The shape of the United States is not what you see on a map, but rather your mental picture of what you can explore, blocked by other people.
random
Infinitesimal (Wikipedia)In mathematics, an infinitesimal number is a non-zero quantity that is closer to 0 than any non-zero real number is. The word infinitesimal comes from a 17th-century Modern Latin coinage infinitesimus, which originally referred to the “infinity-eth” item in a sequence.