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Frequently Asked Questions
(About The Introductory Courses)

If you have any feedback on these questions/answers, or if you would like a new question added to this list, please contact David Morin.

Click on a question to show or hide the answer.

GENERAL QUESTIONS RELATED TO PHYSICS COURSES:



1. In deciding between two (or more) courses with different levels of difficulty, how can I be sure that I sign up for the right one?

   In most cases, you can’t. The best you can do is make an educated guess by reading the available materials (course catalog, course webpages, departmental documents, Q Guide, etc.) and by talking with your various advisors and also with students who have taken the courses. Then it comes down to shopping the possibilities. Sometimes there is simply no way to determine which course is the right one for you without checking them all out. This is all the more true because even for a given course description and syllabus, two different professors might end up teaching two highly different versions of the same course. In the event of conflicting time blocks, it’s generally best to start out by attending the higher-level course (for example, Phys 16 instead of Phys 15a) and then dropping to the lower one if the workload is too much. But beware: courses invariably start off a little slow and then pick up the pace, so don’t be fooled by an initial light workload. Keep an eye on what is required in a course if you are thinking of switching into it after a couple weeks.



2. I want to take three science courses (among Math, Physics, Chem, Bio, EngSci, CompSci, Astro, etc.) in my first semester. Is this advisable?

   The answer is a definite “maybe.” It depends on many things - your background in these areas, learning style, goals, extracurriculars, and so on. You are strongly encouraged to talk with your freshman advisor about the particulars of your schedule, and see what works best for you. But one piece of advice: In your first semester, it’s best to play it safe and not get in over your head. There will be plenty of time to get creamed in future semesters if you so desire. Courses invariably end up being more difficult than anticipated, but in the (very unlikely) event that you are completely bored because your schedule is too easy, you can simply ace all your courses and get involved in a few more of the zillion extracurriculars on your wish list. Things could be worse.



3. What are the physics requirements for my concentration?

   You should check specifically with the advisors of your concentration. But a few comments: The general rule is that even if you have AP physics credits, you still need to take the physics course(s) here at Harvard. And for the concentrations that require Phys 11a/b, it generally also suffices to take 15a/b; that is, there is no need to complete the 15 series by taking Phys 15c. But again, you should take this paragraph with a grain of salt and be sure to check with your concentration for the official rules.



4. I took a college physics course somewhere other than at Harvard. Does it count for my concentration?

   You should check specifically with the advisors of your concentration, because the rules on this vary from department to department.



5. I did very well in my high school physics course, but it was a number of years ago so I’m a bit rusty. Which course should I take?

   This is highly student dependent, so it's best if you get some one-on-one advice by stopping by to talk with Howard Georgi or David Morin (contact info at the end of this page). But in short, it depends on how well the material sunk in originally, and also how comfortable you are with reading up on topics that you discover you need to review. And comfort level with math also plays a part.



6. Which multivariable math course will help me more in my physics courses, Math 21 or something higher?

   If your goal is to obtain the math tools that will help you in physics, then Math (or Applied Math) 21 is probably the right course for you. However, if you are someone who likes math simply for math’s sake, and if you are confident that you can pick up math concepts as needed, then Math 23, 25, or 55 is probably the way to go. The tough decision arises if you like math for math’s sake, but you’re not confident that you can pick things up as needed. At any rate, shop a couple of the courses if you’re undecided, and keep the option open for switching within the first couple weeks. And be sure to discuss things with the advisors from the Math department, who offer a large number of advising opportunities during freshman week.



7. I am planning on taking math at the 21 level. Should I take the Math or Applied Math version?

   It depends on what you want out of the class. The two courses cover basically the same material, but the Math version is more proof based, while the Applied Math version has more applications. You should discuss similarites/differences with the advisors from the Math department. But in the end, just as with many questions of this type, it probably comes down to shopping both classes and seeing which one better fits you. The courses are also organized differently, so as always, shopping is important to see which style you like better.




SPECIFIC QUESTIONS ABOUT THE INTRODUCTORY PHYSICS COURSES (PHYSICAL SCIENCES 2/3, PHYSICS 11A/B, 15A/B/C, 16):



8. Which of PS2, Phys 11a, 15a, or 16 should I take?

   It depends on you background, interests, and schedule. PS2/3 is geared toward students in the life sciences. It is a physics course that contains many biological examples and applications. This page contains a comprehensive FAQ list for the PS1/2/3 courses. Phys 11a/b is geared toward engineers and chemists. Phys 15a/b/c is required for Physics, Chem/Phys, and Astro concentrators, although many students from other concentrations take this sequence too. Phys 15 involves more derivations and more problem solving than Phys 11. Phys 16 is the honors version of Phys 15a (and like 15a, it funnels into 15b). See also the "Should I take Phys 15a or Phys 16?" question below.

   Give or take, the difficulty levels of PS2/3 and 11a/b are about the same. But 15a is harder, and 16 is harder still. The main point in 15a and 16 is to learn physics and solve crazy problems simply because physics is cool. The emphasis isn't so much on applications (as it is in PS2/3 and 11a/b), although applications of course inevitably show up.



9. Which physics courses satisfy the premed requirements?

   The premed requirement is two semesters of physics, with one of the semesters including a lab component. So you can take PS2/3 or 11a/b or 15a/b, which all have labs both semesters. And you can also take 16/15b, even though 16 has no lab (or very minimal lab).



10. When do students take normally PS2/3, Phys 11a/b, 15a/b/c, and 16?

    PS2/3 is generally taken in the junior year (about 75% are juniors), because premed students need it for the MCAT. Phys 11a/b is taken anywhere from freshman to junior year (the largest group is juniors, at about 50%). Phys 15a is a foundational course for the Physics, Chem/Phys, and Astro concentrations, so these concentrators take it freshman year (freshmen make up about 55% of the class), or perhaps sophomore year for Chem/Phys. However, students in related science concentrations who opt for 15a often take it in the sophomore or sometimes the junior year. Phys 16 is generally taken freshman year, although it’s certainly open to everyone. Note that each of the 15a/b/c courses is taught in both the fall and spring semesters.



11. Can I switch from one of the PS, 11, 15, and 16 courses to another after a few weeks if the difficulty isn’t right?

    Yes, but keep close tabs on what you need to do to enter a course late. It is your responsibility to check that work can be transferred form one course to another. Keep an eye on the add/drop deadline and any possible early exam dates.



12. What benefits do I get from having taken an AP physics course in high school?

    If you have enough AP credits overall, you can declare “Advanced Standing” which makes it possible to obtain a Master’s degree through the AB/AM program or to graduate in three years. However, it turns out that very few students end up taking either of these routes, so in nearly all cases the sole benefit of a high school AP course is that it gives you the background to start with a higher-level course here at Harvard (for example, Phys 16 instead of 15a, or 15a instead of 11a).

    But one major exception to this is with the foreign-language requirement; a sufficient score on the SAT II test or on the Harvard placement test allows you to skip the otherwise required yearlong language course requirement. The full rules are here.



13. I reached a very high level of math in high school (and did very well in it), but I had only a weak physics course (or none at all). If I am interested in physics now, which physics course should I take?

    If your math level is very high, and if you are comfortable reviewing and picking up things on your own, and if you want to enthusiastically put in the extra effort, then Phys 16 might be the right course for you. Otherwise, 15a should work. At any rate, you can shop 16 and see how it goes. Of course, you may also choose PS2 or 11a, depending on your concentration.



14. What level of math is needed for PS2/3 and 11a/b?

    The prerequisite for both courses is Math 1b. In addition, for Phys 11a it is advised that students at least take Math 21a concurrently. However, this isn’t a showstopper if you are willing to read up on a few things as the course goes along. At any rate, you should check with the professor to get his/her advice in the event that you aren’t taking math 21a.



15. What level of math is needed for 15a and 16?

    The corequisite for 15a is Math 1b; this will work fine if you are very confident with the Math 1a material. But if you’re shaky with it, then you should probably finish Math 1b before taking 15a. The corequisite for 16 is Math 21a. But perhaps more importantly, a very high level of comfort with Math 1b material is needed.



16. What level of math is needed for 15b?

    The prerequisite is math 21a. So if you took Math 1b concurrently with Physics 15a, you should delay taking 15b until you have completed Math 21a. There are exceptions to this if you feel confident in your ability to read up on the 21a material on your own before you encounter the applications in 15b. But this is risky, and you should definitely talk with Howard Georgi or David Morin (contact info at the end of this page) if you are thinking of doing this.



17. Can I take PS3 before PS2, or 11b before 11a?

    Possibly, but it depends on two things: 1) How comfortable you are with your high school physics course, and also with your math skills. You will probably need to review material as the course goes along, so you should be prepared to do this. And 2) the final decision is the professor’s, so you must check with him/her.



18. Can I take both PS2 and 11a, or both PS3 and 11b?

    No. There is too much overlap in the courses.



19. Can I transition from PS2 to 11b, or 11a to PS3?

    Generally yes, but the professor of the spring course has the final say. Although PS2 and 11a cover many of the same topics, you should check to see what material you may have missed, and how relevant it is to the spring course.



20. Can I take Phys 11b after taking Phys 15a?

    Yes. A number of students take this route. This combination counts as equivalent to the 11a/11b sequence for all concentrations, as far as we know, but you should always verify such substitutions directly with your concentration, since they have the final say on what is required.



21. Phys 11a and Phys 15a seem to cover the same topics as a high school AP mechanics class. Does that mean I’ll be bored in them?

    In most cases, the answer is a definite No. Although the topics are roughly the same as in a high school course, these college courses move much more quickly and study things in much more detail. So even if you aced your AP course, it is still very likely that you will find these courses challenging. However, there are certainly students who are ready for a course beyond Phys 15a, and this is precisely why we formed Phys 16. The goal of Phys 16 is to make sure that no student is bored. We’re pretty successful at this.



22. Is it ok to postpone Phys 15a to freshman spring or later?

    Definitely yes, up to point, and it depends on the concentration you choose. From a requirements standpoint, Physics and Astro concentrators can easily start in the spring of freshman year and still have plenty of time to finish the requirements. Sophomore fall can technically also work, but this will make things a little squeezed in later years. Chem/Phys concentrators can easily start in sophomore fall. However, requirements aside in any case, if you plan on going to grad school in Physics, the more important issue is your overall set of courses. If you start late, it will be more difficult (but still doable if you plan things right) to take the necessary courses that will prepare you properly. You should talk in person with Howard Georgi or David Morin (contact info at the end of this page) about this.



23. Do I need a certain Harvard physics placement-test score or a certain AP score to get into Physics 16?

    No, but these scores may be helpful in deciding if you want to start out in the course. In any event, if you are interested in Phys 16 and feel that you have the right background, then simply show up on the first day and see how it goes. You can always switch to Phys 15a in the next few weeks. Just be sure to keep an eye on the 15a material and to complete a problem set in its entirety for one of the courses during the week that you switch.



24. Should I take Phys 15a or Phys 16?

    Phys 15a covers roughly the same topics as an advanced high school course (although special relativity might not be covered in high school), but with a more in-depth treatment and with harder problems. Phys 16 covers many new and more advanced topics. You should skim through the first problem sets and any lecture notes that are available on the web, and then see which class is more suitable for you. There is no clear-cut criterion for deciding, but a major consideration is that of time. Phys 15a will take a substantial amount of time. But Phys 16 will take more.

    If you think there is a reasonable chance (say, greater than 15%) that you will take Phys 16, then you should start out there. In the event that you wish to switch to Phys 15a, we promise to make the transition a hassle-free one. (Homework credit will be transferred. Just be sure to do either one of the homework sets in its entirety during the week that you switch.) Furthermore, if you are someone who is thinking of taking Phys 16, then the first few Phys 15a lectures will probably be mainly review, so you have little to lose by trying out Phys 16.

    Either course is sufficient for the intro mechanics requirement for the Phys, Chem/Phys, and Astro concentrations (roughly half of the Phys concentrators come from each course).The advantage of taking 16 is that you will learn about some advanced topics, such as the Lagrangian formalism and gyroscopic motion. However, Phys 151 (Advanced Classical Mechanics) goes well beyond the level of Phys 16, so if you eventually take Phys 151, then it’s all a wash.



25. Is the workload for the Math 55/Phys 16 and the Math 25/Phys 16 combinations manageable?

    The answer completely depends on your background, course schedule, extracurriculars, eagerness to put in huge amounts of time, and so on. Many students have taken these combinations in the past, and in most cases things turned out fine, but in some cases the workload was too much. In all cases it required a very focused effort. So if you’re planning on taking one of these routes, get ready to work! Don’t hesitate to drop to Phys 15a or to a lower math course after a couple weeks if things get out of hand.



26. Can I take Phys 15b before (or concurrently with) Phys 15a? And likewise for Phys 15c/15b, and for 143a/15c?

    Although we don’t advise this, there have been some compelling cases in the past, and sometimes it has been done successfully. It depends on many things (your background, math level, courseload, learning style, etc.), so you should talk in person with Howard Georgi or David Morin (contact info at the end of this page) to sort things out.

We hope that you find these FAQs helpful. But if you would like some more personal advice, don't hesitate to email us or stop by our office hours:
(Head Tutor) Howard Georgi: email, office hours
(Assistant Head Tutor) David Morin: email, office hours

 

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