Final answer:
When a lens clock's indicator does not move while rotating, it means the surface being measured is flat. A lens clock measures curvature, and no movement indicates no curvature to measure.
Step-by-step explanation:
If the indicator on a lens clock does not move while rotating, the surface is planar or flat. A lens clock, also known as a spherometer, is designed to measure the curvature of a surface. When used on lenses, it measures their concave or convex curvature. If it's placed on a perfectly flat surface, there will be no curvature for the tool to measure, and therefore the indicator will not move. This principle is similar to that of a clock's hands on a wall; if the second hand does not move, it suggests that time is not being measured or the clock is not working. However, the comparison in the information provided seems to be metaphorical, as it references a 'clock molecule' and its degradation over time, which could be related to another scientific concept entirely.
If the indicator on a lens clock does not move while rotating the surface, it indicates that the surface is perpendicular to the axis of rotation. This means that the surface is flat and parallel to the base of the lens clock. In other words, there is no deviation or tilt of the surface.