The geocentric model (in Greek: geo = Earth and centron = center) of the universe is a paradigm which places the Earth at its center. Common in ancient Greece after the discovery of the approximately spherical shape of Earth, it was believed by both Aristotle and Ptolemy. Most Greeks assumed that the Sun, Moon, stars, and planets orbit Earth. Similar ideas were held in ancient China. The geocentric model assumes a spherical Earth; thus it is not the same as the older flat Earth model. Also, according to this model, ...

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Geocentric model - Notes

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Modern geocentrism, Modern geocentrism - Overview of modern geocentrism, Modern geocentrism - History of modern geocentrism, Modern geocentrism - Biblical references, Modern geocentrism - Catholic geocentricity, Modern geocentrism - The modern scientific point of view, Modern geocentrism - There is no special position., Modern geocentrism - The cosmic microwave background radiation determines the only special velocity., Modern geocentrism - The inertial frame is the only special rotation., Modern geocentrism - Non-falsifiability of geocentrism, Modern geocentrism - Modern geocentrism and astronomical observations, Modern geocentrism - Gamma ray bursts, Modern geocentrism - Quantization of redshifts, Modern geocentrism - Forms of modern geocentrism, Modern geocentrism - The observations, Modern geocentrism - Geocentrism based on classical gravitation, Modern geocentrism - Geocentrism based on a rigid aether, Modern geocentrism - Geocentrism based on a radically different cosmology

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The Ptolemaic model of the solar system held sway into the early modern age; from the late 16th century onward it was gradually replaced as the consensus description by the heliocentric model. Geocentrism as a separate religious belief, however, never completely died out. In the United States between 1870 and 1920, for example, various members of the Lutheran Church - Missouri Synod published articles disparaging Copernican astronomy, and ...

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Modern geocentrism, Modern geocentrism - Overview of modern geocentrism, Modern geocentrism - History of modern geocentrism, Modern geocentrism - Biblical references, Modern geocentrism - Catholic geocentricity, Modern geocentrism - The modern scientific point of view, Modern geocentrism - There is no special position., Modern geocentrism - The cosmic microwave background radiation determines the only special velocity., Modern geocentrism - The inertial frame is the only special rotation., Modern geocentrism - Non-falsifiability of geocentrism, Modern geocentrism - Modern geocentrism and astronomical observations, Modern geocentrism - Gamma ray bursts, Modern geocentrism - Quantization of redshifts, Modern geocentrism - Forms of modern geocentrism, Modern geocentrism - The observations, Modern geocentrism - Geocentrism based on classical gravitation, Modern geocentrism - Geocentrism based on a rigid aether, Modern geocentrism - Geocentrism based on a radically different cosmology

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The Tychonian system was an effort by Tycho Brahe to create a model of the solar system which would combine what he saw as the mathematical benefits of the Copernican system with the philosophical and "physical" benefits of the Ptolemaic system. It is essentially a geocentric model (with the Earth at the center of the universe), around which revolves the sun, and around the sun revolve the other planets. It can be shown through a geometric argument that the motions of the planets and the sun relative to the Earth in the Tychoni ...

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Modern geocentrists have been known to point to certain astronomical observations as evidence which could be interpreted as placing the earth at the center of the universe. However, all of the proposed falsifications have explanations that are compatible with the current scientific model of the solar system and universe. Modern geocentrism - Gamma ray bursts. One such observation is reported in "The Biggest Bangs: The Mystery of Gamma-Ray Bursts" (ISBN 0-19-514570-4), by Jonathan I. Katz, professor of phys ...

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Modern geocentrism, Modern geocentrism - Overview of modern geocentrism, Modern geocentrism - History of modern geocentrism, Modern geocentrism - Biblical references, Modern geocentrism - Catholic geocentricity, Modern geocentrism - The modern scientific point of view, Modern geocentrism - There is no special position., Modern geocentrism - The cosmic microwave background radiation determines the only special velocity., Modern geocentrism - The inertial frame is the only special rotation., Modern geocentrism - Non-falsifiability of geocentrism, Modern geocentrism - Modern geocentrism and astronomical observations, Modern geocentrism - Gamma ray bursts, Modern geocentrism - Quantization of redshifts, Modern geocentrism - Forms of modern geocentrism, Modern geocentrism - The observations, Modern geocentrism - Geocentrism based on classical gravitation, Modern geocentrism - Geocentrism based on a rigid aether, Modern geocentrism - Geocentrism based on a radically different cosmology

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An Epitome of the Almagest (Epitome in Ptolemaei Almagestum) was written between 1460 and 1463 by the Austrian astronomer Georg Peurbach and his famous pupil Johannes Regiomontanus at the suggestion of Cardinal Bessarion. It gave Europeans the first sophisticated understanding of Ptolemy's astronomy, and was studied by every competent astronomer of the 16th century. Unlike earlier systems (such as 'the stars move because that is the will of the gods', or the model of concentric spheres), the Ptolemaic model explained all ...

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Ptolemaic system, Ptolemaic system - The Almagest, Ptolemaic system - Geocentricity, Ptolemaic system - Problems with geocentricity, Ptolemaic system - Replacement with Copernican system

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The oldest part of the Orloj, the mechanical clock and astronomical dial, dates back to 1410 when it was made by clockmaker Mikuláš of Kadaň and Jan Šindel, the latter a professor of mathematics and astronomy at Charles University. The Prague Orloj was the third clock of its kind, the first having been constructed in Padua in 1344. Later, presumably around 1490, the calendar dial was added and clock facade decorated with gothic sculptures. In 1552 it was repaired by Jan Taborský, clockmaster of Orloj, who also wrote a report on the clock where he mentioned Hanuš as maker of the clock. This was a mistake, an ...

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Prague Orloj, Prague Orloj - History, Prague Orloj - Astronomical dial, Prague Orloj - Stationary background, Prague Orloj - Zodiacal ring, Prague Orloj - Old Czech time scale, Prague Orloj - Sun, Prague Orloj - Moon

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The astronomical dial is a form of mechanical astrolabe, a device used in medieval astronomy. Alternatively, one may consider the Orloj to be a primitive planetarium, displaying the current state of universe. The astronomical dial has a background that represents the standing Earth and sky, and surrounding it operate four main moving components: the zodiacal ring, an outer rotating ring, an icon representing the Sun, and an icon representing the Moon. See also:

Prague Orloj, Prague Orloj - History, Prague Orloj - Astronomical dial, Prague Orloj - Stationary background, Prague Orloj - Zodiacal ring, Prague Orloj - Old Czech time scale, Prague Orloj - Sun, Prague Orloj - Moon

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Three of Sungenis' best-known works are Not by Faith Alone (1997) on the doctrine of justification by faith alone, Not by Scripture Alone (1997) rebutting the Protestant doctrine of sola scriptura, and Not by Bread Alone (2000) on the Eucharist. A fourth "Not...Alone" book, Not by Science Alone, is yet to be released. Galileo Was Wrong is due out in 2005 defending his geocentric model of the universe. In addition to his own works, he has also contributed essays to various Catholic apologetics ...

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Robert Sungenis, Robert Sungenis - Biography, Robert Sungenis - Theological Works and Views, Robert Sungenis - Geocentrism Controversy

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The only work of Aristarchus which has survived to the present time, On the Sizes and Distances of the Sun and Moon, is based on a geocentric worldview. We know through citations, however, that Aristarchus wrote another book in which he advanced an alternative hypothesis of the heliocentric model. Archimedes wrote: "You King Gelon are aware the 'universe' is the name given by most astronomers to the sphere the centre of which is the center of the Earth, while its radius is equal to the straight line between the center of ...

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Aristarchus, Aristarchus - Heliocentrism, Aristarchus - Size of the Moon, Aristarchus - Distance to the Sun

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In 1543 Copernicus' work on the heliocentric model of the solar system was published, in which he tried to prove that the sun was the centre of the universe. Ironically, this was at the behest of the Catholic Church as part of the Catholic Reformation efforts for a means of creating a more accurate calendar for its activities. For almost two millennia, the geocentric model had been accepted by all but a few astronomers. The idea that the earth moved around the sun, as advocated by Copernicus, was to most of his contemporaries preposterous. I ...

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Scientific revolution, Scientific revolution - Emergence of the revolution, Scientific revolution - Early and Medieval Views of Science, Scientific revolution - New Scientific Thought, Scientific revolution - Theoretical developments, Scientific revolution - Experimental developments, Scientific revolution - Methodological developments, Scientific revolution - Mechanisation, Scientific revolution - Empiricism, Scientific revolution - Literary criticisms

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Spherical harmonics are often used to approximate the shape of the geoid. The current best such set of spherical harmonic coefficients is EGM96 (Earth Gravity Model 1996), determined in an international collaborative project led by NIMA. It contains a full set of coefficients to degree and order 360, describing details in the global geoid as small as 55 km. The mathematical description of this model is where and are geocentric latitude and longitude respectively, are the fully normalized Legendre ...

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Geoid, Geoid - Spherical harmonics representation

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SLR data has provided the standard, highly accurate, long wavelength gravity field reference model which supports all precision orbit determination and provides the basis for studying temporal gravitational variations due to mass redistribution. The height of the geoid has been determined to less than ten centimeters at long wavelengths less than 1500 km. SLR provides mm/yr accurate determinations of tectonic drift station motion on a global scale in a geocentric reference frame. Combined with gravity models and decadal changes in Ear ...

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Satellite laser ranging, Satellite laser ranging - History, Satellite laser ranging - Uses of SLR data

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The total surface area of the solar system's objects that have solid surfaces and a diameter greater than 1 km is ~1.7×109 km2 —about 11 times the area of the Earth's land masses. It has been suggested that the Sun may be part of a binary star system, with a distant companion named Nemesis. Nemesis was proposed to explain some timing regularities of the great extinctions of life on Earth. The hypothesis says that Nemesis creates periodical perturbations in the Oort cloud of comets surrounding the solar system, ...

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Solar system, Solar system - Structure and layout of the solar system, Solar system - Origin and age of the solar system, Solar system - Regions of the solar system, Solar system - Interplanetary medium, Solar system - The inner planets, Solar system - The asteroid belt, Solar system - The outer planets, Solar system - The trans-Neptunian region, Solar system - And beyond, Solar system - Galactic orbit of the solar system, Solar system - Planetary system formation, Solar system - Discovery of the solar system, Solar system - Exploration of the solar system, Solar system - Attributes of major planets, Solar system - Attributes of the largest minor planets, Solar system - Other facts

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The Sun (astronomical symbol ☉) is a main sequence G2 star that contains 99.86% of the system's known mass. Its two largest orbiting bodies, Jupiter and Saturn, account for 91% of the remainder (The Oort Cloud might hold a substantial percentage, but as yet its existence is unconfirmed). In broad terms, the charted regions of our solar system consist of the Sun and its planetary system: the eight bodies in relatively unique orbits (commonly called planets or major planets) and two belts of smaller objects (which can be called minor ...

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Solar system, Solar system - Structure and layout of the solar system, Solar system - Origin and age of the solar system, Solar system - Regions of the solar system, Solar system - Interplanetary medium, Solar system - The inner planets, Solar system - The asteroid belt, Solar system - The outer planets, Solar system - The trans-Neptunian region, Solar system - And beyond, Solar system - Galactic orbit of the solar system, Solar system - Planetary system formation, Solar system - Discovery of the solar system, Solar system - Exploration of the solar system, Solar system - Attributes of major planets, Solar system - Attributes of the largest minor planets, Solar system - Other facts

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According to their location, the objects in the solar system are divided into three zones: Zone I or the inner solar system, including terrestrial planets and the Main belt of asteroids; Zone II, including the giant planets, their satellites and the centaurs, and Zone III, or the outer solar system, comprising the area of the Trans-Neptunian objects including the Kuiper Belt, the Oort cloud, and the vast region in between.

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Solar system, Solar system - Structure and layout of the solar system, Solar system - Origin and age of the solar system, Solar system - Regions of the solar system, Solar system - Interplanetary medium, Solar system - The inner planets, Solar system - The asteroid belt, Solar system - The outer planets, Solar system - The trans-Neptunian region, Solar system - And beyond, Solar system - Galactic orbit of the solar system, Solar system - Planetary system formation, Solar system - Discovery of the solar system, Solar system - Exploration of the solar system, Solar system - Attributes of major planets, Solar system - Attributes of the largest minor planets, Solar system - Other facts

Read more here: » Solar system: Encyclopedia II - Solar system - Regions of the solar system

For many years, our solar system had the only planetary system known, and so theories of planetary formation only had to explain one system to be plausible. The discovery in recent years of many extrasolar(exo) planets has uncovered systems very different to our own, and theories have had to be revised accordingly. Exoplanets have not been seen by astronomers yet, however we know they exist because of the gravitational tug the planets induce on the star, and hence making the star ‘wobble’. Astronomers can calculate how massive the ...

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Solar system, Solar system - Structure and layout of the solar system, Solar system - Origin and age of the solar system, Solar system - Regions of the solar system, Solar system - Interplanetary medium, Solar system - The inner planets, Solar system - The asteroid belt, Solar system - The outer planets, Solar system - The trans-Neptunian region, Solar system - And beyond, Solar system - Galactic orbit of the solar system, Solar system - Planetary system formation, Solar system - Discovery of the solar system, Solar system - Exploration of the solar system, Solar system - Attributes of major planets, Solar system - Attributes of the largest minor planets, Solar system - Other facts

Read more here: » Solar system: Encyclopedia II - Solar system - Planetary system formation

The planets out to Saturn were known to ancient astronomers, who observed the wandering of these objects against the apparently fixed pattern of stars. Venus and Mercury were each identified as single objects despite the difficulty of connecting "evening" and "morning stars". It was also identified that the two non-pointlike objects, the sun and the Moon, moved across the same fixed background. However knowledge of the nature of these cele ...

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Solar system, Solar system - Structure and layout of the solar system, Solar system - Origin and age of the solar system, Solar system - Regions of the solar system, Solar system - Interplanetary medium, Solar system - The inner planets, Solar system - The asteroid belt, Solar system - The outer planets, Solar system - The trans-Neptunian region, Solar system - And beyond, Solar system - Galactic orbit of the solar system, Solar system - Planetary system formation, Solar system - Discovery of the solar system, Solar system - Exploration of the solar system, Solar system - Attributes of major planets, Solar system - Attributes of the largest minor planets, Solar system - Other facts

Read more here: » Solar system: Encyclopedia II - Solar system - Discovery of the solar system

Since the start of the space age, a great deal of exploration has been performed by unmanned space missions that have been organized and executed by various space agencies. The first probe to land on another solar system body was the Soviet Union's Luna 2 probe, which impacted on the Moon in 1959. Since then, increasingly distant planets have been reached, with probes landing on Venus in 1965, Mars in 1976, the asteroid 433 Eros in 2001, and Saturn's moon Titan in 2005. Spacecraft have also made close approa ...

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Solar system, Solar system - Structure and layout of the solar system, Solar system - Origin and age of the solar system, Solar system - Regions of the solar system, Solar system - Interplanetary medium, Solar system - The inner planets, Solar system - The asteroid belt, Solar system - The outer planets, Solar system - The trans-Neptunian region, Solar system - And beyond, Solar system - Galactic orbit of the solar system, Solar system - Planetary system formation, Solar system - Discovery of the solar system, Solar system - Exploration of the solar system, Solar system - Attributes of major planets, Solar system - Attributes of the largest minor planets, Solar system - Other facts

Read more here: » Solar system: Encyclopedia II - Solar system - Exploration of the solar system

All attributes below are measured relative to the Earth: Of the other objects, Ganymede has the largest mass (0.02). Note: Although 2003 UB313 is a minor planet, it is being considered as possibly being a major planet (the tenth in the solar system). For a more comprehensive table, see table of planets in the solar system. ...

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Solar system, Solar system - Structure and layout of the solar system, Solar system - Origin and age of the solar system, Solar system - Regions of the solar system, Solar system - Interplanetary medium, Solar system - The inner planets, Solar system - The asteroid belt, Solar system - The outer planets, Solar system - The trans-Neptunian region, Solar system - And beyond, Solar system - Galactic orbit of the solar system, Solar system - Planetary system formation, Solar system - Discovery of the solar system, Solar system - Exploration of the solar system, Solar system - Attributes of major planets, Solar system - Attributes of the largest minor planets, Solar system - Other facts

Read more here: » Solar system: Encyclopedia II - Solar system - Attributes of major planets