Baghramyan mystery revealed
Previously, I posted three mysterious photos. Today, let's solve the puzzle.
These triangles are the result of a strange coincidence. Shadows of handrails intersect in the middle of the step. So you see three zones:
I - brightest, lit by two lamps
II - mid shadow: lit by one lamp
III - deepest shadow: both lamps are blocked
Finally, there is a long "lever arm" in geometry, so a small shift of the lamps moves the shadows boundaries a lot. Near the bottom the bright zone dominates, near the top - the deep-shadow zone does.