Editing Talk:1905: Cast Iron Pan

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:There is only one solstice (the summer one) that has 24-hour sunlight (a.k.a. midnight sun) in the Arctic circle. However, near the North pole, you have close to 6 months of daylight (a.k.a. polar day), bounded by the equinoxes. So, you could theoretically visit the North Pole in late March and mid-September to have two days of 24-hour sunlight nearly 6 months apart.  <sub> [[User:Nialpxe|<span style="color: #055; text-decoration: none;">Nialpxe</span>]], 2017. [[User_talk:Nialpxe|<span style="color: #055; text-decoration: none;">(Arguments welcome)</span>]] (From the subtropics) </sub>
 
:There is only one solstice (the summer one) that has 24-hour sunlight (a.k.a. midnight sun) in the Arctic circle. However, near the North pole, you have close to 6 months of daylight (a.k.a. polar day), bounded by the equinoxes. So, you could theoretically visit the North Pole in late March and mid-September to have two days of 24-hour sunlight nearly 6 months apart.  <sub> [[User:Nialpxe|<span style="color: #055; text-decoration: none;">Nialpxe</span>]], 2017. [[User_talk:Nialpxe|<span style="color: #055; text-decoration: none;">(Arguments welcome)</span>]] (From the subtropics) </sub>
 
::It is also for this reason it says close to the equinoxes. At the equinoxes the sun sets for the first time in 6 months at one of the poles (rises at the other), splitting that 24 hour cycle in two times 12 hours of sun/no sun. And then it either stays up of stays down the next half a year. So if you come just after the sun rose and then again just before the sun sets on the North Pole you could get 24 hours sun shine with about a half year apart, but not completely. So this is White Hat's objection, although the title text also states that it doesn't have to be equally spaced. But in White Hat's opinion (of his teasing Cueball) it should be exactly half a year apart, and probably preferably on the two poles when the sun is highest at the Summer/Winter Solstices... ;-) --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 09:29, 20 October 2017 (UTC)
 
::It is also for this reason it says close to the equinoxes. At the equinoxes the sun sets for the first time in 6 months at one of the poles (rises at the other), splitting that 24 hour cycle in two times 12 hours of sun/no sun. And then it either stays up of stays down the next half a year. So if you come just after the sun rose and then again just before the sun sets on the North Pole you could get 24 hours sun shine with about a half year apart, but not completely. So this is White Hat's objection, although the title text also states that it doesn't have to be equally spaced. But in White Hat's opinion (of his teasing Cueball) it should be exactly half a year apart, and probably preferably on the two poles when the sun is highest at the Summer/Winter Solstices... ;-) --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 09:29, 20 October 2017 (UTC)
:Two details:
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:a) The equinoxes are not exactly 6 months apart.  The earths orbit is not circular.  A daylight "day" at the south pole is about 9 days longer than at the north pole.  There is a narrow window to pull off 24 hours of daylight six months apart using only the south pole, whether "6 months" is 6 calendar months or exactly half a year.
 
:b) Because sunrise and sunset (and direct sunlight) are defined by the upper limb of the sun and because of refraction polar, polar sunrise is about 3 days before the equinox and polar sunset is about 3 days after the next equinox.  This widens the window at the south pole and just about makes it possible to do at the north pole. 
 
:  [[Special:Contributions/162.158.63.232|162.158.63.232]] 18:01, 20 October 2017 (UTC)
 
  
 
Just to make sure, the "iron filings" part has no real use. Isn't it? --[[User:Lou Crazy|Lou Crazy]] ([[User talk:Lou Crazy|talk]]) 09:21, 20 October 2017 (UTC)
 
Just to make sure, the "iron filings" part has no real use. Isn't it? --[[User:Lou Crazy|Lou Crazy]] ([[User talk:Lou Crazy|talk]]) 09:21, 20 October 2017 (UTC)

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