The Probert Encyclopaedia of Science & Technology

SPECTRUM

A spectrum is coloured bands formed by dispersion when a ray of light from any source is passed through a prism. The visible portion of the spectrum varies from red through orange, yellow, green and blue to violet, but the spectrum is continued beyond the red and violet. The spectra of the sun and other stars are crossed by dark lines, characteristic of the chemical elements. These lines have enabled the composition of the stars to be suggested.
Research Spectrum