Here they are again with solutions. (Do check out the hundreds of great comments posted below the line in the original story.) In a cranberry sorting facility, thousands of cranberries are dropped every minute onto a board. Good cranberries are firm, and bounce, while bad cranberries are soft, and don’t bounce. What simple trick allows sorters to catch all of the good ones and none of the bad?
The board is at an angle. Good berries bounce off onto a conveyor belt. Bad ones fall down into a discard box.
In the US, medicine bottle caps are designed to be secure against only 85 per cent of children under five. Why is this percentage not higher? Eighty-five seems quite low.
If the child-resistance rate was 100 per cent, the mechanism would also be hard for weak or arthritic hands. If the bottle is too hard for an elderly person to open, they may leave the cap off entirely, which is more dangerous than the small percentage of clever or strong kids who’d have taken it off anyway. The standard isn’t “as safe as possible” — it’s tuned to the point where making it safer for kids would make it less safe overall.
In 2020, engineers replaced the pedestrian handrail on the Golden Gate Bridge. The old handrail rested on metal balusters in the shape of an H, so the support looked like “HHHH…” where the H’s horizontal section was 10cm wide. The new handrail was supported only by thin vertical slats, making it look like “IIII…” and where each slat was only 0.6cm wide.
The aim of the new handrail was to make it less resistant to wind, and hence safer during high winds. But it brought two serious unintended consequences. 1) The wind level on the bridge was much higher, to the great annoyance of cyclists. 2) During certain winds, the whole bridge began to make an unbearable whistling noise that could be heard for miles. Essentially, the new slats behaved like reeds, and the bridge turned into in a gigantic harmonica.
Extract — continue reading at the source.
