Reply to comment by Squirrel851 in TIL Early drones were developed during the First World War. These radio controlled planes were primarily for target practice but by 1942 a drone with a built in TV camera was capable of delivering a torpedo to a ship 20 miles from the controller. by jamescookenotthatone

Reply to comment by Dicky_Penisburg in TIL about Lillan Bloodworth, who donated blood every 56 days for nearly 50 years. By the time she stopped at age 85, she had donated 23 gallons. (The average person's body contains about 1.5 gallons.) by WouldbeWanderer

Reply to comment by TryPokingIt in TIL that the red lights on top of tall buildings in cities are called “aviation obstruction lighting,” and are used to help pilots of low-flying aircraft avoid collisions with otherwise hard-to-see structures. by bearjew64