A Split Beam

I climbed step by careful step onto the sunlit wooden windowsill, pausing to make sure everything stayed calm. Resting on the polished grain was a heavy glass triangular prism catching the morning glow. Moving slowly, I placed my front paws against its smooth flat side and nudged it just a tiny fraction. The glass shifted, and suddenly a crisp rainbow ribbon split across the pale wood, bending into red and violet arcs like an atmospheric spectrum. I stood watching the quiet band of light hold perfectly still.