# Learning Goals

#### Program Mission and Objectives

The physics major program at Johns Hopkins University is built around giving its students a grasp of the physical principles underlying our universe and equipping them with the tools so that they can understand physical phenomena in terms of those principles. However, learning to “think like a physicist” also means assimilating a quantitative, critical intellectual style, firmly grounded in empiricism, that can be applied to problems far outside the conventional domain of our discipline; indeed, this is one of the reasons that over time physics has spawned new scientific fields such as biophysics or operations research, and continues to provide the underlying conceptual scheme for large parts of engineering.

The breadth of potential applications for “physics thinking” also explains why the physics major at JHU is not one program, but two, and we offer two degree options, a B.S. and a B.A. The former is designed for students who want to be professionals in physics or allied subjects, whether they go directly into the workforce or immediately embark on a graduate program; the latter is for those who want to learn deeply about physics, but also have the time in their undergraduate careers to study more widely in other fields, in order to prepare for careers less exclusively focused on physical sciences.

Although the detailed course requirements for the two programs are somewhat different, they share the same broad objectives. All our students should graduate with a solid understanding of the basic laws of physics. More generally, we also wish for all of them to emerge trained to think critically and quantitatively. At least some serious laboratory experience is essential for students to develop a sense of what real experiments are like and to recognize the fundamental grounding of abstract physical concepts in concrete empirical data. In addition, we hope that their Hopkins physics education will have led them to develop a genuine enthusiasm for learning about the natural world. So equipped, they will be prepared for success in many potential future careers, whether as physical scientists or in a variety of other professions.

Finally, we note that because science is a dynamic enterprise, the preparation most appropriate for its students gradually changes over time. This means that even our basic goals gradually evolve.

#### Student Learning Goals

The general objectives listed above can be restated in terms of more specific accomplishments:

- Mastery of core subject material: The most fundamental of the basic laws of physics are the central concepts of classical mechanics, electromagnetism, and quantum mechanics. We list in the following paragraphs the specific topics we consider most essential to a physics undergraduate education, grouping them by subfield. This set comprises both key facts about the physical world and widely useful techniques for analyzing physical systems.
- Classical mechanics: Both the fact that energy, momentum, and angular momentum are conserved and how to employ that knowledge to solve problems; how all small-amplitude oscillatory motion can be characterized in terms of harmonic oscillators, both isolated and coupled; how to analyze generic wave motions and relate the dynamics of specific waves to that analysis; the use of Lagrangians and Hamiltonians; how to calculate orbits in a potential; the properties of two-body scattering; the nature of rigid body rotation; and the principles of special relativity.
- Electromagnetism: What it means to define a field and how charged particles respond to electric and magnetic fields; how to solve for static electric and magnetic fields given boundary conditions; how electric charges and currents act as sources for electric and magnetic fields; how changing electric and magnetic fields influence each other; the significance of Maxwell’s Equations; the basics of electromagnetic waves, and how they propagate; how electromagnetic waves are radiated.
- Quantum mechanics: The meaning of quantum eigenstates and eigenvalues; operator and wave-function descriptions of quantum states; the significance of non-commuting operators, their relationship to uncertainty principles and wave-particle duality; the physical interpretation of wave functions and how they may be calculated from the Schrodinger equation; the basic properties of quantized angular momentum, including the existence of spin; how quantum mechanics determines the structure of atoms; the character of quantized harmonic oscillators; and how to analyze scattering events in quantum mechanical terms.

- Critical thinking: In the context of physics, the ability to think critically and quantitatively means that one is able not just to solve set problems, but also to transform puzzling phenomena into well-formulated questions. Solving quantitative problems is accomplished in several steps: deciding which basic principles apply, translating them into equations, and only lastly mathematical manipulation. Skill in this process is best developed by practice. Learning problem-formulation is subtler because it is never as straightforward. It involves developing a sense of “physical intuition,” how to connect logical relationships to quantitative dependences, and, in the case of experimental problems, how to mirror those quantitative dependences in measurable physical systems, and how to construct quantitatively meaningful summaries of the resulting measurements. First-hand experience doing genuine cutting-edge research is the only way we know for students to build the mental “muscles” required. Because most scientific work is experimental, laboratory experience is essential for all our students, even those intending to specialize in theoretical work once they become professional scientists.
- Enthusiasm for learning: Developing an appreciation for the pleasure of self-directed individual intellectual investigation as well as for the gains in understanding that can be accomplished by cooperative efforts with others. Here, too, independent research plays a central role. On the one hand, it can provide opportunities for students to feel the excitement and satisfaction of learning a topic on their own, without the guidance of a class syllabus. On the other hand, it can also provide them with real-life examples of how teams of people with complementary expertise can achieve results impossible to any one of them.
- Preparation to pursue career objectives: Our program has two tracks. One prepares students for either an entry-level job or graduate study leading toward a PhD in physics, astronomy, or related fields; the other gives students a solid grounding in physics, but is geared more toward other kinds of careers or enrollment in professional schools such as law or medicine. Depending on which track a student follows, we expect them to have the background necessary for the associated next steps.