Egg of Columbus
An egg of Columbus or Columbus's egg (Italian: uovo di Colombo [ˈwɔːvo di koˈlombo]) refers to a seemingly impossible task that becomes easy once understood. The expression refers to an apocryphal story, dating from at least the 16th century, in which it is said that Christopher Columbus, having been told that finding a new trade route was inevitable and no great accomplishment, challenges his critics to make an egg stand on its tip.