Spectral lines

Meticulously crafted prisms could be used to observe dark lines in the solar spectrum, leading to the identification of nearly six hundred lines. These lines, known as Fraunhofer lines, marked the wavelengths where light was absorbed and became foundational in the fields of chemistry and astronomy for identifying elemental composition.
 Joseph von Fraunhofer Germany 1814 Spectral lines

Meticulously crafted prisms could be used to observe dark lines in the solar spectrum, leading to the identification of nearly six hundred lines. These lines, known as Fraunhofer lines, marked the wavelengths where light was absorbed and became foundational in the fields of chemistry and astronomy for identifying elemental composition.