Final answer:
Spectroscopy is a technique used in physics to study the absorption, emission, or scattering of electromagnetic radiation by atoms or molecules.
Step-by-step explanation:
Spectroscopy is a technique used in physics to study the absorption, emission, or scattering of electromagnetic radiation by atoms or molecules. It is commonly used to analyze and understand the composition, temperature, and motion of celestial objects like stars and galaxies. By observing the patterns of light emitted or absorbed by these objects, astronomers can determine the elements present and gain insights into their physical properties.