What is Spectroscopy?
Spectroscopy is a type of chemical analysis done by shining light on a sample to determine what is inside. Chemists commonly measure the absorbance, how much light is absorbed by the sample, or the transmittance, how much light passes through the sample. An analogy of how spectroscopy woks, is that f you imagine that light is food and the sample is a room full of people, a complete spectrum of light would be like giving all the food in a grocery store to the people in the room. As you might imagine, almost all of the food would be wasted. But some of the food would be eaten. Imagine that you knew there was only one person who would eat asparagus. If all of the asparagus came through the room uneaten, that person could not be in the room, but if some were missing, you would know that person was in the room. Furthermore, no matter how much broccoli you put in the room, the asparagus-lover would never eat any, and so you could never know if she was in the room or not. Similarly, in a chem
Spectroscopy is the study of light as it breaks into its constituent colors. By examining these different colors, one can determine any number of properties of the object being studied, as the colors of the light reflect the energy states. More technically, spectroscopy looks at the interaction between any matter and radiation. It is used to analyze compounds in chemistry, to determine what different elements make up something, and is also used in astronomy to get insight into both the composition and velocities of astronomical bodies. One can divide spectroscopy into many sub-disciplines, depending on what is being measured, and how it is being measured. Some major divisions include mass spectrometry, electron spectroscopy, absorption spectroscopy, emission spectroscopy, x-ray spectroscopy, and electromagnetic spectroscopy. There are many other types of spectroscopy as well, however, including those that look at sound as it scatters, or electrical fields. In x-ray spectroscopy, for ex
Spectroscopy pertains to the dispersion of an object’s light into its component colors (i.e. energies). By performing this dissection and analysis of an object’s light, astronomers can infer the physical properties of that object (such as temperature, mass, luminosity and composition). But before we hurtle headlong into the wild and woolly field of spectroscopy, we need to try to answer some seemingly simple questions, such as what is light? And how does it behave? These questions may seem simple to you, but they have presented some of the most difficult conceptual challenges in the long history of physics. It has only been in this century, with the creation of quantum mechanics that we have gained a quantitative understanding of how light and atoms work. You see, the questions we pose are not always easy, but to understand and solve them will unlock a new way of looking at our Universe.
