Special and General Relativity, and an Introduction to Mathematical Methods in Physics

Physics 225, Spring 2018

Lecture (50 minutes): Loomis 151, Tuesdays at 4 pm

Discussion sections (110 minutes): Thursdays at 9 am, 11 am, 1 pm, 3 pm, 5 pm in Loomis 64; Fridays at 8 am, 10 am in Loomis 147.

2 credit hours

Course policies

The rhythm of things

New material will be introduced in discussion section as you work through a series of problems in which you will derive for yourself the origins (and consequences) of Special Relativity. You will attend one discussion section per week, either on Wednesday or Friday. Please go to your assigned section: we want your TAs to get to know you, and we don't want to overload any of the sections. Your understanding of the physics will be reinforced by the Tuesday lectures, along with the weekly homework assignment, due Tuesdays at 9:00 pm.


You are required to attend each and every one of the course meetings, arriving on time with your hardcopy of the lecture notes and discussion material. Excused absences will be granted and documented in accordance with University policy as described in Article 1, Part 5 Class Attendance, of the Student Code.

You must file your documentation concerning an excused absence on the Physics Department's Excused absences portal within two weeks of your absence.

Excused absences fall into the following categories as defined by the code:

  • • illness
  • • emergency beyond the student's control (e.g. an auto accident or death in the family)
  • • required attendance at a University event (e.g. varsity athletics)
  • • serving as a volunteer emergency worker
  • • religious observance or practice: this requires you to file a "request for accommodation for religious observances form." The form must be uploaded to the Excused Absences portal no later than two weeks after the first day of class.
I will reduce your final grade by half a letter grade per unexcused absence from discussion sections. If you have an unavoidable interview for an internship, discuss it with me in advance as well as filing your documentation here.


    Weekly assignments will usually consist of four problems. In the interests of consistency, one TA will grade all problem 1 submissions, another will grade all problem 2 submissions, and so forth. Very important:
    • • We need you to submit on separate pieces of paper, not stapled together, your work for each of the problems. This way we can distribute your work to the graders.You must write your name and discussion section (e.g. D4E) on EVERY piece of paper you submit.
    • • If you need more than one sheet of paper for your, say, problem 1 solutions, staple together all of the sheets for problem 1 that you submit.
    • • Homework assignments are due Tuesday nights at 9:00 pm; please place your solutions in the yellow homework box on the second floor of Loomis.
    • • Late assignments that are submitted up to one week past the due date will receive at most 50% of full credit. We will not grade assignments that are more than one week late.
    • • You are not to use computers, sophisticated calculators, and so forth to perform the algebraic or symbolic manipulations necessary to solve assigned problems. Do them by hand. And you are not to seek out solutions to the problems that might be floating around on the web.


    If you show up to class, do a pretty good job on all of your homework, and a decent job on the exams, you will receive at least an A- for the course. If you do a really good job on your homework and write good exams you'll get an A. If you stumble onto something in some of your solutions that really blows me away, I'll give you an A+ and brag about you in the letters of recommendation I will write on your behalf.

    Calculators, smart phones, and network access to irrelevant content

    Laptops, cellphones, and smart watches are not to be in evidence in class, or during exams. You may find a calculator useful during lecture or discussion sections, but do not use this as a blind to effect covert access to your email accounts or social media sites. Period.

    You will not be allowed to use a calculator during exams.

    About using solutions you find on the web

    Perhaps the quickest way to deal with the arcana of special relativity is to ask Google for examples of what you are seeking to understand. But you will need to use your judgment in doing this: the Google search “is the speed of light always constant?” is fine, while “show me how to solve the equations for Compton scattering” is not.

    I have two principal goals in this course. I want all of you to become Relativity aces who know in your bones how to think about fast-moving objects. And I want you to develop a real flair for using multi-variable calculus as a tool for solving problems. For this to work, you’ll need to generate your problem set solutions largely on your own before discussing them with classmates.

    Academic integrity

    You must never submit the work of someone else as your own. We understand that many of you will find it helpful to work with other students to master Physics 225. But when you collaborate with your study group on homework assignments, you must be a full, active participant in developing the solutions that you submit for credit.

    It is cheating to receive answers from another student and then use them as your own. It is cheating to submit as your own work solutions that you find by searching on the worldwide web (though see "About using solutions you find on the web"), or by engaging with an online service that suborns cheating. It is cheating—and a violation of U.S. copyright law—to give (or sell) course material to someone else who intends to redistribute and/or sell it. In my experience the web sites that illegally redistribute copyrighted material and sell solutions to assigned work are cooperative when I ask them to identify the customer who has uploaded Illinois course content. These scurrilous organizations will rat you out.

    Cheating will be penalized harshly: I will award zero credit for any assignment in which a student is found to have cheated. I will also probably reduce your course grade by two letter grades (so that an A becomes a C), though I reserve the right to issue an F for the entire course to any student who is found to have cheated. In previous semesters there have always been one or two students who sold course material to a cheating site, then purchased solutions to homework problems from that site. I dragged these students through the university’s academic integrity violation process and then reduced their grades, sometimes retroactively.

    All activities in this course, including documentation submitted for petition for an excused absence, are subject to the Academic Integrity rules as described in Article 1, Part 4, Academic Integrity, of the Student Code.

    Simulating eXtreme Spacetimes [CC BY-SA 4.0 (http://creativecommons.org/licenses/by-sa/4.0)], via Wikimedia Commons

    Unless otherwise noted, all material copyright George Gollin, University of Illinois, 2018.