How is wavelength measured?

Wavelength is measured in nanometers, particularly when discussing the electromagnetic spectrum, which includes visible light and other forms of radiation like ultraviolet and infrared. A nanometer is one billionth of a meter, which is particularly suitable for measuring wavelengths of light, as they typically fall within the range of about 400 to 700 nanometers for visible light.

Other units of measurement, such as millimeters, centimeters, and micrometers, are generally used for different scales or applications. Millimeters and centimeters are more applicable for larger physical dimensions, while micrometers (one millionth of a meter) are often used in fields like microbiology and materials science for measuring small objects but still do not capture the fine scale of light wavelengths as effectively as nanometers do. In the context of light and optics, nanometers provide a more precise measurement suited to the wavelengths involved.