Grad School Advice - Taking Jackson Level E&M Course?

[nicksauce]

I'm starting grad school this fall - direct entry PhD in astronomy & astrophysics. I eventually want to do theoretical cosmology, although I am not sure in what capacity yet. In the 5 years of the program, we're only required to take 4 classes, and they can be pretty much whatever, as long as they're approved. Should I take the Jackson level E&M course if I don't have to? Is it going to be useful, or just torture?

 

[diazona]

Well, Jackson can get you used to doing a certain level of problems, but I don't think it's worth taking the course just for that. You'd probably be much better off taking a more specific, higher-level course that actually relates to something you might want to be studying.

Of course, if you're required to take an E&M course (possibly as a prerequisite) or if you are going into an area of research which relies heavily on electromagnetism, you'd probably get some reasonable benefit out of taking the Jackson-based course.

 

[Fredrik]

I would choose not to. I felt that Jackson was mainly an exercise in solving difficult boundary value problems.

 

[arunma]

You're only required to take four courses for a PhD program? Is your department purely astrophysics? This is just somewhat surprising to me, because those of us who are PhD students in combined physics and astronomy departments have to take a lot more than four courses.

Anyway, just so you know where I'm coming from, I'm a PhD student in particle astrophysics (experimental), which I guess is a tad bit like cosmology. The first semester of Jackson is pretty worthless as far as learning physics goes. It's basically just grad student hazing. Now, I will say that the course certainly has some "character building" value. It gets you used to the rigor of grad school, and it forces you to work with other grad students on the homework. And I do believe that anyone with a PhD in physics or astrophysics should know how to do Jackson-level problems. I'm definitely better off for taking it. But I have never used the material in my research. Seriously: how often do astrophysicists need to solve Laplace's Equation in spherical coordinates? Heck, even the condensed matter people don't do this. Maybe if you're in helioseismology you might, but even then the same math can be learned in quantum (which I think is a far more important class for any physicist).

Having said all this, I've actually found the second semester of Jackson E&M to be surprisingly useful. You learn about transmission and reflection of EM waves, as well as radiation processes and relativistic E&M. Relativity is really important in particle physics, which you'll be doing a lot of too if you're in cosmology. Also, my research has a lot to do with interaction cross-sections and angular distributions of radiation, which you also learn about in second semester Jackson. It's rather useful in astrophysics, only problem is that you need to get through first semester to take it.

Sorry I can't give a definitive answer, but I hope this helps.

 

[n!kofeyn]

I am not in this field, so I don't really know, but I have a suggestion. The book https://www.amazon.com/dp/0226519589/?tag=pfamazon01-20 is an alternate text on electrodynamics. I have only browsed through it, but the book definitely has the tone of wanting you to get the bigger picture and to be able to apply the knowledge gained from electrodynamics. It doesn't have any exercises, but I just thought I would suggest replacing Jackson with more relevant and useful texts since others basically stated Jackson is a workbook of problems. You could use the time to take another class, while going through this text with a professor or on your own. It's just an alternate suggestion. By the way, from Wikipedia's article on Fulio Melia, he has published 230 articles on theoretical astrophysics and has authored multiple popularizing books on the subject.

 

[ZapperZ]

I'm starting grad school this fall - direct entry PhD in astronomy & astrophysics. I eventually want to do theoretical cosmology, although I am not sure in what capacity yet. In the 5 years of the program, we're only required to take 4 classes, and they can be pretty much whatever, as long as they're approved. Should I take the Jackson level E&M course if I don't have to? Is it going to be useful, or just torture?

The question is, are you required to take graduate level E&M?

Considering that you are starting grad school "this fall", one would think you would know already by now. I would be very surprised if a Ph.D in astronomy/astrophysics isn't required to take such a course, considering that it is almost a standard requirement for every graduate physics student.

And I disagree with people calling Jackson as simply a "workbook". I'm not diminishing the fact that it is difficult, and it has a lot and lengthy exercises. But compare the type of problems that one sees in undergraduate E&M (i.e. Griffith), and then compare that to the type of problems in Jackson. The undergraduate E&M deals mainly with, say, finding solutions along some symmetry axis ONLY, such as the axis of symmetry perpendicular to a loop. Since WHEN is this sufficient? Now look in Jackson and consider the fact that you now have to find the field solution to such off-symmetry axis situation. Of course it will be difficult and time-consuming, but this is now closer to what you have to deal with in REAL problems! In accelerator physics, we refer to Jackson quite often when we're dealing with solving various field equations in waveguides and structures. That in itself is ample proof that this is a useful and important book.

Zz.

 

[cristo]

Should I take the Jackson level E&M course if I don't have to?

That depends: what other courses are you taking, and what courses have you taken in the past? If you're looking to study theoretical cosmology, then I'd imagine you are taking courses in general relativity, advanced quantum mechanics & field theory, some sort of introductory cosmology course. Maybe some programming course, depending on what you want to do. Have you done/are you doing these?(Of course, take my comments with the usual caveat that I'm British, and thus not that well versed on the courses etc that US grad students are required to/usually take).

 

[mal4mac]

Just torture. They have to have some way to weed out the unwashed masses who want to do physics PhDs...

 

[nicksauce]

Thanks very much for the replies everyone. Taking them in order...

You're only required to take four courses for a PhD program? Is your department purely astrophysics?

Yes. It does seem like not very many courses. The department says they like to focus on research. However, there are 1 month classes on specialized topics offered. You can take three of these to count as one class, but it seems like most people just audit such classes. The astro and physics departments are indeed separate.

You learn about transmission and reflection of EM waves, as well as radiation processes and relativistic E&M. Relativity is really important in particle physics, which you'll be doing a lot of too if you're in cosmology. Also, my research has a lot to do with interaction cross-sections and angular distributions of radiation, which you also learn about in second semester Jackson.

We take something called "Radiation processes and gas dynamics", so I imagine that I'd learn some of things there.

The question is, are you required to take graduate level E&M?

No.

Considering that you are starting grad school "this fall", one would think you would know already by now. I would be very surprised if a Ph.D in astronomy/astrophysics isn't required to take such a course, considering that it is almost a standard requirement for every graduate physics student.

I was surprised too. But I guess since the astro department is separate from the physics department, they like to play by their own rules... or something. Most people in the program take just classes offered by the astro department, with maybe a physics/math/CS course.

If you're looking to study theoretical cosmology, then I'd imagine you are taking courses in general relativity, advanced quantum mechanics & field theory, some sort of introductory cosmology course. Maybe some programming course, depending on what you want to do. Have you done/are you doing these?

Right now I was thinking of taking four out of QFT1, Introductory cosmology, Advanced GR, Radiation processes, and Galactic structure and dynamics... not totally sure yet. Doesn't leave much room for an advanced E&M course, but I figured there might be something important about such a course, since almost everyone seems to take one in grad school.

(Of course, take my comments with the usual caveat that I'm British, and thus not that well versed on the courses etc that US grad students are required to/usually take).

I'm Canadian by the way. :)

 

[Count Iblis]

I'm starting grad school this fall - direct entry PhD in astronomy & astrophysics. I eventually want to do theoretical cosmology, although I am not sure in what capacity yet. In the 5 years of the program, we're only required to take 4 classes, and they can be pretty much whatever, as long as they're approved. Should I take the Jackson level E&M course if I don't have to? Is it going to be useful, or just torture?

You should master electromagnetism at the level of Jackson, whether or not you actually decide to take the course is not important.
If you decide not to take the course, (e.g. due to time limitations), study it in your free time. If you don't like the book by Jackson, you could also study this from other books, e.g. the book by Landau & Lifschitz: "The classical theory of Fields".