A man is imprisoned in a 10 ft. by 10 ft. by 10 ft. room. The walls are made of concrete, the floor is made of dirt. The only openings are a locked door and a skylight. The only tool he has is a small shovel with which he begins to dig a hole in the floor. The man knows it is impossible to tunnel out of his prison cell but continues anyway.
What is the man’s plan?