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Old 21-04-2014, 09:06 PM   #165
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Lightbulb Equinox

An Equinox occurs twice a year, around 20 March and 22 September. The word itself has several related definitions. The oldest meaning is the day when daytime and night are of approximately equal duration..The word equinox comes from this definition, derived from the Latin aequus (equal) and nox (night). The equinox is not exactly the same as the day when period of daytime and night are of equal length for 2 reasons. Firstly, sunrise, which begins daytime, occurs when the top of the Sun's disk rises above the eastern horizon. At that instant, the disk's center is still below the horizon. Secondly, Earth's atmosphere refracts sunlight. As a result, an observer sees daylight before the first glimpse of the Sun's disk above the horizon..In Norse mythology, is an immense tree that is central in Norse cosmology, in connection to which the 9 worlds exist..In stanza 137 of the poem Hávamál, Odin describes how he once sacrificed himself to himself by hanging on a tree.. I know that I hung on a windy tree 9 long nights,wounded with a spear, dedicated to Odin,myself to myself,on that tree of which no man knows from where its roots run..The Mesoamerican world tree connects the planes of the Underworld and the sky with that of the terrestrial realm..Parallax is a displacement or difference in the apparent position of an object viewed along 2 different lines of sight, and is measured by the angle or semi-angle of inclination between those 2 lines..A gravitational lens refers to a distribution of plates (such as a cluster of galaxies) between a distant source (a background galaxy) and an observer, that is capable of bending (lensing) the light from the source, as it travels towards the observer...
Refraction is essentially a surface phenomenon. The phenomenon is mainly in governance to the law of conservation of energy and momentum. Due to change of medium, the phase velocity of the wave is changed but its frequency remains constant. This is most commonly observed when a wave passes from one medium to another at any angle other than 90° or 0°..Refraction can be seen when looking into a bowl of water. Air has a refractive index of about 1.0003, and water has a refractive index of about 1.3330. If a person looks at a straight object, such as a pencil or straw, which is placed at a slant, partially in the water, the object appears to bend at the water's surface. This is due to the bending of light rays as they move from the water to the air..When Julius Caesar established his calendar in 45 BC he set 25 March as the spring equinox. Because a Julian year (365.25 days) is slightly longer than an actual year the calendar drifted with respect to the equinox, such that the equinox was occurring on about 21 March in AD 300 and by AD 1500 it had reached 11 March..While refraction allows for phenomena such as rainbows, it may also produce peculiar optical phenomena, such as mirages and Fata Morgana.. These are caused by the change of the refractive index of air with temperature...
This drift induced Pope Gregory XIII to create a modern Gregorian calendar. The Pope wanted to restore the edicts concerning the date of Easter of the Council of Nicaea of AD 325. (Incidentally, the date of Easter itself is fixed by an approximation of lunar cycles used in the Hebraic calendar, but according to the historian Bede the English name "Easter" comes from a pagan celebration by the Germanic tribes of the vernal (spring) equinox).. So the shift in the date of the equinox that occurred between the 4th and the 16th centuries was annulled with the Gregorian calendar, but nothing was done for the first four centuries of the Julian calendar. The days of 29 February of the years AD 100, AD 200, AD 300, and the day created by the irregular application of leap years between the assassination of Caesar and the decree of Augustus re-arranging the calendar in AD 8, remained in effect. This moved the equinox 4 days earlier than in Caesar's time..Some of the statements above can be made clearer by picturing the day arc (i.e., the path the Sun tracks along the celestial dome in its diurnal movement).. In addition, some 'ghost' suns are also indicated below the horizon, up to 18° below it; the Sun in such areas still causes twilight..The consensual chronology we live with was essentially crafted in the 16th century by Jesuits..The first successful measurements of stellar parallax were made by Bessel in 1838 for the star 61 Cygni using a Heliometer.. Ancient history is based on documents, manuscripts, printed books, paintings, monuments and artefacts called primary sources. The problem is that neither these primary sources, nor events described therein can be irrefutably dated, moreover they contradict each other for the most part..The speed of light in vacuum, commonly denoted c, is a universal physical constant important in many areas of physics...Axis mundi symbolism may be seen in much of the romance surrounding space travel. A rocket on the pad takes on all the symbolism of a tower and the astronaut enacts a mythic story.. Each embarks on a perilous journey into the heavens and, if successful, returns with a boon for dissemination. The Apollo 13 insignia stated it succinctly: Ex luna scientia ("From the Moon, knowledge")... that you are in Jupiter's space and the entire crew is revived it can be told to you..18 months ago the first evidence of intelligent life off the Earth was discovered. It was buried 40 feet below the lunar surface near the crater Tycho.. Except for a single very powerful radio emission aimed at Jupiter the 4-million year old black monolith has remained completely inert. Its origin and purpose are still a total mystery...

Last edited by lightgiver; 21-04-2014 at 09:10 PM.
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