# Starting a Journey into Physics: Seeking Advice!

1. Nov 21, 2014

### bacte2013

Dear Physics Forum friends,

I am an U.S. sophomore with a major in microbiology and a minor in physics (but seriously considering a major). When I was in high school and during my college freshman, I confess that I genuinely hated physics; to me, physics seemed like a worthless numerical/formula game with no clear understanding of the phenomena. HOWEVER, that thought totally changed with my current undergraduate research in the computational/biophysical microbiology that I joined since summer. I realized how fool I was thinking that physics is a worthless subject and has no applications! Physics is deeply involved in the biological science and gives very different insight and deep understanding of the mechanisms of biological phenomena that I could not find from the traditional "wet experiment" biological methodology! Physics has so many applications in biological science like the genome sequencing, microorganisms' behaviors, metabolism thermodynamics, etc! Since that enlightenment, I decided to pursue a minor in physics rather than my initial planning to do a minor in mathematics and computer science. As a first step in my journey to thrilling world of physics, I will be taking a semester of "Modern Physics: Relativistic, Atomic, Quantum Mechanics + Solid-State Physics". The Modern Physics course requires a year-long introductory physics sequence, which I did not take. I cannot take the introductory physics due to a conflict with my major biological and chemistry courses. I had a discussion with the physics adviser, and he kindly gave a permission me enroll for the Modern Physics as long as I do the extensive self-study on the introductory physics sequence during the rest of semester and especiallt the Winter Break, which I am determined to do so. I took AP Physics B during my high school ,and I do have a good computational (non proof-based) knowledge in the multi-variable calculus, differential equations, linear algebra, and fourier analysis. I am planning to start studying the Calculus Vol. II by Tom Apostol as soon as this semester is over.

How should I study for the introductory, calculus-based physics during rest of this semester and the Winter Break? Should I purchase a formal textbook like Holiday or Serway, or should I purchase the Schaum's Outlines/AP Physics C books on Mechanics & EM and study them? Or can I directly jump into the classical mechanics and EM textbooks without the introductory calculus? I am pretty confident in my mathematical ability, at least in the computational, working knowledge). I just checked my research lab's physics bookshelf, and I found the following textbooks (I organized the textbooks by physics fields):

Classical Mechanics: Taylor, Goldstein, Thornton & Marion, Kleppner & Kolenkow, Feynman Lectures 1
Electrodynamics: Griffiths, Jackson, Purcell, Feynman Lectures 2
Quantum: Griffiths, Shankar, Sakurai, Zettili, Feynman Lectures 3

My "Modern Physics" course will utilize a textbook called Modern Physics, 3rd edition by Kenneth S. Krane. After completing my modern physics course, I am going to take the mechanics and thermal physics-statistical mechanics or electrodynamics.

Thank you very much for your time, and I apologize for this very long thread! I am very excited to do a formal study in physics, which is a center of every natural science!

Sincerely,

MSK

2. Nov 21, 2014

### UVCatastrophe

3. Nov 21, 2014

### Staff: Mentor

I would get a copy of whatever textbook your university uses for the calculus-based intro physics course. Your physics classmates should be familiar with it (some of them, at any rate ) and it will be easier for them to help you out when you get stuck somewhere in it. Also, your professor in the modern physics and later courses may assume you know specific topics from that book.

4. Nov 21, 2014

### bacte2013

Hello! Thank you very much for the advice! I just talked with the modern physics professor, and he said that he would not recommend studying the textbook now since it is difficult to cover it within two months. In that case, should I purchase review books like Schaum's Outlines or AP Calculus C books on Mechanics & EM or just use one of textbooks for Classical Mechanics and EM?

5. Nov 23, 2014

### bacte2013

6. Nov 23, 2014

### Staff: Mentor

I taught an intro modern course for many years. From its title, your course looks like it might be similar to mine except that I did some nuclear physics instead of solid state physics. I would say the most important things you should review from your Physics B background and update to a higher level with calculus are things related to energy and momentum: work, kinetic energy, potential energy, work-energy theorem, conservation of energy, conservation of momentum (including in multiple dimensions using vectors), how to calculate work and potential energy using integrals instead of just F·d. From the electricity and magnetism material: electric and magnetic forces on a point charge in E and B fields; electric field produced by a point charge (Coulomb's Law) and the uniform electric field between two flat plates; magnetic field produced by a straight wire and inside a solenoid; electrical potential energy and electric potential (volts).

You should also be acquainted with waves. Be able to work with a wave equation like $y = A \cos (kx - \omega t)$ and relate k to wavelength and ω to frequency. You will probably also see waves described using complex numbers in QM, e.g. $\psi = A e^{i(kx - \omega t)}$, so you should know enough about complex numbers to be able to handle complex exponents.

[added] Oh, I forgot angular momentum at first. You'll need that for the QM treatment of the hydrogen atom. Not so much the $L = \frac{1}{2}I \omega^2$ stuff for rigid bodies, but $\vec L = \vec r \times \vec p$ for a particle. The vector nature of angular momentum is important here.

All of these books except for the Feynman Lectures are above the level you're shooting for. They're either upper-level undergraduate books or even graduate level (Goldstein and Jackson). You might be able to use parts of the Feynman Lectures in conjunction with a source of exercises to work through. Schaum's Outlines might work for exercises, although I've never used them myself so I have no direct experience with them. Just make sure you stay at the calculus-based intro physics level.

Even the Feynman Lectures have a lot more material than you need at the moment. You'll have to pick and choose chapters and topics.

Last edited: Nov 23, 2014
7. Nov 24, 2014

### UVCatastrophe

Schaum's outlines are great. Doing problems is the best way to learn physics. It's also good to have the solutions. I remember there was a Schaum's vector calculus, which started with problems on trajectories and parametrized curves and worked up to vector fields. The first physics classes you will take will be mechanics (with calculus) and electromagnetism (with vector calculus), so these skills will be highly relevant.

All the vector stuff, plus wave mechanics (which involves complex algebra) should give you a good familiarity with the math you'll be encountering. Vibrations and Waves by A. P. French is a good start. I learned this stuff from Introduction to Wave Phenomena by Hirose and Lonngren.

That's enough for the technical background. You also should learn about the history of physics, from the early days of classical physics (Kepler, Galileo, Newton, Leibniz) through the discovery of electromagnetism (Maxwell et al) and thermodynamics (Boltzmann et al). The beginnings of "modern physics" (relativity and quantum mechanics) are built on discoveries such as electromagnetic (blackbody) radiation, the electron, Rutherford scattering, etc. Without knowing at least something about what was happening in the "classical era", i.e. pre-20th century, all the modern physics will seem somewhat arbitrary. Feynman Lectures is a good place to start.

And you should also have some idea of how contemporary physics research is divided into subfields. Rather than learn this from a book you can simply talk to your professors, classmates, and TAs.