Asimov’s “Understanding physics”: review, study guide


Asimov is perhaps good choice because:

  1. students may have read his scifi, or seen movies based on his ideas;
  2. he is one of the few (or maybe only one!) who have written a book for the educated layperson on basic standard physics, including classical physics, rather than only on ‘cool topics’ in quantum physics, GR etc;
  3. it is appropriate level for large audience and he is a suberb writer.
  4. reading the first chapter of these two books may create an interest in physics, and also provide a portal to some students to read the entirety of his book.
  5. young people trying to get a grasp on cool new theories such as string theory or others involving quantum physics or cosmology will generally of course look for material on those topics. However, even a student capable of grasping physics, who wishes a deeper treatment of these topics than is provided by the popular sources on the web or in print, will find that the treatment in the sources they find is far beyond them.      The best place to start a serious study of any of these topics is not some website about quantum physics or even a textbook devoted to that topic, but  rather with basic fundamental physics, and Asimov’s books are exceptionally suited for this. 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 is a book like Asimov’s (three volume) “Understanding Physics”.


 Asimov vol 1&2: The first chapter of Vol 1 is somewhat about science in general not just physics, and even the aspect which is about physics certainly does not treat of an actual physics topic. Chapter 1 is general, history of science. Starting with Chapter 2 the material is hard physics, so it is not appropriate for general science students (but is an excellent introduction for students studying physics).

The first part of Vol II discusses a major topic of physics, and it is also one which underlies the transformation from Newtonian to ‘modern’ physics.

A little more detail: Newtonian physics was a great advance over the prior Aristotelian conceptions, and was based on ideas of mechanism, and for many scientists this also implied an acceptance of ‘action at a distance’. However newer conceptions such as the notion of fields, and then relativity and quantum physics soon overthrew the Newtonian ones.

Asimov’s description of this process is a pedagogically instructive illustration of the scientific approach, studying natural phenomena employing reasoning coupled with experiment, and trying to find patterns, laws, naturalistic explanations, as well as a good example of how science constantly re-invents itself as a result of new information and insights.


Asimov vol I&II: For physics students:

Vol 1: “Mechanics, Sound, Heat?” Can you figure out why he puts these into one volume, what do they have in common? If you were writing a book about physics, how would you organize it? Which topics would you lump together, and why?

The book stands on its own as an intro to Mechanics, Sound, Heat, but it can also be seen as an exploration of a specific unifying topic:  Newtonian physics and ‘mechanism’, and the beginning of the abandonment of that paradigm. In addition, students will acquire an understanding of the term ‘energy’, and can see perhaps how this is meant in a different manner than the same term as it is used in much popular (‘New Age’ etc) literature of modern times.


Vol II Light, Magnetism and Electricity

Can you figure out why he puts these into one volume, what do they have in common?

Vol II as a prelude to modern physics: The book stands on its own as an intro to Light, E, & M, but it can also be seen as an exploration of a specific unifying topic, indeed his book can be subtitled: “Two paradigms: “mechanism, and fields(particles)” or “particle vs wave”. Below, I trace the evolution of this topic throughout the book. Although only a small part of the book (in terms of amount of pages) deals with this, it can be a subtitle since it is a central topic, and weaves the entirety of the book together.

Note: Quantum physics is very much discussed in the popular literature, and this is an opportunity for students to benefit from an introductory discussion of part of the reasoning which led to its development.

The evolution of this topic throughout the book

Ch 1 presents “Mechanism” in two sections “The Newtonian view” ie mechanistic, and “Action at a distance”, providing four examples: light, gravity, electricity, and magnetism. There are two ways out of the dilemma of action at a distance: no vacuum, but rather ether filling everything, and light etc is a disturbance of the ether; or: light as particle (Of course is if light is a particle it does not belong in this list with gravity, elec, mag)

Ch 4 “Color”. P60 section “Diffraction” VIP, light as a wave?! (See also the last paragraph of the previous section, interesting re Auguste Comte

Ch 5 “Light Waves” first 1.5 pages: light is a wave!

Ch 6 “The Ether” first page

Ch 7 Relativity

Ch 8 Quanta: first page, no ether. Last section “Photons” first few paragraphs: light is a particle; last few paragraphs: light is both particle and wave!!

Ch 14 EM radiation: most of p238 (2nd to last page of book).


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