Editing 2172: Lunar Cycles
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==Explanation== | ==Explanation== | ||
+ | {{incomplete|Created by a MOONBOT. Joke cycle explanations need to be expanded and title text needs to be explained. Do NOT delete this tag too soon.}} | ||
− | This comic shows a mixture of real, scientific lunar cycles and cycles that are comedic or fictional in nature | + | This comic shows a mixture of real, scientific lunar cycles and cycles that are comedic or fictional in nature. |
− | *'''Nodal precession:''' The Moon's orbital plane is tilted slightly compared to the Earth's orbital plane around the sun (the {{w|ecliptic}}). This tilt is why we don't constantly see eclipses; most of the time, the Moon's orbital plane is tilted higher or lower than the Sun, so they generally don't cross each other. The two points at which these planes ''do'' cross are called {{w|lunar nodes}}. {{w|Nodal precession}} is the gradual rotation of these nodes over time, | + | *'''Nodal precession:''' The Moon's orbital plane is tilted slightly compared to the Earth's orbital plane around the sun (the {{w|ecliptic}}). This tilt is why we don't constantly see eclipses; most of the time, the Moon's orbital plane is tilted higher or lower than the Sun, so they generally don't cross each other. The two points at which these planes ''do'' cross are called {{w|lunar nodes}}. {{w|Nodal precession}} is the gradual rotation of these nodes over time, which for the Moon follows an 18.6 year cycle. |
*'''Apsidal precession:''' All orbits have two points where the orbiting body is either closest to, or furthest away from, the thing they are orbiting. These points are called {{w|apsides}}, and the imaginary line between them is called the ''line of apsides''. {{w|Apsidal precession}} is the gradual rotation of this line over time, which occurs in cycles of around 8.9 years for the Moon. | *'''Apsidal precession:''' All orbits have two points where the orbiting body is either closest to, or furthest away from, the thing they are orbiting. These points are called {{w|apsides}}, and the imaginary line between them is called the ''line of apsides''. {{w|Apsidal precession}} is the gradual rotation of this line over time, which occurs in cycles of around 8.9 years for the Moon. | ||
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*'''Phase:''' {{w|Lunar phase}} describes the change in shape of the sunlit side of the Moon as viewed from the Earth's surface, which is caused by the changing angle between Moon and Sun as the Moon revolves around the Earth. The cycle of lunar phases takes 29.5 days, a figure referred to as the ''synodic month''. | *'''Phase:''' {{w|Lunar phase}} describes the change in shape of the sunlit side of the Moon as viewed from the Earth's surface, which is caused by the changing angle between Moon and Sun as the Moon revolves around the Earth. The cycle of lunar phases takes 29.5 days, a figure referred to as the ''synodic month''. | ||
− | *'''Distance:''' Because the Moon's orbit around the Earth is elliptical, its distance from the Earth varies slightly over the course of an orbit. This means that the moon's distance also follows a cycle which is the same as the length of one lunar orbit: approximately 27.5 days. This figure is referred to as the '' | + | *'''Distance:''' Because the Moon's orbit around the Earth is elliptical, its distance from the Earth varies slightly over the course of an orbit. This means that the moon's distance also follows a cycle which is the same as the length of one lunar orbit: approximately 27.5 days. This figure is referred to as the ''sidereal month''. Note that the synodic month is (perhaps counterintuituvely) two days ''longer'' than the sidereal month - or to put it another way, it takes 2 more days for the Moon's phases to cycle than it does for the Moon to go around the Earth. This is due to the fact that the Earth is also moving ''around'' the Sun while the phases are going on, which means that the Moon has to spend 2 extra days "catching up" to the point at which the lunar phase cycle can restart. |
− | *'''Earth-Moon relative size''': This is a joke cycle; the Earth and Moon do not | + | *'''Earth-Moon relative size''': This is a joke cycle; the Earth and Moon do not change size, nor does the Moon ever become larger than the Earth. This may be playing on the idea that the Moon often ''appears'' to change size due to a various factors; most commonly, this is due to the {{w|Moon illusion}}, which tricks the brain into perceiving the Moon as much larger than it really is. There are also so-called {{w|supermoon}}s, which occur when the full moon coincides with the Moon's closest approach to Earth; these actually ''do'' increase the Moon's apparent size, although by a relatively insignificant amount. |
*'''Lunar shape:''' Again, this is a joke cycle; the Moon does not actually change shape. A shape intermediate between circle and square is known as a {{w|squircle}}, a subclass of the {{w|superellipse}}. | *'''Lunar shape:''' Again, this is a joke cycle; the Moon does not actually change shape. A shape intermediate between circle and square is known as a {{w|squircle}}, a subclass of the {{w|superellipse}}. | ||
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*'''Lunar mood:''' The moon does not have a mood, although humans can have moods that fluctuate over time, sometimes with a regularity akin to a cycle. Ironically, the section of the graph that shows a good (i.e. happy) mood has the graph line curving up then down like the mouth of a frown, and for the bad (unhappy) mood it curves down and then up, as in the mouth of a smile. | *'''Lunar mood:''' The moon does not have a mood, although humans can have moods that fluctuate over time, sometimes with a regularity akin to a cycle. Ironically, the section of the graph that shows a good (i.e. happy) mood has the graph line curving up then down like the mouth of a frown, and for the bad (unhappy) mood it curves down and then up, as in the mouth of a smile. | ||
− | * The final diagram shows many different cycles superimposed on each other, highlighting areas where several cycles are coinciding. This is likely satirizing the media trend of overhyping astronomical coincidences and giving them grand-sounding names | + | * The final diagram shows many different cycles superimposed on each other, highlighting areas where several cycles are coinciding. This is likely satirizing the media trend of overhyping astronomical coincidences and giving them grand-sounding names (which get longer and more impressive the more cycles are coinciding). |
− | + | **'''Supermoon:''' see [[1394:_Superm*n]]. | |
− | + | **Two-week window in which astrology works. {{w|Astrology}} is a pseudoscience which claims that the positions of the celestial bodies can be used to predict human affairs. This is a joke on how astrology does not actually work but occasionally seems to by coincidence. | |
− | : | + | **A [[wikipedia:harvest moon|harvest moon]] is full moon closest to the autumnal equinox, possibly orange. |
− | + | **The [[wikipedia:Golden Age of Television|Golden Age of Television]] is said to have occurred in the 1940s and 50s, and the 2000s. | |
− | + | **A [[wikipedia:blue moon|blue moon]] is the extra full moon in years with 13 full moons. An event that occurs once every two or three years. Blue moons don't look any different from regular full moons. | |
− | + | **There are no occurrences of '''super blood moon''', '''dire moon''' or '''pork moon''' in the Google Books N-Gram viewer, which includes many works from the 1800s through 2008. A [[wikipedia:blood moon|blood moon]] refers to the moon during a lunar eclipse. | |
− | + | **While the popularity of '''skinny jeans''' ([[wikipedia:Slim-fit pants|slim-fit pants]]) does change over time, the idea that this is connected to a lunar cycle is also a joke. | |
− | :*''' | + | *The '''{{w|Antikythera_mechanism|Antikythera mechanism}}''' mentioned in the title text is an ancient Greek machine, rediscovered in 1901, designed to calculate astronomical positions. The title text jokes that there is a set of gears on said mechanism that is used to predict the popularity of "skinny jeans" and "low-rise waists." |
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− | The '''{{w|Antikythera_mechanism|Antikythera mechanism}}''' mentioned in the title text is an ancient Greek machine, rediscovered in 1901, designed to calculate astronomical positions. The title text jokes that there is a set of gears on said mechanism that is used to predict the popularity of "skinny jeans" and "low-rise waists." | ||
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==Transcript== | ==Transcript== | ||
+ | {{incomplete transcript|Do NOT delete this tag too soon.}} | ||
+ | |||
:Understanding lunar cycles | :Understanding lunar cycles | ||
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:[A superimposed graph of all the above waves. Different points on the graph are labelled: Harvest moon, Supermoon, Blue moon, Skinny Jeans popular, Super blood moon, Golden age of TV, Dire moon, Pork moon, Two week window in which astrology works, Total eclipse of the sea.] | :[A superimposed graph of all the above waves. Different points on the graph are labelled: Harvest moon, Supermoon, Blue moon, Skinny Jeans popular, Super blood moon, Golden age of TV, Dire moon, Pork moon, Two week window in which astrology works, Total eclipse of the sea.] | ||
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{{comic discussion}} | {{comic discussion}} |