In addition to using the universe as a laboratory to illustrate the laws of physics, the study of cosmology can demonstrate the potential for understanding the universe on the basis of physical law. Every physics student knows that Newton discovered the law of gravity. However, they must also realize that an even greater insight of Newton's was the concept of the universality of gravity. The idea that forces measurable on earth are the same forces responsible for the motion of planets in the cosmos had an enormous social impact. The belief that the study of physics in terrestrial laboratories can shed light on the origin and structure of the universe has guided our modern efforts in cosmology.
Students elect to take physics because they have some curiosity about the physical world.
I can think of no more exciting and challenging arena to nurture this curiosity than cosmology. These are questions that can excite the imagination and hold the student's interest. The universe is the ultimate playground for the curious mind. It is crucial for students to realize that the laws of physics are not something only for the textbooks but make the universe work. Finally, whether the students realize it or not, their view of the universe plays an important role in their cultural heritage.