# Physics

Physics is the study of the behavior of the universe, especially the fundamental laws underlying natural phenomena. The Department of Physics has offerings to meet a range of interests, from a Topics in Physics course, to a minor, to a complete major program on the principles and analytic methods of the field. The curriculum leading to a bachelor’s degree can provide a solid foundation for graduate study in physics, applied physics, engineering, medicine, or law; or for entry-level positions in research, business, teaching, and other fields.

## Introductory Courses

Students required to take a one-year course in general physics as part of their academic program should take PHYS 115 Introductory Physics 1: Mechanics, Fluids and Waves, PHYS 116 Introductory Physics 2: Electromagnetism, Optics and Modern Physics. This is a two-semester, calculus-based sequence, suitable for majors of physics, chemistry, or biology, as well as for those participating in the Health Professions Advisory Program (premedical, predental, etc.), the 3-2 Engineering Program, or in ROTC

## Advanced Placement Credit

Holy Cross awards credit for Advanced Placement exams taken through the College Board Advanced Placement Program and the International Baccalaureate Program and will accept some Advanced Level General Certificate of Education (A-Level) exams. One unit of credit is awarded for an Advanced Placement score of 4 or 5 in any discipline recognized by the College. One unit of credit is awarded for a score of 6 or 7 on a Higher Level International Baccalaureate Examination in a liberal arts subject. One unit of credit is awarded for a score of A/A* or B on an A-Level exam in a liberal arts subject. **The College does not award credit for the IB Standard Exam or the AS-Level Exam**. AP, IB, and A-Level credit may be used to satisfy deficiencies and common area requirements. Each academic department has its own policy regarding the use of AP or IB credit for placement in courses and progress in the major. The Department Chair must also review the A-Level score to determine placement in courses and progress in the major. See departmental descriptions for further information.

Students who scored 4 or 5 on the AP Physics exam may receive advanced standing in the Physics curriculum. Contact the department chair to discuss this option.

Matthew B. Koss, Ph.D., *Professor*

Janine Shertzer, Ph.D., *Distinguished Professor of Science*

De-Ping Yang, Ph.D., *Professor*

Benjamin Kain, Ph.D., *Associate Professor*

Tomohiko Narita, Ph.D., *Associate Professor and Chair*

Paul K. Oxley, Ph.D., *Associate Professor*

Timothy M. Roach, Ph.D., *Associate Professor*

Shreyashi Chakdar, Ph.D., *Assistant Professor*

**PHYS 100 —**

**Topics in Physics**Course count: 1

These courses introduce non-science majors to important principles and modes of inquiry of physics, explored in a particular context. Recent offerings: Earth Science; Electricity and Magnetism in Everyday Life; How Things Work; Gravity and Science in Orbit. Non-science majors only. One unit

GPA units: 1

Common Area: Natural Science

**PHYS 101 —**

**Introduction To Astronomy**Course count: 1

Motions of celestial bodies; the sun, Earth and moon; other terrestrial planets; Jovian planets; asteroids and comets; nebular model for the origin of the solar system; stars and stellar systems; Milky Way galaxy; the universe and the big-bang model. Non-science majors only.

GPA units: 1

Common Area: Natural Science

Typically Offered: Annually

**PHYS 105 —**

**Foundations for Science**Course count: 1

GPA units: 1

Common Area: Natural Science

**PHYS 115 —**

**Introductory Physics 1: Mechanics, Fluids and Waves**Course count: 1

First semester course of a two-semester, calculus-based sequence, suitable for majors of physics, chemistry, or biology, as well as for those participating in the Health Professions Advisory Program (premedical, predental, etc.), the 3-2 Engineering Program, or in ROTC. Covers the theory of Newtonian mechanics and methods for solving quantitative and qualitative problems. Specific topics include motion in one and two dimensions; vectors, Newton's laws of motion, work and energy, linear momentum and collisions, rotational motion, static equilibrium, oscillatory motion, gravitation, fluid mechanics, and mechanical waves. There is an emphasis on applications of physics to natural phenomena and aspects of everyday life. The course meets four days per week and each class is a mixture of lecture and laboratory exercises; there is no separate lab meeting.

Prerequisite or Corequisite: MATH 133 or MATH 134 or MATH 135 or MATH 136 or equivalent.

GPA units: 1.25

Common Area: Natural Science

Typically Offered: Fall

**PHYS 116 —**

**Introductory Physics 2: Electromagnetism, Optics and Modern Physics**Course count: 1

Second part of a two-semester sequence (see PHYS 115). Covers electricity and magnetism, optics, and some aspects of modern physics. Specific topics include electric forces, fields, and potential, electrical components and circuits, magnetic forces and fields, electromagnetic induction, geometric optics, wave optics, relativity, and atomic and nuclear physics. There is an emphasis on applications of physics to natural phenomena and aspects of everyday life. The course meets four days per week and each class is a mixture of lecture and laboratory exercises; there is no separate lab meeting.

Prerequisite: PHYS 115

GPA units: 1.25

Common Area: Natural Science

Typically Offered: Spring

**PHYS 221 —**

**Methods Of Physics**Course count: 1

Mathematical and numerical techniques needed for the study of physics at the intermediate and advanced level. Ordinary differential equations; vector calculus; partial differential equations; matrices; Fourier series; and complex variables.

Prerequisite: PHYS 116.

GPA units: 1

**PHYS 223 —**

**Modern Physics**Course count: 1

Introduction to several major areas of physics, including relativity, quantum physics (photons and deBroglie waves), atomic structure, nuclear physics, and elementary particles. One unit.

Prerequisite: PHYS 116.

GPA units: 1

**PHYS 225 —**

**Modern Physics Lab**Course count: 0

This course introduces students to advanced laboratory equipment and techniques, in the context of key experiments from modern physics. Examples of the experiments to be performed are: Nuclear Decay, Speed of Light, Gamma Rays, Balmer Lines Spectroscopy, and Cosmic Ray Muons. There is a strong emphasis on analytical methods and presentations of results. Taken as a fifth course.

Corequisite: PHYS 223

GPA units: 1

Typically Offered: Spring

**PHYS 231 —**

**Optics**Course count: 1

Through an in-depth study of geometric and wave optics, this course allows students to understand electromagnetic fields and optical phenomena under one coherent theory and fosters the concurrent use of many different mathematical methods. Students will also see how the concept of wave-particle duality of the photon is manifested in geometric and wave optics. Geometric optics focuses on topics such as the Fermat's Principle, laws of reflection and refraction, image-forming properties of mirrors and lenses, analysis and designs of optical systems (the eye, microscopes, telescopes, etc.). Wave optics covers topics such as dispersion by prisms, interference by two coherence sources (e.g., double-slits) or multiple sources (e.g., gratings), diffraction and scattering of light, thin films, polarization, optical spectra, lasers and holography.

Prerequisite: PHYS 116 and PHYS 221 with Co-requisite: PHYS 233.

GPA units: 1

**PHYS 233 —**

**Optics Lab**Course count: 0

In this advanced laboratory course students will assemble optical systems and test their performance, to understand the principles but also the quantitative relations between parameters such as wave length, intensity, geometric sizes and shapes, refractive index, polarization, etc. The experiments allow students to develop skills in a variety of areas, including precision adjustments of optical instruments, working with lasers, computer simulations of image formation, spectrometry, holography and use of optical fibers. Taken concurrently with Physics 231. Overload.

Corequisite: PHYS 231.

GPA units: 1

Typically Offered: Alternate Years

**PHYS 234 —**

**Electronics**Course count: 1

An introduction to analog and digital electronics using discrete semiconductor components and integrated circuit chips. Theory and methodology are discussed in terms of Kirchhoff 's laws applied to DC and AC circuits, the characteristics of diodes and transistors, and the properties of IC chips. This course also explores the physics of semiconductors, behaviors of diodes and transistors, and their circuit applications including rectifiers, regulators, amplifiers, oscillators, and feedback systems, specifically operational amplifier circuits. The digital circuitry focuses on logic gates, comparators, binary number counting and processing, and programmable microcontrollers.

Prerequisite: PHYS 116 and corequisite: PHYS 236

GPA units: 1

Typically Offered: Alternate Years

**PHYS 236 —**

**Electronics Lab**Course count: 0

This is the advanced laboratory course accompanying Physics 234. It is designed to allow students to explore various analog and digital circuits. Professional equipment including digital oscilloscopes, prototyping boards, digital multimeters are used in the design, construction, and testing of AC and DC circuits, including low- and high-pass filters, resonance circuits, rectifiers, transistor amplifiers with feedback, oscillators, 555-timer circuits, operational amplifiers, transistor-transistor logic (TTL) integrated circuits, logic gates, flip-flops, binary counters, binary-coded decimal representations and displays, binary computations, and a programmable microcontroller. Taken concurrently with Physics 234. Overload.

Corequisite: PHYS 234

GPA units: 1

Typically Offered: Alternate Years

**PHYS 275 —**

**Intermediate Topics in Physics**Course count: 1

Exploration of a selected topic at an intermediate level. Recent offerings: Introduction to Quantum Computation and Quantum Information; Introduction to Particle Physics; Atomic Physics; Solid State Physics; Fulfills one elective requirement for majors.

Prerequisite: PHYS 221 and PHYS 223.

GPA units: 1

**PHYS 342 —**

**Classical Mechanics**Course count: 1

Newtonian (non-relativistic) mechanics is studied in detail using advanced mathematical methods. One-dimensional motions that are studied include those with fluid friction, where the force is a function of velocity, and the forced harmonic oscillator. Two-dimensional motions include projectiles with air friction and motion under an inverse-square law central force. Motion of a system of particles includes the rocket problem, the two-body problem, coupled harmonic oscillators, and rigid-body rotation. Coriolis and centrifugal forces on the rotating Earth are studied. Finally, a thorough introduction of Lagrangian dynamics is presented.

Prerequisite: PHYS 221 and MATH 241

GPA units: 1

Typically Offered: Spring

**PHYS 344 —**

**Thermal Physics**Course count: 1

How does a refrigerator work, and what is its maximum efficiency? How much energy do we need to add to a kettle of water to change it to steam? How and why does a snowflake form and how and why do liquids turn into solids? Why does an iron magnet lose its magnetism above a certain temperature? In fact, what do we mean by temperature, heat, and energy? Our understanding of these topics formed in two distinctly different ways starting about two-hundred years ago. James Joule, Sadi Carnot, and others developed what we now call classical thermodynamics, which treats matter and energy in terms of macroscopic quantities that obey the four "laws of thermodynamics." Later, Ludwig Boltzmann, James Clark Maxwell, Josiah Willard Gibbs, and others applied classical mechanics and probability theory to molecules in an approach now called statistical mechanics and kinetic theory. In our modern approach to thermal physics, we add our understanding of quantum physics and use both classical and statistical approaches as best suits the question under investigation.

Prerequisite: PHYS 221and MATH 241

GPA units: 1

Typically Offered: Fall

**PHYS 351 —**

**Electromagnetic Theory**Course count: 1

The aim of this course is to introduce the basic principles of electricity and magnetism and their application in a variety of situations. The focus is on the physics behind how electric and magnetic fields are created, but the course includes substantial mathematical complexity. A solid foundation of multivariable calculus is, therefore, required. Specific topics covered include: the electrostatic field and potential; work and energy in electrostatics; special techniques for calculating potentials; electric fields in matter; the Lorentz force and the Biot-Savart law; magnetic vector potential; magnetostatic fields in matter; electromagnetic induction and Maxells equations.

Prerequisite: PHYS 221 and MATH 241

GPA units: 1

Typically Offered: Spring

**PHYS 353 —**

**Quantum Mechanics**Course count: 1

The formalism of quantum mechanics; solutions of the one-dimensional Schrödinger equation including the infinite square well, the harmonic oscillator, and the finite well/barrier; solutions of the three-dimensional Schrödinger equation; the hydrogen atom; angular momentum and spin.

Prerequisite: PHYS 221 and PHYS 223 and MATH 241

GPA units: 1

Typically Offered: Fall

**PHYS 355 —**

**Introduction To Astrophysics**Course count: 1

Celestial mechanics; spectra; solar physics; equations of stellar structure; thermonuclear reactions; stars and stellar systems; polytropes; stellar evolution; white dwarfs, neutron stars, and black holes; Milky Way galaxy; Hubble's law; active galactic nuclei; big-bang model.

Prerequisite: PHYS 223

GPA units: 1

Typically Offered: Alternate Years

**PHYS 461 —**

**Independent Study**Course count: 1

One unit each semester.

GPA units: 1

Typically Offered: Fall, Spring

**PHYS 471 —**

**Undergraduate Research**Course count: 1

Supervised research in theory or experiment.

GPA units: 1

Typically Offered: Fall, Spring

**PHYS 472 —**

**Undergraduate Research**Course count: 1

Supervised research in theory or experiment.

GPA units: 1