Along, perfectly level, frictionless bowling alley, over 2000 meters long, is built by a group of students as a class project. the center of the alley just touches the earth near their school and the ends of the alley extend tangentially into outer space. a bowling ball released at either end starts rolling towards the center of the alley and will continue moving- indefinitely.- until it strikes the pins at the far end and stops.- for a while but slows to a stop before reaching the pins.