Assignments in More Detail
Purpose of Assignments (In Order of Importance)
They are an extension of instruction: they represent applications of principles covered in class to astrophysical systems.
They venture into areas related to this course but not covered explicitly in the lectures.
They offer practice in solving problems. As such they constitute preparation for exams.
They earn one credit towards the final grade for the course.
General Rules and Regulations
To receive credit for an assignment, it must be turned in on time. There are no extensions to the deadline for problem sets, since solutions are distributed at the deadline, nor can problem sets be made up. Similarly, short papers must be turned in on time so that they can be graded in a timely manner and presentations must be given asccording to a predetermined schedule.
While working on problem sets you can exchange ideas with your classmates (brainstorm/strategize). However, you should figure out the details and write out the solutions on your own. See also the section of the syllabus on assessed work.
In some assignments (e.g., papers, presentations) you will be asked to work with a team. For those assignments turn in only one set of answers per team (team members will get the same score; see more details below).
Assignments and Submission of Responses
Assignments will be distributed electronically through Canvas. The due date will be announced with the assignment. The written responses have to be submitted on time to earn one credit. Typically, you will have a week for the problem sets and one to two weeks for the short papers. Some of the papers may need substantial background reading so they will be assigned early in the semester and will be due late in the semester.
The written responses to all assignments should be submitted through Canvas as single, self-contained PDF files (one file per assignment). It is the responsibility of the students to make sure that the files they upload are readable and can be manipulated by Canvas without problems.
Presentations will be assigned early in the semester after negotiation with student teams. These will require substantial preparation and they will be presented in class after the Thanksgiving break.
How to Approach Problem Sets and Present Their Solutions
To get full credit for your solutions to problem sets, you must follow the instructions below.
Always solve problems algebraically (without inserting numbers) to the maximum extent possible. Derive final formulae and insert numbers only at the very end. There are many good reasons for this:
It is very instructive and it allows you you to see how different physical effects come into play in the problem (this is a major goal of this course).
It reduces number crunching (which is more prone to error and more difficult to check).
It is easier to grade and increases the probability of earning partial credit, if you do not solve the problem correctly.
Carry the units around in all your numerical calculations. They provide a sanity check and can help you spot mistakes. And do not forget to attach units on your final answers.
Always present the solutions to integrals and differential equations that you encounter. If you do not know how to solve them, you can look up the solution and reproduce it; do not just quote an answer. The only exception are integrals that are discussed and solved in class and/or whose analytic solutions are known to be long and tedious or known not to exist .
Your solutions should be complete, clear, well organized, and neat:
Write neatly and spread out the text and equations.
Write text to explain your logic and the steps of the calculation.
Show all the details of your work. Do not skip any steps.
You are likely to loose points if your solutions are difficult to understand, if they are missing essential elements or steps, or if you do not express the answers in the appropriate form, format, or convention. Therefore, it always pays to read the problem carefully and follow the instructions therein.
Use proper, conventional scientific notation.
The answers for each problem set should be submitted as a single, self-contained PDF file; they can be written by hand and then scanned or photographed (e.g., using Microsoft Lens or Adobe Scan), or they can be written on a tablet and exported to PDF, or they can be typed (or they can be produced by some other method that creates a PDF file). A PDF resolution of 200–300 dpi (dots per inch) is preferred because it results in readable text and files that are not too big to be unwieldy.
Short Papers
All the principles described above in the context of problem sets also apply to papers and other assignments.
Papers should be typed in LaTeX in 11-point Roman font, in single-column layout, and with 1-inch margins in all directions. This applies to all parts of the text, including figure captions, tables, and table captions. A style file will be provided. Do not use the layout of journal papers (i..e, avoid the small font sizes and 2-column layout). All figures, tables, and references should be included at the end of the text, not embedded within it.
Paper assignments will come with instructions, including the topic and scope of the paper, the page quota, and the deadline. Make sure that you follow these instructions.
Pay attention to the clarity of the presentation and use correct grammar and syntax. Aim to write text that slows smoothly and conveys the ideas effectively and concisely. Since all team members will contribute to the content of the paper, case must be taken so that the transitions between sections or contributions by different team members are smooth.
Presentations
Presentation topics will be assigned early on in the semester so that teams will have time to prepare. Each time will write a paper on the topic of their presentation and turn it in before the Thanksgiving break. That paper will also be distributed to the class so that they can familiarize themselves with the topic and be ready to ask questions. The paper will be graded wll before the presentaiton so that the presenting teams can receive feedback that they can incorporate in the presentation.
General Advice
Start working on assignments early! Some of the problems require a lot of thought and/or consultation with the instructor (by design). Be ready to come to office hours with your questions. If you wait until the day before the assignment is due you will not have enough time to do a good job and you will not have enough time to ask for help.
Study the lecture material carefully before attempting the problems. Attempting the problems "cold" is inefficient and defeats the purpose of the problem sets.
Read questions carefully and understand what you are asked to do. Then, answer the questions completely (do not leave parts out).
Think critically about the answers you get at every step and ask yourselves if they make sense. This is a very important part of the exercise because (a) it helps you catch mistakes that are sometimes subtle and (b) it forces you to take a step back and look at the solution critically and test your general understanding of what is going on.
When carrying out numerical calculations keep at least 4 significant figures until you get a final answer. This improves the accuracy of your calculation and protects you from round-off errors and other numerical traps. You can truncate the number at the end, if you think you do not need to report that many significant figures.
When you get the official solutions for the problem sets, study them carefully even if you got the answer right. They may show you a different way of approaching the problem that what you came up with and they may add to your understanding of the physical system that is the topic of the problem.