Advice and guidance to self-taught physics enthusiasts
If you are trying to get a grasp on cool new theories you have heard of, such as string theory or others involving quantum physics or cosmology, you would of course look for web and print material on those topics. However, if you are capable of grasping physics, and wish to study a deeper treatment of these topics than is provided by the popular sources on the web or in print, you will find that the treatment in textbooks about any of these topics is far beyond you. The best place to start a serious study of any of these topics is not a textbook devoted to that topic, but rather with basic fundamental physics, and Asimov’s books are exceptionally suited for this.
An analogy: you saw a documentary about cool new surgical techniques and want to work in the field. You buy a textbook teaching the techniques and sit down to read, and from the first page you realize that it assumes you have taken all the pre-med courses in college and have completed medical school with both its theoretical and hands-on training, and have already taken a two-year advanced course of surgery geared to medical-school graduates. And the same for new genetic engineering advances – the documentary inspired you, and now you want to start discovering new theories, but you will quickly discover that you need to first take 6 years of theoretical courses and lab to get to that point.
When you read a popular account of some fascinating field, you have to understand that it took great pedagogical skill and deep understanding on the part of the write to be able to present very complex and advanced material at a level comprehensible to a novice such as yourself. What you are reading is NOT the actual material as studied by those who eventually make the discoveries, it is the popular version, written specifically for those without the technical training required to make advances in those fields. As a reality check, you can look for the original research articles in the field quoted in the reference section of any good popular science book written by physics researchers (and perhaps in some books written by science writers as well). On the web you can access these articles (perhaps only from a university or public library computer which has a free online subscription). See if you truly understand everything they say. If it is a real research report you probably will not get beyond the first few sentences.
Despite the rapid advances in physics, the foundation is always required, and has not changed. Every modern physics theory considers Newtonian physics as the ‘correct’ approximate theory to be utilized for studying ordinary natural phenomena. And every treatment of an advanced theory will assume the reader’s familiarity with Newtonian physics. And so those whose interest in ‘wormholes’ ‘black holes’ ‘cosmology’ ‘string theory’ quantum physics’ and so on was stimulated by popular books on the subject should not think that they can now pick up serious books on these topics as the next step. The appropriate next step for self-studiers is a book like Asimov’s (three volume) “Understanding Physics”.
Following this, one can study from one of the many introductory physics textbooks used in standard undergraduate physics-major courses. These will all utilize calculus, and so of course one would be recommended to simultaneously study a pedagogically-recommended introduction to calculus text. After completing the material in the calculus and physics texts and solving the problems (without which one does NOT obtain true understanding of the material), it would be recommended that the student supplement this newly-gained understanding with excellent texts such as the Berkeley series, and of course should not miss out on reading through the Feynman lectures. By the time a student has completed all this (equivalent to the first year and a half of a typical undergrad physics major’s curriculum), they will have the grounding to continue on to more advanced courses, and will have become sufficiently familiar with the basics for them to be able to find appropriate textbooks. One good way is to see which books are used in undergrad courses in the best university physics departments, and to follow online student discussions about these and other texts.
After completing the undergraduate material and the graduate level courses, one is prepared to begin to read the real physics research literature. At any step in the middle, use a reading of some current research reports, or an actual talk given by researchers to their peers (not to the public or to undergrad students) as a reality check to see whether or not you are prepared to join the ranks of physics researchers.
What is required in order to obtain a PhD in theoretical physics it will be necessary to do original research. Generally your research will only begin in your third or fourth year, certainly only after having taken a year or two of graduate-level course work (or more than two years in some advanced fields). In most physics department, after taking the first year or two of basic grad courses you will need to pass a comprehensive exam on the material, and success on that exam really only means that you are now prepared to take the advanced courses in your specific chosen field.
At the beginning of your grad studies you will also be expected to attend colloquia for undergrads given by the departments researchers and guests from other universities, and after a few years of study you will be expected to attend advanced level seminars given by researchers to their colleagues.
After passing the comprehensive exams, and then taking some advanced graduate courses and attending various seminars on current research, you will be able to look around for a PhD research topic and to interview with researchers who can be your thesis advisor.
If you have completed an undergraduate degree in physics but are not in a formal university program for graduate studies, and perhaps will not be able for some reason to pursue formal studies, but you wish to already begin thinking about phd research topics, my advice is to pursue several tracks, perhaps simultaneously.
- Read the physics articles in science news, science reports, and Scientific American and any other such, and look through ‘physics today’ thoroughly (all these are available in any good public or university library in print or online, and some is freely available online). This will give you an excellent overview of the recent developments.
- Go to the largest bookstore in your region and look through the science section for popular books (not text books) on the subjects you saw mentioned in the magazines/journals mentioned above. (Some advice: Don’t just buy a bunch of books; people sometimes do that and end up catharsized by the purchase alone and don’t actually read them, so just buying books can be a psychological red herring – sit in the bookstore and read them for a while first; after a few hours on any one book, having read enough to get a good sense of it and seeing that it is relevant, interesting, informative and comprehensible, and after deciding that you will definitely read the whole of it, you can decide to buy it.) Then do an internet search for other books; you can search for sites which mention the relevant books you saw in the store, and for example Amazon will recommend other books based on the one you are looking at. So finding a few good books can in this way lead you to more.
- Visit a good research university to attend their physics colloquia, meant for the general public and undergrads, and then go on to attend seminars at graduate physics departments.
- After that stage you will be ready for the next step – looking through some research papers written on these topics. Try to work through some of the calculations the authors did in the paper. In this way you will be able to identify aspects of physics and math which you need to cover or refresh yourself on.
- Find text books which cover this material, and then sit it on courses on those topics. You can often obtain permission to audit a course or sit in on the first few lectures of the semester. There is nothing like attending a course, and seeing what other students are capable of – there is no way you can reproduce this via self-study.
- After all the above you should be able to find original research papers of interest which you can thoroughly understand and whose calculations you can reproduce independently. Then you will be able to approach individual researchers and speak to them personally, and if you are referencing papers they wrote they will be very receptive. Or, if on reading a paper you find something on which you have some original insight, you can email them your insight, using key words from their paper in the subject heading to get their attention. In general if a researcher’s work catches your interest, you should attend a seminar given by the author(s) and then perhaps speak up to ask a good question or make a point; as long as you are present at one of their presentation it will be a simple matter to meet with them in person afterward.
If you have comments or critiques of the below, or more advice, please add them!