In astronomy, heliocentrism is the theory that the Sun is at the center of the Universe and/or the Solar System. The word is derived from the Greek (Helios = "Sun" and kentron = "Center"). Historically, heliocentrism is opposed to geocentrism and currently to modern geocentrism, which places the earth at the center. (The distinction between the Solar System and the Universe was not clear until modern times, but extremely important relative to the controversy over cosmology and religion.) In the 16th and 17th centuries, w ...

Including:

Heliocentrism - Development of the idea Heliocentrism - Religious disputes over heliocentrism Heliocentrism - The view of modern science
Heliocentrism - Modern use of geocentric and heliocentric

Read more here: » Heliocentrism: Encyclopedia - Heliocentrism

See also:

Heliocentrism, Heliocentrism - Development of the idea, Heliocentrism - Religious disputes over heliocentrism, Heliocentrism - The view of modern science, Heliocentrism - Modern use of geocentric and heliocentric

Read more here: » Heliocentrism: Encyclopedia II - Heliocentrism - Religious disputes over heliocentrism

To anyone who stands and looks at the sky, it seems clear that the earth stays in one place while everything in the sky goes around once every day. Observing over a longer time, one sees more complicated movements. The Sun makes a slower circle over the course of a year; the planets have similar motions, but they sometimes turn around and move in the reverse direction for a while (retrograde motion). As these motions became better understood, they required more and more elaborate descriptions, the most famous of which ...

See also:

Heliocentrism, Heliocentrism - Development of the idea, Heliocentrism - Religious disputes over heliocentrism, Heliocentrism - The view of modern science, Heliocentrism - Modern use of geocentric and heliocentric

Read more here: » Heliocentrism: Encyclopedia II - Heliocentrism - Development of the idea

Aristarchus (310 BC - circa 230 BC) was a Greek astronomer and mathematician, born in Samos, Greece. He is the first recorded person to propose a heliocentric model of the solar system, placing the Sun, not the Earth, at the center of the known universe (hence he is sometimes known as the "Greek Copernicus"). His astronomical ideas were not well-received and were subordinated to those of Aristotle and Ptolemy, until they were successfully revived an ...

Including:

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

Read more here: » Aristarchus: Encyclopedia - Aristarchus

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 ...

See also:

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

Read more here: » Aristarchus: Encyclopedia II - Aristarchus - Heliocentrism

Mikołaj Kopernik (February 19, 1473 – May 24, 1543), more commonly known by the Latin form Nicolaus Copernicus, was a Polish[1] astrologer, astronomer, mathematician, administrator and economist. He is mainly remembered for developing a scientifically-useful heliocentric (Sun-centered) theory of the solar system. Copernicus worked in Royal Prussia as a church canon, governor, administrator, economist, jurist, physician, astrologer and, in con ...

Including:

Nicolaus Copernicus - Biography Nicolaus Copernicus - The Copernican heliocentric system
Nicolaus Copernicus - Earlier theories Nicolaus Copernicus - The Ptolemaic system Nicolaus Copernicus - Copernican theory Nicolaus Copernicus - De revolutionibus orbium coelestium
Nicolaus Copernicus - Copernicus and Copernicanism Nicolaus Copernicus - Quotes Nicolaus Copernicus - University Nicolaus Copernicus - Grave

Read more here: » Nicolaus Copernicus: Encyclopedia - Nicolaus Copernicus

Tycho Brahe, born Tyge Ottesen Brahe (December 14, 1546 – October 24, 1601), was a Danish nobleman astrologer and astronomer as well as an alchemist. He was granted an estate on the island of Hven and the funding to build the Uraniborg, an early research institute, where he built large astronomical instruments and took many careful measurements. As an astronomer, Tycho worked to combine what he saw as the geometrical benefits of the Copernican system with the philosophical benefits of the Ptolemaic system into his own model o ...

Including:

Tycho Brahe - Early years Tycho Brahe - Death of his father Tycho Brahe - Family life Tycho Brahe - Nova Tycho Brahe - Heliocentrism Tycho Brahe - Uraniborg Stjerneborg and Benátky nad Jizerou Tycho Brahe - Tycho and astronomy Tycho Brahe - Tycho and Astrology Tycho Brahe - Tycho's moose Tycho Brahe - Tycho's death Tycho Brahe - Named after Tycho

Read more here: » Tycho Brahe: Encyclopedia - Tycho Brahe

Nicolaus Copernicus - Earlier theories. Much has been written about earlier heliocentric theories. Philolaus (4th century BC) was one of the first to hypothesize movement by the Earth, probably inspired by Pythagoras' theories about a spherical Globe. Aristarchus of Samos in the 3rd century BC had developed some theories of Heraclides Ponticus (speaking of a revolution by Earth on its axis) to propose what was, so far as is known, the first serious model of a heliocentric solar system. His work about a hel ...

See also:

Nicolaus Copernicus, Nicolaus Copernicus - Biography, Nicolaus Copernicus - The Copernican heliocentric system, Nicolaus Copernicus - Earlier theories, Nicolaus Copernicus - The Ptolemaic system, Nicolaus Copernicus - Copernican theory, Nicolaus Copernicus - De revolutionibus orbium coelestium, Nicolaus Copernicus - Copernicus and Copernicanism, Nicolaus Copernicus - Quotes, Nicolaus Copernicus - University, Nicolaus Copernicus - Grave

Read more here: » Nicolaus Copernicus: Encyclopedia II - Nicolaus Copernicus - The Copernican heliocentric system

De revolutionibus orbium coelestium (English: On the Revolutions of the Heavenly Spheres, Polish: O obrotach sfer niebieskich) is the seminal work on heliocentric theory and the masterpiece of the great Polish astronomer Nicolaus Copernicus. The book set out to offer an alternative model of the universe to the Ptolemaic system. Copernicus began to write it in 1506 and finishe ...

Including:

De revolutionibus orbium coelestium - Bibliography

Read more here: » De revolutionibus orbium coelestium: Encyclopedia - De revolutionibus orbium coelestium

1633 - Events. February 13 - Galileo Galilei arrives in Rome for his trial before the Inquisition. March 1 - Samuel de Champlain reclaims his role as commander of New France on behalf of Cardinal Richelieu. June 22 - Catholic church forces Galileo Galilei to recant his heliocentric view of the solar system. Eppur si muove. Jews of Poznan are granted a privilege of forbidding Christians to enter into their city quarter. In Ethiopia, Negus Fasilidas expels foreign mi ...

Including:

1633 - Events 1633 - Births 1633 - Deaths

Read more here: » 1633: Encyclopedia - 1633

An orbital node is one of the two points where an inclined orbit crosses a plane of reference (e.g. the equator for geocentric orbits, the ecliptic for heliocentric orbits). Nodes do not exist for orbits with inclination equal to zero (equatorial orbits or ecliptic orbits). The ascending (or north) node is where the object moves north from the southern hemisphere to the northern, the descending (or south) node is where the object moves back south. The line of nodes is the intersection of the object's orbital plane with the plane of reference, a ...

Read more here: » Orbital node: Encyclopedia - Orbital node

Aryabhata (आर्यभट) Āryabhaṭa) is the first of the great astronomers of the classical age of India. He was born in 476 AD in Ashmaka but later lived in Kusumapura, which his commentator Bhāskara I (629 AD) identifies with Pataliputra (modern Patna). His book, the Āryabhatīya, presented astronomical and mathematical theories in which the Earth was taken to be spinning on its axis and the periods of the planets were given with respect to the sun (in other words, it was heliocentric).He believes that the Mo ...

Including:

Aryabhata - Overview

Read more here: » Aryabhata: Encyclopedia - Aryabhata

Nicolaus Copernicus - Earlier theories. Much has been written about earlier heliocentric theories. Philolaus (4th century BC) was one of the first to hypothesize movement by the Earth, probably inspired by Pythagoras' theories about a spherical Globe. Aristarchus of Samos in the 3rd century BC had developed some theories of Heraclides Ponticus (speaking of a revolution by Earth on its axis) to propose what was, so far as is known, the first serious model of a heliocentric solar system. His work about a hel ...

See also:

Nicolaus Copernicus, Nicolaus Copernicus - Biography, Nicolaus Copernicus - The Copernican heliocentric system, Nicolaus Copernicus - Earlier theories, Nicolaus Copernicus - The Ptolemaic system, Nicolaus Copernicus - Copernican theory, Nicolaus Copernicus - De revolutionibus orbium coelestium, Nicolaus Copernicus - Copernicus and Copernicanism, Nicolaus Copernicus - Quotes, Nicolaus Copernicus - Grave

Read more here: » Nicolaus Copernicus: Encyclopedia II - Nicolaus Copernicus - The Copernican heliocentric system

Tycho Brahe was born Tyge Ottesen Brahe (de Knudstrup), adopting the Latinised form Tycho at around age fifteen (sometimes written Tÿcho). He is often misnamed Tycho de Brahe. He was born at his family's ancestral seat of Knudstrup Castle, Denmark to Otte Brahe and Beate Bille. His twin brother was stillborn (Tycho wrote a Latin ode (Wittendorf 1994, p. 68) to his dead twin which was printed as his first publication in 1572). He also had two sisters, one older (Kirstine Brahe) and one younger (Sophie Brahe). Otte ...

See also:

Tycho Brahe, Tycho Brahe - Early years, Tycho Brahe - Death of his father, Tycho Brahe - Family life, Tycho Brahe - Nova, Tycho Brahe - Heliocentrism, Tycho Brahe - Uraniborg Stjerneborg and Benátky nad Jizerou, Tycho Brahe - Tycho and astronomy, Tycho Brahe - Tycho and Astrology, Tycho Brahe - Tycho's moose, Tycho Brahe - Tycho's death, Tycho Brahe - Named after Tycho

Read more here: » Tycho Brahe: Encyclopedia II - Tycho Brahe - Early years

In 1572, in Knudstrup, Tycho fell in love with Kirsten Jørgensdatter, a commoner whose father, Pastor Jorgen Hansen, was the Lutheran clergyman of Knudstrup's village church. Under Danish law, when a nobleman and a common woman lived together openly as husband and wife, and she wore the keys to the household at her belt like any true wife, their alliance became a binding morganatic marriage after three years. The husband retained his noble status and privileges; the wife remained a commoner. Their children were legitimate in the eyes of the ...

See also:

Tycho Brahe, Tycho Brahe - Early years, Tycho Brahe - Death of his father, Tycho Brahe - Family life, Tycho Brahe - Nova, Tycho Brahe - Heliocentrism, Tycho Brahe - Uraniborg Stjerneborg and Benátky nad Jizerou, Tycho Brahe - Tycho and astronomy, Tycho Brahe - Tycho and Astrology, Tycho Brahe - Tycho's moose, Tycho Brahe - Tycho's death, Tycho Brahe - Named after Tycho

Read more here: » Tycho Brahe: Encyclopedia II - Tycho Brahe - Family life

On November 11, 1572, Tycho observed (from Herrevad Abbey) a very bright star which unexpectedly appeared in the constellation Cassiopeia, now named SN 1572. Since it had been maintained since antiquity that the world beyond the orbit of the moon, i.e. that of the fixed stars, was eternal and unchangeable (a fundamental axiom of the Aristotelian world view: celestial immutability), other observers held that the phenomenon was something in the Earth's atmosphere. Tycho, however, observed that the parallax of the object did not change from nig ...

See also:

Tycho Brahe, Tycho Brahe - Early years, Tycho Brahe - Death of his father, Tycho Brahe - Family life, Tycho Brahe - Nova, Tycho Brahe - Heliocentrism, Tycho Brahe - Uraniborg Stjerneborg and Benátky nad Jizerou, Tycho Brahe - Tycho and astronomy, Tycho Brahe - Tycho and Astrology, Tycho Brahe - Tycho's moose, Tycho Brahe - Tycho's death, Tycho Brahe - Named after Tycho

Read more here: » Tycho Brahe: Encyclopedia II - Tycho Brahe - Nova

King Frederick II of Denmark and Norway, impressed with Tycho's 1572 observations, financed the construction of two observatories for Tycho on the island of Hven in Oresund. These were Uraniborg and Stjerneborg. Uraniborg also had a laboratory for his alchemical experiments. Because Tycho disagreed with Christian IV, the new king of his country, he left Hven in 1597 and moved to Prague in 1599. Sponsored by Rudolf II, the Holy Roman Emperor, he built a new observatory in in a castle in Benátky nad Jizerou, 50 km from Prague, and he worked there for one year. ...

See also:

Tycho Brahe, Tycho Brahe - Early years, Tycho Brahe - Death of his father, Tycho Brahe - Family life, Tycho Brahe - Nova, Tycho Brahe - Heliocentrism, Tycho Brahe - Uraniborg Stjerneborg and Benátky nad Jizerou, Tycho Brahe - Tycho and astronomy, Tycho Brahe - Tycho and Astrology, Tycho Brahe - Tycho's moose, Tycho Brahe - Tycho's death, Tycho Brahe - Named after Tycho

Read more here: » Tycho Brahe: Encyclopedia II - Tycho Brahe - Uraniborg Stjerneborg and Benátky nad Jizerou

Tycho was the preeminent observational astronomer of the pre-telescopic period, and his observations of stellar and planetary positions achieved unparalleled accuracy for their time. For example, Tycho measured Earth's axial tilt as 23 degrees and 31.5 minutes, which he claimed to be more acurate than Copernicus by 3.5 minutes. After his death, his records of the motion of the planet Mars enabled Kepler to discover the laws of planetary motion, which provided powerful support for the ...

See also:

Tycho Brahe, Tycho Brahe - Early years, Tycho Brahe - Death of his father, Tycho Brahe - Family life, Tycho Brahe - Nova, Tycho Brahe - Heliocentrism, Tycho Brahe - Uraniborg Stjerneborg and Benátky nad Jizerou, Tycho Brahe - Tycho and astronomy, Tycho Brahe - Tycho and Astrology, Tycho Brahe - Tycho's moose, Tycho Brahe - Tycho's death, Tycho Brahe - Named after Tycho

Read more here: » Tycho Brahe: Encyclopedia II - Tycho Brahe - Tycho and astronomy

Like the fifteenth century astronomer Regiomontanus, Tycho Brahe appears to have accepted astrological prognostications on the principle that the heavenly bodies undoubtedly influenced (yet did not determine) terrestrial events, but expressed skepticism about the multiplicity of interpretative schemes, and increasingly preferred to work on establishing a sound mathematical astronomy. Two early tracts, one entitled Against Astrologers for Astrology, and one on a new method of dividing the sky into astrological houses, w ...

See also:

Tycho Brahe, Tycho Brahe - Early years, Tycho Brahe - Death of his father, Tycho Brahe - Family life, Tycho Brahe - Nova, Tycho Brahe - Heliocentrism, Tycho Brahe - Uraniborg Stjerneborg and Benátky nad Jizerou, Tycho Brahe - Tycho and astronomy, Tycho Brahe - Tycho and Astrology, Tycho Brahe - Tycho's moose, Tycho Brahe - Tycho's death, Tycho Brahe - Named after Tycho

Read more here: » Tycho Brahe: Encyclopedia II - Tycho Brahe - Tycho and Astrology

Tycho died on October 24, 1601, several days after straining his bladder during a banquet. It has been said that to leave the banquet before it concluded, would be the height of bad manners and so he remained. His weakened state allowed an infection to invade his body and led ultimately to his death. He was succeeded as Imperial Mathematicus by Kepler, two days later. However, recent investigations have suggested that Tycho did not die from urinary problems but most likely from mercury poisoning: toxic levels of it have been fo ...

See also:

Tycho Brahe, Tycho Brahe - Early years, Tycho Brahe - Death of his father, Tycho Brahe - Family life, Tycho Brahe - Nova, Tycho Brahe - Heliocentrism, Tycho Brahe - Uraniborg Stjerneborg and Benátky nad Jizerou, Tycho Brahe - Tycho and astronomy, Tycho Brahe - Tycho and Astrology, Tycho Brahe - Tycho's moose, Tycho Brahe - Tycho's death, Tycho Brahe - Named after Tycho

Read more here: » Tycho Brahe: Encyclopedia II - Tycho Brahe - Tycho's death