In addition, we can say that there is natural and artificial lighting. Natural light is the sun, moon, or sunlit clouds covering the sky. Artificial lighting is the light of candles, a torch, light bulbs, car headlights, etc.
Natural light gives straight and direct rays falling on objects. This is because the sun and moon are at a very great distance. Artificial lighting gives rays diverging from a light source in the form of a hand fan. It should be noted that artificial light is always concentrated.
The intensity of lighting depends on the strength of the light source, the distance between the object and the light source and the angle of falling of light rays. In addition, the perception of the illumination of an object depends on the distance between this object and the viewer.
I actually know this from game design because the math behind how a light like the sun works is completely different than a point light. Anyway.
When you see crepuscular rays coming down, as linked below, does the light look parallel to you? Or does it look like we have a small local sun, which you can trace the rays back to their source?
Anyway, forget the sundial thing. Just focus on local aparent noon, that is when the sun is highest in the sky at your given longitude on earth. If the globe earth is on a 23.4° tilt, then the spring and fall equinox would cast shadows at noon in radically different directions. The winter and summer solstice would both cast shadows directly north (or south depending on latitude), though the length of the shadow would be different.
I understand the procession of the equinox, that is not what I was talking about, although both models agree it occures. The analemma explains why an unadjusted sundial will drift between 15 minutes early to 15 minutes late throughout the year. This angle is very small though, about 3.75° of error maximum.
You know that a desk lamp is way to small and close to make parallel lines for starters?
https://www.drawingforall.net/light-and-shadow/
I actually know this from game design because the math behind how a light like the sun works is completely different than a point light. Anyway.
https://sundials.org/index.php/teachers-corner/sundial-mathematics
The math isnt that hard. In fact, if anything it makes the case for spherical earth stronger.
https://www.gi.alaska.edu/alaska-science-forum/sundial-fairbanks
What your thinking of likely is https://en.wikipedia.org/wiki/Axial_precession
Precession of equinox and unless your older than 20,000 years, the marks would stay true.
When you see crepuscular rays coming down, as linked below, does the light look parallel to you? Or does it look like we have a small local sun, which you can trace the rays back to their source?
https://epod.usra.edu/blog/2020/07/crepuscular-rays-off-la-palma-canary-islands.html
Anyway, forget the sundial thing. Just focus on local aparent noon, that is when the sun is highest in the sky at your given longitude on earth. If the globe earth is on a 23.4° tilt, then the spring and fall equinox would cast shadows at noon in radically different directions. The winter and summer solstice would both cast shadows directly north (or south depending on latitude), though the length of the shadow would be different.
I understand the procession of the equinox, that is not what I was talking about, although both models agree it occures. The analemma explains why an unadjusted sundial will drift between 15 minutes early to 15 minutes late throughout the year. This angle is very small though, about 3.75° of error maximum.