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Great Year
The term Great Year has multiple meanings. In scientific astronomy, it refers to the time required for the equinoxes to complete one full cycle around the ecliptic, a period of approximately 25,800 years. According to Ptolemy, his teacher Hipparchus discovered this phenomenon by comparing the position of the vernal equinox against the fixed stars, noting that it Axial precession, shifts westward by about one degree every 72 years. This means that a full cycle through all the zodiac constellations takes roughly 25,920 years. In the heliocentric model, this precession can be visualized as the Earth’s rotational axis slowly tracing a circular path around the normal to the plane of the ecliptic. Currently, Earth's axis points close to Polaris, the North Star, but due to precession, this alignment is temporary and will shift over time, returning only after one complete Great Year has passed. By extension, the term "Great Year" can be used for any concept of eternal return in the worl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plato
Plato ( ; Greek language, Greek: , ; born BC, died 348/347 BC) was an ancient Greek philosopher of the Classical Greece, Classical period who is considered a foundational thinker in Western philosophy and an innovator of the written dialogue and dialectic forms. He influenced all the major areas of theoretical philosophy and practical philosophy, and was the founder of the Platonic Academy, a philosophical school in History of Athens, Athens where Plato taught the doctrines that would later become known as Platonism. Plato's most famous contribution is the theory of forms, theory of forms (or ideas), which aims to solve what is now known as the problem of universals. He was influenced by the pre-Socratic thinkers Pythagoras, Heraclitus, and Parmenides, although much of what is known about them is derived from Plato himself. Along with his teacher Socrates, and his student Aristotle, Plato is a central figure in the history of Western philosophy. Plato's complete ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Precession Of The Equinox
In astronomy, axial precession is a gravity-induced, slow, and continuous change in the orientation of an astronomical body's rotational axis. In the absence of precession, the astronomical body's orbit would show axial parallelism. In particular, axial precession can refer to the gradual shift in the orientation of Earth's axis of rotation in a cycle of approximately 26,000 years.Hohenkerk, C.Y., Yallop, B.D., Smith, C.A., & Sinclair, A.T. "Celestial Reference Systems" in Seidelmann, P.K. (ed.) ''Explanatory Supplement to the Astronomical Almanac''. Sausalito: University Science Books. p. 99. This is similar to the precession of a spinning top, with the axis tracing out a pair of cones joined at their apices. The term "precession" typically refers only to this largest part of the motion; other changes in the alignment of Earth's axis— nutation and polar motion—are much smaller in magnitude. Earth's precession was historically called the precession of the equinoxes, b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exeligmos
An exeligmos () is a period of 54 years, 33 days that can be used to predict successive eclipses with similar properties and location. For a solar eclipse, after every exeligmos a solar eclipse of similar characteristics will occur in a location close to the eclipse before it. For a lunar eclipse the same part of the earth will view an eclipse that is very similar to the one that occurred one exeligmos before it (see main text for visual examples). The exeligmos is an eclipse cycle that is a triple saros (astronomy), saros, three saroses (or saroi) long, with the advantage that it has nearly an integer number of days so the next eclipse will be visible at locations and times near the eclipse that occurred one exeligmos earlier. In contrast, each saros, an eclipse occurs about eight hours later in the day or about 120° to the west of the eclipse that occurred one saros earlier. It corresponds to: * * * * () * The 57 eclipse years means that if there is a solar eclipse (or lunar ecl ... [...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] |
Censorinus
Censorinus () was a Roman grammarian and miscellaneous writer. Name From its grammatical form, Censorinus is presumably his cognomen, the shared surname of a branch of a Roman family (). The cognomen would typically be used by those descended from, adopted by, or related by prominent marriage to someone who had held the office of censor. Censorinus's given name () and family name () are unknown, although the Marcii Censorini were by far the most prominent family to use the cognomen. The author is sometimes distinguished as (). Life Little is known of Censorinus, although he lived during the 3rd century and apparently dedicated to his patron Quintus Caerellius as a birthday gift. Works Censorinus was the author of a lost work as well as the surviving . (Latin for "On the Natal Day" or "On the Birthday") or ("Little Work on the Birthday") was apparently written in 238 for the birthday of Censorinus's patron Quintus Caerellius. The contents are of a varied character ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Somnium Scipionis
The ''Dream of Scipio'' (Latin: ''Somnium Scipionis''), written by Cicero, is the sixth book of ''De re publica'', and describes a (postulated fictional or real) dream vision of the Roman general Scipio Aemilianus, set two years before he oversaw the destruction of Carthage in 146 BC. Textual history The ''Somnium Scipionis'' is a portion of the sixth and final book from Cicero's ''De re publica'', but because parts of Cicero's whole work are missing, ''Somnium Scipionis'' represents nearly all that remains of the sixth book.Stahl (1952), p. 10. The main reason that the ''Somnium Scipionis'' survived was because in the fifth-century, the Latin writer Macrobius wrote a Neoplatonic commentary on the work, in which he excerpted large portions from Cicero. Additionally, many copies of Macrobius's work were amended with a copy of the ''Somnium Scipionis'' at their end. However, during the Middle Ages, the ''Somnium Scipionis'' became so popular that its transmission was pollut ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Macrobius
Macrobius Ambrosius Theodosius, usually referred to as Macrobius (fl. AD 400), was a Roman provincial who lived during the early fifth century, during late antiquity, the period of time corresponding to the Later Roman Empire, and when Latin was as widespread as Greek among the elite. He is primarily known for his writings, which include the widely copied and read '' Commentarii in Somnium Scipionis'' ("Commentary on the Dream of Scipio") about '' Somnium Scipionis'', which was one of the most important sources for Neoplatonism in the Latin West during the Middle Ages; the ''Saturnalia'', a compendium of ancient Roman religious and antiquarian lore; and ''De differentiis et societatibus graeci latinique verbi'' ("On the Differences and Similarities of the Greek and Latin Verb"), which is now lost. He is the basis for the protagonist Manlius in Iain Pears' book '' The Dream of Scipio''. Name Macrobius's given name () is unrecorded as is his family name (). His recorded nam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Timaeus (dialogue)
''Timaeus'' (; , ) is one of Plato's dialogues, mostly in the form of long monologues given by Critias and Timaeus, written 360 BC. The work puts forward reasoning on the possible nature of the physical world and human beings and is followed by the dialogue '' Critias''. Participants in the dialogue include Socrates, Timaeus, Hermocrates, and Critias. Some scholars believe that it is not the Critias of the Thirty Tyrants who appears in this dialogue, but his grandfather, also named Critias. At the beginning of the dialogue, the absence of another, unknown dialogue participant, present on the day before, is bemoaned. It has been suggested from some traditions— Diogenes Laertius (VIII 85) from Hermippus of Smyrna (3rd century BC) and Timon of Phlius ( 320 – 235 BC)—that ''Timaeus'' was influenced by a book about Pythagoras, written by Philolaus, although this assertion is generally considered false. Introduction The dialogue takes place the day after Socrates de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
De Natura Deorum
''De Natura Deorum'' (''On the Nature of the Gods'') is a philosophical dialogue by Roman Academic Skeptic philosopher Cicero written in 45 BC. It is laid out in three books that discuss the theological views of the Hellenistic philosophies of Epicureanism, Stoicism, and Academic Skepticism. Writing ''De Natura Deorum'' belongs to the group of philosophical works which Cicero wrote in the two years preceding his death in 43 BC. He states near the beginning of ''De Natura Deorum'' that he wrote them both as a relief from the political inactivity to which he was reduced by the supremacy of Julius Caesar, and as a distraction from the grief caused by the death of his daughter Tullia. The dialogue is supposed to take place in Rome at the house of Gaius Aurelius Cotta. In the dialogue he appears as pontiff, but not as consul. He was made pontiff soon after 82 BC, and consul in 75 BC, and as Cicero, who is present at the dialogue as a listener, did not return from Athens till 77 B ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cicero
Marcus Tullius Cicero ( ; ; 3 January 106 BC – 7 December 43 BC) was a Roman statesman, lawyer, scholar, philosopher, orator, writer and Academic skeptic, who tried to uphold optimate principles during the political crises that led to the establishment of the Roman Empire. His extensive writings include treatises on rhetoric, philosophy and politics. He is considered one of Rome's greatest orators and prose stylists and the innovator of what became known as "Ciceronian rhetoric". Cicero was educated in Rome and in Greece. He came from a wealthy municipal family of the Roman equestrian order, and served as consul in 63 BC. He greatly influenced both ancient and modern reception of the Latin language. A substantial part of his work has survived, and he was admired by both ancient and modern authors alike. Cicero adapted the arguments of the chief schools of Hellenistic philosophy in Latin and coined a large portion of Latin philosophical vocabulary via ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Axial Precession
In astronomy, axial precession is a gravity-induced, slow, and continuous change in the orientation of an astronomical body's rotational axis. In the absence of precession, the astronomical body's orbit would show axial parallelism. In particular, axial precession can refer to the gradual shift in the orientation of Earth's axis of rotation in a cycle of approximately 26,000 years.Hohenkerk, C.Y., Yallop, B.D., Smith, C.A., & Sinclair, A.T. "Celestial Reference Systems" in Seidelmann, P.K. (ed.) ''Explanatory Supplement to the Astronomical Almanac''. Sausalito: University Science Books. p. 99. This is similar to the precession of a spinning top, with the axis tracing out a pair of cones joined at their apices. The term "precession" typically refers only to this largest part of the motion; other changes in the alignment of Earth's axis— nutation and polar motion—are much smaller in magnitude. Earth's precession was historically called the precession of the equinoxes, b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
