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Biogenesis
Spontaneous generation is a superseded scientific theory that held that living creatures could arise from nonliving matter and that such processes were commonplace and regular. It was hypothesized that certain forms, such as fleas, could arise from inanimate matter such as dust, or that maggots could arise from dead flesh. The doctrine of spontaneous generation was coherently synthesized by Aristotle, who compiled and expanded the work of earlier natural philosophers and the various ancient explanations for the appearance of organisms. Spontaneous generation was taken as scientific fact for two millennia. Though challenged in the 17th and 18th centuries by the experiments of Francesco Redi and Lazzaro Spallanzani, it was not discredited until the work of the French chemist Louis Pasteur and the Irish physicist John Tyndall in the mid-19th century. Rejection of spontaneous generation is no longer controversial among biologists. By the middle of the 19th century, experiments ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Abiogenesis
In biology, abiogenesis (from a- 'not' + Greek bios 'life' + genesis 'origin') or the origin of life is the natural process by which life has arisen from non-living matter, such as simple organic compounds. The prevailing scientific hypothesis is that the transition from non-living to living entities on Earth was not a single event, but an evolutionary process of increasing complexity that involved the formation of a habitable planet, the prebiotic synthesis of organic molecules, molecular self-replication, self-assembly, autocatalysis, and the emergence of cell membranes. Many proposals have been made for different stages of the process. The study of abiogenesis aims to determine how pre-life chemical reactions gave rise to life under conditions strikingly different from those on Earth today. It primarily uses tools from biology and chemistry, with more recent approaches attempting a synthesis of many sciences. Life functions through the specialized chemistry of carbon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Origin Of Life
In biology, abiogenesis (from a- 'not' + Greek bios 'life' + genesis 'origin') or the origin of life is the natural process by which life has arisen from non-living matter, such as simple organic compounds. The prevailing scientific hypothesis is that the transition from non-living to living entities on Earth was not a single event, but an evolutionary process of increasing complexity that involved the formation of a habitable planet, the prebiotic synthesis of organic molecules, molecular self-replication, self-assembly, autocatalysis, and the emergence of cell membranes. Many proposals have been made for different stages of the process. The study of abiogenesis aims to determine how pre-life chemical reactions gave rise to life under conditions strikingly different from those on Earth today. It primarily uses tools from biology and chemistry, with more recent approaches attempting a synthesis of many sciences. Life functions through the specialized chemistry of carbon a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spontaneous Generation Of Seashells , also known as spontaneism, the belief that social revolution can and should occur spontaneously without the aid or guidance of a vanguard party.
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Spontaneous may refer to: * Spontaneous abortion * Spontaneous bacterial peritonitis * Spontaneous combustion * Spontaneous declaration * Spontaneous emission * Spontaneous fission * Spontaneous generation * Spontaneous human combustion * Spontaneous Music Ensemble * Spontaneous order * Spontaneous process * Spontaneous remission * Spontaneous symmetry breaking * ''Spontaneous'' (album) by William Parker & the Little Huey Creative Music Orchestra * ''Spontaneous'' (film), an American sci-fi fantasy film See also * Revolutionary spontaneity Revolutionary spontaneity, also known as spontaneism, is a revolutionary socialist tendency that believes the social revolution can and should occur spontaneously from below by the working class itself, without the aid or guidance of a vanguar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PNAS
''Proceedings of the National Academy of Sciences of the United States of America'' (often abbreviated ''PNAS'' or ''PNAS USA'') is a peer-reviewed multidisciplinary scientific journal. It is the official journal of the National Academy of Sciences, published since 1915, and publishes original research, scientific reviews, commentaries, and letters. According to ''Journal Citation Reports'', the journal has a 2021 impact factor of 12.779. ''PNAS'' is the second most cited scientific journal, with more than 1.9 million cumulative citations from 2008 to 2018. In the mass media, ''PNAS'' has been described variously as "prestigious", "sedate", "renowned" and "high impact". ''PNAS'' is a delayed open access journal, with an embargo period of six months that can be bypassed for an author fee ( hybrid open access). Since September 2017, open access articles are published under a Creative Commons license. Since January 2019, ''PNAS'' has been online-only, although print issues are av ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xenophanes
Xenophanes of Colophon (; grc, Ξενοφάνης ὁ Κολοφώνιος ; c. 570 – c. 478 BC) was a Greek philosopher, theologian, poet, and critic of Homer from Ionia who travelled throughout the Greek-speaking world in early Classical Antiquity. As a poet, Xenophanes was known for his critical style, writing poems that are considered among the first satires. He also composed elegiac couplets that criticised his society's traditional values of wealth, excesses, and athletic victories. He also criticised Homer and the other poets in his works for representing the gods as foolish or morally weak. His poems have not survived intact; only fragments of some of his work survives in quotations by later philosophers and literary critics. Xenophanes is seen as one of the most important pre-Socratic philosophers. A highly original thinker, Xenophanes sought explanations for physical phenomena such as clouds or rainbows without references to divine or mythological explanations, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aether (classical Element)
According to ancient and medieval science, aether (, alternative spellings include ''æther'', ''aither'', and ''ether''), also known as the fifth element or quintessence, is the material that fills the region of the universe beyond the terrestrial sphere. The concept of aether was used in several theories to explain several natural phenomena, such as the traveling of light and gravity. In the late 19th century, physicists postulated that aether permeated all throughout space, providing a medium through which light could travel in a vacuum, but evidence for the presence of such a medium was not found in the Michelson–Morley experiment, and this result has been interpreted as meaning that no such luminiferous aether exists. Mythological origins The word (''aithḗr'') in Homeric Greek means "pure, fresh air" or "clear sky". In Greek mythology, it was thought to be the pure essence that the gods breathed, filling the space where they lived, analogous to the '' air'' br ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anaxagoras
Anaxagoras (; grc-gre, Ἀναξαγόρας, ''Anaxagóras'', "lord of the assembly"; 500 – 428 BC) was a Pre-Socratic Greek philosopher. Born in Clazomenae at a time when Asia Minor was under the control of the Persian Empire, Anaxagoras came to Athens. According to Diogenes Laërtius and Plutarch, in later life he was charged with impiety and went into exile in Lampsacus; the charges may have been political, owing to his association with Pericles, if they were not fabricated by later ancient biographers. Responding to the claims of Parmenides on the impossibility of change, Anaxagoras introduced the concept of ''Nous'' (Cosmic Mind) as an ordering force. He also gave a number of novel scientific accounts of natural phenomena, including the notion of panspermia, that life exists throughout the universe and could be distributed everywhere. He deduced a correct explanation for eclipses and described the Sun as a fiery mass larger than the Peloponnese, as w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anaximenes Of Miletus
Anaximenes of Miletus (; grc-gre, Ἀναξιμένης ὁ Μιλήσιος, translit=Anaximenēs ho Milēsios; ) was an Ancient Greek, Ionian Pre-Socratic philosopher from Miletus in Asia Minor (modern-day Turkey), active in the latter half of the 6th century BC. The details of his life are obscure because none of his work has been preserved. Anaximenes' ideas are only known today because of comments about him made by later writers, such as Aristotle. As the last of the three philosophers of the Milesian School, considered the first philosophers of the Western world, Anaximenes is best known and identified as a younger friend or student of Anaximander, who was himself taught by the first philosopher Thales. Each developed a distinct cosmology without completely rejecting their predecessors views. Each were material monists who sought to discover the ''arche;'' the one, underlying physical yet divine basis of everything. Thales proposed all was made of water; Anaximander pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hippolytus Of Rome
Hippolytus of Rome (, ; c. 170 – c. 235 AD) was one of the most important second-third century Christian theologians, whose provenance, identity and corpus remain elusive to scholars and historians. Suggested communities include Rome, Palestine, Egypt, Anatolia and other regions of the Middle East. The best historians of literature in the ancient church, including Eusebius of Caesarea and Jerome, openly confess they cannot name where Hippolytus the biblical commentator and theologian served in leadership. They had read his works but did not possess evidence of his community. Photios I of Constantinople describes him in his '' Bibliotheca'' (cod. 121) as a disciple of Irenaeus, who was said to be a disciple of Polycarp, and from the context of this passage it is supposed that he suggested that Hippolytus so styled himself. This assertion is doubtful. One older theory asserts he came into conflict with the popes of his time and seems to have headed a schismatic group as a riva ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Substance Theory
Substance theory, or substance–attribute theory, is an ontological theory positing that objects are constituted each by a ''substance'' and properties borne by the substance but distinct from it. In this role, a substance can be referred to as a ''substratum'' or a '' thing-in-itself''. ''Substances'' are particulars that are ontologically independent: they are able to exist all by themselves. Another defining feature often attributed to substances is their ability to ''undergo changes''. Changes involve something existing ''before'', ''during'' and ''after'' the change. They can be described in terms of a persisting substance gaining or losing properties. ''Attributes'' or ''properties'', on the other hand, are entities that can be exemplified by substances. Properties characterize their bearers, they express what their bearer is like. ''Substance'' is a key concept in ontology and metaphysics, which may be classified into monist, dualist, or pluralist varieties according ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apeiron (cosmology)
''Apeiron'' (; ) is a Greek word meaning "(that which is) unlimited," "boundless", "infinite", or "indefinite" from ''a-'', "without" and ''peirar'', "end, limit", "boundary", the Ionic Greek form of ''peras'', "end, limit, boundary". Origin of everything The ''apeiron'' is central to the cosmological theory created by Anaximander, a 6th-century BC pre-Socratic Greek philosopher whose work is mostly lost. From the few existing fragments, we learn that he believed the beginning or ultimate reality (''arche'') is eternal and infinite, or boundless (''apeiron''), subject to neither old age nor decay, which perpetually yields fresh materials from which everything we can perceive is derived. ''Apeiron'' generated the opposites (hot–cold, wet–dry, etc.) which acted on the creation of the world ( cf. Heraclitus). Everything is generated from ''apeiron'' and then it is destroyed by going back to ''apeiron'', according to necessity. He believed that infinite worlds are genera ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anaximander
Anaximander (; grc-gre, Ἀναξίμανδρος ''Anaximandros''; ) was a pre-Socratic Greek philosopher who lived in Miletus,"Anaximander" in '' Chambers's Encyclopædia''. London: George Newnes, 1961, Vol. 1, p. 403. a city of Ionia (in modern-day Turkey). He belonged to the Milesian school and learned the teachings of his master Thales. He succeeded Thales and became the second master of that school where he counted Anaximenes and, arguably, Pythagoras amongst his pupils. Little of his life and work is known today. According to available historical documents, he is the first philosopher known to have written down his studies, although only one fragment of his work remains. Fragmentary testimonies found in documents after his death provide a portrait of the man. Anaximander was an early proponent of science and tried to observe and explain different aspects of the universe, with a particular interest in its origins, claiming that nature is ruled by laws, just like h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
