Course Descriptions

Course Descriptions

Physics lecture courses will have the designation PHY (followed by three digits) and physics lab courses will have the designation PHL (followed by three digits). The letter after the three digit number corresponds to the semester when the course is normally offered (a = Fall; b = Winter; f = Full Year). Finally note that the hyphenated 3-digit number (x-y-z) after the title of each course corresponds to the number of credits (x), number of lecture hours per week (y), and the number of laboratory hours per week (z), respectively.

UNDERGRADUATE COURSES

Physics 101a  Statistical Methods  3-3-1

This course is specifically designed to meet the needs of students of physics, chemistry, biology, mathematics and computer science. Topics include: errors of observation, graphical visualization of data; descriptive analysis, elementary probability, permutations and combinations; the binomial, normal and Poisson distributions; random sampling; testing hypotheses, significance levels, confidence limits, large and small sampling methods; regression and correlation; chi-square distribution; analysis of variance.

Note: In order for students to obtain credit for both Physics 101 and Mathematics 313, Physics 101 must be taken first or concurrently.

Physics 111ab  The Physics of Everyday Phenomena  3-3-1

This course is designed to meet the needs of non-science students by providing them with a practical introduction to physics and science as it is applies to everyday life. Students are assumed to have no background in math or science. By allowing students to practice science through practical demonstrations of physical phenomena and engaging in small-group inquiry and discussion, they will learn to think logically when solving problems, enhance their scientific literacy, and develop their physical intuition. Typical questions that will be addressed include: Why is the sky blue? What causes a rainbow even when it is not raining? Why purchase a car with an anti-locking brake system (ABS)? Where is lightning most likely to strike and how can you best protect yourself? How do medical scanning procedures such as MRI work? Does a curve ball really curve or is it an optical illusion?

Note: Students enrolled in a program in the Division of Natural Sciences and Mathematics cannot use this course as a science elective.

Physics 112ab  Introduction to Holography  3-1-4

This course is designed to give students an introduction to the principles of laser holography (3-D photography) while at the same time providing them with the opportunity to create holograms in the laboratory. Students are assumed to have no background in math or science. Students will make holograms using single and multiple beam reflection and transmission techniques. Special topics related to the making of rainbow, colour, and other types of holograms will be discussed and attention will be given to the application of this medium as a form of visual expression. In addition, students will be able to apply their knowledge to create holograms at home (sandbox holography).

Prerequisite: Permission of the instructor. Students in Fine Arts are strongly advised to take a course in Photography before enrolling in this course.
Note: See Fin 207ab. Students may not take this course for credit if they have received credit for Fin 207ab. Students enrolled in a program in the Division of Natural Sciences and Mathematics cannot use this course as a science elective.

Physics 113b  Introduction to Astronomy  3-3-0

An outline of our knowledge of the size, structure and possible origin of the Universe. Starting with the primitive speculations of the Greeks, the course ends with the theory of the expanding universe and its origin in the “Big Bang”.

Prerequisite: Students should have a background in high school mathematics.

Physics 191a Introductory Physics I (Mechanics) 3-3-0

This course is designed to give students an introduction to classical mechanics. Topics that will be covered include statics, particle kinematics in one and two dimensions, particle dynamics and Newton’s Laws, conservation of energy and momentum, and rotational kinematics and dynamics. This course should be taken concurrently with Physics Lab 191.

Corequisite: Mathematics 191a

Physics Lab 191a Introductory Physics Laboratory I 1-0-4

A series of experiments in General Physics to complement the material covered in Physics 191a. This course must be taken concurrently with Physics 191a.

Physics 192b Introductory Physics II (Electricity and Magnetism) 3-3-0

This course is designed to give students an introduction to electromagnetism and its applications. Topics that will be covered include Coulomb’s Law, electric fields, electric potential, capacitance, direct current circuits, magnetism, electromagnetic induction, alternating current circuits, and electromagnetic waves. This course should be taken concurrently with Physics Lab 192.

Prerequisite: Physics 191a or the permission of the instructor. Corequisite: Mathematics 192b

Physics Lab 192b  Introductory Physics Laboratory II  1-0-4

A series of experiments in General Physics to complement the material covered in Physics 192b. This course must be taken concurrently with Physics 192b.

Physics 193a  Physics for the Life Sciences I  3-3-0

This course is designed to emphasize topics of particular relevance to the life sciences. Topics that will be covered include: mechanics (statics, kinematics, dynamics, conservation of energy and momentum, rotational motion); fluid dynamics (pressure, elasticity, viscosity, diffusion); and, thermodynamics (temperature, heat transport, kinetic theory of gases). Concepts and problem-solving skills are emphasized. This course should be taken concurrently with Physics Lab 193a. This course is required for all students in Biology and Biochemistry.

Students who have received credit for an equivalent course taken elsewhere may not register for this course. Credit will be given for only one of Physics 191a, 193a, and 199f.
Corequisite: Mathematics 198a or Mathematics 191a

Physics Lab 193a  Physics for the Life Sciences Laboratory I  1-0-4

A series of experiments in college physics to complement the material covered in Physics 193a. This course must be taken concurrently with Physics 193a.

May not be taken for credit if credit has been granted for Physics Lab 191a or Physics Lab 199f.

Physics 194b  Physics for the Life Sciences II  3-3-0

This course is designed to emphasize topics of particular relevance to the life sciences. Topics that will be covered include: vibrations and waves; sound; electrostatics (charges, electric fields and potential); circuits; magnetism (forces, induction, electromagnetic waves); optics (interference, diffraction, instruments); and, modern physics (atoms, radioactivity, MRI, CAT). This course should be taken concurrently with Physics Lab 194b. This course is required for all students in Biology and Biochemistry.

Students who have received credit for an equivalent course taken elsewhere may not register for this course. Credit will be given for only one of Physics 192b, 194b, and 199f.
Prerequisite: Physics 193a or Physics 191a or the permission of the instructor.
Corequisite: Mathematics 199b or Mathematics 192b

Physics Lab 194b  Physics for the Life Sciences Laboratory II  1-0-4

A series of experiments in college physics to complement the material covered in Physics 194b. This course must be taken concurrently with Physics 194b.

May not be taken for credit if credit has been granted for Physics Lab 192b or Physics Lab 199f.

Physics 199f  Introduction to University Physics  6-6-0

An introduction to the fundamentals of classical physics. Concepts and problem-solving skills are emphasized. Topics in the area of mechanics include: translational, rotational, and oscillatory motion; Newtonian dynamics; conservation of energy, linear momentum, and angular momentum; heat and the kinetic theory of gases. Topics in the area of electricity and magnetism include: electric fields and potentials; AC and DC circuit theory; magnetism and the properties of magnetic materials; electromagnetic waves and optics.

Prerequisites: Students must normally have completed upper-level high school physics and mathematics courses, or must satisfy admission requirements into the B.Sc. degree at Bishop’s University. Students taking this course require a knowledge of basic calculus which may be gained concurrently.
Corequisite: Physics Lab 199f
Students may not have credit for both Physics 199 and other introductory physics courses (i.e., Physics 191 and 192 or their equivalents).

Physics Lab 199f  Introduction to University Physics Laboratory  2-0-8

A series of experiments that complements the lecture material in PHY199. This laboratory course includes experiments in measurement and uncertainty, statics, dynamics, collisions, AC and DC circuit analysis, electrostatics, and magnetism.

Corequisite: Physics 199f
Students may not have credit for both Physics Lab 199f and other introductory physics laboratory courses (i.e., Physics Lab 191a and 192b or their equivalents).

Physics 206a  Waves and Optics  3-3-0

Wave phenomena. Wave and photon theories of light. Huygen’s Principle and its applications. Geometrical optics. Optical instruments. Simple versions of Interference, Diffraction and Polarization of light.

Co-requisite: Physics Lab 206a

Physics Lab 206a  Waves and Optics Laboratory  1-0-4

Experiments in geometrical and physical optics. Data analysis software such as SigmaPlot and Maple will be used. This course must be taken concurrently with Physics 206a.

Physics 207b  Thermal and Fluid Physics  3-3-0

Pressure, hydrostatics, and hydrodynamics. Temperature and Heat. Kinetic theory of gases. Energy, work, heat. First, second, and third laws of thermodynamics. Entropy and Disorder. Specific heat of solids, black body radiation, statistical thermodynamics involving different distributions and their applications.

Physics 208b  Introduction to Mechanics  3-3-0

Statics: equilibrium of bodies subject to many forces. Kinematics; rectilinear, plane, circular and simple harmonic motion. Dynamics: conservation of mechanical energy and momentum; plane and circular motion of particles; rotation of macroscopic bodies.

Prerequisite: Physics 191a or equivalent, Mathematics 106a
Note: See Mat 177a. Students may not take this course for credit if they have received credit for Mat 177a.

Physics 214b  Astronomy and Astrophysics  3-3-0

A survey of our understanding of the physical properties of the universe. Topics to be studied include: observational astronomy, stellar evolution, binary stars, white dwarfs, neutron stars, black holes, galaxies, quasars, large scale structure of the universe, and cosmology.

Prerequisite: Physics 191, Mathematics 191 (or equivalent), or permission of the instructor; Physics 113 or equivalent is recommended.

Physics 270a  Differential Equations  3-3-0

Techniques for solving first and second order linear differential equations. Systems of first order equations. Power series solutions for second order equations including the method of Frobenius. Various applications of differential equations.

Prerequisite: Mathematics 192b
Note: See Mathematics 310a. Students may not take this course for credit if they have received credit for Mathematics 310a.

Physics 279b  FORTRAN Programming  3-3-3

This course will cover the programming language FORTRAN. Subroutines, libraries, and the use of segmentation techniques will be covered as well as the syntax characteristics of FORTRAN. The course assumes that the student already knows how to program. Programming is done in FORTRAN 90.

Prerequisite: Computer Science 211ab

Physics Lab 286b  Waves, Optics, & Electromagnetism Laboratory  1-0-4

A series of experiments in wave motion, geometrical and physical optics, and electricity and magnetism to complement the material covered in the lecture courses Physics 192 and Physics 206. This course must be taken concurrently with Physics 192 and Physics 206.

May not be taken for credit if credit has been granted for Physics Lab 192b and Physics Lab 206a.

Physics 315b  Relativity Theory  3-3-0

The geometry of space-time. Relativistic mechanics of particles in curved space-times. Electromagnetic radiation. Applications to cosmology. Introduction to elementary particles.

Prerequisite: Physics 207b

Physics 316a  Physical and Contemporary Optics  3-3-0

Wave theory, polarization, interference diffraction. Basics of coherence theory, lasers, holography. Quantum nature of light.

Prerequisite: Physics 206a
Offered alternate years

Physics 317b  Statistical and Thermal Physics  3-3-0

The statistical definition of entropy and temperature. Statistical Ensembles. The Planck and Maxwell-Boltzmann distributions. The Fermi and Bose distributions. Thermodynamic functions. Applications of Fermi-Dirac and Bose-Einstein statistics.

Prerequisite: Physics 207b
Offered alternate years

Physics 318a  Advanced Mechanics  3-3-0

Newtonian gravitation: planetary orbits; tides. Relativistic dynamics of particles. The Lagrangian and Hamilton’s Principle. Theory of Vibrations and Small Oscillations. Dynamics of macroscopic bodies.

Prerequisite: Physics 208b, Physics 270a, or permission of the instructor.
Note: See Mathematics 278. Students may not take this course for credit if they have received credit for Mathematics  278.
Offered alternate years

Physics 319b  Electric Circuits and Electronics  3-3-0

Review of D.C. circuits, Kirchoff’s laws, network theorems. Network analysis for A.C. circuits, phasors. Diode circuits and filters. The physical basis of semiconductor devices including semiconductor diodes, junction transistors, and field-effect transistors. The operation of transistor amplifiers, digital electronics and integrated circuits will also be covered.

Note: See CSC 379.
Students may not take this course for credit if they have received credit for Computer Science 379.
Prerequisite: Permission of instructor.

Physics 320a  Electricity and Magnetism I  3-3-0

Review of vector calculus. Electrostatics: fields and potentials of point charges, dipoles, and distributed charges; Gauss’s theorem; Poisson’s and Laplace’s equations; dielectrics; capacitance. Current electricity.

Prerequisite: Physics 208b, Mathematics 207b
Offered alternate years

Physics 321b  Electricity and Magnetism II  3-3-0

Magnetic phenomena, magnetic induction, Ampere’s Law, and solenoids. Faraday’s Law and the displacement current. Magnetic and dielectric materials. Magnetic and electric fields: Maxwell’s equations of the electro-magnetic field; plane electromagnetic radiation in dielectrics and conducting media. Current electricity: filters; transmission lines. Radiation and Antennae.

Prerequisite: Physics 320a
Offered alternate years

Physics 335b  Environmental Physics  3-3-0

This quantitative, calculus-based, course discusses fundamental environmental problems within a physical context. Topics covered include: the greenhouse effect, blackbody radiation, the ozone problem, mathematical techniques, heat transfer, electricity, the transport of pollutants, plumes, and basic groundwater hydrology.

Prerequisites: Environmental Science 101; Physics 207.
Note: See Environmental Science 375. Students may not take this course for credit if they have received credit for Environmental Science 375.

Physics 361a  Quantum Mechanics I  3-3-0

Foundation of quantum mechanics; Schrodinger equation, angular momentum, central potentials, harmonic oscillator, hydrogen atom.

Prerequisite: Physics 208b or permission of the instructor.

Physics 365b  Data Communications  3-3-0

This course will cover how data flows in communications networks. Topics: Hardware, software and basic components of data communications; frequency domain representation, modulation, multiplexing; network configurations.

Prerequisite: Computer Science 211ab, Computer Science 216, or permission of the instructor.
Note: See Computer Science 315ab. Students may not take this course for credit if they have received credit for Computer Science 265b.

Physics 371b  Mathematical Methods of Physics  3-3-0

Discussion of series solutions in connection with the gamma function and Bessel, Legendre and hypergeometric functions. Laplace transform with applications. Elementary trigonometric Fourier series and boundary value problems. Certain partial differential equations of physics.

Prerequisites: Physics 270a or Mathematics 310a
Note: See Mathematics 311b. Students may not take this course for credit if they have received credit for Mathematics 311b.

Physics 375b  Numerical Methods  3-3-0

A course introducing those numerical methods best suited to a computer. Error analysis, roots of equations, QR-algorithm, interpolation, Numerical approaches to differentiation, integration and solutions of differential equations.

Prerequisites: Computer Science 211ab. Mathematics 108, 207
Note: See Mathematics 325 and Computer Science 375. Students may not take this course for credit if they have received credit for Mathematics 325 or Computer Science 375.

Physics 376b  Calculus of Variations  3-3-0

Euler-Lagrange equations for constrained and unconstrained single and double integral variational problems. Parameter-invariant single integrals. General variational formula. The canonical formalism. Hilbert’s independent integral. Hamilton-Jacobi equation and the Caratheodory complete figure. Fields and the Legendre and Weierstrass sufficient conditions.

Prerequisite: Permission of the Instructor
Note: See Mathematics 405. Students may not take this course for credit if they have received credit for Mathematics 405.

Physics 378b  Scientific Programming  3-3-3

This course is designed as an introduction to programming languages and environments suitable for the numerically intensive applications in the natural sciences and mathematics. Examples will be given to illustrate the use of Fortran in numerical calculations. Other examples will be tackled using the Maple language initially developed to handle problems in symbolic computation.

Prerequisite: Computer Science 304
Note: See Computer Science 308. Students may not take this course for credit if they have received credit for Computer Science 208.

Physics 380b  Experiential Learning in Astronomy  3-3-0

Students will be expected to work in the Observatory as a telescope operator, guide, and/or public speaker. These activities will help fulfill the Observatory’s role as a resource for public outreach in the field of science. Students will be expected to become conversant with the essentials of observational astronomy and to develop their ability to articulate the importance of astronomy and science to the general public through oral and/or written communication. Students must seek out an internal supervisor (a full-time faculty member) who will supervise their activities. Assessment of the student will be based on a mark assigned by the supervisor and will reflect the quality of the work carried out by the student. Students must also submit a journal detailing the actual daily work that was accomplished. Projects may be intensive in nature (i.e., 3 weeks during the summer), or may extend over longer durations (i.e., 6-8 hours per week during the semester).

Note: Students may only take one experiential learning course for credit. Permission of the instructor.

Physics Lab 385a  Intermediate Physics Laboratory I  2-0-6

Introduction to data acquisition and analysis of experiments which serve to measure the fundamental constants or properties of nature (e.g., Planck’s constant, Boltzmann’s constant, speed of light, charge of electron, Landé g-factor). Data will be collected by using a variety of instruments including oscilloscopes, computer interfaces using A/D converters, and other data sensors.

Offered alternate years

Physics Lab 386b  Intermediate Physics Laboratory II  2-0-6

Experiments in quantum physics, non-linear dynamics (chaos), thermodynamics, and low temperature physics will be carried out. Computer interfaces and nuclear counters will be used to collect and analyze data.

Offered alternate years

Physics Lab 387a  Intermediate Physics Laboratory III  2-0-6

Introduction to data acquisition and the analysis of data related to experiments in electricity and magnetism, electronics, and physical optics. Experiments include the magnetization of various materials, the Hall effect, and advanced spectroscopy. Computer interfaces will be used to collect and analyze data.

Offered alternate years

Physics Lab 388b  Intermediate Physics Laboratory IV  2-0-6

Experiments in electricity and magnetism, electronics, holography, and optical astronomy will be carried out. Students will also be allowed to carry out numerical simulations in any area pertaining to computational physics.

Offered alternate years

Physics 462b  Quantum Mechanics II  3-3-0

Matrix mechanics and applications of quantum mechanics to various branches of physics. Perturbation theory, scattering, molecular applications, and Hartree-Fock Theory.

Prerequisite: Physics 361a

Physics 463  Nuclear Physics  3-3-0

Nuclear structure and systematics; alpha emission, beta decay, gamma emission, two-body systems and nuclear reactions; neutron physics; sub-nuclear particles.

Prerequisite: Physics 361a

Physics 464 Condensed Matter Physics   3-3-0

Topics to be studied include the one-electron theory of solids, energy bands, lattice vibrations, transport theory, and thermodynamic properties.

Prerequisite: Physics 361a, 317b, or permission of the department.

Physics 465  Electromagnetic Theory  3-3-0

Static and dynamic electric and magnetic fields; Maxwell’s equations and solutions involving plane waves. Covariant formulation of electromagnetic field theory.

Prerequisite: Physics 315b, 321b

Physics 466  Theoretical Topics  3-3-0

Topics to be studied will be selected from the areas of special and general relativity, particle physics, astrophysics and cosmology. In particular, the covariant nature of physics and various physical symmetries will be investigated.

Prerequisites: Physics 361a, 318a, 317b; or the permission of the instructor

Physics 467  Statistical Mechanics  3-3-0

Derivation of the laws of thermodynamics from statistical principles. Quantum statistics, arbitrarily degenerate and relativistic perfect gases, transport theory, thermodynamic fluctuations, and low-temperature physics will also be studied.

Prerequisite: Physics 317b

Physics 469a  Independent Studies I  3-3-0

Topics to be determined by the instructor based on student needs.

Prerequisite: Permission of the department

Physics 470b  Independent Studies II  3-3-0

Topics to be determined by the instructor based on student needs.

Prerequisite: Permission of the department

Physics 474 Relativistic Astrophysics   3-3-0

Topics to be studied include: Cosmology, inflation, dark energy, compact objects, relativistic fluid dynamics, gravitational lensing, and gravitational waves.

Prerequisite: Permission of the department

Physics 475b  Numerical Methods and Simulations   3-3-0

This course will cover selected topics in High Performance Computing including cellular automata, finite element methods, molecular dynamics, Monte Carlo methods, and multigrid methods, with applications to classical fields, fluid dynamics, materials properties, nanostructures, and biomolecules.

Prerequisite: Permission of the department

Physics 476b  Stellar Astrophysics   3-3-0

An introduction to the properties of stellar atmospheres and interiors. The equations of stellar evolution, nuclear energy generation, radiative transport and stellar model building will be studied. Further topics include the formation of stars, and the physics associated with supernovae, white dwarfs, neutron stars, pulsars and black holes.

Prerequisite: Permission of the department

Physics 480f  Honours Research Dissertation  6-1-6

Each student is required to carry out either an experimental or theoretical project under the supervision of a faculty member. A plan outlining the proposed research must be submitted for approval during the first four weeks of the course. Each student will present his/her results in the form of a seminar and a written dissertation.

Prerequisite: U3 Honours Physics registration or permission of the department.

GRADUATE COURSES

Physics 561a  Quantum Mechanics I  3-3-0

Foundation of quantum mechanics; Schrodinger equation, angular momentum, central potentials, harmonic oscillator, hydrogen atom.

Physics 562b  Quantum Mechanics II  3-3-0

Matrix mechanics and applications of quantum mechanics to various branches of physics. Perturbation theory, scattering, molecular applications, and Hartree-Fock Theory.

Prerequisite: Physics 561a

Physics 564b  Condensed Matter Physics  3-3-0

Topics to be studied include the one-electron theory of solids, energy bands, lattice vibrations, transport theory, and thermodynamic properties.

Physics 565a  Electromagnetic Theory  3-3-0

Static and dynamic electric and magnetic fields; Maxwell’s equations and solutions involving plane waves. Covariant formulation of electromagnetic field theory.

Physics 566ab  Theoretical Topics  3-3-0

Topics to be studied will be selected from the areas of special and general relativity, particle physics, astrophysics and cosmology. In particular, the covariant nature of physics and various physical symmetries will be investigated.

Physics 567b  Statistical Mechanics  3-3-0

Derivation of the laws of thermodynamics from statistical principles. Quantum statistics, arbitrarily degenerate and relativistic perfect gases, transport theory, thermodynamic fluctuations, and low-temperature physics will also be studied.

Physics 571 Advanced Quantum Theory 3-3-0

Topics to be studied include: Path integral and second quantization approaches to non-relativistic quantum mechanics. Feynman rules and diagrams. Relativistic quantum field of spin-zero particles.

Physics 572 Particle Physics 3-3-0

Quantum field theory of spin 1/2 and spin 1 particles will be introduced. Topics include: renormalization and the renormalization group; quantum electrodynamics and quantum chromodynamics; the Standard Model of particle physics; overview of string theory.

Physics 573 Advanced General Relativity 3-3-0

Topics to be studied include: differential geometry, Einstein equations, the weak field limit, gravitational waves, black holes, and relativistic cosmology.

Physics 574 Relativistic Astrophysics 3-3-0

Topics to be studied include: Cosmology, inflation, dark energy, compact objects, relativistic fluid dynamics, gravitational lensing, and gravitational waves.

Physics 575 Numerical Methods and Simulations 3-3-0

This course will cover selected topics in High Performance Computing including cellular automata, finite element methods, molecular dynamics, Monte Carlo methods, and multigrid methods, with applications to classical fields, fluid dynamics, materials properties, nanostructures, and biomolecules.

Physics 576 Stellar Astrophysics I 3-3-0

An introduction to the properties of stellar atmospheres and interiors. The equations of stellar evolution, nuclear energy generation, radiative transport and stellar model building will be studied. Further topics include the formation of stars, and the physics associated with supernovae, white dwarfs, neutron stars, and pulsars.

Physics 577 Many-Body Quantum Theory in Condensed Matter Systems 3-3-0

The following topics will be studied: Green’s functions at zero and finite temperature; the interacting electron gas; the Hubbard model and strong correlated systems; electron-phonon interaction; superconductivity and superfluidity.

Physics 578 Selected Topics in Astronomy and Astrophysics 3-3-0

Topics to be determined in consultation with prospective students.

Physics 579 Selected Theoretical Topics 3-3-0

Topics to be determined in consultation with prospective students.

Physics 580f Graduate Seminar I 9-0-0

Students are expected to participate in the departmental seminar series and to make a presentation on either their own work or on a research-related topic. All M.Sc. students are normally expected to enrol in this course at the beginning of their first year of studies.

Offered alternate years with Physics 581.

Physics 581f Graduate Seminar II 9-0-0

Students in the second year of their degree program are expected to participate in the departmental seminar series and to make a presentation on either their own work or on a research-related topic. Offered alternate years with Physics 580.

Physics 586 Stellar Astrophysics II 3-3-0

A detailed study of the physics that determines the evolution of stars during all of their possible phases. This includes radiative hydrodynamics and atmospheric modeling, specialized equations of state, and the nuclear physics needed to understand the various channels that lead to the creation of the heavy elements. The physics of neutrino production and detection will also be investigated. These topics will form the basis for a study of the evolution of supernovae and other high-energy phenomena in stellar astrophysics.

Physics 600 Thesis Research Dissertation 15-0-0

Each student is required to carry out independent, publishable research that is presented in the form of a thesis. The research is conducted under the supervision of a faculty member. The thesis will be evaluated externally and must be successfully defended in a meeting that is open to all members of the department.