Pearl oysters: the systemic riddles



A pearl oyster groups a riddle and an answer which reveals often the hidden meaning of the riddle...

And therefore let us begin if you want!

Pearl oyster N° 1
Three birds are on a branch. A hunter points his gun, shoots and kills one of the birds.
Question: how many birds remain on the branch?


Pearl oyster N° 2
Dear Systemnetizen, let us examine together this true story! The shafts of the warships are thick cylindrical stems, made of steel, which actuate the helices. In a factory of the 1940s, the procedure to make the shafts included an operation which occurred in the middle of the process: an operator asked to stop the process. He approached the flowing and threw above it a white powder brought out from a small bag that he always kept with him. A few years later, this operator left in retirement. The operation was no longer done and..... shafts became significantly less solid than before!? One came to the conclusion that the explanation was connected to this famous white powder spread out over the flowing in the middle of the shaft’s manufacturing. One went then to ask this information to the operator left in retirement. And dear Systemnetizen the operator stated finally that it was.... flour!?
Question: what is the effect of flour on the quality of shafts?