The Sun Rose In the West!

"The most beautiful experience we can have is the mysterious. It is the fundamental emotion which stands at the cradle of true art and true science. Whoever does not know it and can no longer wonder, no longer marvel, is as good as dead, and his eyes are dimmed." ~ Albert Einstein, Ideas and Opinions

Gentle Readers and Loved Ones,

I beg that you turn your attention back to the post below this one, Sunset Launch.

The pictures were presented in chronological order. You probably noticed that the sun rose in the west. In the picture of the icebreaker, the island and the volcanoes, the sun was below the horizon. In the next picture of my First Officer flying there was Mr Sun beaming bright through the windscreen. How can this be? Is it time to get right with God because the Apocalypse looms near?

Yesterday was Winter Solstice and I have been meaning for some time to present the astrophysics of living at high latitude. I just realized that this last post presented a wonderful opportunity.

If you are unfamiliar with the reasons why the earth experiences seasons please look a this link built by the Allentown School District Planetarium. It does a bang up job of explanation. Recall that the Earth is tilted away from its orbital plane by 23° 26'. This latitude establishes the Arctic Circle. Everything on Earth above roughly 66° N latitude and below 66° S latitude will experience at least one day a year with no direct sunlight. Anchorage sits at just over 61° N latitude - it is not above the Arctic Circle but "you can see it from here."

The other side of this phenomenon is that the sun does not lurk very far below the horizon when you are this far north. As you climb up in altitude in an airplane, the horizon drops below where a ground observer sees it. Further, during the initial part of our climb, we were flying incrementally to the west. These two factors were enough to cause the sun to appear to rise just above above the southwestern horizon. My pictures do not do justice to what we really saw. The limb of the sun slowly climbed up above the horizon and I think I saw a glint of green flash.

Yesterday, Dec 21st was the Winter Solstice, the longest night of the year. I used Chris Marriot's estimable SkyMap program to produce these numbers all in Anchorage Local Time.

Civil Twilight began at 0912L.
Sun actually rose at 1014L and set at 1542L
Civil Twilight ended 1644L

So...yesterday we had 5 hours and 32 minutes of sunshine and one hour and two minutes of twilight.

Compare this to Honolulu, Hawaii, situated at 21°N Latitude.

Civil Twilight began at 0640L.
Sun actually rose at 0705L and set at 1755L
Civil Twilight ended 1819L.

Ten hours and 50 minutes of sunshine and 25 minutes of twilight.

Not to mention that it was probably around 80° F yesterday in Honolulu while it was a scorching 5°F here.

The good news is that it's all downhill to summer from here on out!

On that happy note, I remain,

Dad / Geoff