This hole in the ceiling of the cosmic room, shows the complete time curve on the floor.
This hole in the ceiling is very important for our explanation. In the picture, the wall that is near the hole is the south wall of the cosmic room. In summertime the aces of light fall almost perpendicularly and only a few days during the year they bent to the north just a little bit, so despite of the closeness of the hole in the ceiling to the wall, the aces of light never climb the wall.
This very ray of light that during the summertime falls perpendicularly, in wintertime bents so much that it passes through the whole room getting an inclination near the 45 degrees.