I created a geometrical simulation of how the Sun is reflected on a wall along the day and along the year, using Geogebra:
Playing with parameters, I found an oddity: in some specific cases, changing the "season angle", i.e. inclination of su circle w.r.t. horizon, I can see the "sun reflection line" always passing in same point on the wall along whole year:
Is this a real behaviour or just an error in my simulation?
Does it happens always at same time of the ay? My simulation currently does not show the times along the "sunLine" segment.
How could I build a Geogebra formula to directly draw the "convergence point" of all the sunLine lines along the year?