Chapter 6 Spectroscopy 6.1 Purpose In the experiment atomic spectra will be investigated. The spectra of three know materials will be observed. The composition of an unknown material will be determined. 6.2 Introduction Spectroscopy, or the study of the spectrum of light, is probably the most important tool in all of modern astrophysics. By analyzing the spectrum of astronomical objects, Earth-bound science has been able to determine the temperature and chemical makeup of the stars, measure their velocities relative to our own, and even confirm that the Universe is expanding. In fact, it is the information extracted from the spectra of astronomical objects that gives the strongest and most incontrovertible evidence that the physical laws discovered on Earth also apply throughout the entire Universe. Without the use of spectral analysis, it is difficult to imagine that we could understand very much at all about the distant Universe. In this lab, you will make measurements of known spectra emitted by several hot dilute gases and use this information to calibrate a simple spectroscope. Then, this information will be