This is a revamped version of my puzzle Mysterious loss of weight . I plan to make a series of puzzles on mysterious loss of ... say a number.
A man went into a black room full of white papers lying around him. He presses a button. All the papers rise and he also loses one of his documents lying on the ground
How did it happen?
HINT 1 :
I have not included the link to the last puzzle for no reason