Course Syllabus


A survey of atomic and nuclear phenomena, relativity and the main trends in modern physics. Appropriate for students in engineering and other physical sciences:

Phys 420 picks up where intro mechanics and electrodynamics end and provides a window into the excitement of early 20th century physics with a goal of elucidating how some of the fascinating conceptual developments in modern physics have revolutionized technology.


Some of the topics covered are (suggestions welcome):

  • Relativity, Lorentz transformations, space-time
  • Relativistic energy and momentum 
  • Quantum theory of light, blackbody radiation, Compton scattering, photoelectric effect...
  • Wave particle duality and a review of wave phenomena
  • Schrodinger wave equation (i.e. intro to quantum mechanics)
  • Quantum mechanics in one dimension, the particle in a box and oscillators (i.e. quantum wells)
  • Reflection and transmission problems (i.e. nuclear decay)
  • Hydrogen atom ( i.e. atomic spectra etc)
  •  Atomic structure (i.e. the periodic table of elements)
  • Quantum statistics - Fermions and Bosons

Relevant to these topics, after successfully completing students will be able to:

  • Analyze relativistic corrections to distances and time intervals relevant to satellite communications, as well as masses of reaction products from nuclear and subatomic reactions.
  • Apply concepts related to the wave-nature of particles to various kinds of microscopy such as electron and scanning tunneling microscopy as well as material characterization such as electron diffraction.
  • Contrast the various characters of the electromagnetic spectra emitted by stars, atoms, molecules, metals and evaluate the nature (i.e. size, constitution etc) of the source based on these.
  • Apply the principles of quantum mechanics to predict the chemical properties of various atoms



Required Resources

Course website:

Text book: Modern Physics, Serway, Moses and Moyer, 3rd edition, Thomson, Brooks and Cole 2005


Dr. Jay D. Sau


Class Meets

Mondays & Wednesdays

3:30pm – 4:45pm

PHY/Toll #0405


Office Hours

PHY/Toll #2308

Fri   3:00-4:00pm

and by appointment



Wang, Yihang



mechanics, electrodynamics, waves, differential equation (MATH246. And PHYS271 and PHYS270; or PHYS273)


Course Communication

All updates and information regarding the course will be made using the announcements on ELMS – please make sure your ELMS settings do not delay announcements. I may or may not repeat in class.

Please send any questions or notifications of absences that you need to inform me preferably by email (see above).  



Campus Policies

It is our shared responsibility to know and abide by the University of Maryland’s policies that relate to all courses, which include topics like:

  • Academic integrity
  • Student and instructor conduct
  • Accessibility and accommodations
  • Attendance and excused absences
  • Grades and appeals
  • Copyright and intellectual property

Please visit for the Office of Undergraduate Studies’ full list of campus-wide policies and follow up with me if you have questions.


Activities, Learning Assessments, & Expectations for Students

Lectures: Class time will be occupied by lectures that follow a set of PowerPoint slides that you can download from the lecture slides folder on the course page. The lectures will explain the description of phenomena with the aid of three kinds of demonstrations

  • Mathematical: derivations of equations elaborated on the board will be used to quantify characteristics of predictions of a concept
  • Numerical: computer simulations of some phenomenon embedded in the Power point
  • Physical: real life experimental demonstrations will provide the most convincing validation of the utility of some of the concepts

Participation: The lectures assume that you are keeping track of the material of the previous lecture. This will enhance your learning and participation in the class, which is crucial to the classes success. To ensure a minimal level of participation, I will keep track of your participation through questions you ask or answer. You get full credit for participation if you ask or answer 6 questions in the semester related to the material presented in the lectures.

Homework : Problem sets will be posted as assignments on ELMS. The problems can also be downloaded from the assignments folder. Homework submission should be preferably by paper in class or at instructor office. Email submission to TA is allowed but should not be hand written. Homework will be assigned roughly once a week, and is to be turned in at the beginning of class on the due date. Homework will typically be posted on Friday and due the Wednesday two weeks later (i.e. about 10 days). 20% will be marked off on homework turned in after the end of class. Homeworks turned in after the solutions are posted will not be graded. If you cannot attend class, please get your homework to me before class starts.  New assignments will be posted on the course website, along with the homework solutions. Homework problems are carefully chosen to highlight some of the important topics covered in lecture, as well as important applications of the material. It is important that you carefully complete and make sure you understand all of the homework. You are encouraged to work with others on homework, however, it is forbidden to blindly copy another person’s work. There are 9 homework sets and one will be dropped. Each homework will be worth two percentage points towards the final grade.

Exams Three in-class exams midterm 1 ( October ), midterm 2 ( November ) and final exam. Both exams and solutions will be posted in the exam folder after the exams. 

Exams are meant to test your understanding and ability to apply concepts covered in the course. I therefore do not expect you to memorize constants and equations. I will provide you with a sheet of relevant equations that will be posted in the exam a week before the exam. I will give you the value of any constants you need. Although the main focus of the exams will be problem solving, all exams will likely contain one conceptual question with a written part to verify that you understand and can explain the physical concepts. Exam and homework problems will be from the textbook.

Course-Specific Policies

No computers, phones or tablet devices are permitted during our class meetings.  I understand and have considered arguments for permitting laptop and tablet computers in the classroom.  However, in my experience (and based on the research evidence) the reality is that they present an irresistible distraction and detract from the cooperative learning environment.  Researchers have found that these distractions do in fact interfere with learning and active participation.  For that reason, the use of computers and phones will not be permitted during class meetings (except when required for DSS accommodations).  If a computer is needed to accomplish a class objective for the day I will provide it or give you advanced notice to bring one with you.

I expect you to make the responsible and respectful decision to refrain from using your cellphone in class.  If you have critical communication to attend to, please excuse yourself and return when you are ready.  For more information about the science behind the policy watch:

Please give me as much advanced notice as possible if you are unable to make it to any of the exams. This is crucial since exams are worth most of the credit. We will try to work out some solution such as either shift the exam (possible other than final) or arrange a makeup with some equivalent (but not necessarily identical) exam.

Get Some Help!

You are expected to take personal responsibility for you own learning. This includes acknowledging when your performance does not match your goals and doing something about it. Everyone can benefit from some expert guidance on time management, note taking, and exam preparation, so I encourage you to consider visiting and schedule an appointment with an academic coach. Sharpen your communication skills (and improve your grade) by visiting and schedule an appointment with the campus Writing Center. Finally, if you just need someone to talk to, visit

Everything is free because you have already paid for it, and everyone needs help… all you have to do is ask for it.



Grades are not given, but earned.  Your grade is determined by your performance on exams, homeworks and participation in the course and is assigned based on your score according to a curve. Typically I follow a curve scheme where the median score would be graded at B-. The lowest grade would be C- (very few). The top grades will be A+ and As. The number in each category would be roughly equal depends on appropriate breaks in the score distribution. 

Of course, all this being said this rule is subject to change depending on the performance of the class. If some students do extremely poorly (e.g. score well below 40%) I might consider going below C- for the lowest grade.  On the other hand, if everyone does well (i.e. above 90%) I have no hesitation giving the entire class an A. Also, if someone scores above 80 that is a B or better independent of whether the average is above 80.

If earning a particular grade is important to you, please speak with me at the beginning of the semester so that I can offer some helpful suggestions for achieving your goal.

All assessment scores will be posted on the course ELMS page.  If you would like to review any of your grades (including the exams), or have questions about how something was scored, please email me to schedule a time for us to meet in my office.

Late work (as explained in the instruction) will not be accepted for course credit so please plan to have it submitted well before the scheduled deadline.  I am happy to discuss any of your grades with you, and if I have made a mistake I will immediately correct it.  Any formal grade disputes must be submitted in writing and within one week of receiving the grade.

Learning Assessments


Category Weight

Participation points



Midterm 1



Midterm 2






Homework (out of 9 assignments)




Course Schedule


Week 1

Monday, August 28

  • Overview of modern physics
  • Galilean relativity (Sec. 1.2)

Wednesday, August 30

  • Michelson-Morley experiment (Sec 1.3)
  • Postulates of special relativity (Sec. 1.4)
  • Relativity of simultaneity (Sec. 1.5)

Week 2

Monday, September 4

Labor Day

Wednesday,  September 6

  • Time-dilation (Sec. 1.5)
  •  Length-contraction (Sec.1.5)

Week 3

Monday, September 11

  • Relativistic Doppler effect – Hubble law (Sec. 1.5)
  • Derivation of the Lorentz Transformation (Sec. 1.6)
  • Relativistic velocity addition formula (Sec. 1.6)
  • Space-time and invariant length in space-time (Sec. 1.7)

Wednesday,  September 13

  • Space-like, time-like separation and causality (Sec. 1.7)
  • Velocity addition formula (Sec. 1.6)

Week 4

Monday, September 18

  • Relativistic momentum (Sec. 2.1)
  • Relativistic  energy (Sec 2.2)

Wednesday,  September 20

  • Mass-energy conversion (Sec. 2.3)

Week 5

Monday, September 25

  • Conservation of energy/momentum (Sec. 2.4)
  • General Relativity (Sec. 2.5)

Wednesday,  September 27

  • Blackbody radiation/Raleigh-Jeans paradox (Sec. 3.1, 3.2)

Week 6

Monday, October 2

  • Planck’s law (Chapter 3)

Wednesday,  October 4

  • Photoelectric effect (Chapter 3)

Week 7

Monday, October 9

  • Compton scattering (Chapter 3)
  • Faraday’s law (Sec. 4.2)
  • Thompson’s experiment (Sec. 4.2)

Wednesday,  October 11

  • Millikan’s Oil drop experiment (Sec. 4.2)
  • Rutherford scattering (Sec. 4.2)

Week 8

Monday, October 16

  • Bohr’s atomic theory
  • Frank-Hertz experiment (Sec. 4.3)
  • Midterm review

Wednesday,  October 18

  • Midterm 1 (chapter 1-4)

Week 9

Monday, October 23

  • De Broglie waves and a review of wave phenomena (Chapter 5)
  • Review waves/Fourier transforms/uncertainty principle

Wednesday,  October 25

  • Wave-property of particles double slit experiment (Chapter 5)

Week 10

Monday, October 30

  • Intro to wave-functions (Chapter 6)
  • Schrodinger wave-equation (Chapter 6)

Wednesday,  November 1

  • Free particle and wave-packets (Chapter 6)

Week 11

Monday,  November 6

  • Time-independent Schrodinger equation (Chapter 6)

Wednesday,  November 8

  • Quantum mechanics in one dimension: particle in a box (Chapter 6)

Week 12

Monday,  November 13

  • Quantum mechanics in one dimension: harmonic oscillator (Chapter 6)
  • Observables and expectation values (Chapter 6)

Wednesday,  November 15

  • Tunneling in a sqaure barrier  (Chapter 7.1)

Week 13

Monday,  November 20

  • Applications of tunneling: STM and radioactivity (Chapter 7.2)

Wednesday,  November 22

Thanksgiving break

Week 14

Monday,  November 27

  • Midterm 2 (chapter 5-7)

Wednesday,  November 29


  • Three dimensional Square well, separation of variables  (Chapter 8.1,8.2)

Week 15

Monday,  December 4

  • Angular momentum (Chapter 8.3)
  • Hydrogen atom (Section 8.4-8.5)

Wednesday,  December 6

  • Radial wave-function (Chapter 8.5)
  • Zeeman field (Chapter 9)

Final Week

Monday,  December 11

  • Electron spin (Chapter 9)
  • Exclusion principle (Chapter 9)
  • Periodic table (Chapter 9)

Friday, December 15

Final exam PHY0405 from 1:30pm to 3:30pm


Note: This is a tentative schedule, and subject to change as necessary – monitor the course ELMS page for current deadlines.  In the unlikely event of a prolonged university closing, or an extended absence from the university, adjustments to the course schedule, deadlines, and assignments will be made based on the duration of the closing and the specific dates missed.

Course Summary:

Date Details Due