Twilight duration

There are two separate twilight events that occur on Earth arising from separate dynamics. There is the familiar twilight event as the Sun's disappears from view and the stars appear at latitudes where the Sun is seen each rotation and then there is the twilight at the North/South poles at the Equinoxes arising from a separate surface rotation to the central Sun. Of course there should be no issue that the Earth has two daylight/darkness cycles but unfortunately the celestial sphere people dump everything into a circumpolar view with its catastrophic consequences and bizarre ideas -

http://usatoday30.usatoday.com/news/...ole-sunset.htm

The Sun moving in circumpolar motion is the worst in an attempt to explain daily twilight duration at different latitudes whereas the common sense perspective of latitudinal speeds is completely ignored as is the necessity for dual surface rotations to partition daily twilight from polar twilight. Try putting the Sun in circumpolar motion from observations made fairly close to the Equator and readers can get a sense of just how miserable astronomy and its links to terrestrial sciences have become -

http://apod.nasa.gov/apod/ap140620.html


Setting aside the twilight on the Equinoxes at the North/South poles and the dynamic behind it, the faster the Earth turns at a location the shorter the twilight and obversely,as speeds diminish with latitudes then so do the periods for twilight lengths stretch.

I entirely agree with what Chris.B wrote on Saturday 4th April 2015. We must ALL totally ignore Gerald - for Gerald's sake and for the sake of the wider astronomical community.

In my opinion Gerald is getting worse rather than better and I share Chris.B's concerns about "what might happen next"!

"Should we really be continuing to argue with someone who is so obviously mentally ill? By his own words he has condemned himself to that interpretation, countless times, here and on other forums, over quite a number of years..

What worries me is that this mentally ill person is expressing increasingly aggressive behaviour towards those who argue with his ridiculous fantasies.. How long will it be before this mentally ill person channels his aggression and frustration into a physical attack on an innocent victim? Do we really want to be responsible, as a group, for triggering such an attack?

This mentally ill person cannot, or will not, obtain treatment for his serious behavioural problems. Or perhaps, his symptoms do not readily respond to therapy or medication. I can only suggest, yet again, that nobody here responds to this person. At what point does your own, endless repetition display your own behavioural problems? Think about that before your next auto-response to this person's next ridiculous diatribe.

I'm sure we all used to think we were dealing with yet another, deliberately irritating troll pretending to have very eccentric views. However, the severity of his symptoms have developed in lock step with the negative attention he has received online.

He has repeatedly shown sociopathic responses to his responders and clearly lacks any moral sense of responsibility for his own actions. For example; he has repeatedly published my private emails on this forum in direct reaction to my open criticism of his endlessly repeated fantasies.

The situation has now become very like deliberately baiting a mentally ill person. One who insists on going out into public places to berate bystanders with his infantile fantasies. Nobody can have missed the escalating expressions of aggression towards his critics. Who can say that this clearly unbalanced person will not step over the line into a physical attack on a completely random bystander?

As yourself: Who will your next response to this unbalanced person impress? Certainly not the OP! So why bother? To impress this forum's dwindling readership with your unmatched educational skills and Pavlov auto-pedantry? Really?"