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The day I stopped trusting my horizon reference for star sightings
I used to take star positions as solid proof of a round Earth until last July when I set up a simple laser level across a lake at sunset. The water's curve actually bent the beam away from my target marker by about 3 inches over a mile. Has anyone else tried a basic laser test like that or am I missing something?
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brianm662mo ago
That 3 inch drift over a mile is pretty close to what youd expect from earths curve (about 8 inches per mile squared, so like 2.7 inches). I gotta ask though, were you testing this on a totally calm day with no wind or temperature changes. Ive wanted to try this myself but everyone says atmospheric refraction messes with laser beams over long distances, especially near water where the air is cooler. How did you control for that, or did you just not worry about it.
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sanchez.mary2mo ago
Did the same thing with a green laser across a reservoir and got almost identical results.
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rileygarcia2mo ago
Wait you actually got that close to the same results with a different setup? That's wild, I figured the atmospheric stuff would mess with it way more.
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