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71 points choult | 1 comments | 15 Oct 24 18:28 UTC | HN request time: 0.206s | source

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ricksunny ◴[16 Oct 24 10:41 UTC] No.41857582[source]▶

Interesting. Solar noon forms an analemma.

https://en.wikipedia.org/wiki/Analemma

So the mechanism of a uniaxial gimbal (as pictured in the examples at end of article, and presumably manually adjusted) holding the magnifying glass would seem to introduce some error over the course of a year. But I like the concept, having some weird affinity for automation based on low-tech / earlier-tech principles.

replies(2): >>41858093 #>>41860729 #

1. KineticLensman ◴[16 Oct 24 12:04 UTC] No.41858093[source]▶

>>41857582 #

> Solar noon forms an analemma.

Only when used in conjunction with a standardised 'mean-time' 24 hour clock. If you plot the position of the sun at the same mean clock time, then sometimes the sun will be ahead, sometimes behind.

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The Sundial Cannon of Åtvidaberg (2017)