Dogs Have Three Eyelids

In Latin, 'trivium' (tri + via = three + road) referred to the junction where three roads met — a crossroads or small public square where people gathered to gossip and exchange minor information. From this, 'trivialis' came to mean 'commonplace, found everywhere'. In the medieval curriculum, 'trivium' also named the three foundational liberal arts: grammar, rhetoric, and logic.

Cats, like most birds, fish, reptiles, and amphibians, possess a nictitating membrane — a translucent third eyelid that moves horizontally across the eye from the inner corner. Normally hidden in healthy, alert cats, it becomes visible when a cat is drowsy, ill, or under stress. Humans lost this structure through evolution.

Natural rubber degrades primarily through oxidation — a chemical reaction with oxygen in the air. Cold temperatures significantly slow this process. According to van't Hoff's rule, every 10°C drop in temperature roughly halves the reaction rate. Storing rubber bands in the refrigerator (not the freezer) can extend their lifespan by years.

In 1995, Pierre Omidyar created 'AuctionWeb' (later renamed eBay) and listed a broken laser pointer as a test. It sold for $14.83. When he contacted the buyer to confirm they understood it was broken, the buyer replied: 'I'm a collector of broken laser pointers.' Omidyar called it the moment he realized there was an online market for everything.