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Anthropology | Further reading | Further reading |
Anthropology | Dictionaries and encyclopedias | Dictionaries and encyclopedias
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Anthropology | Fieldnotes and memoirs | Fieldnotes and memoirs
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Anthropology | Histories | Histories
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Anthropology | Textbooks and key theoretical works | Textbooks and key theoretical works
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Anthropology | External links | External links
Open Encyclopedia of Anthropology.
(AIO)
Category:Behavioural sciences
Category:Humans |
Anthropology | Table of Content | Short description, Etymology, Origin and development of the term, Through the 19th century, 20th and 21st centuries, Fields, Sociocultural, Biological, Archaeological, Linguistic, Ethnography, Key topics by field: sociocultural, Art, media, music, dance and film, Art, Media, Music, Visual, Economic, political economic, applied and development, Economic, Political economy, Applied, Development, Kinship, feminism, gender and sexuality, Kinship, Feminist, Medical, nutritional, psychological, cognitive and transpersonal, Medical, Nutritional, Psychological, Cognitive, Transpersonal, Political and legal, Political, Legal, Public, Nature, science, and technology, Cyborg, Digital, Ecological, Environment, Historical, Religion, Urban, Key topics by field: archaeological and biological, Anthrozoology, Biocultural, Evolutionary, Forensic, Palaeoanthropology, Organizations, List of major organizations, Ethics, Cultural relativism, Military involvement, Post-World War II developments, Basic trends, Commonalities between fields, See also, Lists, Notes, References, Works cited, Further reading, Dictionaries and encyclopedias, Fieldnotes and memoirs, Histories, Textbooks and key theoretical works, External links |
Agricultural science | short description | Agricultural science (or agriscience for short) is a broad multidisciplinary field of biology that encompasses the parts of exact, natural, economic and social sciences that are used in the practice and understanding of agriculture. Professionals of the agricultural science are called agricultural scientists or agriculturists. |
Agricultural science | History | History
In the 18th century, Johann Friedrich Mayer conducted experiments on the use of gypsum (hydrated calcium sulfate) as a fertilizer.John Armstrong, Jesse Buel. A Treatise on Agriculture, The Present Condition of the Art Abroad and at Home, and the Theory and Practice of Husbandry. To which is Added, a Dissertation on the Kitchen and Garden. 1840. p. 45.
In 1843, John Bennet Lawes and Joseph Henry Gilbert began a set of long-term field experiments at Rothamsted Research in England, some of which are still running as of 2018.
In the United States, a scientific revolution in agriculture began with the Hatch Act of 1887, which used the term "agricultural science". The Hatch Act was driven by farmers' interest in knowing the constituents of early artificial fertilizer. The Smith–Hughes Act of 1917 shifted agricultural education back to its vocational roots, but the scientific foundation had been built.Hillison J. (1996). The Origins of Agriscience: Or Where Did All That Scientific Agriculture Come From? . Journal of Agricultural Education. For the next 44 years after 1906, federal expenditures on agricultural research in the United States outpaced private expenditures.Huffman WE, Evenson RE. (2006). Science for Agriculture. Blackwell Publishing. |
Agricultural science | Prominent agricultural scientists | Prominent agricultural scientists
thumb|200px|Norman Borlaug, father of the Green Revolution.
Wilbur Olin Atwater
Robert Bakewell
Norman Borlaug
Luther Burbank
George Washington Carver
Carl Henry Clerk
George C. Clerk
René Dumont
Sir Albert Howard
Kailas Nath Kaul
Thomas Lecky
Justus von Liebig
Jay Laurence Lush
Gregor Mendel
Louis Pasteur
M. S. Swaminathan
Jethro Tull
Artturi Ilmari Virtanen
Sewall Wright |
Agricultural science | Fields or related disciplines | Fields or related disciplines |
Agricultural science | Occupations in Agricultural Science | Occupations in Agricultural Science
Following are occupations in Agricultural Science listed in the Dictionary of Occupational Titles. 040 Occupations in Agricultural Sciences . Occupations in Agricultural Sciences. |
Agricultural science | Scope | Scope
Agriculture, agricultural science, and agronomy are closely related. However, they cover different concepts:
Agriculture is the set of activities that transform the environment for the production of animals and plants for human use. Agriculture concerns techniques, including the application of agronomic research.
Agronomy is research and development related to studying and improving plant-based crops.
is the science of cultivating the earth.“Geoponics.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/geoponics. Accessed 17 Nov. 2024.
Hydroponics involves growing plants without soil, by using water-based mineral nutrient solutions in an artificial environment. |
Agricultural science | Research topics | Research topics
Agricultural sciences include research and development on:
Improving agricultural productivity in terms of quantity and quality (e.g., selection of drought-resistant crops and animals, development of new pesticides, yield-sensing technologies, simulation models of crop growth, in-vitro cell culture techniques)
Minimizing the effects of pests (weeds, insects, pathogens, mollusks, nematodes) on crop or animal production systems.
Transformation of primary products into end-consumer products (e.g., production, preservation, and packaging of dairy products)
Prevention and correction of adverse environmental effects (e.g., soil degradation, waste management, bioremediation)
Theoretical production ecology, relating to crop production modeling
Traditional agricultural systems, sometimes termed subsistence agriculture, which feed most of the poorest people in the world. These systems are of interest as they sometimes retain a level of integration with natural ecological systems greater than that of industrial agriculture, which may be more sustainable than some modern agricultural systems.
Food production and demand globally, with particular attention paid to the primary producers, such as China, India, Brazil, the US, and the EU.
Various sciences relating to agricultural resources and the environment (e.g. soil science, agroclimatology); biology of agricultural crops and animals (e.g. crop science, animal science and their included sciences, e.g. ruminant nutrition, farm animal welfare); such fields as agricultural economics and rural sociology; various disciplines encompassed in agricultural engineering. |
Agricultural science | See also | See also
Agricultural Research Council
Agricultural sciences basic topics
Agriculture ministry
Agroecology
American Society of Agronomy
Consultative Group on International Agricultural Research (CGIAR)
Crop Science Society of America
Genomics of domestication
History of agricultural science
Indian Council of Agricultural Research
Institute of Food and Agricultural Sciences
International Assessment of Agricultural Science and Technology for Development
International Food Policy Research Institute, IFPRI
International Institute of Tropical Agriculture
International Livestock Research Institute
List of agriculture topics
National Agricultural Library (NAL)
National FFA Organization
Research Institute of Crop Production (RICP) (in the Czech Republic)
Soil Science Society of America
USDA Agricultural Research Service
University of Agricultural Sciences |
Agricultural science | References | References |
Agricultural science | Further reading | Further reading
Agricultural Research, Livelihoods, and Poverty: Studies of Economic and Social Impacts in Six Countries Edited by Michelle Adato and Ruth Meinzen-Dick (2007), Johns Hopkins University Press Food Policy ReportAgricultural research, livelihoods, and poverty | International Food Policy Research Institute (IFPRI)
Claude Bourguignon, Regenerating the Soil: From Agronomy to Agrology, Other India Press, 2005
Pimentel David, Pimentel Marcia, Computer les kilocalories, Cérès, n. 59, sept-oct. 1977
Russell E. Walter, Soil conditions and plant growth, Longman group, London, New York 1973
Saltini Antonio, Storia delle scienze agrarie, 4 vols, Bologna 1984–89, , , ,
Vavilov Nicolai I. (Starr Chester K. editor), The Origin, Variation, Immunity and Breeding of Cultivated Plants. Selected Writings, in Chronica botanica, 13: 1–6, Waltham, Mass., 1949–50
Vavilov Nicolai I., World Resources of Cereals, Leguminous Seed Crops and Flax, Academy of Sciences of Urss, National Science Foundation, Washington, Israel Program for Scientific Translations, Jerusalem 1960
Winogradsky Serge, Microbiologie du sol. Problèmes et methodes. Cinquante ans de recherches, Masson & c.ie, Paris 1949
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Agricultural science | Table of Content | short description, History, Prominent agricultural scientists, Fields or related disciplines, Occupations in Agricultural Science, Scope, Research topics, See also, References, Further reading |
Alchemy | Short description | thumb|upright=1.3|Depiction of an Ouroboros from the alchemical treatise (15th century), Zentralbibliothek Zürich, Switzerland
Alchemy (from the Arabic word , ) is an ancient branch of natural philosophy, a philosophical and protoscientific tradition that was historically practised in China, India, the Muslim world, and Europe. In its Western form, alchemy is first attested in a number of pseudepigraphical texts written in Greco-Roman Egypt during the first few centuries AD.Principe, Lawrence M. The secrets of alchemy . University of Chicago Press, 2012, pp. 9–14. Greek-speaking alchemists often referred to their craft as "the Art" (τέχνη) or "Knowledge" (ἐπιστήμη), and it was often characterised as mystic (μυστική), sacred (ἱɛρά), or divine (θɛíα).
Alchemists attempted to purify, mature, and perfect certain materials. Common aims were chrysopoeia, the transmutation of "base metals" (e.g., lead) into "noble metals" (particularly gold); the creation of an elixir of immortality; and the creation of panaceas able to cure any disease. The perfection of the human body and soul was thought to result from the alchemical magnum opus ("Great Work"). The concept of creating the philosophers' stone was variously connected with all of these projects.
Islamic and European alchemists developed a basic set of laboratory techniques, theories, and terms, some of which are still in use today. They did not abandon the Ancient Greek philosophical idea that everything is composed of four elements, and they tended to guard their work in secrecy, often making use of cyphers and cryptic symbolism. In Europe, the 12th-century translations of medieval Islamic works on science and the rediscovery of Aristotelian philosophy gave birth to a flourishing tradition of Latin alchemy. This late medieval tradition of alchemy would go on to play a significant role in the development of early modern science (particularly chemistry and medicine).
Modern discussions of alchemy are generally split into an examination of its exoteric practical applications and its esoteric spiritual aspects, despite criticisms by scholars such as Eric J. Holmyard and Marie-Louise von Franz that they should be understood as complementary. The former is pursued by historians of the physical sciences, who examine the subject in terms of early chemistry, medicine, and charlatanism, and the philosophical and religious contexts in which these events occurred. The latter interests historians of esotericism, psychologists, and some philosophers and spiritualists. The subject has also made an ongoing impact on literature and the arts. |
Alchemy | Etymology | Etymology
The word alchemy comes from old French alquemie, alkimie, used in Medieval Latin as . This name was itself adopted from the Arabic word (). The Arabic in turn was a borrowing of the Late Greek term khēmeía (), also spelled khumeia () and khēmía (), with al- being the Arabic definite article 'the'. Together this association can be interpreted as 'the process of transmutation by which to fuse or reunite with the divine or original form'. Several etymologies have been proposed for the Greek term. The first was proposed by Zosimos of Panopolis (3rd–4th centuries), who derived it from the name of a book, the Khemeu.George Syncellus, Chronography, 18–9On the ancient definitions of alchemy in ancient Greek and Syriac texts see Matteo Martelli. 2014. "The Alchemical Art of Dyeing: The Fourfold Division of Alchemy and the Enochian Tradition", In: Dupré S. (eds) Laboratories of Art, Springer, Cham. Hermann Diels argued in 1914 that it rather derived from χύμα,Hermann Diels, Antike Technik, Leipzig: Teubner, 1914, pp. 108–109. Read online used to describe metallic objects formed by casting.
Others trace its roots to the Egyptian name (hieroglyphic 𓆎𓅓𓏏𓊖 ), meaning 'black earth', which refers to the fertile and auriferous soil of the Nile valley, as opposed to red desert sand. According to the Egyptologist Wallis Budge, the Arabic word ʾ actually means "the Egyptian [science]", borrowing from the Coptic word for "Egypt", (or its equivalent in the Mediaeval Bohairic dialect of Coptic, ). This Coptic word derives from Demotic , itself from ancient Egyptian . The ancient Egyptian word referred to both the country and the colour "black" (Egypt was the "black Land", by contrast with the "red Land", the surrounding desert). |
Alchemy | History | History
Alchemy encompasses several philosophical traditions spanning some four millennia and three continents. These traditions' general penchant for cryptic and symbolic language makes it hard to trace their mutual influences and genetic relationships. One can distinguish at least three major strands, which appear to be mostly independent, at least in their earlier stages: Chinese alchemy, centered in China; Indian alchemy, centered on the Indian subcontinent; and Western alchemy, which occurred around the Mediterranean and whose center shifted over the millennia from Greco-Roman Egypt to the Islamic world, and finally medieval Europe. Chinese alchemy was closely connected to Taoism and Indian alchemy with the Dharmic faiths. In contrast, Western alchemy developed its philosophical system mostly independent of but influenced by various Western religions. It is still an open question whether these three strands share a common origin, or to what extent they influenced each other. |
Alchemy | Hellenistic Egypt | Hellenistic Egypt
thumb|Ambix, cucurbit and retort of Zosimos, from Marcelin Berthelot, Collection des anciens alchimistes grecs (3 vol., Paris, 1887–1888)
The start of Western alchemy may generally be traced to ancient and Hellenistic Egypt, where the city of Alexandria was a center of alchemical knowledge, and retained its pre-eminence through most of the Greek and Roman periods.New Scientist, 24–31 December 1987 Following the work of André-Jean Festugière, modern scholars see alchemical practice in the Roman Empire as originating from the Egyptian goldsmith's art, Greek philosophy and different religious traditions. Tracing the origins of the alchemical art in Egypt is complicated by the pseudepigraphic nature of texts from the Greek alchemical corpus. The treatises of Zosimos of Panopolis, the earliest historically attested author (fl. c. 300 AD), can help in situating the other authors. Zosimus based his work on that of older alchemical authors, such as Mary the Jewess,See Pseudo-Democritus, and Agathodaimon, but very little is known about any of these authors. The most complete of their works, The Four Books of Pseudo-Democritus, were probably written in the first century AD.
Recent scholarship tends to emphasize the testimony of Zosimus, who traced the alchemical arts back to Egyptian metallurgical and ceremonial practices. It has also been argued that early alchemical writers borrowed the vocabulary of Greek philosophical schools but did not implement any of its doctrines in a systematic way. Zosimos of Panopolis wrote in the Final Abstinence (also known as the "Final Count").The title of the τελευταὶα ἀποχή is traditionally translated as the "Final Count". Considering that the treatise does not mention any count nor counting and that it makes a case against the use of sacrifice in the practice of alchemy, a preferable translation would be "the Final Abstinence". See Zosimos explains that the ancient practice of "tinctures" (the technical Greek name for the alchemical arts) had been taken over by certain "demons" who taught the art only to those who offered them sacrifices. Since Zosimos also called the demons "the guardians of places" (, ) and those who offered them sacrifices "priests" (, ), it is fairly clear that he was referring to the gods of Egypt and their priests. While critical of the kind of alchemy he associated with the Egyptian priests and their followers, Zosimos nonetheless saw the tradition's recent past as rooted in the rites of the Egyptian temples. |
Alchemy | Mythology | Mythology
Zosimos of Panopolis asserted that alchemy dated back to Pharaonic Egypt where it was the domain of the priestly class, though there is little to no evidence for his assertion. Alchemical writers used Classical figures from Greek, Roman, and Egyptian mythology to illuminate their works and allegorize alchemical transmutation.Yves Bonnefoy. 'Roman and European Mythologies'. University of Chicago Press, 1992. pp. 211–213 These included the pantheon of gods related to the Classical planets, Isis, Osiris, Jason, and many others.
The central figure in the mythology of alchemy is Hermes Trismegistus (or Thrice-Great Hermes). His name is derived from the god Thoth and his Greek counterpart Hermes.A survey of the literary and archaeological evidence for the background of Hermes Trismegistus in the Greek Hermes and the Egyptian Thoth may be found in Bull, Christian H. 2018. The Tradition of Hermes Trismegistus: The Egyptian Priestly Figure as a Teacher of Hellenized Wisdom. Leiden: Brill, pp. 33–96. Hermes and his caduceus or serpent-staff, were among alchemy's principal symbols. According to Clement of Alexandria, he wrote what were called the "forty-two books of Hermes", covering all fields of knowledge.Clement, Stromata, vi. 4. The Hermetica of Thrice-Great Hermes is generally understood to form the basis for Western alchemical philosophy and practice, called the hermetic philosophy by its early practitioners. These writings were collected in the first centuries of the common era. |
Alchemy | Technology | Technology
The dawn of Western alchemy is sometimes associated with that of metallurgy, extending back to 3500 BC. Many writings were lost when the Roman emperor Diocletian ordered the burning of alchemical books after suppressing a revolt in Alexandria (AD 292). Few original Egyptian documents on alchemy have survived, most notable among them the Stockholm papyrus and the Leyden papyrus X. Dating from AD 250 to 300, they contained recipes for dyeing and making artificial gemstones, cleaning and fabricating pearls, and manufacturing of imitation gold and silver.Caley, E. R. (1927) "The Stockholm Papyrus : An English Translation with brief notes" Journal of Chemical Education IV:8 : 979–1002. These writings lack the mystical, philosophical elements of alchemy, but do contain the works of Bolus of Mendes (or Pseudo-Democritus), which aligned these recipes with theoretical knowledge of astrology and the classical elements.A History of Chemistry, Bensaude-Vincent, Isabelle Stengers, Harvard University Press, 1996, p13 Between the time of Bolus and Zosimos, the change took place that transformed this metallurgy into a Hermetic art. |
Alchemy | Philosophy | Philosophy
Alexandria acted as a melting pot for philosophies of Pythagoreanism, Platonism, Stoicism and Gnosticism which formed the origin of alchemy's character. An important example of alchemy's roots in Greek philosophy, originated by Empedocles and developed by Aristotle, was that all things in the universe were formed from only four elements: earth, air, water, and fire. According to Aristotle, each element had a sphere to which it belonged and to which it would return if left undisturbed. The four elements of the Greek were mostly qualitative aspects of matter, not quantitative, as our modern elements are; "True alchemy never regarded earth, air, water, and fire as corporeal or chemical substances in the present-day sense of the word. The four elements are simply the primary, and most general, qualities by means of which the amorphous and purely quantitative substance of all bodies first reveals itself in differentiated form." Later alchemists extensively developed the mystical aspects of this concept.
Alchemy coexisted alongside emerging Christianity. Lactantius believed Hermes Trismegistus had prophesied its birth. St Augustine later affirmed this in the 4th and 5th centuries, but also condemned Trismegistus for idolatry.Fanning, Philip Ashley. Isaac Newton and the Transmutation of Alchemy: An Alternative View of the Scientific Revolution. 2009. p.6 Examples of Pagan, Christian, and Jewish alchemists can be found during this period.
Most of the Greco-Roman alchemists preceding Zosimos are known only by pseudonyms, such as Moses, Isis, Cleopatra, Democritus, and Ostanes. Others authors such as Komarios, and Chymes, we only know through fragments of text. After AD 400, Greek alchemical writers occupied themselves solely in commenting on the works of these predecessors.F. Sherwood Taylor. Alchemists, Founders of Modern Chemistry. p.26. By the middle of the 7th century alchemy was almost an entirely mystical discipline.Allen G. Debus. Alchemy and early modern chemistry: papers from Ambix. p. 36 It was at that time that Khalid Ibn Yazid sparked its migration from Alexandria to the Islamic world, facilitating the translation and preservation of Greek alchemical texts in the 8th and 9th centuries.Glen Warren Bowersock, Peter Robert Lamont Brown, Oleg Grabar. Late antiquity: a guide to the postclassical world. pp. 284–285 |
Alchemy | Byzantium | Byzantium
Greek alchemy was preserved in medieval Byzantine manuscripts after the fall of Egypt, and yet historians have only relatively recently begun to pay attention to the study and development of Greek alchemy in the Byzantine period. |
Alchemy | India | India
The 2nd millennium BC text Vedas describe a connection between eternal life and gold. A considerable knowledge of metallurgy has been exhibited in a third-century AD text called Arthashastra which provides ingredients of explosives (Agniyoga) and salts extracted from fertile soils and plant remains (Yavakshara) such as saltpetre/nitre, perfume making (different qualities of perfumes are mentioned), granulated (refined) Sugar. Buddhist texts from the 2nd to 5th centuries mention the transmutation of base metals to gold. According to some scholars Greek alchemy may have influenced Indian alchemy but there are no hard evidences to back this claim.Multhauf, Robert P. & Gilbert, Robert Andrew (2008). Alchemy. Encyclopædia Britannica (2008).
The 11th-century Persian chemist and physician Abū Rayhān Bīrūnī, who visited Gujarat as part of the court of Mahmud of Ghazni, reported that they
The goals of alchemy in India included the creation of a divine body (Sanskrit divya-deham) and immortality while still embodied (Sanskrit jīvan-mukti). Sanskrit alchemical texts include much material on the manipulation of mercury and sulphur, that are homologized with the semen of the god Śiva and the menstrual blood of the goddess Devī.
Some early alchemical writings seem to have their origins in the Kaula tantric schools associated to the teachings of the personality of Matsyendranath. Other early writings are found in the Jaina medical treatise Kalyāṇakārakam of Ugrāditya, written in South India in the early 9th century.
Two famous early Indian alchemical authors were Nāgārjuna Siddha and Nityanātha Siddha. Nāgārjuna Siddha was a Buddhist monk. His book, Rasendramangalam, is an example of Indian alchemy and medicine. Nityanātha Siddha wrote Rasaratnākara, also a highly influential work. In Sanskrit, rasa translates to "mercury", and Nāgārjuna Siddha was said to have developed a method of converting mercury into gold.
Scholarship on Indian alchemy is in the publication of The Alchemical Body by David Gordon White.See bibliographical details and links at https://openlibrary.org/works/OL3266066W/The_Alchemical_Body
A modern bibliography on Indian alchemical studies has been written by White.
The contents of 39 Sanskrit alchemical treatises have been analysed in detail in G. Jan Meulenbeld's History of Indian Medical Literature. The discussion of these works in HIML gives a summary of the contents of each work, their special features, and where possible the evidence concerning their dating. Chapter 13 of HIML, Various works on rasaśāstra and ratnaśāstra (or Various works on alchemy and gems) gives brief details of a further 655 (six hundred and fifty-five) treatises. In some cases Meulenbeld gives notes on the contents and authorship of these works; in other cases references are made only to the unpublished manuscripts of these titles.
A great deal remains to be discovered about Indian alchemical literature. The content of the Sanskrit alchemical corpus has not yet (2014) been adequately integrated into the wider general history of alchemy. |
Alchemy | Islamic world | Islamic world
thumb|upright|15th-century artistic impression of Jabir ibn Hayyan (Geber), Codici Ashburnhamiani 1166, Biblioteca Medicea Laurenziana, Florence
After the fall of the Roman Empire, the focus of alchemical development moved to the Islamic World. Much more is known about Islamic alchemy because it was better documented: indeed, most of the earlier writings that have come down through the years were preserved as Arabic translations. The word alchemy itself was derived from the Arabic word al-kīmiyā (الكيمياء). The early Islamic world was a melting pot for alchemy. Platonic and Aristotelian thought, which had already been somewhat appropriated into hermetical science, continued to be assimilated during the late 7th and early 8th centuries through Syriac translations and scholarship.
In the late ninth and early tenth centuries, the Arabic works attributed to Jābir ibn Hayyān (Latinized as "Geber" or "Geberus") introduced a new approach to alchemy. Paul Kraus, who wrote the standard reference work on Jabir, put it as follows:
Islamic philosophers also made great contributions to alchemical hermeticism. The most influential author in this regard was arguably Jabir. Jabir's ultimate goal was Takwin, the artificial creation of life in the alchemical laboratory, up to, and including, human life. He analysed each Aristotelian element in terms of four basic qualities of hotness, coldness, dryness, and moistness. According to Jabir, in each metal two of these qualities were interior and two were exterior. For example, lead was externally cold and dry, while gold was hot and moist. Thus, Jabir theorized, by rearranging the qualities of one metal, a different metal would result. By this reasoning, the search for the philosopher's stone was introduced to Western alchemy. Jabir developed an elaborate numerology whereby the root letters of a substance's name in Arabic, when treated with various transformations, held correspondences to the element's physical properties.
The elemental system used in medieval alchemy also originated with Jabir. His original system consisted of seven elements, which included the five classical elements (aether, air, earth, fire, and water) in addition to two chemical elements representing the metals: sulphur, "the stone which burns", which characterized the principle of combustibility, and mercury, which contained the idealized principle of metallic properties. Shortly thereafter, this evolved into eight elements, with the Arabic concept of the three metallic principles: sulphur giving flammability or combustion, mercury giving volatility and stability, and salt giving solidity.Strathern, Paul. (2000), Mendeleyev's Dream – the Quest for the Elements, New York: Berkley Books The atomic theory of corpuscularianism, where all physical bodies possess an inner and outer layer of minute particles or corpuscles, also has its origins in the work of Jabir.
From the 9th to 14th centuries, alchemical theories faced criticism from a variety of practical Muslim chemists, including Alkindus,Felix Klein-Frank (2001), "Al-Kindi", in Oliver Leaman & Hossein Nasr, History of Islamic Philosophy, p. 174. London: Routledge. Abū al-Rayhān al-Bīrūnī, AvicennaRobert Briffault (1938). The Making of Humanity, pp. 196–197. and Ibn Khaldun. In particular, they wrote refutations against the idea of the transmutation of metals.
From the 14th century onwards, many materials and practices originally belonging to Indian alchemy (Rasayana) were assimilated in the Persian texts written by Muslim scholars. |
Alchemy | East Asia | East Asia
Researchers have found evidence that Chinese alchemists and philosophers discovered complex mathematical phenomena that were shared with Arab alchemists during the medieval period. Discovered in BC China, the "magic square of three" was propagated to followers of Abū Mūsā Jābir ibn Ḥayyān at some point over the proceeding several hundred years. Other commonalities shared between the two alchemical schools of thought include discrete naming for ingredients and heavy influence from the natural elements. The silk road provided a clear path for the exchange of goods, ideas, ingredients, religion, and many other aspects of life with which alchemy is intertwined.
thumb|upright|Taoist alchemists often use this alternate version of the taijitu.
Whereas European alchemy eventually centered on the transmutation of base metals into noble metals, Chinese alchemy had a more obvious connection to medicine.[Obed Simon Johnson, A Study of Chinese Alchemy, Shanghai, Commercial P, 1928. rpt. New York: Arno P, 1974.] The philosopher's stone of European alchemists can be compared to the Grand Elixir of Immortality sought by Chinese alchemists. In the hermetic view, these two goals were not unconnected, and the philosopher's stone was often equated with the universal panacea; therefore, the two traditions may have had more in common than initially appears.
As early as 317 AD, Ge Hong documented the use of metals, minerals, and elixirs in early Chinese medicine. Hong identified three ancient Chinese documents, titled Scripture of Great Clarity, Scripture of the Nine Elixirs, and Scripture of the Golden Liquor, as texts containing fundamental alchemical information. He also described alchemy, along with meditation, as the sole spiritual practices that could allow one to gain immortality or to transcend. In his work Inner Chapters of the Book of the Master Who Embraces Spontaneous Nature (317 AD), Hong argued that alchemical solutions such as elixirs were preferable to traditional medicinal treatment due to the spiritual protection they could provide. In the centuries following Ge Hong's death, the emphasis placed on alchemy as a spiritual practice among Chinese Daoists was reduced. In 499 AD, Tao Hongjing refuted Hong's statement that alchemy is as important a spiritual practice as Shangqing meditation. While Hongjing did not deny the power of alchemical elixirs to grant immortality or provide divine protection, he ultimately found the Scripture of the Nine Elixirs to be ambiguous and spiritually unfulfilling, aiming to implement more accessible practising techniques.
In the early 700s, Neidan (also known as internal alchemy) was adopted by Daoists as a new form of alchemy. Neidan emphasized appeasing the inner gods that inhabit the human body by practising alchemy with compounds found in the body, rather than the mixing of natural resources that was emphasized in early Dao alchemy. For example, saliva was often considered nourishment for the inner gods and did not require any conscious alchemical reaction to produce. The inner gods were not thought of as physical presences occupying each person, but rather a collection of deities that are each said to represent and protect a specific body part or region. Although those who practised Neidan prioritized meditation over external alchemical strategies, many of the same elixirs and constituents from previous Daoist alchemical schools of thought continued to be utilized in tandem with meditation. Eternal life remained a consideration for Neidan alchemists, as it was believed that one would become immortal if an inner god were to be immortalized within them through spiritual fulfilment.
Black powder may have been an important invention of Chinese alchemists. It is said that the Chinese invented gunpowder while trying to find a potion for eternal life. Described in 9th-century texts and used in fireworks in China by the 10th century, it was used in cannons by 1290. From China, the use of gunpowder spread to Japan, the Mongols, the Muslim world, and Europe. Gunpowder was used by the Mongols against the Hungarians in 1241, and in Europe by the 14th century.
Chinese alchemy was closely connected to Taoist forms of traditional Chinese medicine, such as Acupuncture and Moxibustion. In the early Song dynasty, followers of this Taoist idea (chiefly the elite and upper class) would ingest mercuric sulfide, which, though tolerable in low levels, led many to suicide. Thinking that this consequential death would lead to freedom and access to the Taoist heavens, the ensuing deaths encouraged people to eschew this method of alchemy in favour of external sources (the aforementioned Tai Chi Chuan, mastering of the qi, etc.) Chinese alchemy was introduced to the West by Obed Simon Johnson. |
Alchemy | Medieval Europe | Medieval Europe
thumb|"An illuminated page from a book on alchemical processes and receipts", ca. 15th century
The introduction of alchemy to Latin Europe may be dated to 11 February 1144, with the completion of Robert of Chester's translation of the ("Book on the Composition of Alchemy") from an Arabic work attributed to Khalid ibn Yazid. p. 116. Although European craftsmen and technicians pre-existed, Robert notes in his preface that alchemy (here still referring to the elixir rather than to the art itself) p. 890; . was unknown in Latin Europe at the time of his writing. The translation of Arabic texts concerning numerous disciplines including alchemy flourished in 12th-century Toledo, Spain, through contributors like Gerard of Cremona and Adelard of Bath. Translations of the time included the Turba Philosophorum, and the works of Avicenna and Muhammad ibn Zakariya al-Razi. These brought with them many new words to the European vocabulary for which there was no previous Latin equivalent. Alcohol, carboy, elixir, and athanor are examples.
Meanwhile, theologian contemporaries of the translators made strides towards the reconciliation of faith and experimental rationalism, thereby priming Europe for the influx of alchemical thought. The 11th-century St Anselm put forth the opinion that faith and rationalism were compatible and encouraged rationalism in a Christian context. In the early 12th century, Peter Abelard followed Anselm's work, laying down the foundation for acceptance of Aristotelian thought before the first works of Aristotle had reached the West. In the early 13th century, Robert Grosseteste used Abelard's methods of analysis and added the use of observation, experimentation, and conclusions when conducting scientific investigations. Grosseteste also did much work to reconcile Platonic and Aristotelian thinking.
Through much of the 12th and 13th centuries, alchemical knowledge in Europe remained centered on translations, and new Latin contributions were not made. The efforts of the translators were succeeded by that of the encyclopaedists. In the 13th century, Albertus Magnus and Roger Bacon were the most notable of these, their work summarizing and explaining the newly imported alchemical knowledge in Aristotelian terms.John Read. From Alchemy to Chemistry. 1995 p.90 Albertus Magnus, a Dominican friar, is known to have written works such as the Book of Minerals where he observed and commented on the operations and theories of alchemical authorities like Hermes Trismegistus, pseudo-Democritus and unnamed alchemists of his time. Albertus critically compared these to the writings of Aristotle and Avicenna, where they concerned the transmutation of metals. From the time shortly after his death through to the 15th century, more than 28 alchemical tracts were misattributed to him, a common practice giving rise to his reputation as an accomplished alchemist.. Albertus Magnus and the Sciences: Commemorative Essays. PIMS. 1980. pp. 187–202 Likewise, alchemical texts have been attributed to Albert's student Thomas Aquinas.
Roger Bacon, a Franciscan friar who wrote on a wide variety of topics including optics, comparative linguistics, and medicine, composed his Great Work () for as part of a project towards rebuilding the medieval university curriculum to include the new learning of his time. While alchemy was not more important to him than other sciences and he did not produce allegorical works on the topic, he did consider it and astrology to be important parts of both natural philosophy and theology and his contributions advanced alchemy's connections to soteriology and Christian theology. Bacon's writings integrated morality, salvation, alchemy, and the prolongation of life. His correspondence with Clement highlighted this, noting the importance of alchemy to the papacy.Edmund Brehm. "Roger Bacon's Place in the History of Alchemy." Ambix. Vol. 23, Part I, March 1976. Like the Greeks before him, Bacon acknowledged the division of alchemy into practical and theoretical spheres. He noted that the theoretical lay outside the scope of Aristotle, the natural philosophers, and all Latin writers of his time. The practical confirmed the theoretical, and Bacon advocated its uses in natural science and medicine. In later European legend, he became an archmage. In particular, along with Albertus Magnus, he was credited with the forging of a brazen head capable of answering its owner's questions.
Soon after Bacon, the influential work of Pseudo-Geber (sometimes identified as Paul of Taranto) appeared. His Summa Perfectionis remained a staple summary of alchemical practice and theory through the medieval and renaissance periods. It was notable for its inclusion of practical chemical operations alongside sulphur-mercury theory, and the unusual clarity with which they were described. By the end of the 13th century, alchemy had developed into a fairly structured system of belief. Adepts believed in the macrocosm-microcosm theories of Hermes, that is to say, they believed that processes that affect minerals and other substances could have an effect on the human body (for example, if one could learn the secret of purifying gold, one could use the technique to purify the human soul). They believed in the four elements and the four qualities as described above, and they had a strong tradition of cloaking their written ideas in a labyrinth of coded jargon set with traps to mislead the uninitiated. Finally, the alchemists practised their art: they actively experimented with chemicals and made observations and theories about how the universe operated. Their entire philosophy revolved around their belief that man's soul was divided within himself after the fall of Adam. By purifying the two parts of man's soul, man could be reunited with God.
In the 14th century, alchemy became more accessible to Europeans outside the confines of Latin-speaking churchmen and scholars. Alchemical discourse shifted from scholarly philosophical debate to an exposed social commentary on the alchemists themselves.Tara E. Nummedal. Alchemy and Authority in the Holy Roman Empire. University of Chicago Press, 2007. p. 49 Dante, Piers Plowman, and Chaucer all painted unflattering pictures of alchemists as thieves and liars. Pope John XXII's 1317 edict, Spondent quas non-exhibent forbade the false promises of transmutation made by pseudo-alchemists.John Hines, II, R. F. Yeager. John Gower, Trilingual Poet: Language, Translation, and Tradition. Boydell & Brewer. 2010. p.170 Roman Catholic Inquisitor General Nicholas Eymerich's Directorium Inquisitorum, written in 1376, associated alchemy with the performance of demonic rituals, which Eymerich differentiated from magic performed in accordance with scripture. This did not, however, lead to any change in the Inquisition's monitoring or prosecution of alchemists. In 1404, Henry IV of England banned the practice of multiplying metals by the passing of the (5 Hen. 4. c. 4) (although it was possible to buy a licence to attempt to make gold alchemically, and a number were granted by Henry VI and Edward IV).D. Geoghegan, "A licence of Henry VI to practise Alchemy" Ambix, vol. 6, 1957, pp. 10–17 These critiques and regulations centered more around pseudo-alchemical charlatanism than the actual study of alchemy, which continued with an increasingly Christian tone. The 14th century saw the Christian imagery of death and resurrection employed in the alchemical texts of Petrus Bonus, John of Rupescissa, and in works written in the name of Raymond Lull and Arnold of Villanova.Leah DeVun. From Prophecy, Alchemy, and the End of Time: John of Rupescissa in the late Middle Ages. Columbia University Press, 2009. p. 104
thumb|left|upright|The Alchemist in Search of the Philosopher's Stone, by Joseph Wright, 1771
Nicolas Flamel is a well-known alchemist to the point where he had many pseudepigraphic imitators. Although the historical Flamel existed, the writings and legends assigned to him only appeared in 1612."Nicolas Flamel. Des Livres et de l'or" by Nigel Wilkins
A common idea in European alchemy in the medieval era was a metaphysical "Homeric chain of wise men that link[ed] heaven and earth" that included ancient pagan philosophers and other important historical figures. |
Alchemy | Renaissance and early modern Europe | Renaissance and early modern Europe
During the Renaissance, Hermetic and Platonic foundations were restored to European alchemy. The dawn of medical, pharmaceutical, occult, and entrepreneurial branches of alchemy followed.
In the late 15th century, Marsilio Ficino translated the Corpus Hermeticum and the works of Plato into Latin. These were previously unavailable to Europeans who for the first time had a full picture of the alchemical theory that Bacon had declared absent. Renaissance Humanism and Renaissance Neoplatonism guided alchemists away from physics to refocus on mankind as the alchemical vessel.
Esoteric systems developed that blended alchemy into a broader occult Hermeticism, fusing it with magic, astrology, and Christian cabala.Peter J. Forshaw. '"Chemistry, That Starry Science" – Early Modern Conjunctions of Astrology and Alchemy' (2013)Peter J. Forshaw, 'Cabala Chymica or Chemia Cabalistica – Early Modern Alchemists and Cabala' (2013) A key figure in this development was German Heinrich Cornelius Agrippa (1486–1535), who received his Hermetic education in Italy in the schools of the humanists. In his De Occulta Philosophia, he attempted to merge Kabbalah, Hermeticism, and alchemy. He was instrumental in spreading this new blend of Hermeticism outside the borders of Italy.Glenn Alexander Magee. Hegel and the Hermetic Tradition. Cornell University Press. 2008. p.30Nicholas Goodrick-Clarke. The Western Esoteric Traditions: A Historical Introduction. Oxford University Press. 2008 p.60
Paracelsus (Philippus Aureolus Theophrastus Bombastus von Hohenheim, 1493–1541) cast alchemy into a new form, rejecting some of Agrippa's occultism and moving away from chrysopoeia. Paracelsus pioneered the use of chemicals and minerals in medicine and wrote, "Many have said of Alchemy, that it is for the making of gold and silver. For me such is not the aim, but to consider only what virtue and power may lie in medicines."
His hermetical views were that sickness and health in the body relied on the harmony of man the microcosm and Nature the macrocosm. He took an approach different from those before him, using this analogy not in the manner of soul-purification but in the manner that humans must have certain balances of minerals in their bodies, and that certain illnesses of the body had chemical remedies that could cure them. Iatrochemistry refers to the pharmaceutical applications of alchemy championed by Paracelsus.
John Dee (13 July 1527 – December 1608) followed Agrippa's occult tradition. Although better known for angel summoning, divination, and his role as astrologer, cryptographer, and consultant to Queen Elizabeth I, Dee's alchemical"Monas hieroglyphica is not a traditional alchemical work, but has important theoretical insights about a cosmic vision, in which alchemy played an important part." Monas Hieroglyphica, written in 1564 was his most popular and influential work. His writing portrayed alchemy as a sort of terrestrial astronomy in line with the Hermetic axiom As above so below.William Royall Newman, Anthony Grafton. Secrets of Nature: Astrology and Alchemy in Early Modern Europe. MIT Press, 2001. P.173. During the 17th century, a short-lived "supernatural" interpretation of alchemy became popular, including support by fellows of the Royal Society: Robert Boyle and Elias Ashmole. Proponents of the supernatural interpretation of alchemy believed that the philosopher's stone might be used to summon and communicate with angels. Journal of the History of Ideas, 41, 1980, pp. 293–318
The Aspiring Adept: Robert Boyle and His Alchemical Quest, by Lawrence M. Principe, 'Princeton University Press', 1998, pp. 188 90
Entrepreneurial opportunities were common for the alchemists of Renaissance Europe. Alchemists were contracted by the elite for practical purposes related to mining, medical services, and the production of chemicals, medicines, metals, and gemstones.Tara E. Nummedal. Alchemy and authority in the Holy Roman Empire. p.4 Rudolf II, Holy Roman Emperor, in the late 16th century, famously received and sponsored various alchemists at his court in Prague, including Dee and his associate Edward Kelley. King James IV of Scotland,Accounts of the Lord High Treasurer of Scotland, vol. iii, (1901), 99, 202, 206, 209, 330, 340, 341, 353, 355, 365, 379, 382, 389, 409. Julius, Duke of Brunswick-Lüneburg, Henry V, Duke of Brunswick-Lüneburg, Augustus, Elector of Saxony, Julius Echter von Mespelbrunn, and Maurice, Landgrave of Hesse-Kassel all contracted alchemists.Tara E. Nummedal. Alchemy and authority in the Holy Roman Empire. pp. 85–98 John's son Arthur Dee worked as a court physician to Michael I of Russia and Charles I of England but also compiled the alchemical book Fasciculus Chemicus.
thumb|Alchemist Sendivogius (1566–1636) by Jan Matejko, 1867
Although most of these appointments were legitimate, the trend of pseudo-alchemical fraud continued through the Renaissance. Betrüger would use sleight of hand, or claims of secret knowledge to make money or secure patronage. Legitimate mystical and medical alchemists such as Michael Maier and Heinrich Khunrath wrote about fraudulent transmutations, distinguishing themselves from the con artists.Tara E. Nummedal. Alchemy and authority in the Holy Roman Empire. p.171 False alchemists were sometimes prosecuted for fraud.
The terms "chemia" and "alchemia" were used as synonyms in the early modern period, and the differences between alchemy, chemistry and small-scale assaying and metallurgy were not as neat as in the present day. There were important overlaps between practitioners, and trying to classify them into alchemists, chemists and craftsmen is anachronistic. For example, Tycho Brahe (1546–1601), an alchemist better known for his astronomical and astrological investigations, had a laboratory built at his Uraniborg observatory/research institute. Michael Sendivogius (Michał Sędziwój, 1566–1636), a Polish alchemist, philosopher, medical doctor and pioneer of chemistry wrote mystical works but is also credited with distilling oxygen in a lab sometime around 1600. Sendivogious taught his technique to Cornelius Drebbel who, in 1621, applied this in a submarine. Isaac Newton devoted considerably more of his writing to the study of alchemy (see Isaac Newton's occult studies) than he did to either optics or physics. Other early modern alchemists who were eminent in their other studies include Robert Boyle, and Jan Baptist van Helmont. Their Hermeticism complemented rather than precluded their practical achievements in medicine and science. |
Alchemy | Later modern period | Later modern period
thumb|upright|Robert Boyle
thumb|right|An alchemist, pictured in Charles Mackay's Extraordinary Popular Delusions and the Madness of Crowds
The decline of European alchemy was brought about by the rise of modern science with its emphasis on rigorous quantitative experimentation and its disdain for "ancient wisdom". Although the seeds of these events were planted as early as the 17th century, alchemy still flourished for some two hundred years, and in fact may have reached its peak in the 18th century. As late as 1781 James Price claimed to have produced a powder that could transmute mercury into silver or gold. Early modern European alchemy continued to exhibit a diversity of theories, practices, and purposes: "Scholastic and anti-Aristotelian, Paracelsian and anti-Paracelsian, Hermetic, Neoplatonic, mechanistic, vitalistic, and more—plus virtually every combination and compromise thereof."
Robert Boyle (1627–1691) pioneered the scientific method in chemical investigations. He assumed nothing in his experiments and compiled every piece of relevant data. Boyle would note the place in which the experiment was carried out, the wind characteristics, the position of the Sun and Moon, and the barometer reading, all just in case they proved to be relevant. This approach eventually led to the founding of modern chemistry in the 18th and 19th centuries, based on revolutionary discoveries and ideas of Lavoisier and John Dalton.
Beginning around 1720, a rigid distinction began to be drawn for the first time between "alchemy" and "chemistry". By the 1740s, "alchemy" was now restricted to the realm of gold making, leading to the popular belief that alchemists were charlatans, and the tradition itself nothing more than a fraud. In order to protect the developing science of modern chemistry from the negative censure to which alchemy was being subjected, academic writers during the 18th-century scientific Enlightenment attempted to divorce and separate the "new" chemistry from the "old" practices of alchemy. This move was mostly successful, and the consequences of this continued into the 19th, 20th and 21st centuries.
During the occult revival of the early 19th century, alchemy received new attention as an occult science. The esoteric or occultist school that arose during the 19th century held the view that the substances and operations mentioned in alchemical literature are to be interpreted in a spiritual sense, less than as a practical tradition or protoscience. This interpretation claimed that the obscure language of the alchemical texts, which 19th century practitioners were not always able to decipher, were an allegorical guise for spiritual, moral or mystical processes.
Two seminal figures during this period were Mary Anne Atwood and Ethan Allen Hitchcock, who independently published similar works regarding spiritual alchemy. Both rebuffed the growing successes of chemistry, developing a completely esoteric view of alchemy. Atwood wrote: "No modern art or chemistry, notwithstanding all its surreptitious claims, has any thing in common with Alchemy." Atwood's work influenced subsequent authors of the occult revival including Eliphas Levi, Arthur Edward Waite, and Rudolf Steiner. Hitchcock, in his Remarks Upon Alchymists (1855) attempted to make a case for his spiritual interpretation with his claim that the alchemists wrote about a spiritual discipline under a materialistic guise in order to avoid accusations of blasphemy from the church and state. In 1845, Baron Carl Reichenbach, published his studies on Odic force, a concept with some similarities to alchemy, but his research did not enter the mainstream of scientific discussion.Daniel Merkur. Gnosis: An Esoteric Tradition of Mystical Visions and Unions. SUNY Press. 1993 p.55
In 1946, Louis Cattiaux published the Message Retrouvé, a work that was at once philosophical, mystical and highly influenced by alchemy. In his lineage, many researchers, including Emmanuel and Charles d'Hooghvorst, are updating alchemical studies in France and Belgium. |
Alchemy | Women | Women
Several women appear in the earliest history of alchemy. Michael Maier names four women who were able to make the philosophers' stone: Mary the Jewess, Cleopatra the Alchemist, Medera, and Taphnutia.Raphael Patai. The Jewish Alchemists: A History and Source Book. p. 78. Zosimos's sister Theosebia (later known as Euthica the Arab) and Isis the Prophetess also played roles in early alchemical texts.
The first alchemist whose name we know was Mary the Jewess (). Early sources claim that Mary (or Maria) devised a number of improvements to alchemical equipment and tools as well as novel techniques in chemistry. Her best known advances were in heating and distillation processes. The laboratory water-bath, known eponymously (especially in France) as the bain-marie, is said to have been invented or at least improved by her. Essentially a double-boiler, it was (and is) used in chemistry for processes that required gentle heating. The tribikos (a modified distillation apparatus) and the kerotakis (a more intricate apparatus used especially for sublimations) are two other advancements in the process of distillation that are credited to her. Although we have no writing from Mary herself, she is known from the early-fourth-century writings of Zosimos of Panopolis. After the Greco-Roman period, women's names appear less frequently in alchemical literature.
Towards the end of the Middle Ages and beginning of the Renaissance, due to the emergence of print, women were able to access the alchemical knowledge from texts of the preceding centuries. Caterina Sforza, the Countess of Forlì and Lady of Imola, is one of the few confirmed female alchemists after Mary the Jewess. As she owned an apothecary, she would practice science and conduct experiments in her botanic gardens and laboratories. Being knowledgeable in alchemy and pharmacology, she recorded all of her alchemical ventures in a manuscript named ('Experiments'). The manuscript contained more than four hundred recipes covering alchemy as well as cosmetics and medicine. One of these recipes was for the water of talc. Talc, which makes up talcum powder, is a mineral which, when combined with water and distilled, was said to produce a solution which yielded many benefits. These supposed benefits included turning silver to gold and rejuvenation. When combined with white wine, its powder form could be ingested to counteract poison. Furthermore, if that powder was mixed and drunk with white wine, it was said to be a source of protection from any poison, sickness, or plague. Other recipes were for making hair dyes, lotions, lip colours. There was also information on how to treat a variety of ailments from fevers and coughs to epilepsy and cancer. In addition, there were instructions on producing the quintessence (or aether), an elixir which was believed to be able to heal all sicknesses, defend against diseases, and perpetuate youthfulness. She also wrote about creating the illustrious philosophers' stone.
Some women known for their interest in alchemy were Catherine de' Medici, the Queen of France, and Marie de' Medici, the following Queen of France, who carried out experiments in her personal laboratory. Also, Isabella d'Este, the Marchioness of Mantua, made perfumes herself to serve as gifts. Due to the proliferation in alchemical literature of pseudepigrapha and anonymous works, however, it is difficult to know which of the alchemists were actually women. This contributed to a broader pattern in which male authors credited prominent noblewomen for beauty products with the purpose of appealing to a female audience. For example, in ("Gallant Recipe-Book"), the distillation of lemons and roses was attributed to Elisabetta Gonzaga, the duchess of Urbino. In the same book, Isabella d'Aragona, the daughter of Alfonso II of Naples, is accredited for recipes involving alum and mercury. Ippolita Maria Sforza is even referred to in an anonymous manuscript about a hand lotion created with rose powder and crushed bones.
As the sixteenth century went on, scientific culture flourished and people began collecting "secrets". During this period "secrets" referred to experiments, and the most coveted ones were not those which were bizarre, but the ones which had been proven to yield the desired outcome. In this period, the only book of secrets ascribed to a woman was ('The Secrets of Signora Isabella Cortese'). This book contained information on how to turn base metals into gold, medicine, and cosmetics. However, it is rumoured that a man, Girolamo Ruscelli, was the real author and only used a female voice to attract female readers.
In the nineteenth-century, Mary Anne Atwood's A Suggestive Inquiry into the Hermetic Mystery (1850) marked the return of women during the occult revival. |
Alchemy | Modern historical research | Modern historical research
The history of alchemy has become a recognized subject of academic study.Lawrence Principe. The Secrets of Alchemy. University of Chicago Press, 2015. As the language of the alchemists is analysed, historians are becoming more aware of the connections between that discipline and other facets of Western cultural history, such as the evolution of science and philosophy, the sociology and psychology of the intellectual communities, kabbalism, spiritualism, Rosicrucianism, and other mystic movements. Institutions involved in this research include The Chymistry of Isaac Newton project at Indiana University, the University of Exeter Centre for the Study of Esotericism (EXESESO), the European Society for the Study of Western Esotericism (ESSWE), and the University of Amsterdam's Sub-department for the History of Hermetic Philosophy and Related Currents. A large collection of books on alchemy is kept in the Bibliotheca Philosophica Hermetica in Amsterdam.
Journals which publish regularly on the topic of Alchemy include Ambix, published by the Society for the History of Alchemy and Chemistry, and Isis, published by the History of Science Society. |
Alchemy | Core concepts | Core concepts
thumb|Mandala illustrating common alchemical concepts, symbols, and processes. From Spiegel der Kunst und Natur.
Western alchemical theory corresponds to the worldview of late antiquity in which it was born. Concepts were imported from Neoplatonism and earlier Greek cosmology. As such, the classical elements appear in alchemical writings, as do the seven classical planets and the corresponding seven metals of antiquity. Similarly, the gods of the Roman pantheon who are associated with these luminaries are discussed in alchemical literature. The concepts of prima materia and anima mundi are central to the theory of the philosopher's stone. |
Alchemy | Magnum opus | Magnum opus
The Great Work of Alchemy is often described as a series of four stages represented by colours.
nigredo, a blackening or melanosis
albedo, a whitening or leucosis
citrinitas, a yellowing or xanthosis
rubedo, a reddening, purpling, or iosisJoseph Needham. Science & Civilisation in China: Chemistry and chemical technology. Spagyrical discovery and invention: magisteries of gold and immortality. Cambridge. 1974. p.23 |
Alchemy | Modernity | Modernity
Due to the complexity and obscurity of alchemical literature, and the 18th-century diffusion of remaining alchemical practitioners into the area of chemistry, the general understanding of alchemy in the 19th and 20th centuries was influenced by several distinct and radically different interpretations. Those focusing on the exoteric, such as historians of science Lawrence M. Principe and William R. Newman, have interpreted the 'Decknamen' (or code words) of alchemy as physical substances. These scholars have reconstructed physicochemical experiments that they say are described in medieval and early modern texts.Richard Conniff. "Alchemy May Not Have Been the Pseudoscience We All Thought It Was." Smithsonian Magazine. February 2014. At the opposite end of the spectrum, focusing on the esoteric, scholars, such as Florin George Călian and Anna Marie Roos, who question the reading of Principe and Newman, interpret these same Decknamen as spiritual, religious, or psychological concepts.
New interpretations of alchemy are still perpetuated, sometimes merging in concepts from New Age or radical environmentalism movements. Groups like the Rosicrucians and Freemasons have a continued interest in alchemy and its symbolism. Since the Victorian revival of alchemy, "occultists reinterpreted alchemy as a spiritual practice, involving the self-transformation of the practitioner and only incidentally or not at all the transformation of laboratory substances", which has contributed to a merger of magic and alchemy in popular thought. |
Alchemy | Esoteric interpretations of historical texts | Esoteric interpretations of historical texts
In the eyes of a variety of modern esoteric and Neo-Hermetic practitioners, alchemy is primarily spiritual. In this interpretation, transmutation of lead into gold is presented as an analogy for personal transmutation, purification, and perfection.Antoine Faivre, Wouter J. Hanegraaff. Western esotericism and the science of religion. 1995. p. 96
According to this view, early alchemists such as Zosimos of Panopolis () highlighted the spiritual nature of the alchemical quest, symbolic of a religious regeneration of the human soul.Allen G. Debus. Alchemy and early modern chemistry. The Society for the History of Alchemy and Chemistry. p.34. This approach is held to have continued in the Middle Ages, as metaphysical aspects, substances, physical states, and material processes are supposed to have been used as metaphors for spiritual entities, spiritual states, and, ultimately, transformation. In this sense, the literal meanings of 'Alchemical Formulas' hid a spiritual philosophy. In the Neo-Hermeticist interpretation, both the transmutation of common metals into gold and the universal panacea are held to symbolize evolution from an imperfect, diseased, corruptible, and ephemeral state toward a perfect, healthy, incorruptible, and everlasting state, so the philosopher's stone then represented a mystic key that would make this evolution possible. Applied to the alchemist, the twin goal symbolized their evolution from ignorance to enlightenment, and the stone represented a hidden spiritual truth or power that would lead to that goal. In texts that are believed to have been written according to this view, the cryptic alchemical symbols, diagrams, and textual imagery of late alchemical works are supposed to contain multiple layers of meanings, allegories, and references to other equally cryptic works; which must be laboriously decoded to discover their true meaning.
In his 1766 Alchemical Catechism, Théodore Henri de Tschudi suggested that the usage of the metals was symbolic: |
Alchemy | Psychology | Psychology
Alchemical symbolism has been important in analytical psychology and was revived and popularized from near extinction by the Swiss psychologist Carl Gustav Jung. Jung was initially confounded and at odds with alchemy and its images but after being given a copy of The Secret of the Golden Flower, a Chinese alchemical text translated by his friend Richard Wilhelm, he discovered a direct correlation or parallel between the symbolic images in the alchemical drawings and the inner, symbolic images coming up in his patients' dreams, visions, or fantasies. He observed these alchemical images occurring during the psychic process of transformation, a process that Jung called "individuation". Specifically, he regarded the conjuring up of images of gold or Lapis as symbolic expressions of the origin and goal of this "process of individuation".Jung, C. G. (1944). Psychology and Alchemy (2nd ed. 1968 Collected Works Vol. 12 ). London: Routledge. E.g. § 41, § 116, § 427, § 431, § 448. Together with his alchemical mystica soror (mystical sister) Jungian Swiss analyst Marie-Louise von Franz, Jung began collecting old alchemical texts, compiled a lexicon of key phrases with cross-references,Anthony Stevens: On Jung. (A new and authoritiative introduction to Jung's life and thought), Penguin Books, London 1990, , p. 193. and pored over them. The volumes of work he wrote shed new light onto understanding the art of transubstantiation and renewed alchemy's popularity as a symbolic process of coming into wholeness as a human being where opposites are brought into contact and inner and outer, spirit and matter are reunited in the hieros gamos, or divine marriage. His writings are influential in general psychology, but especially to those who have an interest in understanding the importance of dreams, symbols, and the unconscious archetypal forces (archetypes) that comprise all psychic life.Polly Young-Eisendrath, Terence Dawson. The Cambridge companion to Jung. Cambridge University Press. 1997. p.33C.G. Jung Preface to Richard Wilhelm's translation of the I Ching.C.-G. Jung Preface to the translation of The Secret of The Golden Flower.
Both von Franz and Jung have contributed significantly to the subject and work of alchemy and its continued presence in psychology as well as contemporary culture. Among the volumes Jung wrote on alchemy, his magnum opus is Volume 14 of his Collected Works, Mysterium Coniunctionis. |
Alchemy | Literature | Literature
Alchemy has had a long-standing relationship with art, seen both in alchemical texts and in mainstream entertainment. Literary alchemy appears throughout the history of English literature from Shakespeare to J. K. Rowling, and also the popular Japanese manga Fullmetal Alchemist. Here, characters or plot structure follow an alchemical magnum opus. In the 14th century, Chaucer began a trend of alchemical satire that can still be seen in recent fantasy works like those of the late Sir Terry Pratchett. Another literary work taking inspiration from the alchemical tradition is the 1988 novel The Alchemist by Brazilian writer Paulo Coelho.
Visual artists have had a similar relationship with alchemy. While some used it as a source of satire, others worked with the alchemists themselves or integrated alchemical thought or symbols in their work. Music was also present in the works of alchemists and continues to influence popular performers. In the last hundred years, alchemists have been portrayed in a magical and spagyric role in fantasy fiction, film, television, novels, comics and video games. |
Alchemy | Science | Science
One goal of alchemy, the transmutation of base substances into gold, is now known to be impossible by means of traditional chemistry, but possible by other physical means. Although not financially worthwhile, gold was synthesized in particle accelerators as early as 1941. |
Alchemy | See also | See also
Alchemical symbol
Chemistry
Corentin Louis Kervran § Biological transmutation
Cupellation
Historicism
History of chemistry
List of alchemical substances
List of alchemists
List of obsolete occupations
Nuclear transmutation
Outline of alchemy
Porta Alchemica
Renaissance magic
Spagyric
Superseded theories in science
Synthesis of precious metals
Thaumaturgy
Western esotericism |
Alchemy | Notes | Notes |
Alchemy | References | References |
Alchemy | Citations | Citations |
Alchemy | Sources used | Sources used
|
Alchemy | Bibliography | Bibliography |
Alchemy | Introductions and textbooks | Introductions and textbooks
(focus on technical aspects)
(focus on technical aspects)
(general overview)
(Greek and Byzantine alchemy)
(focus on technical aspects)
(Greek and Byzantine alchemy)
(the second part of volume 1 was never published; the other volumes deal with the modern period and are not relevant for alchemy)
(general overview, focus on esoteric aspects)
(general overview, written in a highly accessible style)
|
Alchemy | Greco-Egyptian alchemy | Greco-Egyptian alchemy |
Alchemy | Texts | Texts
Marcellin Berthelot and Charles-Émile Ruelle (eds.), Collection des anciens alchimistes grecs (CAAG), 3 vols., 1887–1888, Vol 1: https://gallica.bnf.fr/ark:/12148/bpt6k96492923, Vol 2: https://gallica.bnf.fr/ark:/12148/bpt6k9680734p, Vol. 3: https://gallica.bnf.fr/ark:/12148/bpt6k9634942s.
André-Jean Festugière, La Révélation d'Hermès Trismégiste, Paris, Les Belles Lettres, 2014 (, OCLC 897235256).
and (eds.), Les alchimistes grecs, t. 1 : Papyrus de Leyde – Papyrus de Stockholm – Recettes, Paris, Les Belles Lettres, 1981.
Otto Lagercrantz (ed), Papyrus Graecus Holmiensis, Uppsala, A.B. Akademiska Bokhandeln, 1913, Papyrus graecus holmiensis (P. holm.); Recepte für Silber, Steine und Purpur, bearb. von Otto Lagercrantz. Hrsg. mit Unterstützung des Vilh. Ekman'schen Universitätsfonds.
Michèle Mertens and (ed.), Les alchimistes grecs, t. 4.1 : Zosime de Panopolis. Mémoires authentiques, Paris, Les Belles Lettres, 1995.
Andrée Collinet and (ed.), Les alchimistes grecs, t. 10 : L'Anonyme de Zuretti ou l'Art sacré and divin de la chrysopée par un anonyme, Paris, Les Belles Lettres, 2000.
Andrée Collinet (ed), Les alchimistes grecs, t. 11 : Recettes alchimiques (Par. Gr. 2419; Holkhamicus 109) – Cosmas le Hiéromoine – Chrysopée, Paris, Les Belles Lettres, 2000.
Matteo Martelli (ed), The Four Books of Pseudo-Democritus, Maney Publishing, 2014. |
Alchemy | Studies | Studies
Dylan M. Burns, " μίξεώς τινι τέχνῃ κρείττονι : Alchemical Metaphor in the Paraphrase of Shem (NHC VII,1) ", Aries 15 (2015), p. 79–106.
Alberto Camplani, " Procedimenti magico-alchemici e discorso filosofico ermetico " in Giuliana Lanata (ed.), Il Tardoantico alle soglie del Duemila, ETS, 2000, p. 73–98.
Alberto Camplani and Marco Zambon, " Il sacrificio come problema in alcune correnti filosofice di età imperiale ", Annali di storia dell'esegesi 19 (2002), p. 59–99.
Régine Charron and Louis Painchaud, " 'God is a Dyer,' The Background and Significance of a Puzzling Motif in the Coptic Gospel According to Philip (CG II, 3), Le Muséon 114 (2001), p. 41-50.
Régine Charron, " The Apocryphon of John (NHC II,1) and the Greco-Egyptian Alchemical Literature ", Vigiliae Christinae 59 (2005), p. 438-456.
Philippe Derchain, "L'Atelier des Orfèvres à Dendara et les origines de l'alchimie," Chronique d'Égypte, vol. 65, no 130, 1990, p. 219–242.
Korshi Dosoo, " A History of the Theban Magical Library ", Bulletin of the American Society of Papyrologists 53 (2016), p. 251–274.
Olivier Dufault, Early Greek Alchemy, Patronage and Innovation in Late Antiquity, California Classical Studies, 2019, Early Greek Alchemy, Patronage and Innovation in Late Antiquity.
Sergio Knipe, " Sacrifice and self-transformation in the alchemical writings of Zosimus of Panopolis ", in Christopher Kelly, Richard Flower, Michael Stuart Williams (eds.), Unclassical Traditions. Volume II: Perspectives from East and West in Late Antiquity, Cambridge University Press, 2011, p. 59–69.
André-Jean Festugière, La Révélation d'Hermès Trismégiste, Paris, Les Belles Lettres, 2014 , .
Kyle A. Fraser, " Zosimos of Panopolis and the Book of Enoch: Alchemy as Forbidden Knowledge ", Aries 4.2 (2004), p. 125–147.
Kyle A. Fraser, " Baptized in Gnosis: The Spiritual Alchemy of Zosimos of Panopolis ", Dionysius 25 (2007), p. 33–54.
Kyle A. Fraser, " Distilling Nature's Secrets: The Sacred Art of Alchemy ", in John Scarborough and Paul Keyser (eds.), Oxford Handbook of Science and Medicine in the Classical World, Oxford University Press, 2018, p. 721–742. 2018. .
Shannon Grimes, Becoming Gold: Zosimos of Panopolis and the Alchemical Arts in Roman Egypt, Auckland, Rubedo Press, 2018,
Paul T. Keyser, " Greco-Roman Alchemy and Coins of Imitation Silver ", American Journal of Numismatics 7–8 (1995–1996), p. 209–234.
Paul Keyser, " The Longue Durée of Alchemy ", in John Scarborough and Paul Keyser (eds.), Oxford Handbook of Science and Medicine in the Classical World, Oxford University Press, 2018, p. 409–430.
Jean Letrouit, "Chronologie des alchimistes grecs," in Didier Kahn and Sylvain Matton, Alchimie: art, histoire et mythes, SEHA-Archè, 1995, p. 11–93.
Lindsay, Jack. The Origins of Alchemy in Greco-Roman Egypt. Barnes & Noble, 1970.
Paul Magdalino and Maria Mavroudi (eds.), The Occult Sciences in Byzantium, La Pomme d'or, 2006.
Matteo Martelli, " Alchemy, Medicine and Religion: Zosimus of Panopolis and the Egyptian Priests ", Religion in the Roman Empire 3.2 (2017), p. 202–220.
Daniel Stolzenberg, " Unpropitious Tinctures: Alchemy, Astrology & Gnosis According to Zosimos of Panopolis ", Archives internationales d'histoire des sciences 49 (1999), p. 3–31.
Cristina Viano, " Byzantine Alchemy, or the Era of Systematization ", in John Scarborough and Paul Keyser (eds.), Oxford Handbook of Science and Medicine in the Classical World, Oxford University Press, 2018, p. 943–964.
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Alchemy | Early modern | Early modern
Principe, Lawrence and William Newman. Alchemy Tried in the Fire: Starkey, Boyle, and the Fate of Helmontian Chymistry. University of Chicago Press, 2002. |
Alchemy | External links | External links
SHAC: Society for the History of Alchemy and Chemistry
ESSWE: European Society for the Study of Western Esotericism
Association for the Study of Esotericism
Category:Eastern esotericism
Category:Western esotericism
Category:Natural philosophy
Category:History of science |
Alchemy | Table of Content | Short description, Etymology, History, Hellenistic Egypt, Mythology, Technology, Philosophy, Byzantium, India, Islamic world, East Asia, Medieval Europe, Renaissance and early modern Europe, Later modern period, Women, Modern historical research, Core concepts, Magnum opus, Modernity, Esoteric interpretations of historical texts, Psychology, Literature, Science, See also, Notes, References, Citations, Sources used, Bibliography, Introductions and textbooks, Greco-Egyptian alchemy, Texts, Studies, Early modern, External links |
Alien | pp-vandalism | Alien primarily refers to:
Alien (law), a person in a country who is not a national of that country
Enemy alien, the above in times of war
Extraterrestrial life, life which does not originate from Earth
Specifically, a lifeform with extraterrestrial intelligence
For fictional extraterrestrial life, see Extraterrestrials in fiction
Introduced species, a species not native to its environment
Adventive plants or alien plants, species that are foreign to the native flora
Alien(s), or The Alien(s) may also refer to: |
Alien | Science and technology | Science and technology
AliEn (ALICE Environment), a grid framework
Alien (file converter), a Linux program
Alien Technology, a manufacturer of RFID technology |
Alien | Arts and entertainment | Arts and entertainment
Alien (franchise), a media franchise
Xenomorph, the titular alien in the franchise |
Alien | Films | Films
Alien (film), a 1979 film by Ridley Scott
Aliens (film), second film in the franchise from 1986 by James Cameron
Alien 3, third film in the franchise from 1992 by David Fincher
Alien Resurrection, fourth film in the franchise from 1997 by Jean-Pierre Jeunet
Alien vs. Predator (film), fifth film in the franchise from 2004 by Paul W. S. Anderson
Aliens vs. Predator: Requiem, sixth film in the franchise from 2007 by the Brothers Strause
Prometheus (2012 film), seventh film in the franchise from 2012 by Ridley Scott
Alien: Covenant, eighth film in the franchise from 2017 by Ridley Scott
Alien: Romulus, ninth film in the franchise from 2024 by Fede Álvarez
Alien 2: On Earth, a 1980 unofficial sequel of the 1979 Alien film
Alien Visitor (also titled Epsilon) (1995 film) AustralianItalian science fiction film by Rolf de Heer
The Alien (2016 film), a 2016 Mexican film
The Alien (unproduced film), an incomplete 1960s IndianAmerican film
Alienoid, a 2022 South Korean film |
Alien | Literature | Literature
Alien novels, an extension of the Alien franchise
Aliens: Colonial Marines Technical Manual, a 1995 book by Lee Brimmicombe-Wood, a guide to the fictional United States Colonial Marines
Aliens (Tappan Wright novel), a 1902 novel by Mary Tappan Wright
Aliens! (anthology) a 1980 anthology of science fiction edited by Gardner Dozois and Jack Dann
The Alien (novel), the eighth book in the Animorphs series by Katherine Applegate
The Aliens (play), a 2010 play by Annie Baker |
Alien | Music | Music |
Alien | Performers | Performers
Alien (band), a 1980s Swedish rock group
The Aliens (Australian band), a 1970s new wave group
The Aliens (Scottish band), a 2005–2008 rock group
The Aliens, the backing band for the American musician Jared Louche on his 1999 solo debut album Covergirl |
Alien | Albums | Albums
Alien (soundtrack), 1979
Alien (Alien album), 1988
Alien (Beam album), 2022
Alien (Northlane album), 2019
Alien (Strapping Young Lad album), 2005
Alien, a 1989 EP by Tankard
Aliens (soundtrack), 1987 |
Alien | Songs | Songs
"Alien" (Britney Spears song), 2013
"Alien" (Jonas Blue and Sabrina Carpenter song), 2018
"Alien", a song by Atlanta Rhythm from the album Quinella, 1981
"Alien", a song by Bush from the album Sixteen Stone, 1994
"Alien", a song by Dead Letter Circus from the EP Dead Letter Circus, 2007
"Alien", a song by The Devil Wears Prada from the EP Space, 2014
"Alien", a song by Erasure from the album Loveboat, 2000
"Alien", a song by Japan from the album Quiet Life, 1979
"Alien", a song by Lamb from the album Fear of Fours, 1999
"Alien", a song by Nerina Pallot from the album Dear Frustrated Superstar, 2001
"Alien", a song by P-Model from the album Landsale, 1980
"Alien", a song by Pennywise from the album Straight Ahead, 1999
"Alien", a song by Stray Kids from the album SKZ-Replay, 2022
"Alien", a song by Structures from the album Life Through a Window, 2014
"Alien", a song by the National from the album First Two Pages of Frankenstein, 2023
"Alien", a song by Third Day from the album Conspiracy No. 5, 1997
"Alien", a song by Thriving Ivory from the album Thriving Ivory, 2003
"Alien", a song by Tokio Hotel from the album Humanoid, 2009
"Alien", a 2018 song by Beach House
"Alien", a 2020 song by Lee Su-hyun
"Alien", a 2020 song by Dennis Lloyd
"Aliens" (song), a 2017 song by Coldplay
"Aliens", a 1984 song by Warlord
"The Alien", a song by Dream Theater from the album A View from the Top of the World, 2021 |
Alien | Video games | Video games |
Alien | Based on the 1979 and 1986 films | Based on the 1979 and 1986 films
Alien (1982 video game), a 1982 maze game based on the 1979 film
Alien (1984 video game), based on the 1979 film
Aliens: The Computer Game (US Version), a 1986 game by Activision based on the 1986 film of the same name
Aliens: The Computer Game (UK Version), a 1986 game by Electric Dreams based on the 1986 film
Aliens (1990 video game), a game by Konami, based on the 1986 film
Alien: Isolation, a 2014 video game based on the Alien science fiction horror film series
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Alien | Other video games | Other video games
Aliens (1982 video game), a text-only clone of Space Invaders written for the CP/M operating system on the Kaypro computer |
Alien | Other media | Other media
Alien (Armenian TV series), a 2017 melodrama series
Alien: Isolation – The Digital Series, web series in the Alien franchise from 2019 by Fabien Dubois
Alien: Earth, an upcoming science fiction horror television series in the franchise by Noah Hawley
Alien (sculpture), a 2012 work by David Breuer-Weil, in Mottisfont, Hampshire, England
Aliens (Dark Horse Comics line)
The Aliens (TV series), 2016 British sci-fi television series
"Aliens" (Roseanne), a 1992 television episode |
Alien | Other uses | Other uses
Alien (shipping company), a Russian company
Alien Sun (born 1974), Singaporean actress
Alien, a perfume by Thierry Mugler
Alian District (Alien), in Taiwan |
Alien | See also | See also
Alians, an Islamic order
Alien Project (disambiguation)
Alien 4 (disambiguation)
Alien vs. Predator (disambiguation)
Astrobiology, the study of hypothetical alien life
ATLiens, a 1996 album by OutKast
Predator (disambiguation)
UFO (disambiguation)
Unidentified flying object (disambiguation)
Outsider (disambiguation) |
Alien | Table of Content | pp-vandalism, Science and technology, Arts and entertainment, Films, Literature, Music, Performers, Albums, Songs, Video games, Based on the 1979 and 1986 films, Other video games, Other media, Other uses, See also |
Astronomer | short description | thumb|upright=1.5|A voting session is conducted in 2006 International Astronomical Union's general assembly for determining a new definition of a planet
An astronomer is a scientist in the field of astronomy who focuses on a specific question or field outside the scope of Earth. Astronomers observe astronomical objects, such as stars, planets, moons, comets and galaxies – in either observational (by analyzing the data) or theoretical astronomy. Examples of topics or fields astronomers study include planetary science, solar astronomy, the origin or evolution of stars, or the formation of galaxies. A related but distinct subject is physical cosmology, which studies the Universe as a whole. |
Astronomer | Types | Types
Astronomers typically fall under either of two main types: observational and theoretical. Observational astronomers make direct observations of celestial objects and analyze the data. In contrast, theoretical astronomers create and investigate models of things that cannot be observed. Because it takes millions to billions of years for a system of stars or a galaxy to complete a life cycle, astronomers must observe snapshots of different systems at unique points in their evolution to determine how they form, evolve, and die. They use this data to create models or simulations to theorize how different celestial objects work.
Further subcategories under these two main branches of astronomy include planetary astronomy, astrobiology, stellar astronomy, astrometry, galactic astronomy, extragalactic astronomy, or physical cosmology. Astronomers can also specialize in certain specialties of observational astronomy, such as infrared astronomy, neutrino astronomy, x-ray astronomy, and gravitational-wave astronomy. |
Astronomer | Academic | Academic |
Astronomer | History | History
left|thumb|upright|Galileo is often referred to as the father of modern astronomy. Portrait by Justus Sustermans.
right|thumb|upright|Johannes Kepler, one of the fathers of modern astronomy
Historically, astronomy was more concerned with the classification and description of phenomena in the sky, while astrophysics attempted to explain these phenomena and the differences between them using physical laws. Today, that distinction has mostly disappeared and the terms "astronomer" and "astrophysicist" are interchangeable. Professional astronomers are highly educated individuals who typically have a PhD in physics or astronomy and are employed by research institutions or universities. They spend the majority of their time working on research, although they quite often have other duties such as teaching, building instruments, or aiding in the operation of an observatory.
The American Astronomical Society, which is the major organization of professional astronomers in North America, has approximately 8,200 members (as of 2024). This number includes scientists from other fields such as physics, geology, and engineering, whose research interests are closely related to astronomy. The International Astronomical Union comprises about 12,700 members from 92 countries who are involved in astronomical research at the PhD level and beyond (as of 2024).
thumb|upright|Portrait of the Flemish astronomer Ferdinand Verbiest who became head of the Mathematical Board and director of the Observatory of the Chinese emperor in 1669
Contrary to the classical image of an old astronomer peering through a telescope through the dark hours of the night, it is far more common to use a charge-coupled device (CCD) camera to record a long, deep exposure, allowing a more sensitive image to be created because the light is added over time. Before CCDs, photographic plates were a common method of observation. Modern astronomers spend relatively little time at telescopes, usually just a few weeks per year. Analysis of observed phenomena, along with making predictions as to the causes of what they observe, takes the majority of observational astronomers' time. |
Astronomer | Activities and graduate degree training | Activities and graduate degree training
Astronomers who serve as faculty spend much of their time teaching undergraduate and graduate classes. Most universities also have outreach programs, including public telescope time and sometimes planetariums, as a public service to encourage interest in the field.
Those who become astronomers usually have a broad background in physics, mathematics, sciences, and computing in high school. Taking courses that teach how to research, write, and present papers are part of the higher education of an astronomer, while most astronomers attain both a Master's degree and eventually a PhD degree in astronomy, physics or astrophysics.
PhD training typically involves 5-6 years of study, including completion of upper-level courses in the core sciences, a competency examination, experience with teaching undergraduates and participating in outreach programs, work on research projects under the student's supervising professor, completion of a PhD thesis, and passing a final oral exam. Throughout the PhD training, a successful student is financially supported with a stipend. |
Astronomer | Amateur astronomers | Amateur astronomers
While there is a relatively low number of professional astronomers, the field is popular among amateurs. Most cities have amateur astronomy clubs that meet on a regular basis and often host star parties. The Astronomical Society of the Pacific is the largest general astronomical society in the world, comprising both professional and amateur astronomers as well as educators from 70 different nations.
As with any hobby, most people who practice amateur astronomy may devote a few hours a month to stargazing and reading the latest developments in research. However, amateurs span the range from so-called "armchair astronomers" to people who own science-grade telescopes and instruments with which they are able to make their own discoveries, create astrophotographs, and assist professional astronomers in research. |
Astronomer | See also | See also
List of astronomers
List of women astronomers
List of Muslim astronomers
List of French astronomers
List of Hungarian astronomers
List of Russian astronomers and astrophysicists
List of Slovenian astronomers |
Astronomer | References | References |
Astronomer | Sources | Sources
|
Astronomer | External links | External links
American Astronomical Society
European Astronomical Society
International Astronomical Union
Astronomical Society of the Pacific
Space's astronomy news
Category:Astronomy
Category:Science occupations |
Astronomer | Table of Content | short description, Types, Academic, History, Activities and graduate degree training, Amateur astronomers, See also, References, Sources, External links |
ASCII | Short description | ASCII ( ), an acronym for American Standard Code for Information Interchange, is a character encoding standard for representing a particular set of 95 (English language focused) printable and 33 control characters a total of 128 code points. The set of available punctuation had significant impact on the syntax of computer languages and text markup. ASCII hugely influenced the design of character sets used by modern computers; for example the first 128 code points of Unicode are the same as ASCII.
ASCII encodes each code-point as a value from 0 to 127 storable as a seven-bit integer. Ninety-five code-points are printable, including digits 0 to 9, lowercase letters a to z, uppercase letters A to Z, and commonly used punctuation symbols. For example, the letter is represented as 105 (decimal). Also, ASCII specifies 33 non-printing control codes which originated with ; most of which are now obsolete. The control characters that are still commonly used include carriage return, line feed, and tab.
ASCII lacks code-points for characters with diacritical marks and therefore does not directly support terms or names such as résumé, jalapeño, or Beyoncé. But, depending on hardware and software support, some diacritical marks can be rendered by overwriting a letter with a backtick (`) or tilde (~).
Despite being an American standard, ASCII does not have a code point for the cent (¢).
The Internet Assigned Numbers Authority (IANA) prefers the name US-ASCII for this character encoding.
ASCII is one of the IEEE milestones. |
ASCII | History | History
ASCII was developed in part from telegraph code. Its first commercial use was in the Teletype Model 33 and the Teletype Model 35 as a seven-bit teleprinter code promoted by Bell data services. Work on the ASCII standard began in May 1961, with the first meeting of the American Standards Association's (ASA) (now the American National Standards Institute or ANSI) X3.2 subcommittee. The first edition of the standard was published in 1963, underwent a major revision during 1967, and experienced its most recent update during 1986. Compared to earlier telegraph codes, the proposed Bell code and ASCII were both ordered for more convenient sorting (i.e., alphabetization) of lists and added features for devices other than teleprinters.
thumb|upright=1.25|right|ASCII (1963). Control Pictures of equivalent controls are shown where they exist, or a grey dot otherwise.
ASCII was developed under the auspices of a committee of the American Standards Association (ASA), called the X3 committee, by its X3.2 (later X3L2) subcommittee, and later by that subcommittee's X3.2.4 working group (now INCITS). The ASA later became the United States of America Standards Institute (USASI) and ultimately became the American National Standards Institute (ANSI).
With the other special characters and control codes filled in, ASCII was published as ASA X3.4-1963, leaving 28 code positions without any assigned meaning, reserved for future standardization, and one unassigned control code. There was some debate at the time whether there should be more control characters rather than the lowercase alphabet. The indecision did not last long: during May 1963 the CCITT Working Party on the New Telegraph Alphabet proposed to assign lowercase characters to sticks 6 and 7,Brief Report: Meeting of CCITT Working Party on the New Telegraph Alphabet, May 13–15, 1963. and International Organization for Standardization TC 97 SC 2 voted during October to incorporate the change into its draft standard.Report of ISO/TC/97/SC 2 – Meeting of October 29–31, 1963. The X3.2.4 task group voted its approval for the change to ASCII at its May 1963 meeting.Report on Task Group X3.2.4, June 11, 1963, Pentagon Building, Washington, DC. Locating the lowercase letters in sticks 6 and 7 caused the characters to differ in bit pattern from the upper case by a single bit, which simplified case-insensitive character matching and the construction of keyboards and printers.
The X3 committee made other changes. It added the brace and vertical bar characters.Report of Meeting No. 8, Task Group X3.2.4, December 17 and 18, 1963 It renamed some control characters SOM became SOH. It moved or removing others RU was removed. ASCII was subsequently updated as USAS X3.4-1967, then USAS X3.4-1968, ANSI X3.4-1977, and finally, ANSI X3.4-1986.
The use of ASCII format for Network Interchange was described in 1969. (NB. Almost identical wording to USAS X3.4-1968 except for the intro.) That document was formally elevated to an Internet Standard in 2015. |
ASCII | Revisions | Revisions
ASA X3.4-1963
ASA X3.4-1965 (approved, but not published, nevertheless used by IBM 2260 & 2265 Display Stations and IBM 2848 Display Control)
USAS X3.4-1967
USAS X3.4-1968
ANSI X3.4-1977
ANSI X3.4-1986
ANSI X3.4-1986 (R1992)
ANSI X3.4-1986 (R1997)
ANSI INCITS 4-1986 (R2002)
ANSI INCITS 4-1986 (R2007)
INCITS 4-1986 (R2012)
INCITS 4-1986 (R2017)
INCITS 4-1986 (R2022)
In the X3.15 standard, the X3 committee also addressed how ASCII should be transmitted (least significant bit first) and recorded on perforated tape. They proposed a 9-track standard for magnetic tape and attempted to deal with some punched card formats. |
ASCII | Design considerations | Design considerations |
ASCII | Bit width | Bit width
The X3.2 subcommittee designed ASCII based on the earlier teleprinter encoding systems. Like other character encodings, ASCII specifies a correspondence between digital bit patterns and character symbols (i.e. graphemes and control characters). This allows digital devices to communicate with each other and to process, store, and communicate character-oriented information such as written language. Before ASCII was developed, the encodings in use included 26 alphabetic characters, 10 numerical digits, and from 11 to 25 special graphic symbols. To include all these, and control characters compatible with the Comité Consultatif International Téléphonique et Télégraphique (CCITT) International Telegraph Alphabet No. 2 (ITA2) standard of 1932, FIELDATA (1956), and early EBCDIC (1963), more than 64 codes were required for ASCII.
ITA2 was in turn based on Baudot code, the 5-bit telegraph code Émile Baudot invented in 1870 and patented in 1874.
The committee debated the possibility of a shift function (like in ITA2), which would allow more than 64 codes to be represented by a six-bit code. In a shifted code, some character codes determine choices between options for the following character codes. It allows compact encoding, but is less reliable for data transmission, as an error in transmitting the shift code typically makes a long part of the transmission unreadable. The standards committee decided against shifting, and so ASCII required at least a seven-bit code.
The committee considered an eight-bit code, since eight bits (octets) would allow two four-bit patterns to efficiently encode two digits with binary-coded decimal. However, it would require all data transmission to send eight bits when seven could suffice. The committee voted to use a seven-bit code to minimize costs associated with data transmission. Since perforated tape at the time could record eight bits in one position, it also allowed for a parity bit for error checking if desired. Eight-bit machines (with octets as the native data type) that did not use parity checking typically set the eighth bit to 0. |
ASCII | Internal organization | Internal organization
The code itself was patterned so that most control codes were together and all graphic codes were together, for ease of identification. The first two so-called ASCII sticks (32 positions) were reserved for control characters. The "space" character had to come before graphics to make sorting easier, so it became position 20hex; for the same reason, many special signs commonly used as separators were placed before digits. The committee decided it was important to support uppercase 64-character alphabets, and chose to pattern ASCII so it could be reduced easily to a usable 64-character set of graphic codes, as was done in the DEC SIXBIT code (1963). Lowercase letters were therefore not interleaved with uppercase. To keep options available for lowercase letters and other graphics, the special and numeric codes were arranged before the letters, and the letter A was placed in position 41hex to match the draft of the corresponding British standard. The digits 0–9 are prefixed with 011, but the remaining 4 bits correspond to their respective values in binary, making conversion with binary-coded decimal straightforward (for example, 5 in encoded to 0110101, where 5 is 0101 in binary).
Many of the non-alphanumeric characters were positioned to correspond to their shifted position on typewriters; an important subtlety is that these were based on mechanical typewriters, not electric typewriters. Mechanical typewriters followed the de facto standard set by the Remington No. 2 (1878), the first typewriter with a shift key, and the shifted values of 23456789- were "#$%_&'() early typewriters omitted 0 and 1, using O (capital letter o) and l (lowercase letter L) instead, but 1! and 0) pairs became standard once 0 and 1 became common. Thus, in ASCII !"#$% were placed in the second stick, positions 1–5, corresponding to the digits 1–5 in the adjacent stick. The parentheses could not correspond to 9 and 0, however, because the place corresponding to 0 was taken by the space character. This was accommodated by removing _ (underscore) from 6 and shifting the remaining characters, which corresponded to many European typewriters that placed the parentheses with 8 and 9. This discrepancy from typewriters led to bit-paired keyboards, notably the Teletype Model 33, which used the left-shifted layout corresponding to ASCII, differently from traditional mechanical typewriters.
Electric typewriters, notably the IBM Selectric (1961), used a somewhat different layout that has become de facto standard on computers following the IBM PC (1981), especially Model M (1984) and thus shift values for symbols on modern keyboards do not correspond as closely to the ASCII table as earlier keyboards did. The /? pair also dates to the No. 2, and the ,< .> pairs were used on some keyboards (others, including the No. 2, did not shift , (comma) or . (full stop) so they could be used in uppercase without unshifting). However, ASCII split the ;: pair (dating to No. 2), and rearranged mathematical symbols (varied conventions, commonly -* =+) to :* ;+ -=.
Some then-common typewriter characters were not included, notably ½ ¼ ¢, while ^ ` ~ were included as diacritics for international use, and < > for mathematical use, together with the simple line characters \ | (in addition to common /). The @ symbol was not used in continental Europe and the committee expected it would be replaced by an accented À in the French variation, so the @ was placed in position 40hex, right before the letter A.
The control codes felt essential for data transmission were the start of message (SOM), end of address (EOA), end of message (EOM), end of transmission (EOT), "who are you?" (WRU), "are you?" (RU), a reserved device control (DC0), synchronous idle (SYNC), and acknowledge (ACK). These were positioned to maximize the Hamming distance between their bit patterns. |
ASCII | <span class="anchor" id="Order"></span>Character order | Character order
ASCII-code order is also called ASCIIbetical order. Collation of data is sometimes done in this order rather than "standard" alphabetical order (collating sequence). The main deviations in ASCII order are:
All uppercase come before lowercase letters; for example, "Z" precedes "a"
Digits and many punctuation marks come before letters
An intermediate order converts uppercase letters to lowercase before comparing ASCII values. |
ASCII | <span class="anchor" id="Code chart"></span><span class="anchor" id="ASCII printable code chart"></span><span class="anchor" id="ASCII printable characters"></span>Character set | Character set
thumb
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ASCII | Character groups | Character groups |
ASCII | <span class="anchor" id="ASCII control characters"></span>Control characters | Control characters
thumb|right|Early symbols assigned to the 32 control characters, space and delete characters. (ISO 2047, MIL-STD-188-100, 1972)
ASCII reserves the first 32 code points (numbers 0–31 decimal) and the last one (number 127 decimal) for control characters. These are codes intended to control peripheral devices (such as printers), or to provide meta-information about data streams, such as those stored on magnetic tape. Despite their name, these code points do not represent printable characters (i.e. they are not characters at all, but signals). For debugging purposes, "placeholder" symbols (such as those given in ISO 2047 and its predecessors) are assigned to them.
For example, character 0x0A represents the "line feed" function (which causes a printer to advance its paper), and character 8 represents "backspace". refers to control characters that do not include carriage return, line feed or white space as non-whitespace control characters. (NB. NO-WS-CTL.) Except for the control characters that prescribe elementary line-oriented formatting, ASCII does not define any mechanism for describing the structure or appearance of text within a document. Other schemes, such as markup languages, address page and document layout and formatting.
The original ASCII standard used only short descriptive phrases for each control character. The ambiguity this caused was sometimes intentional, for example where a character would be used slightly differently on a terminal link than on a data stream, and sometimes accidental, for example the standard is unclear about the meaning of "delete".
Probably the most influential single device affecting the interpretation of these characters was the Teletype Model 33 ASR, which was a printing terminal with an available paper tape reader/punch option. Paper tape was a very popular medium for long-term program storage until the 1980s, less costly and in some ways less fragile than magnetic tape. In particular, the Teletype Model 33 machine assignments for codes 17 (control-Q, DC1, also known as XON), 19 (control-S, DC3, also known as XOFF), and 127 (delete) became de facto standards. The Model 33 was also notable for taking the description of control-G (code 7, BEL, meaning audibly alert the operator) literally, as the unit contained an actual bell which it rang when it received a BEL character. Because the keytop for the O key also showed a left-arrow symbol (from ASCII-1963, which had this character instead of underscore), a noncompliant use of code 15 (control-O, shift in) interpreted as "delete previous character" was also adopted by many early timesharing systems but eventually became neglected.
When a Teletype 33 ASR equipped with the automatic paper tape reader received a control-S (XOFF, an abbreviation for transmit off), it caused the tape reader to stop; receiving control-Q (XON, transmit on) caused the tape reader to resume. This so-called flow control technique became adopted by several early computer operating systems as a "handshaking" signal warning a sender to stop transmission because of impending buffer overflow; it persists to this day in many systems as a manual output control technique. On some systems, control-S retains its meaning, but control-Q is replaced by a second control-S to resume output.
The 33 ASR also could be configured to employ control-R (DC2) and control-T (DC4) to start and stop the tape punch; on some units equipped with this function, the corresponding control character lettering on the keycap above the letter was TAPE and TAPE respectively. |
ASCII | Delete vs backspace | Delete vs backspace
The Teletype could not move its typehead backwards, so it did not have a key on its keyboard to send a BS (backspace). Instead, there was a key marked that sent code 127 (DEL). The purpose of this key was to erase mistakes in a manually-input paper tape: the operator had to push a button on the tape punch to back it up, then type the rubout, which punched all holes and replaced the mistake with a character that was intended to be ignored. Teletypes were commonly used with the less-expensive computers from Digital Equipment Corporation (DEC); these systems had to use what keys were available, and thus the DEL character was assigned to erase the previous character. Because of this, DEC video terminals (by default) sent the DEL character for the key marked "Backspace" while the separate key marked "Delete" sent an escape sequence; many other competing terminals sent a BS character for the backspace key.
The early Unix tty drivers, unlike some modern implementations, allowed only one character to be set to erase the previous character in canonical input processing (where a very simple line editor is available); this could be set to BS or DEL, but not both, resulting in recurring situations of ambiguity where users had to decide depending on what terminal they were using (shells that allow line editing, such as ksh, bash, and zsh, understand both). The assumption that no key sent a BS character allowed Ctrl+H to be used for other purposes, such as the "help" prefix command in GNU Emacs. |
ASCII | Escape | Escape
Many more of the control characters have been assigned meanings quite different from their original ones. The "escape" character (ESC, code 27), for example, was intended originally to allow sending of other control characters as literals instead of invoking their meaning, an "escape sequence". This is the same meaning of "escape" encountered in URL encodings, C language strings, and other systems where certain characters have a reserved meaning. Over time this interpretation has been co-opted and has eventually been changed.
In modern usage, an ESC sent to the terminal usually indicates the start of a command sequence, which can be used to address the cursor, scroll a region, set/query various terminal properties, and more. They are usually in the form of a so-called "ANSI escape code" (often starting with a "Control Sequence Introducer", "CSI", "") from ECMA-48 (1972) and its successors. Some escape sequences do not have introducers, like the "Reset to Initial State", "RIS" command "".
In contrast, an ESC read from the terminal is most often used as an out-of-band character used to terminate an operation or special mode, as in the TECO and vi text editors. In graphical user interface (GUI) and windowing systems, ESC generally causes an application to abort its current operation or to exit (terminate) altogether. |
ASCII | End of line | End of line
The inherent ambiguity of many control characters, combined with their historical usage, created problems when transferring "plain text" files between systems. The best example of this is the newline problem on various operating systems. Teletype machines required that a line of text be terminated with both "carriage return" (which moves the printhead to the beginning of the line) and "line feed" (which advances the paper one line without moving the printhead). The name "carriage return" comes from the fact that on a manual typewriter the carriage holding the paper moves while the typebars that strike the ribbon remain stationary. The entire carriage had to be pushed (returned) to the right in order to position the paper for the next line.
DEC operating systems (OS/8, RT-11, RSX-11, RSTS, TOPS-10, etc.) used both characters to mark the end of a line so that the console device (originally Teletype machines) would work. By the time so-called "glass TTYs" (later called CRTs or "dumb terminals") came along, the convention was so well established that backward compatibility necessitated continuing to follow it. When Gary Kildall created CP/M, he was inspired by some of the command line interface conventions used in DEC's RT-11 operating system.
Until the introduction of PC DOS in 1981, IBM had no influence in this because their 1970s operating systems used EBCDIC encoding instead of ASCII, and they were oriented toward punch-card input and line printer output on which the concept of "carriage return" was meaningless. IBM's PC DOS (also marketed as MS-DOS by Microsoft) inherited the convention by virtue of being loosely based on CP/M, and Windows in turn inherited it from MS-DOS.
Requiring two characters to mark the end of a line introduces unnecessary complexity and ambiguity as to how to interpret each character when encountered by itself. To simplify matters, plain text data streams, including files, on Multics used line feed (LF) alone as a line terminator. The tty driver would handle the LF to CRLF conversion on output so files can be directly printed to terminal, and NL (newline) is often used to refer to CRLF in UNIX documents. Unix and Unix-like systems, and Amiga systems, adopted this convention from Multics. On the other hand, the original Macintosh OS, Apple DOS, and ProDOS used carriage return (CR) alone as a line terminator; however, since Apple later replaced these obsolete operating systems with their Unix-based macOS (formerly named OS X) operating system, they now use line feed (LF) as well. The Radio Shack TRS-80 also used a lone CR to terminate lines.
Computers attached to the ARPANET included machines running operating systems such as TOPS-10 and TENEX using CR-LF line endings; machines running operating systems such as Multics using LF line endings; and machines running operating systems such as OS/360 that represented lines as a character count followed by the characters of the line and which used EBCDIC rather than ASCII encoding. The Telnet protocol defined an ASCII "Network Virtual Terminal" (NVT), so that connections between hosts with different line-ending conventions and character sets could be supported by transmitting a standard text format over the network. Telnet used ASCII along with CR-LF line endings, and software using other conventions would translate between the local conventions and the NVT. The File Transfer Protocol adopted the Telnet protocol, including use of the Network Virtual Terminal, for use when transmitting commands and transferring data in the default ASCII mode. This adds complexity to implementations of those protocols, and to other network protocols, such as those used for E-mail and the World Wide Web, on systems not using the NVT's CR-LF line-ending convention. |
ASCII | End of file/stream | End of file/stream
The PDP-6 monitor, and its PDP-10 successor TOPS-10, used control-Z (SUB) as an end-of-file indication for input from a terminal. Some operating systems such as CP/M tracked file length only in units of disk blocks, and used control-Z to mark the end of the actual text in the file. For these reasons, EOF, or end-of-file, was used colloquially and conventionally as a three-letter acronym for control-Z instead of SUBstitute. The end-of-text character (ETX), also known as control-C, was inappropriate for a variety of reasons, while using control-Z as the control character to end a file is analogous to the letter Z's position at the end of the alphabet, and serves as a very convenient mnemonic aid. A historically common and still prevalent convention uses the ETX character convention to interrupt and halt a program via an input data stream, usually from a keyboard.
The Unix terminal driver uses the end-of-transmission character (EOT), also known as control-D, to indicate the end of a data stream.
In the C programming language, and in Unix conventions, the null character is used to terminate text strings; such null-terminated strings can be known in abbreviation as ASCIZ or ASCIIZ, where here Z stands for "zero". |
ASCII | Table of codes | Table of codes |
ASCII | Control code table<span class="anchor" id="ASCII control code chart"></span> | Control code table
Binary Oct Dec Hex Abbreviation Unicode Control Pictures Caret notation C escape sequence Name (1967) 1963 1965 1967 000 0000 000 0 00NULLNUL ␀ Null 000 0001 001 1 01SOMSOH ␁ Start of Heading 000 0010 002 2 02EOASTX ␂ Start of Text 000 0011 003 3 03EOMETX ␃ End of Text 000 0100 004 4 04EOT ␄ End of Transmission 000 0101 005 5 05WRUENQ ␅ Enquiry 000 0110 006 6 06RUACK ␆ Acknowledgement 000 0111 007 7 07BELLBEL ␇ Bell 000 1000 010 8 08FE0BS ␈ Backspace 000 1001 011 9 09HT/SKHT ␉ Horizontal Tab 000 1010 012 10 0ALF ␊ Line Feed 000 1011 013 11 0BVTABVT ␋ Vertical Tab 000 1100 014 12 0CFF ␌ Form Feed 000 1101 015 13 0DCR ␍ Carriage Return 000 1110 016 14 0ESO ␎ Shift Out 000 1111 017 15 0FSI ␏ Shift In 001 0000 020 16 10DC0DLE ␐ Data Link Escape 001 0001 021 17 11DC1 ␑ Device Control 1 (often XON) 001 0010 022 18 12DC2 ␒ Device Control 2 001 0011 023 19 13DC3 ␓ Device Control 3 (often XOFF) 001 0100 024 20 14DC4 ␔ Device Control 4 001 0101 025 21 15ERRNAK ␕ Negative Acknowledgement 001 0110 026 22 16SYNCSYN ␖ Synchronous Idle 001 0111 027 23 17LEMETB ␗ End of Transmission Block 001 1000 030 24 18S0CAN ␘ Cancel 001 1001 031 25 19S1EM ␙ End of Medium 001 1010 032 26 1AS2SSSUB ␚ Substitute 001 1011 033 27 1BS3ESC ␛ Escape 001 1100 034 28 1CS4FS ␜ File Separator 001 1101 035 29 1DS5GS ␝ Group Separator 001 1110 036 30 1ES6RS ␞ Record Separator 001 1111 037 31 1FS7US ␟ Unit Separator 111 1111 177 127 7FDEL ␡ Delete
Other representations might be used by specialist equipment, for example ISO 2047 graphics or hexadecimal numbers. |
ASCII | <span class="anchor" id="ASCII-printable-characters"></span><span class="anchor" id="Printable_characters"></span>Printable character table | Printable character table
At the time of adoption, the codes 20hex to 7Ehex would cause the printing of a visible character (a glyph), and thus were designated "printable characters". These codes represent letters, digits, punctuation marks, and a few miscellaneous symbols. There are 95 printable characters in total.
The empty space between words, as produced by the space bar of a keyboard, is character code 20hex. Since the space character is visible in printed text it considered a "printable character", even though it is unique in having no visible glyph. It is listed in the printable character table, as per the ASCII standard, instead of in the control character table.
Code 7Fhex corresponds to the non-printable "delete" (DEL) control character and is listed in the control character table.
Earlier versions of ASCII used the up arrow instead of the caret (5Ehex) and the left arrow instead of the underscore (5Fhex).
Binary Oct Dec Hex Glyph 1963 1965 1967010 0000 040 32 20 space (no visible glyph)010 0001 041 33 21 !010 0010 042 34 22 "010 0011 043 35 23 #010 0100 044 36 24 $010 0101 045 37 25 %010 0110 046 38 26 &010 0111 047 39 27 '010 1000 050 40 28 (010 1001 051 41 29 )010 1010 052 42 2A *010 1011 053 43 2B +010 1100 054 44 2C ,010 1101 055 45 2D -010 1110 056 46 2E .010 1111 057 47 2F /011 0000 060 48 30 0011 0001 061 49 31 1011 0010 062 50 32 2011 0011 063 51 33 3011 0100 064 52 34 4011 0101 065 53 35 5011 0110 066 54 36 6011 0111 067 55 37 7011 1000 070 56 38 8011 1001 071 57 39 9011 1010 072 58 3A :011 1011 073 59 3B ;011 1100 074 60 3C <011 1101 075 61 3D =011 1110 076 62 3E >011 1111 077 63 3F ?100 0000 100 64 40 @ ` @100 0001 101 65 41 A100 0010 102 66 42 B100 0011 103 67 43 C100 0100 104 68 44 D100 0101 105 69 45 E100 0110 106 70 46 F100 0111 107 71 47 G100 1000 110 72 48 H100 1001 111 73 49 I100 1010 112 74 4A J100 1011 113 75 4B K100 1100 114 76 4C L100 1101 115 77 4D M100 1110 116 78 4E N100 1111 117 79 4F O101 0000 120 80 50 P101 0001 121 81 51 Q101 0010 122 82 52 R101 0011 123 83 53 S101 0100 124 84 54 T101 0101 125 85 55 U101 0110 126 86 56 V101 0111 127 87 57 W101 1000 130 88 58 X101 1001 131 89 59 Y101 1010 132 90 5A Z101 1011 133 91 5B [101 1100 134 92 5C \ ~ \101 1101 135 93 5D ]101 1110 136 94 5E ↑ ^101 1111 137 95 5F ← _110 0000 140 96 60 @ `110 0001 141 97 61 a110 0010 142 98 62 b110 0011 143 99 63 c110 0100 144 100 64 d110 0101 145 101 65 e110 0110 146 102 66 f110 0111 147 103 67 g110 1000 150 104 68 h110 1001 151 105 69 i110 1010 152 106 6A j110 1011 153 107 6B k110 1100 154 108 6C l110 1101 155 109 6D m110 1110 156 110 6E n110 1111 157 111 6F o111 0000 160 112 70 p111 0001 161 113 71 q111 0010 162 114 72 r111 0011 163 115 73 s111 0100 164 116 74 t111 0101 165 117 75 u111 0110 166 118 76 v111 0111 167 119 77 w111 1000 170 120 78 x111 1001 171 121 79 y111 1010 172 122 7A z111 1011 173 123 7B {111 1100 174 124 7C ACK ¬ |111 1101 175 125 7D }111 1110 176 126 7E ESC | ~ |
ASCII | Usage | Usage
ASCII was first used commercially during 1963 as a seven-bit teleprinter code for American Telephone & Telegraph's TWX (TeletypeWriter eXchange) network. TWX originally used the earlier five-bit ITA2, which was also used by the competing Telex teleprinter system. Bob Bemer introduced features such as the escape sequence. His British colleague Hugh McGregor Ross helped to popularize this work according to Bemer, "so much so that the code that was to become ASCII was first called the Bemer–Ross Code in Europe". (NB. Bemer was employed at IBM at that time.) Because of his extensive work on ASCII, Bemer has been called "the father of ASCII".
On March 11, 1968, US President Lyndon B. Johnson mandated that all computers purchased by the United States Federal Government support ASCII, stating:
I have also approved recommendations of the Secretary of Commerce [Luther H. Hodges] regarding standards for recording the Standard Code for Information Interchange on magnetic tapes and paper tapes when they are used in computer operations.
All computers and related equipment configurations brought into the Federal Government inventory on and after July 1, 1969, must have the capability to use the Standard Code for Information Interchange and the formats prescribed by the magnetic tape and paper tape standards when these media are used.
ASCII was the most common character encoding on the World Wide Web until December 2007, when UTF-8 encoding surpassed it; UTF-8 is backward compatible with ASCII. |
ASCII | <span class="anchor" id="Variants"></span>Variants and derivations | Variants and derivations
As computer technology spread throughout the world, different standards bodies and corporations developed many variations of ASCII to facilitate the expression of non-English languages that used Roman-based alphabets. One could class some of these variations as "ASCII extensions", although some misuse that term to represent all variants, including those that do not preserve ASCII's character-map in the 7-bit range. Furthermore, the ASCII extensions have also been mislabelled as ASCII. |
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