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Heliocentric
Heliocentrism (also known as the heliocentric model) is a Superseded theories in science#Astronomy and cosmology, superseded astronomical model in which the Earth and Solar System, planets orbit around the Sun at the center of the universe. Historically, heliocentrism was opposed to Geocentric model, geocentrism, which placed the Earth at the center. The notion that the Earth revolves around the Sun had been proposed as early as the 3rd century BC by Aristarchus of Samos, who had been influenced by a concept presented by Philolaus of Croton (c. 470 – 385 BC). In the 5th century BC the Greece, Greek Philosophy, philosophers Philolaus and Hicetas had the thought on different occasions that the Earth was spherical and revolving around a "mystical" Pythagorean astronomical system#Central Fire, central fire, and that this fire regulated the universe. In medieval Europe, however, Aristarchus' heliocentrism attracted little attention—possibly because of the loss of scientific works ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nicolaus Copernicus
Nicolaus Copernicus (19 February 1473 – 24 May 1543) was a Renaissance polymath who formulated a mathematical model, model of Celestial spheres#Renaissance, the universe that placed heliocentrism, the Sun rather than Earth at its center. Copernicus likely developed his model independently of Aristarchus of Samos, an List of ancient Greek astronomers, ancient Greek astronomer who had formulated such a model some eighteen centuries earlier. The publication of Copernicus' model in his book ' (''On the Revolutions of the Celestial Spheres''), just before his death in 1543, was a major event in the history of science, triggering the Copernican Revolution and making a pioneering contribution to the Scientific Revolution. Copernicus was born and died in Royal Prussia, a semiautonomous and multilingual region created within the Crown of the Kingdom of Poland from lands regained from the Teutonic Order after the Thirteen Years' War (1454–1466), Thirteen Years' War. A Poly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Copernican Heliocentrism
Copernican heliocentrism is the astronomical scientific modeling, model developed by Nicolaus Copernicus and published in 1543. This model positioned the Sun at the center of the Universe, motionless, with Earth and the other planets orbiting around it in circular trajectory, paths, modified by epicycles, and at uniform speeds. The Copernican model displaced the geocentric model of Ptolemy that had prevailed for centuries, which had placed Earth at the center of the Universe. Although he had circulated an outline of his own heliocentric theory to colleagues sometime before 1514, he did not decide to publish it until he was urged to do so later by his pupil Rheticus. Copernicus's challenge was to present a practical alternative to the Ptolemaic model by more elegantly and accurately determining the length of a solar year while preserving the Pythagoreanism, metaphysical implications of a mathematically ordered cosmos. Thus, his heliocentric model retained several of the Ptolemaic el ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geocentric Model
In astronomy, the geocentric model (also known as geocentrism, often exemplified specifically by the Ptolemaic system) is a superseded scientific theories, superseded description of the Universe with Earth at the center. Under most geocentric models, the Sun, Moon, stars, and classical planet, planets all orbit Earth. The geocentric model was the predominant description of the cosmos in many European Ancient history, ancient civilizations, such as those of Aristotle in Classical Greece and Ptolemy in Roman Egypt, as well as during the Islamic Golden Age. Two observations supported the idea that Earth was the center of the Universe. First, from anywhere on Earth, the Sun appears to revolve around Earth diurnal motion, once per day. While the Moon and the planets have their own motions, they also appear to revolve around Earth about once per day. The stars appeared to be fixed stars, fixed on a celestial sphere rotating once each day about celestial pole, an axis through the geogr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Copernican Revolution
The term "Copernican Revolution" was coined by the German philosopher Immanuel Kant in his 1781 work ''Critique of Pure Reason''. It was the paradigm shift from the Ptolemaic model of the heavens, which described the cosmos as having Earth stationary at the center of the universe, to the heliocentric model with the Sun at the center of the Solar System. This revolution consisted of two phases; the first being extremely mathematical in nature and beginning with the 1543 publication of Nicolaus Copernicus’s ''De revolutionibus orbium coelestium'', and the second phase starting in 1610 with the publication of a pamphlet by Galileo. Contributions to the "revolution" continued until finally ending with Isaac Newton's 1687 work . Heliocentrism Before Copernicus The "Copernican Revolution" is named for Nicolaus Copernicus, whose '' Commentariolus'', written before 1514, was the first explicit presentation of the heliocentric model in Renaissance scholarship. The idea of helioce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aristarchus Of Samos
Aristarchus of Samos (; , ; ) was an ancient Greek astronomer and mathematician who presented the first known heliocentric model that placed the Sun at the center of the universe, with the Earth revolving around the Sun once a year and rotating about its axis once a day. He also supported the theory of Anaxagoras according to which the Sun was just another star. He likely moved to Alexandria, and he was a student of Strato of Lampsacus, who later became the third head of the Peripatetic school in Greece. According to Ptolemy, he observed the summer solstice of 280 BC. Along with his contributions to the heliocentric model, as reported by Vitruvius, he created two separate sundials: one that is a flat disc; and one hemispherical. Aristarchus estimated the sizes of the Sun and Moon as compared to Earth's size. He also estimated the distances from the Earth to the Sun and Moon. His estimate that the Sun was 7 times larger than Earth (while inaccurate by an order of magnitu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Universe
The universe is all of space and time and their contents. It comprises all of existence, any fundamental interaction, physical process and physical constant, and therefore all forms of matter and energy, and the structures they form, from sub-atomic particles to entire Galaxy filament, galactic filaments. Since the early 20th century, the field of cosmology establishes that space and time emerged together at the Big Bang ago and that the Expansion of the universe, universe has been expanding since then. The observable universe, portion of the universe that can be seen by humans is approximately 93 billion light-years in diameter at present, but the total size of the universe is not known. Some of the earliest Timeline of cosmological theories, cosmological models of the universe were developed by ancient Greek philosophy, ancient Greek and Indian philosophy, Indian philosophers and were geocentric model, geocentric, placing Earth at the center. Over the centuries, more prec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar System
The Solar SystemCapitalization of the name varies. The International Astronomical Union, the authoritative body regarding astronomical nomenclature, specifies capitalizing the names of all individual astronomical objects but uses mixed "Solar System" and "solar system" structures in theinaming guidelines document. The name is commonly rendered in lower case ('solar system'), as, for example, in the ''Oxford English Dictionary'' an''Merriam-Webster's 11th Collegiate Dictionary''. is the gravitationally bound Planetary system, system of the Sun and the objects that orbit it. It Formation and evolution of the Solar System, formed about 4.6 billion years ago when a dense region of a molecular cloud collapsed, forming the Sun and a protoplanetary disc. The Sun is a typical star that maintains a hydrostatic equilibrium, balanced equilibrium by the thermonuclear fusion, fusion of hydrogen into helium at its stellar core, core, releasing this energy from its outer photosphere. As ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archimedes
Archimedes of Syracuse ( ; ) was an Ancient Greece, Ancient Greek Greek mathematics, mathematician, physicist, engineer, astronomer, and Invention, inventor from the ancient city of Syracuse, Sicily, Syracuse in History of Greek and Hellenistic Sicily, Sicily. Although few details of his life are known, based on his surviving work, he is considered one of the leading scientists in classical antiquity, and one of the greatest mathematicians of all time. Archimedes anticipated modern calculus and mathematical analysis, analysis by applying the concept of the Cavalieri's principle, infinitesimals and the method of exhaustion to derive and rigorously prove many geometry, geometrical theorem, theorems, including the area of a circle, the surface area and volume of a sphere, the area of an ellipse, the area under a parabola, the volume of a segment of a paraboloid of revolution, the volume of a segment of a hyperboloid of revolution, and the area of a spiral. Archimedes' other math ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Renaissance
The Renaissance ( , ) is a Periodization, period of history and a European cultural movement covering the 15th and 16th centuries. It marked the transition from the Middle Ages to modernity and was characterized by an effort to revive and surpass the ideas and achievements of classical antiquity. Associated with great social change in most fields and disciplines, including Renaissance art, art, Renaissance architecture, architecture, politics, Renaissance literature, literature, Renaissance exploration, exploration and Science in the Renaissance, science, the Renaissance was first centered in the Republic of Florence, then spread to the Italian Renaissance, rest of Italy and later throughout Europe. The term ''rinascita'' ("rebirth") first appeared in ''Lives of the Artists'' () by Giorgio Vasari, while the corresponding French word was adopted into English as the term for this period during the 1830s. The Renaissance's intellectual basis was founded in its version of Renaiss ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hellenistic Period
In classical antiquity, the Hellenistic period covers the time in Greek history after Classical Greece, between the death of Alexander the Great in 323 BC and the death of Cleopatra VII in 30 BC, which was followed by the ascendancy of the Roman Empire, as signified by the Battle of Actium in 31 BC and the Roman conquest of Ptolemaic Egypt the following year, which eliminated the last major Hellenistic kingdom. Its name stems from the Ancient Greek word ''Hellas'' (, ''Hellás''), which was gradually recognized as the name for Greece, from which the modern historiographical term ''Hellenistic'' was derived. The term "Hellenistic" is to be distinguished from "Hellenic" in that the latter refers to Greece itself, while the former encompasses all the ancient territories of the period that had come under significant Greek influence, particularly the Hellenized Middle East, after the conquests of Alexander the Great. After the Macedonian conquest of the Achaemenid Empire in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Sand Reckoner
''The Sand Reckoner'' (, ''Psammites'') is a work by Archimedes, an Ancient Greek mathematician of the 3rd century BC, in which he set out to determine an upper bound for the number of grains of sand that fit into the universe. In order to do this, Archimedes had to estimate the size of the universe according to the contemporary model, and invent a way to talk about extremely large numbers. The work, also known in Latin as ''Arenarius'', is about eight pages long in translation and is addressed to the Syracusan king Gelo II (son of Hiero II). It is considered the most accessible work of Archimedes.Archimedes, The Sand Reckoner 511 R U, by Ilan Vardi accessed 28-II-2007. Naming large numbers [Baidu] |
