Beautiful rooms and concepts, Ruben! A wonderful teaching facility.
Your low latitude is certainly a help in fitting these dial displays to an
interior.
After viewing your pages, I once again looked at my living room with an eye
towards a noon line, as I have a roof window well situated near the South
wall, but due to its height (just over 10 feet) and my latitude (37.3°), the
resulting analemma doesn't fit the living room at all. It's too far from the
South wall in Summer, and extends well past the open floor space in Winter.
However, it did get me to thinking again, and doing some calculations.
If I designed the line for a more southern location, say 9° North, the total
length of the analemma was much shorter, and the Summer end would extend
South of the ceiling hole, quite close to my South wall.
Moving my home 28° to the South isn't very practical, but it occurred to me
that I could introduce a deviation in the incoming rays, and accomplish the
same result! I thought of a prism, but the geometry isn't very good; finding
the right prism (apex angle and refractive index) would be difficult and/or
expensive, and I would have to deal with chromatic dispersion, as well. But
a pair of mirrors, even first-surface mirrors, is much easier. If the first
mirror (to the north of center) was blacked-out, with a small, "pinhole"
reflective aperture, inclined vertically or slightly to the North, its
reflected beam could fall on the second, larger, flat a few inches to the
south, inclined 14° more to the north. The 14° apex angle of the pair would
introduce a 28° deviation towards the south, independent of the exact
inclination of the pair. (They would have to be accurately aligned
East-West, of course.)
Any inaccuracies in mirror angles and orientation would be hard to allow for
in plotting the Noon analemma, but I could always fall back on the ancient
empirical method of driving a tack at 12:00 local solar time, once a week!
Something a little like the ASCII sketch below.
Assume the light enters from above and to the right...
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Dave
-----Original Message-----
On Behalf Of ruben nohuitol
Hi friends, please look my cosmic room,
my page is www.ruben.mx
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