"Einstein asked himself a question... how can the sun and the Earth "attract" each other without touching..? ...[H]e imagined that the sun and the Earth each modified the space and time that surrounded them, just as a body in water displaces the water... This modification of the structure of time influences in turn the movement of the bodies, causing them to "fall" toward one another. ...The Earth is a large mass and slows down time in its vicinity. ...If things fall, it is due to this slowing of time. ...Where time passes uniformly, in interplanetary space, things do not fall. ...[H]ere on ...our planet, the movement of things inclines naturally toward where time passes more slowly, as when we run ...into the sea and the resistance of the water on our legs makes us fall headfirst... [T]ime passes more slowly for your feet than it does for your head."