That Mercedes cars are traditionally silver because in the 1934 racing season new weight rules were introduced, and Mercedes’ car was slightly too heavy? To lose that bit of extra weight Mercedes decided to drop the white paint traditional to German cars, and raced in bare aluminium. The cars became known as the Silver Arrows, and that’s why Mercedes favour silver for their cars.
Auto Union did the same thing and became known as Silverfish, which is why Audi is quite keen on the colour too; although these days they seem to lean towards my favourite colour, black.
That the optics in lighthouses continue to rotate during the day because if they were allowed to settle, they’d act like a magnifying glass and set fire to something? I didn’t, although I kicked myself when I found out!
Thanks to the excellent guide at Hook Head for this little nugget.