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Research in QM or QFT?

  • Thread starter nlsherrill
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Main Question or Discussion Point

Is there anyone on the forums that does research in QM or QFT? I ask because I find this area of physics very interesting at least to read about, and I enjoy challenging mathematics. While I am still only at the freshman/sophomore level in my physics education, I have always been interested in QM far before I even went into school to study physics. What all exactly do you have to know to do research in this field?

Is this http://www.phys.uu.nl/~thooft/theorist.html" [Broken]

a good summation of what you have to know to study/research QM or QFT?

For the longest time I didn't want to go into research for a theory based field because I was always thinking that the theory would eventually be overthrown or be proven wrong somehow, so my studies/work would have been a waste of time(kind of like what might happen with string theory).

I might not necessarily even want to do just theory, but applications involving QM are also interesting, and possibly more accessible.

Lastly, I would really prefer to not forget my physics education, which is why I am considering academia. I always want to know classical mechanics, EM, Thermo, all that stuff. I don't want to just learn it for a job, and I think it would be fun to teach others this exciting stuff.

Before you respond just consider where I said I was in my education, and how little I have been exposed to what "doing" physics really is.

Thanks
 
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Answers and Replies

882
2
Re: Qft

Is there anyone on the forums that does research in QM or QFT? I ask because I find this area of physics very interesting at least to read about, and I enjoy challenging mathematics. While I am still only at the freshman/sophomore level in my physics education, I have always been interested in QM far before I even went into school to study physics. What all exactly do you have to know to do research in this field?
In general, there isn't a whole lot of research in QM these days. QM is typically just a tool in a theorists tool box to describe phenomenon of things that are small. Said another way, QM is used in research, but is not the subject of the research itself**.

Is this http://www.phys.uu.nl/~thooft/theorist.html" [Broken]

a good summation of what you have to know to study/research QM or QFT?
You do not need GR, Solid State, Plasma Physics or Nuclear Physics to study QFT. But otherwise I think that is a good progression in the standard physics education.


**Disclaimer -- yes, yes I know someone will remark on quantum computing or some other field that has "quantum" in the name. Here I am specifically considering QM.
 
Last edited by a moderator:
323
0
Re: Qft

In general, there isn't a whole lot of research in QM these days. QM is typically just a tool in a theorists tool box to describe phenomenon of things that are small. Said another way, QM is used in research, but is not the subject of the research itself**.


You do not need GR, Solid State, Plasma Physics or Nuclear Physics to study QFT. But otherwise I think that is a good progression in the standard physics education.


**Disclaimer -- yes, yes I know someone will remark on quantum computing or some other field that has "quantum" in the name. Here I am specifically considering QM.


You don't need to know nuclear physics to study QFT?

Okay but when you see a faculty position opening at a university that says something along the lines of "Position open for high energy/QCD/nuclear theory research", can we assume they will be working within/on QFT? I'm just a little confused on what it encompasses. There is a department at my university called The Nuclear and Particle Theory group, and I think they mainly work on QCD. Does QCD and QED pretty much cover QFT?
 
882
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Re: Qft

You don't need to know nuclear physics to study QFT?
Things can be a little muddled and it all depends on your exact definition of some of these fields. When I say Nuclear Physics, I am talking about nuclear physics at energies where QCD doesn't work well, below approximately 1 GeV in energy.

Nuclear physics can use QFT (and often does in the modern high energy nuclear physics field of heavy ion collisions), but you do not need to know nuclear physics to learn QFT. For instance, you don't need to know anything about shell structure of nuclei, or how to calculate nuclear binding energies to learn QFT. But these things are fundamental to an understanding of the nucleus (in my opinion).

Okay but when you see a faculty position opening at a university that says something along the lines of "Position open for high energy/QCD/nuclear theory research", can we assume they will be working within/on QFT? I'm just a little confused on what it encompasses. There is a department at my university called The Nuclear and Particle Theory group, and I think they mainly work on QCD. Does QCD and QED pretty much cover QFT?
Right, so a high energy nuclear theorist would very likely use QFT (I cannot think of a situation where someone working in high energy nuclear theory wouldn't, but that doesn't mean there isn't one), but the theorist could also rely heavily on Statistical Mechanics/Thermo, or even just relativistic QM and all the theory that those fields depend on.

Around here, we see a lot of students who confuse a subject of study (most often times QM) for an active research field (not much pure QM research going). I think when it comes down to it, it is a matter of taste how you describe it. You would certainly learn QED (and possibly QCD, depends on the class) in a QFT class. Everything I attempt write seems to carry huge caveats, so I am just going to stop there.

I hope it helps.
 
323
0
Re: Qft

Things can be a little muddled and it all depends on your exact definition of some of these fields. When I say Nuclear Physics, I am talking about nuclear physics at energies where QCD doesn't work well, below approximately 1 GeV in energy.

Nuclear physics can use QFT (and often does in the modern high energy nuclear physics field of heavy ion collisions), but you do not need to know nuclear physics to learn QFT. For instance, you don't need to know anything about shell structure of nuclei, or how to calculate nuclear binding energies to learn QFT. But these things are fundamental to an understanding of the nucleus (in my opinion).


Right, so a high energy nuclear theorist would very likely use QFT (I cannot think of a situation where someone working in high energy nuclear theory wouldn't, but that doesn't mean there isn't one), but the theorist could also rely heavily on Statistical Mechanics/Thermo, or even just relativistic QM and all the theory that those fields depend on.

Around here, we see a lot of students who confuse a subject of study (most often times QM) for an active research field (not much pure QM research going). I think when it comes down to it, it is a matter of taste how you describe it. You would certainly learn QED (and possibly QCD, depends on the class) in a QFT class. Everything I attempt write seems to carry huge caveats, so I am just going to stop there.

I hope it helps.
Hate to resurrect this thread but I just forgot to say thanks for your input.
 
6,814
10
Re: Qft

Is there anyone on the forums that does research in QM or QFT?
Research in QM/QFT or research with QM/QFT?

Pretty much any sort of physics requires you to use quantum mechanics. Think of it as a toolbox. There are people that use the toolbox, and people that work on making better tools.

For the longest time I didn't want to go into research for a theory based field because I was always thinking that the theory would eventually be overthrown or be proven wrong somehow, so my studies/work would have been a waste of time(kind of like what might happen with string theory).
Need to change your perspective a bit. The goal of a theorist is to have their theory proved wrong. The thing that theorists spend their time doing is to come up with ways of proving their theory wrong, and it's not easy. If you spend five years working on a theory and then you can show that if theory X is correct then you must see Y, and you don't see Y, you WIN!!!!

The complaint about string theory is that it's been proven wrong. Someone that spends a few years and comes up with an argument that proves string theory wrong is going to be a very big name in physics. The complaint with string theory is that after spending two decades, people *haven't* come up with a way of proving it wrong.

Lastly, I would really prefer to not forget my physics education, which is why I am considering academia. I always want to know classical mechanics, EM, Thermo, all that stuff. I don't want to just learn it for a job, and I think it would be fun to teach others this exciting stuff.
There is too much to know. What you'll find is that you'll have to specialize and become the world expert on some tiny branch of physics.
 
323
0
Re: Qft

Research in QM/QFT or research with QM/QFT?

Pretty much any sort of physics requires you to use quantum mechanics. Think of it as a toolbox. There are people that use the toolbox, and people that work on making better tools.



Need to change your perspective a bit. The goal of a theorist is to have their theory proved wrong. The thing that theorists spend their time doing is to come up with ways of proving their theory wrong, and it's not easy. If you spend five years working on a theory and then you can show that if theory X is correct then you must see Y, and you don't see Y, you WIN!!!!

The complaint about string theory is that it's been proven wrong. Someone that spends a few years and comes up with an argument that proves string theory wrong is going to be a very big name in physics. The complaint with string theory is that after spending two decades, people *haven't* come up with a way of proving it wrong.



There is too much to know. What you'll find is that you'll have to specialize and become the world expert on some tiny branch of physics.

Thanks for the reply twofish.

What I mean't by wanting to never forget those fields is I would like to know the topics of an undergraduate physics curriculum...and possibly some graduate level stuff in fields that I may not necessarily do research in. For example, if I went into nuclear physics, I would still never want to forget my E&M, CM, Thermo, QM, etc...if that makes sense. I think David Jackson was into nuclear physics research, yet he also knew E&M well apparently, and taught a variety of other subjects within physics.
 

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