FEs say the rising and setting of the sun and moon is an optical illusion right? How can that be possible if the 'height' of the sun corresponds with the length of the resulting shadows, which conveniently have a lower temperature to the sun-bathed areas? Light generates shadows, they can't exists without it, so why do shadows get longer and shorter as time goes by?
So, the illusion isn't psychological; it's purely optical. Usually FE'ers describe it not just as an optical illusion, but more specifically as one due to atmospheric distortion.
If the light appears to be coming from a certain direction, it actually *is* coming from that direction. There's nothing wrong with your eyes.
Thus, the area of the ground occluded from the sun by an object (i.e. a "shadow") would be defined as you'd expect if the sun is where it appears to be, rather than where it actually is. The rim of a shadow is the locus of intersections of lines connecting the rim of the occluding object with the apparent position of the sun.
And why is it that humans are struck by this optical illusion at dawn then gradualy recover until at midday it leaves us, before we decline again until sunset?
Because the degree of atmospheric distortion changes depending on how much atmosphere the sunlight has to travel through to reach the viewer.
Also, if the shadows are also optical illusions :roll: then how can they have been used for accurate timekeeping for centuries before the mechanical clock was invented?
Turns out shadows make for pretty inaccurate measurements, due to the fuzzy boundaries and the umbra/penumbra issue. In fact, shadows are at their fuzziest and least accurate near dawn and dusk. So your question is ill-formed; it is based on false premeses.
... despite the consequencial problem of the 'space wind' not effecting them but everything else on earth.
So much for Newtons Laws...
What? I'm having both syntactic and semantic problems interpreting this last point of yours.
-Erasmus