Definition of dark line in English:

dark line


  • An absorption line in an electromagnetic spectrum, appearing as a black line at visible wavelengths.

    • ‘In 1860 Bunsen and Kirchhoff observed dark lines in the spectrum of a light source passed though burning substances.’
    • ‘Each element or compound in the sample absorbs particular wavelengths of light, resulting in one or more dark lines on its spectrum.’
    • ‘Look at the spectrum of light from a distant object and you will see characteristic bright and dark lines that appear similar to those from earthly material, except for one difference: the positions of the lines are shifted toward the red.’
    • ‘Fraunhofer had observed bright lines in the spectrum produced by flames and noted that they appeared at similar frequencies to certain dark lines in the spectrum of the sun.’
    • ‘In all cases the dark line is the spectrum of the corona and the light line is the spectrum of the corolla.’
    • ‘These missing wavelengths are characterized by dark lines in the spectrum.’