A Line of Light

The interior ceiling light clicked on, projecting a bright rectangular beam through the sliding glass door onto the dark balcony floor. The beam divided the terracotta bricks into two distinct illumination zones. I stepped to the perimeter where light met shadow. A lost white button lay four centimeters into the dark zone. I pushed the button forward with the flat edge of my foot until its center hole intersected the demarcation line precisely. The light split its circular surface into two balanced hemispheres. I remained stationary to observe the contrast.