Relativity text for Physics Olympiad

[loom91]

FIRST drawing a "spacetime diagram" in which the events are clearly labelled.
Once that is done, it is often a matter of doing Minkowski geometry (analogous to Euclidean geometry)... then doing calculations (using rapidities and spacetime trigonometry, preferably) and then interpreting physically.

(You probably could get by memorizing the special-case "length contraction", "time dilation", "doppler effect" formulas... for some problems... but for challenging problems, I think you can reason through the problem a lot better using the plan above.)

The program you describe sounds interesting, something like how we analyse mechanics problems using free-body diagrams and Newton's equations. Is it developed in Spacetime Physics?

Molu

 

[robphy]

The program you describe sounds interesting, something like how we analyse mechanics problems using free-body diagrams and Newton's equations. Is it developed in Spacetime Physics?

Molu

In Spacetime Physics, you'll find aspects of that way of thinking about the geometry of relativity.

 

[loom91]

In Spacetime Physics, you'll find aspects of that way of thinking about the geometry of relativity.

But will I find the actual calculation methods?

Molu

 

[mjsd]

But will I find the actual calculation methods?

Molu

there will be (but from memory they are pretty basic calculations...still, the word "basic" can have different meaning for different ppl)

 

[robphy]

But will I find the actual calculation methods?

Molu

Yes. First, you'll probably find a spacetime diagram of the situation then a calculation using rapidity [the Minkowski angle], which more clearly expresses the geometry underlying the problem. ($$\beta(=v/c)$$ is simply $$\tanh\theta$$ and $$\gamma$$ is simply $$\cosh\theta$$.) Later, you may find re-interpretations in terms of various [secondary] "effects"... like time-dilation or length-contraction. [In the second (1992?) edition of Spacetime Physics, you'll find that the use of rapidity was dropped. https://www.physicsforums.com/showthread.php?p=882610#post882610 ]

So, in that book, you get a more of a "spacetime trigonometry" approach to solving problems, which is a good first step [compared to standard introductory textbook presentations, which are mainly "algebraic"]. One can go a little further by emphasizing, or at least connecting with, the geometry by vectorial and tensorial methods... but that's another book.

 

[FedEx]

I am also from India. Go for Halliday Resnick for the theory and Irodov for the problems.

I am in 11th,so i am also going to give the physics olympiad. Did you give the olympiad in your 11th. For the topics like classical mechanics and electrodynamics is Irodov OK?As you have already given the olympiad you might be having some experience.

 

[easttiger2007]

I recommend A.P.French's book, Feynman's lecture, and Einstein's Meaning of Relativity. But for taking Physics Olympiad, the most efficient way is to work on problems. I recommend you to find some Chinese Physics Olympiad Problems (if english version is available), or Russian, Polish, etc. btw, I take part in Physics Olympiad in my high school also.

 

[loom91]

Yes. First, you'll probably find a spacetime diagram of the situation then a calculation using rapidity [the Minkowski angle], which more clearly expresses the geometry underlying the problem. ($$\beta(=v/c)$$ is simply $$\tanh\theta$$ and $$\gamma$$ is simply $$\cosh\theta$$.) Later, you may find re-interpretations in terms of various [secondary] "effects"... like time-dilation or length-contraction. [In the second (1992?) edition of Spacetime Physics, you'll find that the use of rapidity was dropped. https://www.physicsforums.com/showthread.php?p=882610#post882610 ]

So, in that book, you get a more of a "spacetime trigonometry" approach to solving problems, which is a good first step [compared to standard introductory textbook presentations, which are mainly "algebraic"]. One can go a little further by emphasizing, or at least connecting with, the geometry by vectorial and tensorial methods... but that's another book.

So you are recommending the first edition? Now I'll have to see if I can find the book here. How does it compare to Moore's Traveler's Guide to Spacetime?

Molu

 

[robphy]

So you are recommending the first edition? Now I'll have to see if I can find the book here. How does it compare to Moore's Traveler's Guide to Spacetime?

Molu

Yes, the first edition... sort of.
I presume there was a first edition... then there was a "first edition with worked solutions"... then more recently a rewritten second edition (without rapidity and without worked solutions). Earlier, I mentioned that the first chapter of this first edition with solutions is at one author's (E.F. Taylor) website: http://www.eftaylor.com/download.html#special_relativity (If I recall correctly, Chapter 1 is mainly kinematics... Ch 2 is dynamics and Ch3 is a short chapter setting you up for GR. A lot of the good stuff is in Chapter 1.

Tom Moore's book is a good book... partially inspired by Spacetime Physics. In fact, it's probably a good stepping stone to Spacetime Physics... although there is some overlap. It's a modern presentation emphasizing the "spacetime diagram" and its geometry (unlike what is found in most introductory and intro-modern-physics textbooks where the spacetime diagram is presented like a sketch, if it is presented at all). I used it as a supplementary text for a special topics course I taught. An alternative to "A Traveler's Guide to Spacetime" is Moore's more recent http://www.physics.pomona.edu/sixideas/sitoc.html.

 

[loom91]

You mean it's more basic than Spacetime Physics. I saw that Taylor removed mentions of rapidity apparently because no instructor used them. So how are SR problems commonly solved? Also, is it better to approach a problem using Lorentz transformations or invariance of the Minkowski metric? Thanks.

Molu

 

[robphy]

You mean it's more basic than Spacetime Physics. I saw that Taylor removed mentions of rapidity apparently because no instructor used them. So how are SR problems commonly solved? Also, is it better to approach a problem using Lorentz transformations or invariance of the Minkowski metric? Thanks.

Molu

Yes, it is more introductory... written to be used as a better but longer supplement to a standard introductory textbook, in place of its usually short and merely formula-oriented treatment. However, it does have topics that overlap with Spacetime Physics.. and introduce some detail in more advanced methods not specifically done in Spacetime Physics.

"No instructor" is a little too strong. I'm sure there are some that used it... and I have met other instructors that are unhappy about its omission.. and some of us have mentioned it to Prof. Taylor. I wonder if some kind of survey was done by the publisher or someone else, resulting in some report that rapidity was not being used [much].

You don't need rapidity to "solve" the problems. However, many problems (particularly nonintuitive problems) are efficiently solved using rapidity and an analogue of one's Euclidean-geometric and trigonometric intuition. In my opinion, the geometric formulation of the problem and solution [with its rather clear interpretation] will inform and improve one's physical intuition about relativity.

The nature of the problem often dictates which method is better.