A week ago, someone posted that snowflakes look like snowflakes, and then yesterday someone posted a plain old regular mercury thermostat that's been installed in most homes (in the US) since who-knows-when. Today it's a bog-standard portable AC unit that I think have been around since the 90s or early 2000s at least.

This sub becoming less "here's something slightly interesting" and more "today I learned this is a thing that exists or is true"