{"id":16538,"date":"2026-06-09T06:00:00","date_gmt":"2026-06-09T11:00:00","guid":{"rendered":"https:\/\/ericsiegmund.com\/fireant\/?p=16538"},"modified":"2026-06-04T10:36:51","modified_gmt":"2026-06-04T15:36:51","slug":"sunrise-how-do-it-work","status":"publish","type":"post","link":"https:\/\/ericsiegmund.com\/fireant\/2026\/06\/09\/sunrise-how-do-it-work\/","title":{"rendered":"Sunrise: How do it work?"},"content":{"rendered":"\n

[Editor: The following has been posted in defiance of the Gazette’s longstanding policy against publishing anything that even sniffs of being scientific geekiness. I wash my hands \u2014 figuratively speaking, of course \u2014 of the whole thing. Proceed at your own risk.]<\/em><\/p>\n\n\n\n

[Me: <\/em>\ud83e\udd71]<\/em><\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

I was thinking about sunrises the other day, and specifically about how the exact time of sunrise is determined for our location in the Texas Hill Country.<\/p>\n\n\n\n

We have 45 windows in our house and almost a third of them have automatic shades that can be programmed to open and close at designated times [1<\/a>]<\/sup><\/strong>. Some of them are programmed to open and close at specific times (e.g. open at 8:00 a.m. and close at 8:00 p.m.), while others are set to open at 15 minutes before sunrise and others at sunrise, with corresponding sundown settings.<\/p>\n\n\n\n

But we have some fairly significant hills to our east and so the sun doesn’t actually come into view until some time after the “official” sunrise. I can also remember vacations in the Rocky Mountains where that phenomenon was even more extreme. It all led me to wonder how those “official” sunrise times are determined, and I set out to understand how it works.<\/p>\n\n\n\n

\"Meme:
It’s not a rhetorical question.<\/figcaption><\/figure>\n\n\n\n\n\n\n\n

Unfortunately, I immediately ran into an insurmountable issue: the answer involves math…trigonometry, to be more specific, and spherical trigonometry<\/em><\/a>, to be tragically specific. I have no idea what spherical trigonometry is, except that it may or may not involve computing the dimensions of a bowling ball or Charlie Brown’s head. You can read the above-linked Wikipedia article if you find my explanation a bit lacking in clarity or intelligence. [2<\/a>]<\/sup><\/strong><\/p>\n\n\n\n

Then there’s another obscure component called an analemma<\/a><\/em>. Analemma is an astronomical term for a diagram that shows the position of the sun in the sky over a year, as viewed from a fixed position on earth. It takes the shape of a stretched-out figure eight. [3<\/a>]<\/sup><\/strong><\/p>\n\n\n\n

There are other components to the computations, most of which are as easily decipherable as ancient Egyptian hieroglyphs viewed through beer goggles, including (but not limited to):<\/p>\n\n\n\n