Random Riddle: Lines

Birbal was jester, counselor, and fool to the great Moghul emperor, Akbar. The villagers loved to talk of Birbal’s wisdom and cleverness, and the emperor loved to try to outsmart him. One day Akbar (emperor) drew a line across the floor. “Birbal,” he ordered, “you must make this line shorter, but you cannot erase any bit of it.”

Everyone present thought the emperor had finally outsmarted Birbal. It was clearly an impossible task. Yet within moments the emperor and everyone else present had to agree that Birbal had made the line shorter without erasing any of it.

How could this be?
 

Random Riddle: Lines