Every Indian could stand inside one city. Over 1.4 billion people, packed two to a square metre (the usual safe limit for a standing concert crowd), fill a square just 27 km wide: 732 sq km. Pour it into Delhi (1,483 sq km) and it fills only half the city. The rest of India? Empty.
Now bring everyone on Earth, 8.2 billion people: the square grows to 64 km, too big for Delhi. Fly it to Sikkim, India's least populous state (7,096 sq km, 6.1 lakh people in the 2011 Census), and it fits with 42% to
