Coins: The Anti-Theft RidgesThe crime-fighting reason for grooved edges

From the show

Why it looks like that

The serrated edges on quarters and dimes, known as reeding, were a security update engineered to stop thieves from shaving precious metal off currency. This episode reveals how a 17th-century anti-counterfeiting measure introduced by Isaac Newton became a permanent tactile feature of modern money, surviving long after the silver was removed.