There are two types of competitions conducted by the ASDRC. Two groups of competitors are tested by them. First is Dharmaraja College students. Students in grade 6 and above are tested and rated periodically to keep the standards of their knowledge. The idea beind that is promoting the knowledge as well as building a strong senior Astronomy quiz team to compete in national level quiz competitions representing the school. Second type of competitions are targeted for the countrywide, below college level students.

Having in mind their prorities, ASDRC conducts the ”Astro Olympiad” all-island inter school astronomy quiz competition and all-island inter school observation competition to enhance healthy competition between other schools in Sri Lanka.Quiz competition was first organized in year 2002 and is one of the oldest Astronomy quizzes in Sri Lanka. Usually this competition consists of a written preliminary round, 2 semi finals and a grand final. Both semifinals and final are oral. Preliminary round is divided into 5 sub sections as Cosmology and Astrophysics, General Astronomy, Rocketry and Space Science, History of astronomy and Archaeoastronomy and Observational astronomy. Best four teams selected from this round are taken into the semi finals and teams selected from them to the grand final. Winning team at the final is awarded the ”Astro Olympiad” challenge shield.

Observation competition was initiated in year 2006 and marked the beginning of 2nd sky observation competiion in Sri Lanka. It usually consists of 4 or 5 sky observation tasks depending on the visibility and availability of the objects. Usually competing teams get Lunar Sketching, Jupiter Obsevation, Saturn Obsevation, Mars Obsevation, Constellation Mapping and Deep Sky Obsevation as for their tasks. The best team at these tasks get the ASDRC obsevation shield.

Adapted from the Wikipedia article Astronomical Society of Dharmaraja College (ASDRC), under the G. N. U. Free Documentation License. Please also see http://en.wikipedia.org/wiki

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The main area of research in Tuorla is active galactic nuclei; about half of the researchers are working on the topic. Other areas are dark matter, cosmology, astrodynamics, binary stars, solar neighborhood, solar physics and astrobiology. The optical laboratory produces high quality optics for telescopes.

Adapted from the Wikipedia article Tuorla Observatory, under the G. N. U. Free Documentation License. Please also see http://en.wikipedia.org/wiki

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non-standard cosmology is any physical cosmological model of the universe that has been, or still is, proposed as an alternative to the big bang model of (standard) physical cosmology. In the history of cosmology, various scientists and researchers have disputed parts or all of the big bang due to a rejection or addition of fundamental assumptions needed to develop a theoretical model of the universe. From the 1940s to the 1960s, the astrophysical community was equally divided between supporters of the big bang theory and supporters of a rival steady state universe. It was not until advances in observational cosmology that the big bang would eventually become the dominant theory, and today there are few active researchers who dispute it. The term “non-standard” is applied to any cosmological theory that does not conform to the scientific consensus. Today it is also used to describe theories that accept a “big bang” occurred but differ as to the detailed physics of the origin and evolution of the universe.

Adapted from the Wikipedia article Non-standard cosmology, under the G. N. U. Free Documentation License. Please also see http://en.wikipedia.org/wiki

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Sufi cosmology is a general term for cosmological doctrines associated with the mysticism of Sufism. These may differ from place to place, order to order and time to time, but overall show the influence of several different cosmographies:

*The Quran’s testament concerning God and immaterial beings, the soul and the afterlife, the beginning and end of things, the seven heavens etc.

*The Neoplatonic views cherished by Islamic philosophers like Ibn Sina / Avicenna and Ibn Arabi.

*The Hermetic-Ptolemaic spherical geocentric world.

*The Ishraqi visionary universe as expounded by Suhrawardi Maqtul.

Adapted from the Wikipedia article Sufi cosmology, under the G. N. U. Free Documentation License. Please also see http://en.wikipedia.org/wiki

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Neo-Babylonian astronomy refers to the astronomy developed by Chaldean astronomers during the Neo-Babylonian, Achaemenid, Seleucid, and Parthian periods of Mesopotamian history. A significant increase in the quality and frequency of Babylonian observations appeared during the reign of Nabonassar (747–734 BC), who founded the Neo-Babylonian Empire. The systematic records of ominous phenomena in astronomical diaries that began at this time allowed for the discovery of a repeating 18-year Saros cycle of lunar eclipses, for example. The Egyptian astronomer Ptolemy later used Nabonassar’s reign to fix the beginning of an era, since he felt that the earliest usable observations began at this time.

The last stages in the development of Babylonian astronomy took place during the time of the Seleucid Empire (323–60 BC). In the third century BC, astronomers began to use “goal-year texts” to predict the motions of the planets. These texts compiled records of past observations to find repeating occurrences of ominous phenomena for each planet. About the same time, or shortly afterwards, astronomers created mathematical models that allowed them to predict these phenomena directly, without consulting past records.

Empirical astronomy

Though there is a lack of surviving material on Babylonian planetary theory, it appears most of the Chaldean astronomers were concerned mainly with ephemerides and not with theory. Most of the predictive Babylonian planetary models that have survived were usually strictly empirical and arithmetical, and usually did not involv

In contrast to Greek astronomy which was dependent upon cosmology, Babylonian astronomy was independent from cosmology. Whereas Greek astronomers expressed “prejudice in favor of circles or spheres rotating with uniform motion”, such a preference did not exist for Babylonian astronomers, for whom uniform circular motion was never a requirement for planetary orbits. There is no evidence that the celestial bodies moved in uniform circular motion, or along celestial spheres, in Babylonian astronomy.

Contributions made by the Chaldean astronomers during this period include the discovery of eclipse cycles and saros cycles, and many accurate astronomical observations. For example, they observed that the Sun’s motion along the ecliptic was not uniform, though they were unaware of why this was; it is today known that this is due to the Earth moving in an elliptic orbit around the Sun, with the Earth moving swifter when it is nearer to the Sun at perihelion and moving slower when it is farther away at aphelion.

Chaldean astronomers known to have followed this model include Naburimannu (fl. 6th–3rd century BC), Kidinnu (d. 330 BC), Berossus (3rd century BCE), and Sudines (fl. 240 BCE). They are known to have had a significant influence on the Greek astronomer Hipparchus and the Egyptian astronomer Ptolemy, as well as other Hellenistic astronomers.

Heliocentric astronomy

The only surviving planetary model from among the Chaldean astronomers is that of Seleucus of Seleucia (b. 190 BC), who supported Aristarchus of Samos’ heliocentric model. Seleucus is known from the writings of Plutarch, Aetius, Strabo, and Muhammad ibn Zakariya al-Razi. Strabo lists Seleucus as one of the four most influential Chaldean/Babylonian astronomers, alongside Kidenas (Kidinnu), Naburianos (Naburimannu), and Sudines. Their works were originally written in the Akkadian language and later translated into Greek. Seleucus, however, was unique among them in that he was the only one known to have supported the heliocentric theory of planetary motion proposed by Aristarchus, where the Earth rotated around its own axis which in turn revolved around the Sun. According to Plutarch, Seleucus even proved the heliocentric system through reasoning, though it is not known what arguments he used.

According to Lucio Russo, his arguments were probably related to the phenomenon of tides. Seleucus correctly theorized that tides were caused by the Moon, although he believed that the interaction was mediated by the Earth’s atmosphere. He noted that the tides varied in time and strength in different parts of the world. According to Strabo (1.1.9), Seleucus was the first to state that the tides are due to the attraction of the Moon, and that the height of the tides depends on the Moon’s position relative to the Sun.

According to Bartel Leendert van der Waerden, Seleucus may have proved the heliocentric theory by determining the constants of a geometric model for the heliocentric theory and by developing methods to compute planetary positions using this model. He may have used trigonometric methods that were available in his time, as he was a contemporary of Hipparchus.

None of his original writings or Greek translations have survived, though a fragment of his work has survived only in Arabic translation, which was later referred to by the Persian philosopher Muhammad ibn Zakariya al-Razi (865-925).

Adapted from the Wikipedia article Babylonian astronomy, under the G. N. U. Free Documentation License. Please also see http://en.wikipedia.org/wiki

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Major branches of natural philosophy include astronomy and cosmology, the study of nature on the grand scale; etiology, the study of (intrinsic and sometimes extrinsic) causes; the study of chance, probability and randomness; the study of elements; the study of the infinite and the unlimited (virtual or actual); the study of matter; mechanics, the study of translation of motion and change; the study of nature or the various sources of actions; the study of natural qualities; the study of physical quantities; the study of relations between physical entities; and the philosophy of space and time. (Adler, 1993)

Adapted from the Wikipedia article Natural philosophy, under the G. N. U. Free Documentation License. Please also see http://en.wikipedia.org/wiki

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fractal cosmology is a set of minority cosmological theories which state that the distribution of matter in the Universe, or the structure of the universe itself, is fractal. More generally, it relates to the usage or appearance of fractals in the study of the universe and matter. A central issue in this field is the fractal dimension of the Universe or of matter distribution within it, when measured at very large or very small scales.

The use of fractals to answer questions in cosmology has been employed by a growing number of serious scholars close to the mainstream , but the metaphor has also been adopted by others outside the mainstream of science, so some varieties of fractal cosmology are solidly in the realm of scientific theories and observations, and others are considered Fringe science, or perhaps metaphysical cosmology. Thus, these various formulations enjoy a range of acceptance and/or perceived legitimacy.

Adapted from the Wikipedia article Fractal cosmology, under the G. N. U. Free Documentation License. Please also see http://en.wikipedia.org/wiki

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Planetary models and observational astronomy

The Eudoxan system had several critical flaws. One was its inability to predict motions exactly. Callippus’ work may have been an attempt to correct this flaw. A related problem is the inability of his models to explain why planets appear to change speed. A third flaw is its inability to explain changes in the brightness of planets as seen from Earth. Because the spheres are concentric, planets will always remain at the same distance from Earth. This problem was pointed out in Antiquity by Autolycus of Pitane (c. 310 BCE).

Apollonius of Perga (c. 262 BC–c. 190 BC) responded by introducing two new mechanisms that allowed a planet to vary its distance and speed: the eccentric deferent and the deferent and epicycle. The deferent is a circle carrying the planet around the Earth. (The word ”deferent” comes from the Latin ”ferro, ferre”, meaning “to carry.”) An eccentric deferent is slightly off-center from Earth. In a deferent and epicycle model, the deferent carries a small circle, the epicycle, which carries the planet. The deferent-and-epicycle model can mimic the eccentric model, as shown by Apollonius’ theorem. It can also explain retrogradation, which happens when planets appear to reverse their motion through the zodiac for a short time. Modern historians of astronomy have determined that Eudoxus’ models could only have approximated retrogradation crudely for some planets, and not at all for others.

In the 2nd century BCE, Hipparchus, aware of the extraordinary ac

Hipparchus also compiled a star catalogue. According to Pliny the Elder, he observed a ”nova” (new star). So that later generations could tell whether other stars came to be, perished, moved, or changed in brightness, he recorded the position and brightness of the stars. Ptolemy mentioned the catalogue in connection with Hipparchus’ discovery of precession. (Precession of the equinoxes is a slow motion of the place of the equinoxes through the zodiac, caused by the shifting of the Earth’s axis). Hipparchus thought it was caused by the motion of the sphere of fixed stars.

Heliocentrism and cosmic scales

In the 3rd century BCE, Aristarchus of Samos proposed an alternate cosmology (arrangement of the universe): 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, however, and only a few brief references to them are preserved. We know the name of one follower of Aristarchus: Seleucus of Seleucia.

Aristarchus also wrote a book ”On the Sizes and Distances of the Sun and Moon”, which is his only work to have survived. In this work, he calculated the sizes of the Sun and Moon, as well as their distances from the Earth in Earth radii. Shortly afterwards, Eratosthenes calculated the size of the Earth, providing a value for the Earth radii which could be plugged into Aristarchus’ calculations. Hipparchus wrote another book ”On the Sizes and Distances of the Sun and Moon”, which has not survived. Both Aristarchus and Hipparchus drastically underestimated the distance of the Sun from the Earth.

Adapted from the Wikipedia article Greek astronomy, under the G. N. U. Free Documentation License. Please also see http://en.wikipedia.org/wiki

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Cosmology is the study of the cosmos in several of the above meanings, depending on context. All cosmologies have in common an attempt to understand the implicit order within the whole of being. In this way, most religions and philosophical systems have a cosmology.

In physical cosmology, the term ”cosmos” is often used in a technical way, referring to a particular space-time continuum within the (postulated) multiverse. Our particular cosmos is generally capitalized as the ”Cosmos”.

Adapted from the Wikipedia article Cosmos, under the G. N. U. Free Documentation License. Please also see http://en.wikipedia.org/wiki

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dark matter halo is a hypothetical component of a galaxy, which extends beyond the edge of the visible galaxy and dominates the total mass. Since they consist of dark matter, haloes cannot be observed directly, but their existence is inferred through their effects on the motions of stars and gas in galaxies. Dark matter halos play a key role in current models of galaxy formation and evolution.

Adapted from the Wikipedia article Dark matter halo, under the G. N. U. Free Documentation License. Please also see http://en.wikipedia.org/wiki

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