Building Hengefinder: A Programmer's Guide to Calculating Urban Solar Alignments
By
evakhoury
Pulled from the oven just right. Trustworthy, fact-dense, deeply satisfying.
Summary
A programmer at the Recurse Center describes building "Hengefinder," a tool to calculate when the sun aligns perfectly with city streets (like Manhattanhenge). The article explains the astronomical calculations behind solar alignments, including the sun's declination, the equation of time, and how to compute sunset azimuth angles. The author then generalizes the concept beyond Manhattan, creating a tool that works for any city grid orientation, and shares the technical implementation details including code snippets and mathematical formulas.
Key quotes
· 3 pulledNext week in Manhattan, the sunset will align perfectly with the east-west streets of the city grid. It's beautiful, and people know it.
I wanted to know how astronomers figure out when Manhattanhenge happens. And if I could figure that out, why limit it to Manhattan?
This was one of my first projects at the Recurse Center: Hengefinder.
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