Physicists and astronomers study the fundamental nature of the universe, ranging from the vastness of space to the smallest of subatomic particles. They develop new technologies, methods, and theories based on the results of their research to deepen our understanding of how things work and contribute to innovative, real-world applications. Most physics and astronomy graduate students have bachelor’s degrees in physics or a related field. Because astronomers need a strong background in physics, a bachelor’s degree in physics is often considered the best preparation for Ph.D. programs in astronomy. Undergraduate physics programs provide a broad background in the natural sciences and mathematics. Typical courses are classical and quantum mechanics, thermodynamics, optics, and electromagnetism.