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by gmiller123456 2466 days ago
You need at least one more piece of information, otherwise how would you know it's solar noon? You either need to know where due South is, or you need to make multiple measurements of the sun at different times to determine when it reached its lowest point. The good thing about using two stars is you don't need that information and you didn't need to wait around in the same spot from solar noon until nighttime.
1 comments
4A414B56 2461 days ago
put a stick in the ground and note the time at narrowing intervals until the shadow starts getting longer, taking the shortest shadow as solar noon??? seems like a non-issue since you've already got an accurate watch. if you're lost without a gps and have no idea what your long. is, you've probably got a lot of spare time to figure it out.
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gmiller123456 2459 days ago
That's one way, and it also tells you where due South is too. The watch is only one piece of information, solar noon changes from day to day (called the "Equation of Time"), so you need a way to correlate the two. An almanac would have that info, or the equation could be memorized and computed.

This isn't just recreational fun, most (maybe all) Navys still require having people on board each major ship that can perform sight reductions and wind up watches. The assumption would be that during a war GPS and electronic devices would be destroyed. The "stick in the ground" method doesn't work if you're moving, and takes a while, and speed matters when you're being hunted.

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4A414B56 2446 days ago
solar noon is the time @ the shortest shadow. You don't need an almanac for that. It's got problems, but if you're lost on land with a digital watch and a stick it'll work pretty well.
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gmiller123456 2446 days ago
Just seeing the shortest shadow doesn't tell you anything. You need a way to correlate it to your position on Earth. Having a watch (set to a known time zone) only tells you what time it happened, which is also pretty useless. You need an almanac (or some computation) to correlate what time solar noon happened on a given day with your longitude.
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A484D424 2446 days ago
Lost my last account's login. I'd watch this, you only need to know solar noon in Greenwich and compare it to your own solar noon.

https://www.youtube.com/watch?v=b7yoXhbOQ3Y

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