Spectroscopy describes the study of the interaction between matter and the wavelength of the light it produces, although this definition has been updated to include anything measured as a function of frequency or wavelength.
Isaac Newton was one of the first people to demonstrate that light from the Sun could be scattered into a spectrum of colors. He built a machine with a small opening to focus the light, a lens, a prism, and a screen that would show the results. This was the very first spectroscope. The first spectral lines were observed by Joseph Fraunhofer, who saw dark lines in the continuous spectrum when the light was scattered enough. Later discoveries of the significance of these spectral lines came from Gustav Kirchhoff, a German physicist who established that each element had its own corresponding spectrum.
Spectroscopy has been used in pretty much every aspect of science, but we’ll specifically be focusing on its applications in astronomy. One of its main uses is telling scientists which elements are present in a star. Each element produces a unique spectrum that astronomers can use to identify a star’s composition. Besides this, scientists can also identify the density and temperature of that particular element in the star. They can also learn about how the star is moving, the mass of the star, and much more all from spectral lines. Without spectroscopy, much of the universe would still be unknown to us today.
