properties of the proton, with the exception of the antiproton having opposite electric charge and magnetic moment from the proton. Shortly afterwards, in 1956, the antineutron was discovered in proton–proton collisions at the Bevatron (Lawrence Berkeley National Laboratory) by Bruce Cork and colleagues.

In addition to antibaryons, anti-nuclei consisting of multiple bound antiprotons and antineutrons have been created. These are typically produced at energies far too high to form antimatter atoms (with bound positrons in place of electrons). In 1965, a group of researchers led by Antonino Zichichi reported production of nuclei of antideuterium at the Proton Synchrotron at CERN. At roughly the same time, observations of antideuterium nuclei were reported by a group of American physicists at the Alternating Gradient Synchrotron at Brookhaven National Laboratory.

Antihydrogen atoms
In 1995, CERN announced that it had successfully brought into existence nine hot 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 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, namely, ATHENA and ATRAP.

In 1999, CERN activated the Antiproton Decelerator, a device capable of decelerating antiprotons from $3.5 GeV$ to $5.3 MeV$ – 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 ATRAP project released similar results very shortly thereafter. The antiprotons used in these experiments were cooled by decelerating them with the Antiproton Decelerator, passing them through a thin sheet of foil, and finally capturing them in a Penning–Malmberg trap. The overall cooling process is workable, but highly inefficient; approximately 25 million antiprotons leave the Antiproton Decelerator and roughly 25,000 make it to the Penning–Malmberg trap, which is about $1⁄1000$ or 0.1% of the original amount.

The antiprotons are still hot when initially trapped. To cool them further, they are mixed into an electron plasma. The electrons in this plasma cool via cyclotron radiation, and then sympathetically cool the antiprotons via Coulomb collisions. Eventually, the electrons are removed by the application of short-duration electric fields, leaving the antiprotons with energies less than $100 meV$. While the antiprotons are being cooled in the first trap, a small cloud of positrons is captured from radioactive sodium in a Surko-style positron accumulator. This cloud is then recaptured in a second trap near the antiprotons. Manipulations of the trap electrodes then tip the antiprotons into the positron plasma, where some combine with antiprotons to form antihydrogen. This neutral antihydrogen is unaffected by the electric and magnetic fields used to trap the charged positrons and antiprotons, and within a few microseconds the antihydrogen hits the trap walls, where it annihilates. Some hundreds of millions of antihydrogen atoms have been made in this fashion.

In 2005, ATHENA disbanded and some of the former members (along with others) formed the ALPHA Collaboration, which is also based at CERN. The ultimate goal of this endeavour is to test CPT symmetry through comparison of the atomic spectra of hydrogen and antihydrogen (see hydrogen spectral series).

Most of the sought-after high-precision tests of the properties of antihydrogen could only be performed if the antihydrogen were trapped, that is, held in place for a relatively long time. While antihydrogen atoms are electrically neutral, the spins of their component particles produce a magnetic moment. These magnetic moments can interact with an inhomogeneous magnetic field; some of the antihydrogen atoms can be attracted to a magnetic minimum. Such a minimum can be created by a combination of mirror and multipole fields. Antihydrogen can be trapped in such a magnetic minimum (minimum-B) trap; in November 2010, the ALPHA collaboration announced that they had so trapped 38 antihydrogen atoms for about a sixth of a second. This was the first time that neutral antimatter had been trapped.

On 26 April 2011, ALPHA announced that they had trapped 309 antihydrogen atoms, some for as long as 1,000 seconds (about 17 minutes). This was longer than neutral antimatter had ever been trapped before. ALPHA has used these trapped atoms to initiate research into the spectral properties of the antihydrogen.

In 2016, a new antiproton decelerator and cooler called ELENA (Extra Low ENergy Antiproton decelerator) was built. It takes the antiprotons from the antiproton decelerator and cools them to 90 keV, which is "cold" enough to study. This machine works by using high energy and accelerating the particles within the chamber. More than one hundred antiprotons can be captured per second, a huge improvement, but it would still take several thousand years to make a nanogram of antimatter.

The biggest limiting factor in the large-scale production of antimatter is the availability of antiprotons. Recent data released by CERN states that, when fully operational, their facilities are capable of producing ten million antiprotons per minute. Assuming a 100% conversion of antiprotons to antihydrogen, it would take 100 billion years to produce 1 gram or 1 mole of antihydrogen (approximately $6.02$ atoms of anti-hydrogen). However, CERN only produces 1% of the anti-matter Fermilab does, and neither are designed to produce anti-matter. According to Gerald Jackson, using technology already in use today we are capable of producing and capturing 20 grams of anti-matter particles per year at a yearly cost of 670 million dollars per facility.

Antihelium
Antihelium-3 nuclei (3helium) were first observed in the 1970s in proton–nucleus collision experiments at the Institute for High Energy Physics by Y. Prockoshkin's group (Protvino near Moscow, USSR) and later created in nucleus–nucleus collision experiments. Nucleus–nucleus collisions produce antinuclei through the coalescence of antiprotons and antineutrons created in these reactions. In 2011, the STAR detector reported the observation of artificially created antihelium-4 nuclei (anti-alpha particles) (4helium) from such collisions.

The Alpha Magnetic Spectrometer on the International Space Station has, as of 2021, recorded eight events that seem to indicate the detection of antihelium-3.

Preservation
Antimatter cannot be stored in a container made of ordinary matter because antimatter reacts with any matter it touches, annihilating itself and an equal amount of the container. Antimatter in the form of charged particles can be contained by a combination of electric and magnetic fields, in a device called a Penning trap. This device cannot, however, contain antimatter that consists of uncharged particles, for which atomic traps are used. In particular, such a trap may use the dipole moment (electric or magnetic) of the trapped particles. At high vacuum, the matter or antimatter particles can be trapped and cooled with slightly off-resonant laser radiation using a magneto-optical trap or magnetic trap. Small particles can also be suspended with optical tweezers, using a highly focused laser beam.

In 2011, CERN scientists were able to preserve antihydrogen for approximately 17 minutes. The record for storing antiparticles is currently held by the TRAP experiment at CERN: antiprotons were kept in a Penning trap for 405 days. A proposal was made in 2018 to develop containment technology advanced enough to contain a billion anti-protons in a portable device to be driven to another lab for further experimentation.

Cost
Scientists claim that antimatter is the costliest material to make. In 2006, Gerald Smith estimated $250 million could produce 10 milligrams of positrons (equivalent to $25 billion per gram); in 1999, NASA gave a figure of $62.5 trillion per gram of antihydrogen. This is because production is difficult (only very few antiprotons are produced in reactions in particle accelerators) and because there is higher demand for 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 (the amount used so far for particle/antiparticle collisions). In comparison, to produce the first atomic weapon, the cost of the Manhattan Project was estimated at $23 billion with inflation during 2007.

Several studies funded by the NASA Institute for Advanced Concepts are exploring whether it might be possible to use magnetic scoops to collect the antimatter that occurs naturally in the Van Allen belt of the Earth, and ultimately the belts of gas giants like Jupiter, ideally at a lower cost per gram.

Medical
Matter–antimatter 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 a neutrino is also emitted). Nuclides with surplus positive charge are easily made in a cyclotron and are widely generated for medical use. Antiprotons have also been shown within laboratory experiments to have the potential to treat certain cancers, in a similar method currently used for ion (proton) therapy.

Fuel
Isolated and stored antimatter could be used as a fuel for interplanetary or interstellar travel as part of an antimatter-catalyzed nuclear pulse propulsion or another antimatter rocket. Since the energy density of antimatter is higher than that of conventional fuels, an antimatter-fueled spacecraft would have a higher thrust-to-weight ratio than a conventional spacecraft.

If matter–antimatter collisions resulted only in photon emission, the entire rest mass of the particles would be converted to kinetic energy. The energy per unit mass ($9 J/kg$) is about 10 orders of magnitude greater than chemical energies, and about 3 orders of magnitude greater than the nuclear potential energy that can be liberated, today, using nuclear fission (about $1.56 J/kg$ per fission reaction or $200 MeV$), and about 2 orders of magnitude greater than the best possible results expected from fusion (about $8 J/kg$ for the proton–proton chain). The reaction of $6.3 J/kg$ of antimatter with $1 kg$ of matter would produce $1 kg$ (180 petajoules) of energy (by the mass–energy equivalence formula, E=mc2), or the rough equivalent of 43 megatons of TNT – slightly less than the yield of the 27,000 kg Tsar Bomba, the largest thermonuclear weapon ever detonated.

Not all of that energy can be utilized by any realistic propulsion technology because of the nature of the annihilation products. While electron–positron reactions result in gamma ray photons, these are difficult to direct and use for thrust. In reactions between protons and antiprotons, their energy is converted largely into relativistic neutral and charged pions. The neutral pions decay almost immediately (with a lifetime of 85 attoseconds) into high-energy photons, but the charged pions decay more slowly (with a lifetime of 26 nanoseconds) and can be deflected magnetically to produce thrust.

Charged pions ultimately decay into a combination of neutrinos (carrying about 22% of the energy of the charged pions) and unstable charged muons (carrying about 78% of the charged pion energy), with the muons then decaying into a combination of electrons, positrons and neutrinos (cf. muon decay; the neutrinos from this decay carry about 2/3 of the energy of the muons, meaning that from the original charged pions, the total fraction of their energy converted to neutrinos by one route or another would be about 0.22 + (2/3)⋅0.78 = 0.74). <!--

For more regular (earthly) applications (for example, regular transport, use in portable generators, and the powering of cities) artificially created antimatter is not a suitable energy carrier, despite its high energy density, because the process of creating antimatter is extremely inefficient. According to CERN, only one part in ten billion ($1.8 J$) of the energy invested in the production of antimatter particles can be subsequently retrieved.

Antimatter production is currently very limited, but has been growing at a nearly geometric rate since the observation of the first antiproton in 1955 by Segrè and Chamberlain. 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 US$25 million per gram by optimizing the collision and collection parameters (given current electricity generation costs). 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 that to produce 1 gram of antimatter, CERN would need to spend 100 quadrillion ($$) dollars and run the antimatter factory for 100 billion years.

Antimatter production costs, in mass production, are almost linearly tied to electricity costs, so economical pure-antimatter thrust applications are unlikely to come online unless a very cheap power source is found.

Storage is another problem, as antiprotons are negatively charged and repel each other, so that they cannot be concentrated in a small volume (cf. space charge). Plasma oscillations 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 of neutral charge, they are not as ionically unstable as antiprotons. The drawback is that cold antihydrogen is far more complex to produce than mere antiprotons.

One researcher from the CERN laboratories, which produces antimatter regularly, said: "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."

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Weapons
Antimatter has been considered as a trigger mechanism for nuclear weapons. A major obstacle is the difficulty of producing antimatter in large enough quantities, and there is no evidence that it will ever be feasible. Nonetheless, the U.S. Air Force funded studies of the physics of antimatter in the Cold War, and began considering its possible use in weapons, not just as a trigger, but as the explosive itself.

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title: Antimatter