From different viewpoints on the earth you'll look with a different angle at the sun. (Remember that Australians are standing "upside down" from your perspective ;)

While the sun can reach the zenith only in the tropics¹ at noon (your shadow is between your legs) the perceived curve will become always flatter when distancing from the equator.

This curve is always under the horizon at polar night and always above in polar summer. That's because the rotation axis of the earth has an inclination compared to the sun³

Even a flat horizon is practically perceived like the earth's body hiding the sun like a mountain ridge surrounding you in winter. But in summer the horizon "lowers" to a valley and you are subjectively the one standing on a mountain top.

That's a gradual effect from poles to equator.

The combined effect of flattened curve, "moving" horizon and definition of sun rise or sunset effect the calculation. ²

Plus the flatter the curve, the longer does the sun need to fully pass the horizon from one tip to the other.

I found a German website where you can play with coordinates and check all parameters. The graphics are nice at displaying the perceived curve.

https://www.datum-und-uhrzeit.de/?coordinates=true

I compared points near Berlin and Rome with "integer" coordinates

HTH :)

Cheers Rolf
(addicted to the Perl Programming Language :)
see Wikisyntax for the Monastery

¹) by definition!

²) it's even more complicated because of precession, nutation and uneven shape of the rotating potato ellipsoid we live on

³) more correctly the ecliptic, the plane in which earth is rotating around the sun

In reply to Re: [OT] Astronomical puzzling about daylight hours at different latitudes by LanX
in thread [OT] Astronomical puzzling about daylight hours at different latitudes by Discipulus

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.