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"If you looked at the Sun at the same time each day, from the same
place, would it appear at the same location in the sky? If the Earth were not tilted, and if its orbit around the Sun were perfectly circular, then, yes, it would." http://solar-center.stanford.edu/art/analemma.html Tell me analemmatic guy what the analemma looks like at the Equator over the course of a year seeing you are intent on proposing axial tilt as a component in the Equation of Time. The variations in the Sun's position is a consequence of the orbital path of the Earth and unless you are entirely stupid,I would not recommend that you include the apparent arc of the Sun across the sky as a factor in the Equation of Time,no figure 8,no nothing,in fact take up birdwatching where you can be less destructive. The Equation of Time is a global phenomena and has nothing whatsoever to do with axial tilt but it has quite a lot to do with rotation and the rate of change of the orbital orientation of the planet due to orbital motion. Now,the human devised creation of the 24 hour day may be of little consequence to celestial sphere astrologers and their pseudo-dynamic of a variable tilting Earth but it would be nice to see somebody who can actually appreciate the brilliance of our ancestors in creating the 24 hour day and applying it to axial rotation as a clock correlation. |
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On 4 Mar, 21:55, "oriel36" wrote:
"If you looked at the Sun at the same time each day, from the same place, would it appear at the same location in the sky? If the Earth were not tilted, and if its orbit around the Sun were perfectly circular, then, yes, it would." http://solar-center.stanford.edu/art/analemma.html Tell me analemmatic guy what the analemma looks like at the Equator over the course of a year seeing you are intent on proposing axial tilt as a component in the Equation of Time. The variations in the Sun's position is a consequence of the orbital path of the Earth and unless you are entirely stupid,I would not recommend that you include the apparent arc of the Sun across the sky as a factor in the Equation of Time,no figure 8,no nothing,in fact take up birdwatching where you can be less destructive. The Equation of Time is a global phenomena and has nothing whatsoever to do with axial tilt but it has quite a lot to do with rotation and the rate of change of the orbital orientation of the planet due to orbital motion. Now,the human devised creation of the 24 hour day may be of little consequence to celestial sphere astrologers and their pseudo-dynamic of a variable tilting Earth but it would be nice to see somebody who can actually appreciate the brilliance of our ancestors in creating the 24 hour day and applying it to axial rotation as a clock correlation. First go outside, yes, you can do it, then observe the sun with your own eyes instead of reitterating distorted imaginings. Have you ever made an accurate sundial ? (Google for 'Shadows'). If you have trouble comprehending the article just come back here and ask for help. Remember Jezza, this model works for a great many intelligent, curious, people. It fits and accounts for the observations. On the other hand of course there's you... http://myweb.tiscali.co.uk/moonkmft/...ionOfTime.html The Analemma. At noon, according to mean clock time (GMT if on the Gweenwich zero meridian), the sun will be almost due south. Its altitude will vary substantial throughout the year, as its declination varies from -23.5 to +23.5 degrees. It will also generally vary slightly in position, to the east or west of due south, due to the mean clock time not being the same as sundial time. If one could support a camera stationary throughout the year, pointing due south, and upwards at an angle of about 40 degrees to the horizontal; and expose the film very briefly at exactly noon (mean time) every few days, whenever the sky was clear, throughout the year, then the multiple images of the sun on the resultant multi-exposure photograph would form a very narrow, elongated, figure-of-eight, with the top (northern) lobe smaller than the bottom (southern) part. Such a figure is known as an analemma. In actual fact, if one could travel westwards along the equator at a uniform speed such that we took exactly 24 hours to arrive back where we started (more than 1000 miles per hour), then the Sun would not appear to move noticeably during the course of the day. If however, we continued for a whole year, the Sun would appear to trace out this slender figure-of-eight we call the analemma. If instead, one points the camera in a different direction, and takes the exposures at a different time of day, e.g. late afternoon, one will get a similar effect, but the figure-of-eight will not be vertical, as here. An analemma for Mars can be seen here, from a multiple exposure photograph taken in late afternoons on Mars by the Pathfinder Project. This, instead of being a figure-of-eight, is shaped like a pear. As stated above, due to the eccentricity of its orbit, the Equation of Time on Mars just follows one cycle per Martian year, and the analemma does not cross over itself. There is an encyclopedia article about the analemma here, which shows the Earth's and Mars' analemmas. http://en.wikipedia.org/wiki/Analemma. Have a ball and keep up the trolling. jc |
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On Mar 6, 4:06 pm, "John Carruthers"
wrote: On 4 Mar, 21:55, "oriel36" wrote: "If you looked at the Sun at the same time each day, from the same place, would it appear at the same location in the sky? If the Earth were not tilted, and if its orbit around the Sun were perfectly circular, then, yes, it would." http://solar-center.stanford.edu/art/analemma.html Tell me analemmatic guy what the analemma looks like at the Equator over the course of a year seeing you are intent on proposing axial tilt as a component in the Equation of Time. The variations in the Sun's position is a consequence of the orbital path of the Earth and unless you are entirely stupid,I would not recommend that you include the apparent arc of the Sun across the sky as a factor in the Equation of Time,no figure 8,no nothing,in fact take up birdwatching where you can be less destructive. The Equation of Time is a global phenomena and has nothing whatsoever to do with axial tilt but it has quite a lot to do with rotation and the rate of change of the orbital orientation of the planet due to orbital motion. Now,the human devised creation of the 24 hour day may be of little consequence to celestial sphere astrologers and their pseudo-dynamic of a variable tilting Earth but it would be nice to see somebody who can actually appreciate the brilliance of our ancestors in creating the 24 hour day and applying it to axial rotation as a clock correlation. First go outside, yes, you can do it, then observe the sun with your own eyes instead of reitterating distorted imaginings. Have you ever made an accurate sundial ? (Google for 'Shadows'). If you have trouble comprehending the article just come back here and ask for help. Remember Jezza, this model works for a great many intelligent, curious, people. The analemma is a late 17th century creation,a meaningless exercise in turning the human creation of the equable 24 hour day into a parody based on where the Sun is using that human devised cycle. There is no analemmatic figure 8 at the Equator for the Earth for the equality of time a location at the Equatorial coordinate spends in solar radiation and in the orbital shadow does not change over the course of an annual orbit.To spend time on this artificial 'analemma' creation is an absolute waste of effort however it does draw attention to the pseudo-dynamic of variable axial tilt by which you explain the seasons and how a location experiences differing amounts of time spent in solar radiation and in the orbital shadow over the course of an annual orbit. Unlike many of you I have a clear sense of the neccessary modification based on getting rid of variable axial inclination and replacing it with a change in the solar radiation/orbital shadow boundary based on the dynamic of orbital motion and the path that orbit takes. It fits and accounts for the observations. On the other hand of course there's you... http://myweb.tiscali.co.uk/moonkmft/...ionOfTime.html The Analemma. At noon, according to mean clock time (GMT if on the Gweenwich zero meridian), the sun will be almost due south. Its altitude will vary substantial throughout the year, as its declination varies from -23.5 to +23.5 degrees. It will also generally vary slightly in position, to the east or west of due south, due to the mean clock time not being the same as sundial time. If one could support a camera stationary throughout the year, pointing due south, and upwards at an angle of about 40 degrees to the horizontal; and expose the film very briefly at exactly noon (mean time) every few days, whenever the sky was clear, throughout the year, then the multiple images of the sun on the resultant multi-exposure photograph would form a very narrow, elongated, figure-of-eight, with the top (northern) lobe smaller than the bottom (southern) part. Such a figure is known as an analemma. In actual fact, if one could travel westwards along the equator at a uniform speed such that we took exactly 24 hours to arrive back where we started (more than 1000 miles per hour), then the Sun would not appear to move noticeably during the course of the day. If however, we continued for a whole year, the Sun would appear to trace out this slender figure-of-eight we call the analemma. All you are doing is using a 24 hour day,a human creative construct,to determine the position of the Sun,t means nothing and certainly not in respect to the Total length of the natural unequal day through which the Equation of Time equalises the natural variations to an equable 24 hours. The Equation of Time creates the 24 hour cycle and as the Sun's apparent motion at the Equator is steady throughout the year,yet the Equation of Time is required here as everywhere else,a reasonably intelligent person should at least grasp the difference between the Total length of the natural day as opposed to seasonal variations in daylight/darkness at highere and lower latitudes. The 17th century vandalism which forced a variable axial tilt component into the Equation of Time or created your beloved 'analemma' as a fudge factor to 'prove' constant axial rotation to celestial sphere geometry is by far the worst act ever visited on human involvement in astronomy. If instead, one points the camera in a different direction, and takes the exposures at a different time of day, e.g. late afternoon, one will get a similar effect, but the figure-of-eight will not be vertical, as here. An analemma for Mars can be seen here, from a multiple exposure photograph taken in late afternoons on Mars by the Pathfinder Project. This, instead of being a figure-of-eight, is shaped like a pear. As stated above, due to the eccentricity of its orbit, the Equation of Time on Mars just follows one cycle per Martian year, and the analemma does not cross over itself. There is an encyclopedia article about the analemma here, which shows the Earth's and Mars' analemmas.http://en.wikipedia.org/wiki/Analemma. Have a ball and keep up the trolling. jc- Hide quoted text - - Show quoted text - I have a very difficult task and it is not made easier by the fact that there is no self-correcting mechanism in place,no authority exists to handle the matter in the dignified procedure it deserves. You can keep your analemmas,as far as I am concerned they are for people who know no better and have never had to think of the physical considerations seriously.The fact is that orbital motion can do the job that is presently assigned to variable axial tilt and knowing that it involves modifying Copernican reasoning for the first time since Keplerian orbital geometry should provide for some real excitement for a change. |
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On Mar 6, 11:19 pm, "oriel36" wrote:
On Mar 6, 4:06 pm, "John Carruthers" wrote: On 4 Mar, 21:55, "oriel36" wrote: "If you looked at the Sun at the same time each day, from the same place, would it appear at the same location in the sky? If the Earth were not tilted, and if its orbit around the Sun were perfectly circular, then, yes, it would." http://solar-center.stanford.edu/art/analemma.html Tell me analemmatic guy what the analemma looks like at the Equator over the course of a year seeing you are intent on proposing axial tilt as a component in the Equation of Time. The variations in the Sun's position is a consequence of the orbital path of the Earth and unless you are entirely stupid,I would not recommend that you include the apparent arc of the Sun across the sky as a factor in the Equation of Time,no figure 8,no nothing,in fact take up birdwatching where you can be less destructive. The Equation of Time is a global phenomena and has nothing whatsoever to do with axial tilt but it has quite a lot to do with rotation and the rate of change of the orbital orientation of the planet due to orbital motion. Now,the human devised creation of the 24 hour day may be of little consequence to celestial sphere astrologers and their pseudo-dynamic of a variable tilting Earth but it would be nice to see somebody who can actually appreciate the brilliance of our ancestors in creating the 24 hour day and applying it to axial rotation as a clock correlation. First go outside, yes, you can do it, then observe the sun with your own eyes instead of reitterating distorted imaginings. Have you ever made an accurate sundial ? (Google for 'Shadows'). If you have trouble comprehending the article just come back here and ask for help. Remember Jezza, this model works for a great many intelligent, curious, people. The analemma is a late 17th century creation,a meaningless exercise in turning the human creation of the equable 24 hour day into a parody based on where the Sun is using that human devised cycle. There is no analemmatic figure 8 at the Equator for the Earth for the equality of time a location at the Equatorial coordinate spends in solar radiation and in the orbital shadow does not change over the course of an annual orbit.To spend time on this artificial 'analemma' creation is an absolute waste of effort however it does draw attention to the pseudo-dynamic of variable axial tilt by which you explain the seasons and how a location experiences differing amounts of time spent in solar radiation and in the orbital shadow over the course of an annual orbit. Unlike many of you I have a clear sense of the neccessary modification based on getting rid of variable axial inclination and replacing it with a change in the solar radiation/orbital shadow boundary based on the dynamic of orbital motion and the path that orbit takes. It fits and accounts for the observations. On the other hand of course there's you... http://myweb.tiscali.co.uk/moonkmft/...ionOfTime.html The Analemma. At noon, according to mean clock time (GMT if on the Gweenwich zero meridian), the sun will be almost due south. Its altitude will vary substantial throughout the year, as its declination varies from -23.5 to +23.5 degrees. It will also generally vary slightly in position, to the east or west of due south, due to the mean clock time not being the same as sundial time. If one could support a camera stationary throughout the year, pointing due south, and upwards at an angle of about 40 degrees to the horizontal; and expose the film very briefly at exactly noon (mean time) every few days, whenever the sky was clear, throughout the year, then the multiple images of the sun on the resultant multi-exposure photograph would form a very narrow, elongated, figure-of-eight, with the top (northern) lobe smaller than the bottom (southern) part. Such a figure is known as an analemma. In actual fact, if one could travel westwards along the equator at a uniform speed such that we took exactly 24 hours to arrive back where we started (more than 1000 miles per hour), then the Sun would not appear to move noticeably during the course of the day. If however, we continued for a whole year, the Sun would appear to trace out this slender figure-of-eight we call the analemma. All you are doing is using a 24 hour day,a human creative construct,to determine the position of the Sun,t means nothing and certainly not in respect to the Total length of the natural unequal day through which the Equation of Time equalises the natural variations to an equable 24 hours. The Equation of Time creates the 24 hour cycle and as the Sun's apparent motion at the Equator is steady throughout the year,yet the Equation of Time is required here as everywhere else,a reasonably intelligent person should at least grasp the difference between the Total length of the natural day as opposed to seasonal variations in daylight/darkness at highere and lower latitudes. The 17th century vandalism which forced a variable axial tilt component into the Equation of Time or created your beloved 'analemma' as a fudge factor to 'prove' constant axial rotation to celestial sphere geometry is by far the worst act ever visited on human involvement in astronomy. If instead, one points the camera in a different direction, and takes the exposures at a different time of day, e.g. late afternoon, one will get a similar effect, but the figure-of-eight will not be vertical, as here. An analemma for Mars can be seen here, from a multiple exposure photograph taken in late afternoons on Mars by the Pathfinder Project. This, instead of being a figure-of-eight, is shaped like a pear. As stated above, due to the eccentricity of its orbit, the Equation of Time on Mars just follows one cycle per Martian year, and the analemma does not cross over itself. There is an encyclopedia article about the analemma here, which shows the Earth's and Mars' analemmas.http://en.wikipedia.org/wiki/Analemma. Have a ball and keep up the trolling. jc- Hide quoted text - - Show quoted text - I have a very difficult task and it is not made easier by the fact that there is no self-correcting mechanism in place,no authority exists to handle the matter in the dignified procedure it deserves. You can keep your analemmas,as far as I am concerned they are for people who know no better and have never had to think of the physical considerations seriously.The fact is that orbital motion can do the job that is presently assigned to variable axial tilt and knowing that it involves modifying Copernican reasoning for the first time since Keplerian orbital geometry should provide for some real excitement for a change.- Hide quoted text - - Show quoted text -- Hide quoted text - - Show quoted text -- Hide quoted text - - Show quoted text - To tidy up that last posting At the Equator,the length of time a location spends in daylight and darkness is steady over the course of an annual orbit however the Total length of the natural cycles varies just like everywhere else. As axial orientation remains fixed then so does the Equator - http://astro.wsu.edu/worthey/astro/h...tar-trails.jpg This leaves the orbital motion,orbital path and the change in the solar radiation/orbital shadow boundary to explain why locations either side of the Equator experience variations in day and night (radiation/shadow) but not locations at the Equator. The Equation of Time is a different matter,it has nothing to do with axial tilt but it has quite a lot to do with the Total length of each cycle .In its geocentric aspect, there is no variation in the apparent arc of the Sun at the Equator throughout the year but there is a variation in the length of Time the Sun returns to noon.In its heliocentric aspect this reflects that axial rotation passing through the changing solar radiation/orbital shadow boundary which reflects Keplerian orbital geometry . This is a major modification to the reason for the seasons,it is not easy to deal with as it is a combination of Keplerian orbital motion and the path the Earth takes over an annual orbit.If you can live comfortably with variable inclination then good for you,it spares you having to deal with matters such as how to accurately mesh astronomical data with terrestrail climatological consequences and this is the major reason for the modification. That being said,the cretion of the 24 hour cycle from the natural unequal cycle is still a magnificent achievement borne out of the recognition that no two cycles are the same .Most never get passed the notion of differening amounts of daylight/darkness however timekeeping astronomers did hence we have the Equation of Time correction which generates the equable 24 hour cycle. |
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![]() There is no analemmatic figure 8 at the Equator for the Earth Own up Gez, you've never been there have you ? Your sad vicarious existence bores me so what it's like for you I dread to think. I grew up in Singapore, I have seen the analema from 60 miles north of the equator. Do try not to invent fantasies. The analemma is a late 17th century creation,a meaningless exercise So the 12th C Arabic devices that incorporate it are what pray? See ya next year Jezza :-) Off now to observe the real universe, in real time, with my own eyes. jc |
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On Mar 13, 5:55 pm, "John Carruthers"
wrote: There is no analemmatic figure 8 at the Equator for the Earth Own up Gez, you've never been there have you ? Your sad vicarious existence bores me so what it's like for you I dread to think. I grew up in Singapore, I have seen the analema from 60 miles north of the equator. Do try not to invent fantasies. The analemma is a conceptual dog,end of story. The analemma is a late 17th century creation,a meaningless exercise So the 12th C Arabic devices that incorporate it are what pray? See ya next year Jezza :-) Off now to observe the real universe, in real time, with my own eyes. jc Good for you. Remember that next week the Earth will cross a line perpendicular to the central diameter of the Sun and as it does so,the solar radiation/ orbital shadow boundary will align with the geographical poles exactly as is featured in the Wikipedia images - http://upload.wikimedia.org/wikipedi...easonearth.png The pseudo-dynamic of variable axial tilt through which you derive that analemma nonsense is useless for explaining what only the orbital motion and path of the Earth can do but then again,it is something which has to be learned. To square axial rotation and subsequently the axial orientation to Polaris with the orbital motion of the Earth and variations in daylight/darkness,it is neccessary to drop the idea that the Earth follows the maximum diameter of the Sun whereby you attempt to explain things. So,the information contained in the great astronomical event of the Equinox remains enjoyable for those who want to consider that the dynamic is in the Earth's orbital path and motion rather than the pseudo-dynamic of variable inclination.It is an extremely important modification,even if I say so myself. No point is asking what you think happens on the Equinox seeing that you have your heart set on the imaginary and worthless figure-8. |
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