What is nanometre?
A nanometre is a unit of length equal to one billionth of a metre. It is used to measure wavelengths of visible light, atomic radii, and dimensions of nanostructures in materials science.
What is foot?
A foot is a unit of length in imperial and US customary systems equal to 12 inches. It is commonly used in construction, architecture, body height measurements, and aviation for altitude references.