Physics 235, “Modern Physics I” Fall 1996

Physics 235, “Modern Physics I” Spring 2006

Instructor: Wayne F. Reed

Stern Hall 5068, 862-3185

Class room Tilton 305,

Class hours Tues. and Thurs. 2:00-3:15 p.m.

office hours: Tu, 3:30-4:30pm, W 3-4pm and by appointment

Text: Modern Physics by Serway, Moses and Moyer, 3^ndEd.

The focus of this semester is the introduction of the major theories of modern physics; Special Relativity and Quantum Physics. The formulation of Special Relativity by Einstein is quite unrelated to Quantum Physics. With two simple postulates Einstein attacked and modified the traditional ways of defining and measuring space and time. The consequences are quite surprising and often seem to defy common sense. So much experimental evidence has been accumulated which supports the theory, however, that few scientists doubt its validity. Only one chapter of the text is devoted to this topic, so that we will quickly move on to Quantum Physics for the rest of the course.

Whereas Special Relativity was essentially the work of a sole person, Einstein, the clarification and formulation of modern Quantum Physics was the work of many people spread out over several generations. Key experimental observations included the discovery of x-rays, radioactivity, the photo-electric effect, the diffraction of electrons, the positron, and the neutron, and the measurement of the electromagnetic emission spectrum of heated bodies. Only after the major postulates on the quantization of energy and the so-called ‘wave/particle duality’ of physical entities were made and corroborated for isolated phenomena could the baffling array of exotic experimental phenomena finally be puzzled out. The mathematical formulation was likewise a slow and difficult trail to blaze. Although there are still unresolved paradoxes and plenty of healthy skepticism concerning Quantum Physics, its success at describing astrophysical, molecular, atomic, nuclear and elementary particle phenomena has established it as a useful and powerful theory.

This semester we will work through chapters 1 to 9. The text will be followed closely, although some sections will be skipped.

The objectives of the course are:

1) To familiarize you with the historic chain of events and experimental and conceptual breakthroughs in the nineteenth and twentieth centuries which laid the foundations of Modern Physics.

2) To build up familiarity with relativistic concepts of space-time, and to apply these to a variety of phenomena and applications.

3) To build up the mathematical foundations of quantum mechanics, stressing the formulation of the particle-wave picture and the Schrödinger wave equation. This latter will be solved in a variety of simple situations, before we proceed to the properties of the hydrogen atom. Emphasis then turns to multi-electron atoms, indistinguishability of particles, and the structure of the periodic table of elements. Along the way you will be asked to master the key concepts of uncertainty relations, Fourier integral representations, expectation values and their relation to probability theory, eigenfunctions, symmetry/anti-symmetry properties, separation of variables, differential operator representations, and others.

4) At all times, we will make constant references to other areas of Physics, especially Classical Mechanics, Electromagnetism, Optics, and Thermodynamics. We will contrast classical notions from these areas, build off of some of them for conceptual clarity, and study the profound modifications that occur when they are treated quantum mechanically.

5) At the end of this course you will be prepared for a serious introduction to the main sub-disciplines of Modern Physics: Atoms and Molecules, Condensed Matter, Nuclear Physics, Particle Physics, Astrophysics and Cosmology.

As far as grades; there will be 3 semester tests, each worth 25%, and a cumulative final worth 25%. Homework problems will be assigned for each chapter, but not graded. We will devote some time after each chapter to go over some of the problems. Solutions are posted on my web site, accessible from the Tulane University home page. Test material will be similar to the homework problems.

The exact dates of the semester exams will be announced as the semester proceeds. Make-up exams will be given only if signed notes indicating a valid medical excuse for absence are obtained both from a doctor and from the Office of the Academic Dean. Conflicts due to travel, e.g. at vacation times, are not legitimate excuses for missing exams. Make-up exams will not be curved and will not necessarily follow the same format as the exam missed. No grades will be dropped.

The final exam is scheduled definitively for Saturday April 29, 2006, 11:30am-2:30pm. No changes to this can be made, and students cannot individually ask for separate testing times.

Please seek me out during office hours, or by appointment, whenever you need help or would like to discuss course material.

Problem Assignments for PH235, Modern Physics I

Note: An ugly practice perpetrated by most, if not all college textbook publishers is the unending issuing of 'updated editions'. Updated Physics editions rarely contain changes of any value, despite the Publisher's most earnest pleas to the contrary. Rather, the purpose of these constant new editions is to prevent a substantial used book market from forming, which would allow students to save money but would cut into publishers' profits. The changes in new editions usually consist in renumbering chapters and problems so that old assignments by pages, chapters, and problems can no longer be used, forcing students and instructors to purchase the most current edition. The 3^rd Edition by Serway/Moses/Moyer is no exception to this trend. The handworked problem solutions that this site links to were numbered by chapter and problem from the 3rd edition. The assignment below gives the chapters and problems in the 3rd edition, and, in parentheses the correspondence to the chapter and problem numbers of the 2^nd edition so that you can use the posted, handwritten solutions. An 'x' means there is no problem in the 3^rd edition that corresponds to the 2^nd edition.