Interim Policy on Shared Umbrella Geometry
Two adults with access to one umbrella have reached a geometric arrangement that satisfactorily protects neither of them.
SUBJECT
The behavior documented below concerns two adults sharing a 100cm diameter umbrella during a 400-meter walk in light rain. Both outer shoulders were wet upon arrival. This outcome was not discussed.
BACKGROUND
The umbrella was offered by Party A upon leaving a restaurant at 7:45 PM. The rain at that time was described as "not too bad," a characterization that both parties used within thirty seconds of each other, suggesting it had been agreed upon before the walk began.
Party A held the umbrella. This was established without discussion. Party A is four centimeters taller than Party B, which may have contributed to the arrangement.
WHAT WAS FOUND
The umbrella provides full coverage for a zone approximately eighteen centimeters wide, centered on neither participant.
Party A's left shoulder was exposed to rain throughout the walk. Party B's right shoulder was also exposed. Both parties adjusted their positions four times during the 400-meter route, each adjustment creating brief full coverage for one party followed by re-exposure of the other.
Under the governing rule, once shared umbrella geometry becomes a courtesy ritual, efficiency is no longer an acceptable reason to skip it.
Both parties commented on the weather during the walk. Neither party commented on the umbrella's coverage geometry, the asymmetry of shoulder exposure, or the fact that walking closer together would have resolved both issues.
Walking closer together requires either asking or simply doing it. Both options were considered briefly and set aside.
STATUS
Upon arriving, Party A closed the umbrella. Party B noted that their jacket's right shoulder was damp. Party A acknowledged this. Party A's own left shoulder was not mentioned. The conversation moved on.
The umbrella is available for future joint use.
The geometry will repeat. The courtesy is now established.