# Catalog

### Physics and Astronomy

Professors Semon, Wollman, Smedley (chair), and Lin; Assistant Professors Childress and Lundblad; Visiting Assistant Professor Durst; Lecturer Clough

Physics, the study of space, time, matter, and energy, is a fundamental component of a liberal education. Introductory courses in physics and astronomy are designed to give students a broad background in the fundamentals of the discipline, an introduction to the logic and philosophy of science, and insight into the understanding and applications of contemporary physics and astrophysics. Advanced courses provide greater depth and sophistication as the student's background in physics and mathematics develops. Laboratory investigation, designed to accommodate each student's particular needs, provides direct experience of the central role that experimental research plays in the advancement of science. More information on physics and astronomy can be found on the website (www.bates.edu/PHYS.xml).

Major Requirements. The major in physics can be structured to meet the individual needs of students planning graduate study in physics or engineering, as well as those considering careers in business, teaching, government, law, or medicine. The requirement for a major is ten courses in physics, including the following eight, usually taken in this order: Physics 108 (or First-Year Seminar 274), 222, 211, 231, 301, 308, 409 or 412 or 422, and 457 or 458. The additional two courses must be selected from the following: Physics 107 (only if taken prior to 108, concurrently with First-Year Seminar 274, or if assigned as Advanced Placement credit), 214, 216, 225, 232, s27, s30, or any physics course numbered 300 or higher. Only one semester of senior thesis may count toward satisfying the minimum ten-course requirement. To learn physics effectively, it is important that courses be taken in the recommended order and, if at all possible, with the recommended background. Nevertheless, prerequisites and corequisites can be waived in appropriate circumstances, especially in cases of incoming students with strong backgrounds. Students considering graduate study in physics or engineering should take Physics 409 and 422 as well as other courses numbered 300 or higher. In exceptional cases, a student who otherwise meets the ten-course requirement may petition the department to take a comprehensive examination in lieu of the senior thesis project.

Minor Requirements. The requirement for a minor is six courses in physics, including the following three, usually taken in this order: Physics 108 (or First-Year Seminar 274), 222, 211. The additional three courses must be selected from the following: Physics 107 (only if taken prior to 108, or concurrently with First-Year Seminar 274), s27, s30, and any course numbered 200 or higher, except for Interdisciplinary Studies 228.

Pass/Fail Grading Option. Pass/fail grading may not be elected for courses applied toward the major.

Engineering. A student interested in using physics as a basis for an engineering career should inquire about the Bates dual-degree plans with Dartmouth, Rensselaer, Columbia, Washington University in St. Louis, or Case Western Reserve (see page 25 or consult the website, www.bates.edu/Faculty/Physics/engineer.html). By careful planning at registration time, similar combination curricula may sometimes be designed with other engineering institutions. Students participating in a dual-degree program declare a major in engineering.

#### ASTR 104. Cosmology in the Twentieth Century.

The twentieth century saw the emergence of a coherent scientific understanding of the physical universe as a whole. According to this understanding, the universe has evolved from a hot, dense, and rapidly expanding soup of elementary particles into the system of galaxies we see today. But the picture is not complete, and topping the list of unresolved puzzles is the identity of the so-called dark matter. We cannot see the dark matter (hence its name), but we do measure its gravitational influences on matter we can see. The disconcerting conclusion is that there is much more dark matter than visible matter. This course examines the development of modern cosmology, with attention to both that which seems to be well-understood and that which is not yet understood. Enrollment limited to 64. [S] [Q] Normally offered every year. E. Wollman.Concentrations

This course is referenced by the following General Education Concentrations

#### AT/GE 110. Lunar and Planetary Science.

An introduction to the solar system using the methods of physics and geology. The historical development of our understanding of planetary motion leads to the contemporary view of celestial mechanics essential to exploration by spacecraft. The composition, formation, and age of the solar system are examined, together with the physical processes involved in the development of planetary interiors and surfaces. Basic algebra and geometry are used throughout. Laboratory work emphasizes the principles of remote sensing and exploration technology. Nighttime telescope work is expected. Enrollment limited to 56. [S] [L] [Q] Normally offered every year. G. Clough.Concentrations

This course is referenced by the following General Education Concentrations

#### AT/GE 115. Impacts and Mass Extinctions.

What happens when a ten-kilometer-wide rock, traveling at forty kilometers per second, hits the Earth? As the dinosaurs discovered sixty-five million years ago, it is not a pretty picture. Scientists now believe that such catastrophically violent collisions, apparently common in the past, are inevitable in the future as well. But impacts alone may not explain the mass extinction events that have shaped the history of life on Earth; global-scale volcanism and climate change are examples of more familiar processes. This course examines the role of impacts in the Earth's history and the heated debate regarding the causes of mass extinctions. Enrollment limited to 64. [S] [Q] E. Wollman.Concentrations

This course is referenced by the following General Education Concentrations

#### PHYS 103. Musical Acoustics.

An introduction to the science of sound and the acoustics of musical instruments through the study of mechanical vibrations and waves. Concepts such as resonance, standing waves, and Fourier synthesis and analysis are developed and applied to theoretical and laboratory investigations of musical sound. Additional topics include hearing, psychoacoustics, and musical scales and harmony. No background in physics or mathematics beyond algebra is assumed. Laboratory work, problem solving, and simulations are integrated into class activities. Enrollment limited to 72. [S] [L] [Q] J. Smedley.Concentrations

This course is referenced by the following General Education Concentrations

#### PHYS 105. Physics in Everyday Life.

Designed for nonscience majors, this course introduces physics by studying objects in our everyday environment and the principles upon which they are based. Laws of motion, electric and magnetic forces, light and optics, and other physics topics are examined through the study of colored paints, cameras, microwave ovens, radios, televisions, telephones, photocopying machines, laser printers, electrostatic air filters, electric power generation and distribution, lasers, medical imaging, nuclear radiation, and nuclear bombs. Recommended background: high school algebra and geometry. Enrollment limited to 64. [S] [Q] M. Semon.Concentrations

This course is referenced by the following General Education Concentrations

#### PHYS 106. Energy and Environment.

This course examines energy as a fundamental concept in physics and an essential element of human society. Basic principles of energy conservation and transformation are developed in order to understand sustainable and nonsustainable energy resources, how they are utilized, and their environmental impacts. No background in physics or mathematics beyond algebra is assumed. Not open to students who have received credit for Chemistry 105 or s38. Enrollment limited to 72. [S] [Q] J. Smedley.ConcentrationsInterdisciplinary Programs

This course is referenced by the following General Education Concentrations

This course counts toward the following Interdisciplinary Program(s)

#### PHYS 107. Classical Physics.

A calculus-based introduction to Newtonian mechanics, electricity, and magnetism. Topics include kinematics and dynamics of motion, applications of Newton's laws, energy and momentum conservation, rotational motion, electric and magnetic fields and forces, and electric circuits. Laboratory investigations of these topics are computerized for data acquisition and analysis. Prerequisite(s) or corequisite(s): Mathematics 105. Enrollment limited to 72 per section. [S] [L] [Q] Normally offered every year. M. Semon.Concentrations

This course is referenced by the following General Education Concentrations

#### PHYS 108. Modern Physics.

This course applies the material covered in Physics 107 to a study of physical optics and modern physics, including the wave-particle duality of light and matter, quantum effects, special relativity, nuclear physics, and elementary particles. Laboratory work includes experiments such as the charge-to-mass ratio for electrons, the photoelectric effect, and electron diffraction. Prerequisite: Physics 107. Not open to students who have received credit for First-Year Seminars 274. Enrollment limited to 72 per section. [S] [L] [Q] Normally offered every year. N. Lundblad.Concentrations

This course is referenced by the following General Education Concentrations

#### PHYS 112. Physics of Sports.

Concepts in Newtonian mechanics are developed through the study of motions associated with a wide range of sports activities. Experiments, problem solving, and computer work are integrated into each class meeting. Enrollment limited to 24. [S] [L] [Q] J. Smedley.Concentrations

This course is referenced by the following General Education Concentrations

#### GE/PH 120. The Unexpected Earth.

How do we know that on average every half-million years or so the Earth's magnetic field spontaneously reverses direction? How do we know that the Atlantic Ocean is growing wider and the Pacific Ocean is shrinking about as fast as a fingernail grows? This course takes a multidisciplinary look at amazing and unexpected discoveries about our home planet, exploring how new discoveries come about and how crucial but difficult measurements are conceived and made. The course is designed for students with a strong high school background in the physical sciences and mathematics. Enrollment limited to 48. [S] [Q] E. Wollman, J. Creasy.Concentrations

This course is referenced by the following General Education Concentrations

#### PHYS 211. Newtonian Mechanics.

A rigorous study of Newtonian mechanics. Beginning with Newton's laws, the concepts of energy, momentum, and angular momentum are developed and applied to gravitational, harmonic, and rigid-body motions. Prerequisite(s): Mathematics 106. Prerequisites(s) or corequisite(s): First-Year Seminar 274 or Physics 108. Open to first-year students. [S] [Q] Normally offered every year. H. Lin.Concentrations

This course is referenced by the following General Education Concentrations

#### PHYS 214. Renewable Energy.

Renewable energy sources, including solar, gravitational, and geothermal energy, are considered essential to the pursuit of a sustainable future for technological society. This course focuses on the physics of renewable energy, with some attention to problems inhibiting its development. Prerequisite(s): Mathematics 106 and Physics 108. [S] [Q] J. Smedley.Concentrations

This course is referenced by the following General Education Concentrations

#### PHYS 216. Scientific Computing and Numerical Analysis.

Computing touches every area of physics, from experimental data acquisition and analysis to theoretical predictions. This course provides an introduction to computing and programming with an emphasis on scientific applications. Students learn functional and object-oriented programming, how to use mathematical computing software, and scientific typesetting. Prerequisite(s): Mathematics 106 and Physics 108 or First-Year Seminar 274. Enrollment limited to 20. [S] [Q] Staff.Concentrations

This course is referenced by the following General Education Concentrations

#### PHYS 220. Climate Change and Modeling.

A quantitative introduction to the science of climate change and climate modeling that explores the impact of both human activities and natural variability on climate. Topics include the basic physics of climate, El Niño, climate models, the greenhouse effect and global warming. Prerequisite(s): Mathematics 106 and Physics 108. Recommended background: Geology 108 and 109. J. Smedley.Concentrations

This course is referenced by the following General Education Concentrations

#### PHYS 222. Electricity, Magnetism, and Waves.

A detailed study of the basic concepts and fundamental experiments of electromagnetism. The development proceeds historically, culminating with Maxwell's equations. Topics include the electric and magnetic fields produced by charge and current distributions, forces and torques on such distributions in external fields, properties of dielectrics and magnetic materials, electromagnetic induction, and electromagnetic waves. Prerequisite(s): Mathematics 106 and Physics 107 or First-Year Seminar 274. Open to first-year students. [S] [Q] Normally offered every year. N. Lundblad.Concentrations

This course is referenced by the following General Education Concentrations

#### PHYS 225. The Physics of Fluids.

We are surrounded by fluids, inside and out, and their properties govern much of our everyday experience. As a consequence, the study of fluids underlies a broad spectrum of scientific inquiry ranging from organismic locomotion to meteorology. This course examines fluids and fluid flow, emphasizing the relation between conceptual and simple mathematical descriptions of fluid phenomena. Fundamental topics including viscosity, surface tension, buoyancy, lift, and drag are complemented by applications from engineering, biology, and geophysics. These concepts provide the framework for students to explore a topic of their choice in a final project. Prerequisite(s): Mathematics 106 and Physics 107. Recommended background: Mathematics 206. [S] [Q] L. Childress.Concentrations

This course is referenced by the following General Education Concentrations

#### INDS 228. Caring for Creation: Physics, Religion, and the Environment.

This course considers scientific and religious accounts of the origin of the universe, examines the relations between these accounts, and explores the way they shape our deepest attitudes toward the natural world. Topics of discussion include the biblical Creation stories, contemporary scientific cosmology, the interplay between these scientific and religious ideas, and the roles they both can play in forming a response to environmental problems. Cross-listed in environmental studies, physics, and religious studies. Enrollment limited to 40. [S] J. Smedley, T. Tracy.ConcentrationsInterdisciplinary Programs

This course is referenced by the following General Education Concentrations

This course counts toward the following Interdisciplinary Program(s)

#### PHYS 231. Laboratory Physics I.

Students perform selected experiments important in the development of contemporary physics. They also are introduced to the use of computers, electronic instruments, machine tools, and vacuum systems. Prerequisite(s): Physics 108 or First-Year Seminar 274, and Physics 211, 222, or s30. Enrollment limited to 12. [S] [L] [Q] Normally offered every semester. H. Lin.Concentrations

This course is referenced by the following General Education Concentrations

#### PHYS 232. Laboratory Physics II.

For students with a special interest in experimental research, this course provides an opportunity for open-ended experiments and developmental projects. Prerequisite(s): Physics 231 and s30. [S] [L] [Q] Normally offered every semester. H. Lin.Concentrations

This course is referenced by the following General Education Concentrations

#### PHYS 301. Mathematical Methods of Physics.

A study of selected mathematical techniques necessary for advanced work in physics and other sciences. The interpretation of functions as vectors in Hilbert space provides a unifying theme for developing Fourier analysis, special functions, methods for solving ordinary and partial differential equations, and techniques of vector calculus. These methods are applied to selected problems in acoustics, heat flow, electromagnetic fields, and classical and quantum mechanics. Prerequisite(s) or corequisite(s): Mathematics 206. [S] [Q] Normally offered every year. E. Wollman.Concentrations

This course is referenced by the following General Education Concentrations

#### PHYS 308. Introductory Quantum Mechanics.

An investigation of the basic principles of quantum mechanics in the Schrödinger representation and the application of these principles to tunneling, the harmonic oscillator, and the hydrogen atom. Basic theoretical concepts such as Hermitian operators, Ehrenfest's theorem, commutation relations, and uncertainty principles are developed as the course proceeds. Prerequisite(s): Physics 211 and 301. [S] [Q] Normally offered every year. H. Lin.Concentrations

This course is referenced by the following General Education Concentrations

#### PHYS 341. Solid State Physics.

A study of crystal structures and the electronic properties of solids, together with an investigation of some active areas of research. Topics include crystal binding, X-ray diffraction, lattice vibrations, metals, insulators, semiconductors, electronic devices, superconductivity, and magnetism. Prerequisite(s): Physics 108 or First-Year Seminar 274, and Physics 301. Prerequisite(s) or corequisite(s): Physics 222. Recommended background: Physics 308. [S] [Q] Staff.Concentrations

This course is referenced by the following General Education Concentrations

#### PHYS 360. Independent Study.

Students, in consultation with a faculty advisor, individually design and plan a course of study or research not offered in the curriculum. Course work includes a reflective component, evaluation, and completion of an agreed-upon product. Sponsorship by a faculty member in the program/department, a course prospectus, and permission of the chair are required. Students may register for no more than one independent study per semester. Normally offered every semester. Staff.Concentrations

This course is referenced by the following General Education Concentrations

#### PHYS 361. Thermal Physics.

The theory of equilibrium states is developed in a general way and applied to specific thermodynamic systems. The concepts of classical and quantum statistical mechanics are formulated. The ability to understand partial derivatives is expected. Prerequisite(s): Physics 108 or First-Year Seminar 274. Prerequisite(s) or corequisite(s): Mathematics 206, and Physics 211 or 222. [S] [Q] Staff.Concentrations

This course is referenced by the following General Education Concentrations

#### PHYS 373. Classical and Modern Optics.

A general course on light treated as an electromagnetic wave, including the theory and operation of common optical instruments. A significant part of the course is devoted to topics in modern optics, such as the use of lasers and the nonlinear effects produced by intense light sources. Prerequisite(s): Physics 108 or First-Year Seminar 274, and Physics 222. [S] [Q] H. Lin.Concentrations

This course is referenced by the following General Education Concentrations

#### PHYS 381. Astrophysics.

This course investigates the physics of astronomical phenomena and the instruments and techniques with which these phenomena are studied. Topics, which vary from year to year, include stellar structure and evolution, the interstellar medium, galaxies and galaxy clusters, dark matter, cosmic background radiation, and physical cosmology. Prerequisite(s): Physics 211, 222, and 301. Not open to students who have received credit for Astronomy 381. [S] [Q] E. Wollman.Concentrations

This course is referenced by the following General Education Concentrations

#### PHYS 409. Quantum Theory.

A formal treatment of quantum theory using Dirac notation, including an introduction to approximation methods and applications. The general theory of angular momentum and time-independent perturbation theory are developed and used to derive the fine and hyperfine structures of hydrogen. Additional topics may include quantum statistics, quantum dynamics, and time-dependent perturbation theory. Prerequisite(s): Physics 308. [S] [Q] Normally offered every year. M. Semon.Concentrations

This course is referenced by the following General Education Concentrations

#### PHYS 412. Advanced Classical Mechanics.

A development of the Lagrangian and Hamiltonian formulations of classical mechanics, together with the ideas of symmetry and invariance and their relation to fundamental conservation laws. Additional topics include kinematics and dynamics in noninertial reference frames, a detailed analysis of rigid-body motion, and the theory of small oscillations and normal modes. Prerequisite(s): Physics 211 and 301. [S] [Q] M. Semon.Concentrations

This course is referenced by the following General Education Concentrations

#### PHYS 422. Electromagnetic Theory.

Starting from Maxwell's equations, this course develops electrostatics from solutions to Poisson's equation, magnetostatics using the vector potential, electrodynamics with scalar and vector potentials, and properties of electromagnetic waves. Simple radiation problems are discussed, as well as the relativistic formulation of electrodynamics. Prerequisite(s): Physics 222 and 301. [S] [Q] Normally offered every year. N. Lundblad.Concentrations

This course is referenced by the following General Education Concentrations

#### PHYS 457. Senior Thesis.

An independent study program for students working on a research problem in a field of interest, culminating in the writing of a senior thesis. Students register for Physics 457 in the fall semester and for Physics 458 in the winter semester. Majors writing an honors thesis register for both Physics 457 and 458. Instructor permission is required. [W3] Normally offered every year. Staff.Concentrations

This course is referenced by the following General Education Concentrations

#### PHYS 457, 458. Senior Thesis.

An independent study program for students working on a research problem in a field of interest, culminating in the writing of a senior thesis. Students register for Physics 457 in the fall semester and for Physics 458 in the winter semester. Majors writing an honors thesis register for both Physics 457 and 458. Instructor permission is required. [W3] Normally offered every year. Staff.Concentrations

This course is referenced by the following General Education Concentrations

#### PHYS 458. Senior Thesis.

An independent study program for students working on a research problem in a field of interest, culminating in the writing of a senior thesis. Students register for Physics 458 in the winter semester. Majors writing an honors thesis register for both Physics 457 and 458. Instructor permission is required. [W3] Normally offered every year. Staff.Concentrations

This course is referenced by the following General Education Concentrations

#### PHYS s27. The Asteroid Impact Threat: What Can We Do?.

Sixty-five million years ago, an asteroid or comet the size of Mt. Everest slammed into the Earth, triggering events that led to the extinction of the majority of all species then living. Smaller objects orbiting the Sun are numerous and are capable of obliterating large cities. We may not be able to do anything about an object the size of Mt. Everest heading our way, but we might be able to deflect a smaller yet catastrophically deadly object. Students investigate how to alter the orbit of a threatening asteroid of dangerous but potentially manageable size. Prerequisite(s): Mathematics 106 and Physics 107. [S] [Q] E. Wollman.Concentrations

This course is referenced by the following General Education Concentrations

#### PHYS s30. Electronics.

A laboratory-oriented study of the basic principles and characteristics of semiconductor devices and their applications in circuits and instruments found in a research laboratory. Both analog and digital systems are included. Prerequisite(s): Physics 108 or First-Year Seminar 274. Enrollment limited to 12. [S] [L] [Q] Normally offered every year. L. Childress, N. Lundblad.Concentrations

This course is referenced by the following General Education Concentrations

#### PHYS s50. Independent Study.

Students, in consultation with a faculty advisor, individually design and plan a course of study or research not offered in the curriculum. Course work includes a reflective component, evaluation, and completion of an agreed-upon product. Sponsorship by a faculty member in the program/department, a course prospectus, and permission of the chair are required. Students may register for no more than one independent study during a Short Term. Normally offered every year. Staff.Concentrations

This course is referenced by the following General Education Concentrations