Did any of you have any idea of what subject you would study in grad school

[Benzoate]

I am 100 % certain that I want to earned my Phd in physics . I have some idea ofwhat physics subjects I am interested in. The problem is, each physics subject I am interested in all are in different physics topics. The physics topics I like lie from the structure of neutron stars in astrophysics , to quantum computing which is pretty much an interdisciplinary field, to some topics in particle physics and solid state physics. So once I entered grad school, am I expected to have a physics subtopic I might be interested in studying for the next five years

 

[eri]

I thought I did when I started, and ended up switching grad schools to get away from a particular adviser - and just picked a random project from the groups available at the new grad school, and now I'm very happy with it. What you think you'll end up doing isn't always what works out the best. But many grad schools have a few different areas of concentration, so you might find a few that offers several things you're interested in - look around a bit.

 

[ZapperZ]

I am 100 % certain that I want to earned my Phd in physics . I have some idea ofwhat physics subjects I am interested in. The problem is, each physics subject I am interested in all are in different physics topics. The physics topics I like lie from the structure of neutron stars in astrophysics , to quantum computing which is pretty much an interdisciplinary field, to some topics in particle physics and solid state physics. So once I entered grad school, am I expected to have a physics subtopic I might be interested in studying for the next five years

All I knew when I started graduate schools was that (i) I had to pass the qualifier first and (ii) I didn't want to do high energy physics.

While I had some interest in solid state/condensed matter physics, having taken such classes as an undergraduate elective, I was still "shopping around" for an area and a supervisor after I passed my qualifier. I literally went to a few professors and asked them what they did. Eventually, I settled on the one I wanted to work in and grew to love it.

Zz.

 

[jtbell]

No, you normally don't have to commit to a specific field when you enter (in US graduate schools at least). At my graduate school (Michigan), most students spent the first two years taking the required courses (QM, E&M, etc.), teaching introductory labs or recitations, and preparing for the qualifying exam. You're encouraged to participate in research, of course; Michigan had a program specifically for the summer following the first year, in which students could work for a research project without the project having to pay you out of their own budget (it came out of the departmental budget). You can talk to people, try working for a couple of different groups, and commit to a specific field only when you're ready to form a dissertation committee and become a formal Ph.D. candidate.

I spent my first summer working with one of the low-temperature people, trying to get a helium dilution refrigerator to work. I was also interested in computer programming (this was back in the 1970s before PCs existed), and spent my spare time fiddling with that. The LT guy at that time didn't need much in the way of computing expertise, but he noticed my interest. He mentioned me to one of the profs in the bubble-chamber group, which was doing experimental high-energy neutrino physics, and of course needed a lot of programming done. So during my second year I got an invitation to try that group, and I ended up doing my dissertation with them.

 

[las3rjock]

I think you should have an idea (or some ideas) of research areas that you're interested in, and apply to schools that are good (or at least competent) in those areas, but as eri mentions, it's not uncommon to transfer from one graduate program to another if you realize that you're not at the right place or in the right field.

 

[Benzoate]

No, you normally don't have to commit to a specific field when you enter (in US graduate schools at least). At my graduate school (Michigan), most students spent the first two years taking the required courses (QM, E&M, etc.), teaching introductory labs or recitations, and preparing for the qualifying exam. You're encouraged to participate in research, of course; Michigan had a program specifically for the summer following the first year, in which students could work for a research project without the project having to pay you out of their own budget (it came out of the departmental budget). You can talk to people, try working for a couple of different groups, and commit to a specific field only when you're ready to form a dissertation committee and become a formal Ph.D. candidate.

I spent my first summer working with one of the low-temperature people, trying to get a helium dilution refrigerator to work. I was also interested in computer programming (this was back in the 1970s before PCs existed), and spent my spare time fiddling with that. The LT guy at that time didn't need much in the way of computing expertise, but he noticed my interest. He mentioned me to one of the profs in the bubble-chamber group, which was doing experimental high-energy neutrino physics, and of course needed a lot of programming done. So during my second year I got an invitation to try that group, and I ended up doing my dissertation with them.

Why do you have to take QM, E&M again if you would have already taken it during your undergrad years? What other kinds of courses are all physics grads required to take?

 

[las3rjock]

Why do you have to take QM, E&M again if you would have already taken it during your undergrad years? What other kinds of courses are all physics grads required to take?

The qualifying coursework for a Ph.D. in physics typically includes a year of QM (at the level of Merzbacher), a year of E&M (at the level of Jackson), a semester of statistical mechanics (at the level of Huang), and possibly a semester of classical mechanics (at the level of Goldstein). To some extent this is a review of the undergrad courses, but it also deepens one's understanding of the subject in the same way that a junior- or senior-level course in E&M or mechanics is more sophisticated than a freshman- or sophomore-level course in E&M or mechanics. In addition, an individual's qualifying exam may include questions regarding elective coursework in his or her area of interest, such as condensed matter or solid state (at the level of Chaikin & Lubensky or Ashcroft & Mermin), quantum field theory (at the level of Peskin & Schroeder), general relativity (at the level of Wald), string theory, etc.

 

[ZapperZ]

Why do you have to take QM, E&M again if you would have already taken it during your undergrad years? What other kinds of courses are all physics grads required to take?

If you look at your E&M course, for example, you tend to solve the "simpler", highly symmetric situation. For instance, you tend to find the magnetic field from a circular loop of current at various field points along the axis of symmetry of that loop. Try finding it slight off-axis, and you'll end up with something you can't solve easily. This is what you'll encounter in graduate level E&M. Look in Jackson's Classical Electrodynamics text. That's typically what you'll see at the graduate level.

Same thing with graduate level QM. The problems will be more complex (and in some sense, more realistic).

Zz.