“ On a planet with an ammonia atmosphere, that is inhabited by intelligent aliens, the police carry oxygen spray, that has the same effect on that planet that pepper spray does here.”
“ Surnames: The Chinese were among the very first cultures to adopt the use of hereditary surnames (around 2800 BC). But the custom didn't quite catch on in Europe - at least not until the Venetian aristocracy made it popular sometime between the 10th and 11th centuries AD. What culture made it popular in your setting and why?”