While watching a BBC Documentary on Stonehenge, I was reminded of a project a good friend was assigned while in a beginning astronomy class at university. It involved a photo of the Tucson Mountains, at regular intervals, mark the position of the sunset. Well, 23 Dec 2019 seems as close to the Northern Hemisphere's winter solstice that cooperated with a clear sky (not that I thought of this project then, actual date was 21 Dec). So now I wait for a clear day on or about 19 March, then 20 June, then 21 Dec for the next winter solstice. Stake the photos and see how far the sun travels at N 47°.
""The world is full of obvious things which nobody by any chance ever observes…""
— Arthur Conan Doyle
“The Hound of the Baskervilles”
""Mathematics...