A nanometer (nm) is a unit of length in the metric system equal to one billionth of a meter.

A light-year is the distance that light travels in a vacuum in one Julian year (365.25 days). It's a unit of astronomical distance.

This conversion is rarely practical for direct measurement but is useful for illustrating the extreme difference in scale between the very small and the very large in scientific contexts.

In everyday terms, 1,000,000 nanometers (which equals 1 millimeter) is a small but visible distance. In astronomical terms, it is infinitesimally small, practically zero light-years.