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Dendrochronology
Dendrochronology (or tree-ring dating) is the scientific method of chronological dating, dating tree rings (also called growth rings) to the exact year they were formed in a tree. As well as dating them, this can give data for dendroclimatology, the study of climate and atmospheric conditions during different periods in history from the wood of old trees. Dendrochronology derives from the Ancient Greek (), meaning "tree", (), meaning "time", and (), "the study of". Dendrochronology is useful for determining the precise age of samples, especially those that are too recent for radiocarbon dating, which always produces a range rather than an exact date. However, for a precise date of the death of the tree a full sample to the edge is needed, which most trimmed timber will not provide. It also gives data on the timing of events and rates of change in the environment (most prominently climate) and also in wood found in archaeology or works of art and architecture, such as old pane ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Miyake Event
A Miyake event is an observed sharp enhancement of the production of Cosmogenic nuclide, cosmogenic isotopes by cosmic rays. It can be marked by a spike in the concentration of radioactive carbon isotope Carbon-14, in tree rings, as well as Beryllium-10, and Chlorine-36, in ice cores, which are all independently dated. At present, five significant events are known (7176 BCE, 5259 BCE, 664-663 BCE (historically referred to as 660 BCE), 774–775 carbon-14 spike, 774 CE, 993–994 carbon-14 spike, 993 CE) for which the spike in is quite remarkable, i.e. above 1% rise over a period of two years, and four more events (12,350BCE, 5410 BCE, 1052 CE, 1279 CE) need independent confirmation. It is not known how often Miyake events occur, but from the available data it is estimated to be every 400 to 2,400 years. There is strong evidence that Miyake events are caused by extreme solar particle events and they are likely related to Superflare, super-flares discovered on solar-like stars. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dendroclimatology
Dendroclimatology is the science of determining past climates from trees (primarily properties of the annual tree rings). Tree rings are wider when conditions favor growth, narrower when times are difficult. Other properties of the annual rings, such as maximum latewood density (MXD) have been shown to be better proxies than simple ring width. Using tree rings, scientists have estimated many local climates for hundreds to thousands of years previous. By combining multiple tree-ring studies (sometimes with other climate proxy (climate), proxy records), scientists have estimated past regional and global climates. Advantages Tree rings are especially useful as climate proxy (climate), proxies in that they can be well-dated via dendrochronology, i.e. matching of the rings from sample to sample. This allows extension backwards in time using deceased tree samples, even using samples from buildings or from archeological digs. Another advantage of tree rings is that they are clearly de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiocarbon Dating
Radiocarbon dating (also referred to as carbon dating or carbon-14 dating) is a method for Chronological dating, determining the age of an object containing organic material by using the properties of carbon-14, radiocarbon, a radioactive Isotopes of carbon, isotope of carbon. The method was developed in the late 1940s at the University of Chicago by Willard Libby. It is based on the fact that radiocarbon () is constantly being created in the Atmosphere of Earth, Earth's atmosphere by the interaction of cosmic rays with atmospheric nitrogen. The resulting combines with atmospheric oxygen to form radioactive carbon dioxide, which is incorporated into plants by photosynthesis; animals then acquire by eating the plants. When the animal or plant dies, it stops exchanging carbon with its environment, and thereafter the amount of it contains begins to decrease as the undergoes radioactive decay. Measuring the amount of in a sample from a dead plant or animal, such as a piece of w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Panel Painting
A panel painting is a painting made on a flat panel of wood, either a single piece or a number of pieces joined together. Until canvas became the more popular support medium in the 16th century, panel painting was the normal method, when not painting directly onto a wall ( fresco) or on vellum (used for miniatures in illuminated manuscripts). Wood panels were also used for mounting vellum paintings. History Panel painting is very old; it was a very prestigious medium in Greece and Rome, but only very few examples of ancient panel paintings have survived. A series of 6th century BC painted tablets from Pitsa (Greece) represent the oldest surviving Greek panel paintings. Most classical Greek paintings that were famous in their day seem to have been of a size comparable to smaller modern works – perhaps up to a half-length portrait size. However, for a generation in the second quarter of the fifth-century BC there was a movement, called the "new painting" and led by Polygnotus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chronological Dating
Chronological dating, or simply dating, is the process of attributing to an object or event a date in the past, allowing such object or event to be located in a previously established chronology. This usually requires what is commonly known as a "dating method". Several dating methods exist, depending on different criteria and techniques, and some very well known examples of disciplines using such techniques are, for example, history, archaeology, geology, paleontology, astronomy and even forensic science, since in the latter it is sometimes necessary to investigate the moment in the past during which the death of a cadaver occurred. These methods are typically identified as absolute, which involves a specified date or date range, or relative, which refers to dating which places artifacts or events on a timeline relative to other events and/or artifacts. Other markers can help place an artifact or event in a chronology, such as nearby writings and stratigraphic markers. Absolute an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calibration Of Radiocarbon Dates
Radiocarbon dating measurements produce ages in "radiocarbon years", which must be converted to calendar ages by a process called calibration. Calibration is needed because the atmospheric / ratio, which is a key element in calculating radiocarbon ages, has not been constant historically.Taylor (1987), p. 133. Willard Libby, the inventor of radiocarbon dating, pointed out as early as 1955 the possibility that the ratio might have varied over time. Discrepancies began to be noted between measured ages and known historical dates for artefacts, and it became clear that a correction would need to be applied to radiocarbon ages to obtain calendar dates. Uncalibrated dates may be stated as "radiocarbon years ago", abbreviated "ya". The term Before Present (BP) is established for reporting dates derived from radiocarbon analysis, where "present" is 1950. Uncalibrated dates are stated as "uncal BP", and ''calibrated'' (corrected) dates as "cal BP". Used alone, the term BP is a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leonardo Da Vinci
Leonardo di ser Piero da Vinci (15 April 1452 - 2 May 1519) was an Italian polymath of the High Renaissance who was active as a painter, draughtsman, engineer, scientist, theorist, sculptor, and architect. While his fame initially rested on his achievements as a painter, he has also become known for #Journals and notes, his notebooks, in which he made drawings and notes on a variety of subjects, including anatomy, astronomy, botany, cartography, painting, and palaeontology. Leonardo is widely regarded to have been a genius who epitomised the Renaissance humanism, Renaissance humanist ideal, and his List of works by Leonardo da Vinci, collective works comprise a contribution to later generations of artists matched only by that of his younger contemporary Michelangelo. Born out of wedlock to a successful notary and a lower-class woman in, or near, Vinci, Tuscany, Vinci, he was educated in Florence by the Italian painter and sculptor Andrea del Verrocchio. He began his career ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sarton, George
George Alfred Leon Sarton (; 31 August 1884 – 22 March 1956) was a Belgian-American chemist and historian. He is considered the founder of the discipline of the history of science as an independent field of study. His most influential works were the ''Introduction to the History of Science'', which consists of three volumes and 4,296 pages, and the journal ''Isis''. Sarton ultimately aimed to achieve an integrated philosophy of science that provided a connection between the sciences and the humanities, which he referred to as "the new humanism". Life and work George Alfred Leon Sarton was born to Léonie Van Halmé and Alfred Sarton on August 31, 1884 in Ghent, East Flanders, Belgium. However, within a year of his birth, Sarton's mother died. He attended school first in his hometown before later attending school for a period of four years in the town of Chimay. Sarton enrolled at the University of Ghent in 1902 to study philosophy, but found that the subject did not correspond ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isis (journal)
''Isis'' is a quarterly peer-reviewed academic journal published by the University of Chicago Press for the History of Science Society. It covers the history of science, history of medicine, and the history of technology, as well as their cultural influences. It contains original research articles and extensive book reviews and review essays. Furthermore, sections devoted to one particular topic are published in each issue in open access. These sections consist of the Focus section, the Viewpoint section and the Second Look section. History The journal was established by George Sarton and the first issue appeared in March 1913. Contributions were originally in any of four European languages (English, French, German, and Italian), but since the 1920s, only English has been used. Publication is partly supported by an endowment from the Dibner Fund. Two associated publications are ''Osiris'' (established 1936 by Sarton) and the ''Isis Current Bibliography''. The publication o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tree
In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, e.g., including only woody plants with secondary growth, only plants that are usable as lumber, or only plants above a specified height. But wider definitions include taller palms, tree ferns, bananas, and bamboos. Trees are not a monophyletic taxonomic group but consist of a wide variety of plant species that have independently evolved a trunk and branches as a way to tower above other plants to compete for sunlight. The majority of tree species are angiosperms or hardwoods; of the rest, many are gymnosperms or softwoods. Trees tend to be long-lived, some trees reaching several thousand years old. Trees evolved around 400 million years ago, and it is estimated that there are around three trillion mature trees in the world currently. A tree typically has many secondary branches supported cle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Michel De Montaigne
Michel Eyquem, Seigneur de Montaigne ( ; ; ; 28 February 1533 – 13 September 1592), commonly known as Michel de Montaigne, was one of the most significant philosophers of the French Renaissance. He is known for popularising the the essay, essay as a literary genre. His work is noted for its merging of casual anecdotes and autobiography with intellectual insight. Montaigne had a direct influence on numerous writers of Western literature in the Western world; his ''Essays (Montaigne), Essais'' contain some of the most influential essays ever written. During his lifetime Montaigne was admired more as a statesman than as an author. The tendency in his essays to digress into anecdotes and personal ruminations was seen as detrimental to proper style rather than as an innovation, and his declaration that "I am myself the matter of my book" was viewed by his contemporaries as self-indulgent. In time, however, Montaigne came to be recognised as embodying the spirit of freely enter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
England
England is a Countries of the United Kingdom, country that is part of the United Kingdom. It is located on the island of Great Britain, of which it covers about 62%, and List of islands of England, more than 100 smaller adjacent islands. It shares Anglo-Scottish border, a land border with Scotland to the north and England–Wales border, another land border with Wales to the west, and is otherwise surrounded by the North Sea to the east, the English Channel to the south, the Celtic Sea to the south-west, and the Irish Sea to the west. Continental Europe lies to the south-east, and Ireland to the west. At the 2021 United Kingdom census, 2021 census, the population was 56,490,048. London is both List of urban areas in the United Kingdom, the largest city and the Capital city, capital. The area now called England was first inhabited by modern humans during the Upper Paleolithic. It takes its name from the Angles (tribe), Angles, a Germanic peoples, Germanic tribe who settled du ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
