Physics 34 (Waves, Optics and Thermal Physics) Home Page, Spring 2001

Physics 34: Waves, Optics and Thermal Physics


5/18/01: Finals are now graded. Have a great summer! See you in the fall...

4/20/01: The homework that was originally to be due at 6 pm on Monday 4/23/01 has been extended to 6 pm on Wednesday 4/25/01.

4/4/01: A new problem set was distributed today. Extra copies are available in the envelope outside my office.

4/2/01: (1) The exam will be held on Wednesday as originally scheduled. (2) Two handouts were distributed: one describing Wednesday's lab, the other containing a problem describing the Galileo telescope. You don't need to work the problem, I just distributed it for its description of the telescope.

3/30/01: There's a homework due on Monday that was distributed in class yesterday and is now in the envelope outside my office. Also, in class today I distributed a paper given to me by Professor Hilborn, Improved eddy current driver-detector for elastic vibrations American Journal of Physics 69 (4), April 2001) that he suggested as a technical report written in the style that he wants to see in the latest lab report.

3/26/01: (1) The handout for the Wednesday lab on mirrors was distributed in class today. I'll put extra copies beside my office. (2) Homeworks will now be due at 6pm rather than at 5 pm (that includes the homework due this Wednesday). (3) I've requested that some of the supplemental books I mentioned in class be put on reserve in the library. (4) It's been proposed that the exam scheduled for April 11 be moved to Tuesday, April 10. Please check your schedules and we can decide on this proposal on class on Wednesday. If you won't be on class on Wednesday, please let me know in advance if this change will be problematic.

3/25/01: Reminder: The second hour exam is scheduled for Wednesday, April 11. If there's some reason we should consider moving it to another day that week, you should let me know as soon as possible.

3/25/01: Anne will run the problem session this week on Tuesday night in Merrill Rm. 204.

3/12/01: The problem set due after spring break will be due on Wednesday rather than on Monday.

2/27/01: Wednesday, Professor Hilborn will speak on op-amps and I'll answer thermal physics questions for 10 minutes at the beginning. I'll also schedule extra office hours Wednesday 11-12 and 1-2 (and I can be there 12-1 if you make an appointment with me). I'll also hold an informal question session tonight 7-8:30 in my office.

2/26/01: I've set up a questionnaire for this class on CourseInfo. If you log onto the CourseInfo site, it should be listed under Announcements with a link to the survey. It's set up for you to submit responses anonymously, and of course consequently it's optional. Nonetheless, if you have opinions/suggestions about the class you'd like me to hear, please take a moment and fill it out. I might or might not not follow your suggestions, but I'm grateful to have them. This is probably the only time in your Amherst career that you'll be taking a physics class from a Amherst professor who hasn't taught that class before, so don't miss your chance to weigh in. [I'd also in particular like your opinion of the text by Moore that we've used for this first part of the course.]

2/26/01: To recap a few points made in class: (1) The exam will be on Wednesday night, 7 pm. I'll design it as a one-hour exam, but I'll give you three hours in which to do it. I'll try to reserve Merrill 220. (2) In class I handed out a draft of the formula sheet I'll give you on the exam. I may add formulae to the sheet between now and then. Don't bring that sheet to the exam, I'll give you a fresh copy there. (3) If you find, during the exam, that you need a formula that's not on the sheet, come ask me. Even if you think you might not be entitled to the formula, come ask. I might not give you the formula, but I don't mind if you ask. (4) For the exam, everything in the book by Moore and all the labs done to date are fair game. I will not ask about the latest stuff, on random walks.

2/23/01: I've added the additional problem to problem set #4. The additional problem is listed below.

2/21/01: Problem set #4, due Monday, is posted below. I may add an additional problem on Friday depending on how far we get.

2/21/01: The date of the final has been posted: Thursday May 17, 2-5 pm, Merrill 131. Also, I've posted the weights that the various parts of the course will hold in determining your course grade.

2/15/01: Problem set #3, due Monday, was distributed in class today.

2/9/01: Reminder: Turn in your lab reports to the mailbox outside Prof. Hilborn's office (Merrill 118) before 9 am on Monday, Feb. 12.

In class I distributed several handouts: Reminder, Complex Numbers and AC Circuits, Input and Output Impedance and Thevenin's Theorem, Operational Amplifiers (Diefenderfer), Feedback Operational Amplifiers (Horowitz & Hill) (in two parts). Read the notes on Complex Numbers and AC Circuits and the notes on Op Amps (from the text by Diefenderfer) before coming to class on Thursday, February 15.

2/6/01: I just noticed that the paper and link I had listed for next week's homework was the wrong paper! I've put the correct paper and link on the homework list. Sorry for any inconvenience. If you're having trouble printing out a copy, please let me know and I'll print out a copy for you.

Some of you have had trouble downloading the statmech program. Jessica Willard pointed out a fix, which I've added to the bottom of the page. Let me know if you have problems.

I should point out that problem T4A.2 on next week's homework is optional, in case you feel the need for additional challenge. I'll give you extra credit if you do it and get it right.

2/5/01: Chap. T5 in Six Ideas draws heavily on the Statmech program. I've added a link at the bottom of this page so that you can download an executable version of the program that runs on Windows 95 or 98. I tried it on one of the machines in the computer lab (I downloaded with Internet Explorer) and it ran fine. Please play with the program before class on Wednesday.

I've added the homework that will be due next Monday to the list. It's a bit longer and more difficult than the last, so start it early. In addition, I think it's a good idea that you learn to read scientific papers early on in your career. Pursuant to that, I've added an American Journal of Physics paper that you should read which I hope will complement what we're doing in class. The paper has a problem embedded in it that you should answer. Next week I'll probably ask you another problem from that paper. The link to the HTML version is in the homework table below, and at the top of the HTML version of the paper is a link you can use to download a PDF version. If you want a paper copy of the article and you have trouble printing it out, let me know and I'll print one out for you.

1/31/01: We were unable to find a better time for the fourth hour than Thursday, 9-10 am, so we'll keep it there. The full homework assignment is now listed on the table below (9 problems total).

1/29/01: The first part of hmwk 1 has been added to the table, and some additions/updates have been made to the text.

1/27/01: On Monday I'll hand out the lab manual in class. You should read the writeup for lab #1 before coming to lab on Wednesday. Also, please bring for the first lab a bound lab notebook (any type: spiral, etc.) that can be used solely for Physics 34 (we will want to collect your lab notebooks at some point during the semester). The lab will meet in Room 217.


Course Information

Course Description:

The first part of the course deals with simple thermal phenomena and an introduction to statistical mechanics and thermodynamics. In the latter part of the course the general characteristics of wave motion will be approached through the wave equation and the solution to the boundary value problem. Subsequent discussion cover geometrical optics, energy relationships in waves, diffraction, interference, reflection, refraction and polarization. The associated laboratory/recitation sections will be used for thermodynamics and optical experiments as well as further discussion of lecture material.


Times and places:


Math 13 and Physics 33 or the equivalent, or instructors' permission.

Course requirements

Statement of Intellectual Responsibility:



Required (should be available at the Jeffrey Amherst bookstore): I've asked the library to order copies of these books. They'll be placed on reserve when they arrive.

Additional useful references (if the library doesn't have them, I'll try to get them):

On thermodynamics and statistical mechanics: General texts on waves and optics: Specialty books:

Other Comments:

Class preparation: I strongly recommend that you try to read the relevant sections of the text before the corresponding lecture and that you try and exercises embedded in that text. I will cover similar material in lecture, but I won't feel obliged to be comprehensive, and I may focus only on a few points that I feel are particularly interesting or subtle. You shouldn't expect to understand what's going on without close study of the readings. Further, after we settle into the semester a bit, I expect the classes will become less lecture-oriented and more participatory, and it will be difficult to reap the maximum benefit from that format if you're not sufficiently prepared to fully participate.

Lecture/Lab Schedule
Week Notes Hmwk Lab
1. January 29 Thermal Physics
Jan 29: Administrative stuff / Intro / Reversible and Irreversible Processes (T1)
Jan 31: Temperature (T1)
Feb 1: Ideal Gases (T2)
Feb 2: Ideal Gases (T2) / Gas Processes (T3)
From Moore: T1S.6, T1S.7, T1S.9, T2S.1, T2S.6, T2A.1, T3S.4, T3S.7, T3R.2 Lab 1: Ideal Gas Thermometry EI
2. February 5 Thermal Physics
Feb 5: Macrostates and Microstates (T4)
Feb 7: More on Counting states (T4), Entropy (T5)
Feb 8: Entropy (T5)
Feb 9: Second Law (T6)
From Moore: T4S.6, T4R.1, T4A.2 (optional challenge problem), T5S.8, T5R.1, T5R.2, T6S.4, T6R.1, T6R.2, T6A.1, Read the paper and work Problem 3 from The art of statistical mechanics: Looking at microscopic spectra and seeing macroscopic phenomena (American Journal of Physics, Vol. 67, No. 12, pp. 1123) Lab 2: Latent heat of liquid nitrogen Formal
3. February 12 Thermal Physics
Feb 12: Boltzmann factor and related issues
Feb 14: Boltzmann factor and related issues
Feb 15: Circuits, Complex Numbers, Op Amps (Hilborn)
Feb 16: Calculating entropy changes
T6A.2, T7S.10,T7S.11, T7R.2, T7A.1, three extra problems distributed in class Lab 3: Measurement of Cp/Cv EI
4. February 19 Feb 19: Entropy changes/Heat engines (T8)
Feb 21: More on Op Amps (Hilborn)
Feb 22: Carnot cycle (T9)
Feb 23: Heat engines and a little on random walks
T8S.18, T8S.19, T8R.2, T8A.1, T9R.1, T9A.1, BONUS problem: demonstrate, by analyzing each stage of the four-stage cycle (as we did in class for the carnot cycle) that the efficiency of the stirling cycle engine is the same as that of the carnot cycle engine. Lab 4: Operational amplifiers EI
5. February 26 Feb 26: More on random walks
Feb 28: More on op amps (Hilborn)
Feb 28: Exam #1, 7 pm
Mar 1: Wrap up op amps (Hilborn)
Mar 2: Start optics--reflection, refraction, Snell's law
no homework Operational amplifiers EI
6. March 5 Mar 5: total internal reflection, chromatic dispersion, start Fermat's principle
Mar 7: Fermat's principle, real and virtual images, flat mirrors
Mar 8: Mirrors
Mar 9: Spherical Mirrors
HRW Chap 34: 49,51,56,57; Chap 35: 3,8,11 Operational amplifiers EI
7. March 12 Mar 12: finish spherical mirrors, start refracting surfaces
Mar 14: refracting surfaces; Guest lecturer: Andrew Foss
Mar 15: thin lenses; Guest lecturer: Lindsay Clarke
Mar 16: optical instruments and some more lens stuff
HRW Chap 35: 13,15,20,26,29,31,34,35,37 Lab 5: Operational amplifiers Formal
March 17-25 Spring Break! nada woo-hoo!
8. March 26 Transverse waves on a string
Mar 26: Preview of the rest of the course. Overview on waves. Transverse waves on a string: derivation of the wave equation in the small slopes approximation. A solution of the wave equation.
Mar 28: A solution the wave equation and its qualitative features.
Mar 29: General solution to the wave equation. Kinematics of waves. Start on sinusoidal waves.
Mar 30: Characteristics of sinusoidal waves. Small slope approximation for sinusoidal waves. How to obtain the + and - waves from initial conditions.
HR Chap 17, #22,23,30,31, and two extra problems distributed in class. Lab 6: Mirrors EI
9. April 2 Superposition and Fourier analysis
Apr 2: Superposition of two out-of-phase waves (and discussion of phasors). Standing waves. Statement of Fourier's theorem.
Apr 4: How to calculate the coefficients in the Fourier expansion.
Apr 5: Vector space interpretation of Fourier series. Example: Square wave. Some general features of Fourier coefficients.
Apr 6: General features of Fourier coefficients. Power spectrum. Example: Periodic pulse.
Problem set distributed in class. (Problems 3,4, and 5, which use the Fourier transform, are rolled over to next week.) Lab 7: Lenses EI
10. April 9 Fourier transforms / Plane acoustic waves
Apr 9: Brief review of power spectrum. Introduction to Fourier transforms. Example: Fourier transform of a finite wavetrain.
Apr 11: Pre-exam questions. Finish up Fourier transform of finite wavetrain, including calculation of spectral width. Qualitative aspects of plane acoustic waves.
Apr 11: Exam #1, 7 pm
Apr 12: Characterize an ideal fluid. Derive the wave equation for plane acoustic waves: conservation of mass.
Apr 13:Derive the wave equation for plane acoustic waves: Newton's 2nd law and equation of state
Three problems carried over from last week (Towne, 15-31, 15-32 and Arfken, 3rd ed., 15.3.5). In addition, HRW 18.10, 18.11. Lab 7: Fourier Synthesis/Speed of waves EI
11. April 16 Plane Acoustic Waves/Boundary Value Problems
Apr 16: Wave equation for plane acoustic waves. Speed of sound and equation of state. Bulk modulus and compressibility.
Apr 18: Bulk modulus. Simplified form of three equations for acoustic waves. Wave impedance.
Apr 19: Wave impedance for waves on a string. Boundary value problems: waves on a semi-infinite string reflected from a wall.
Apr 20: Boundary value problems for acoustic waves: hard reflections, pistons, and a start on the transmission-reflection problem. (Crawford, 5)
Towne 2-17, 2-28, 3-3, 3-5, 3-6, 3-9, 3-10 (deadline extended to Wednesday) Finish speed of waves Formal
12. April 23 Transmission-Reflection/Energetics of Waves/Interference
Apr 23: Transmission and reflection of 1D waves (Towne, 3.1-3.6; French, p. 253-264)
Apr 25: Energetics of waves: kinetic and potential energy, power (Towne 4.1,4.10; HRW 17.7; French, p. 237-343); start interference (HRW 36)
Apr 26: Interference in general; interference from two coherent source (dipole interference) (HRW 36; Towne 4.7-4.8, 11.1,11.4,11.6-11.7; Feynman II 29; French, p. 280-283; Crawford, 9)
Apr 27: Two-source interference (Feynman II 29.5, 30.1; French, p. 280-288; Crawford, 9)
Extra problem on power spectrum (handed out); HRW Chap 36, #18, 29, 43, 60; Towne, Chap 11, #6, 11 Lab 9: Measuring light wavelengths with a ruler Formal
13. April 30 N-source interference and diffraction
Apr 30: Two-source and partway through N-source interference
May 2: N-source interference
May 3: Diffraction (Towne, Chap. 12; HRW Chap. 37; Feynman II, Chap. 30)
May 4: Finish Diffraction: single (long) slit diffraction, diffraction from a rectangular slit
HRW Chap. 37, #12, 18, 24, 25, 30, 38, 64 Lab 10: Two-source interference EI
14. May 7 Electromagnetic waves and polarized light
May 7: Begin electromagnetic waves: recall Maxwell's equations in differential and integral forms; application to a pulse: derive relation between the speed of light and the parameters in Maxwell's equation
May 9: Course evaluations, general derivation of wave equation, brief introduction to polarization
May 10: Quantitative introduction and formal description of polarization; Jones vectors; demonstrations using polarized light (Hilborn)
May 11: Jones vectors and matrices in polarization, retarders, birefringence, lots of demos (Hilborn)
No problem set on EM waves. I'll come up with some practice problems and solutions. Finish interference EI
May 14-18 Final exam period Final: Thursday May 17, 2-5 pm, Merrill 131


I'll keep scheduling information on this site primarily. I'm not yet used to Courseinfo, but as I get used to it I may post more stuff on there.

Useful Links

I'll post interesting or useful links pertinent to the course here as they I come across them. If you come across any others, please let me know.

Other Interesting talks in the Five-College area:

Area Seminars and colloquia

Interesting and useful papers:

Interesting and useful websites: