I am an undergraduate student who is looking forward to work in theoretical physics in the future and therefore, I chose a project advisor who is a string theorist. But since, my grades are average and I failed his QFT course (which I am going to repeat anyway), he believes that I may not get a PhD position if I continue to do my undergraduate project with him. And he is trying to push me into fields in which I have no interest whatsoever. And he may be right.

I took his QFT course and I worked hard, despite that I failed, not because I am stupid, it is because I am a bit slow and he went with the course at blazing speeds (but I do not blame him, it is not his fault), but since, I took his course, I got motivated and deeply interested to continue with theoretical physics. In short, I am in this too deep to discontinue. And he keeps asking me this question: “What will I do if I do not get a PhD position in theoretical physics?”. And he wants an answer before he continues.

What should I answer him ?

Resolution: I did it guys. The jokes on him. I am a PhD in theoretical physics now.

  • Most of all, recall that string theory is not the only field in which a theoretical physicist can give contributions (and, honestly, given its history, it's not particularly promising either). Commented May 5, 2016 at 18:41
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    This could be your supervisor's way of saying that he may not write you a very strong letter of recommendation if you intend to pursue that particular topic. You could perhaps try asking how much you should improve to have a good chance of succeeding, and at the same time state your back-up plans.
    – mmh
    Commented May 5, 2016 at 20:32
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    String theorists are, in my experience, extremely smart people, however, they tend to be very dogmatic. I found it is very difficult to get them to cast doubt on what they think should be the research agenda. Modern physics has some exciting fields (foundations of Quantum Mechanics, new phenomena in cosmology etc.) which may be undervalued by string theorists (who seem to be quite locked in on their direction). Is he the only person you can see yourself work with? Commented May 5, 2016 at 23:33
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    I get what you mean as the difference between slow and stupid, but, unfortunately, there are intellectual communities where, either for legitimate or illegitimate reasons, it has the same effect. To succeed as a scientist, you not only need to produce quality research but also to do it at an acceptably high rate. Commented May 6, 2016 at 7:08
  • Theoretical Physics has many very hot interesting branches.For example, dark energy, dark matter, scalar fields in curved space-time, MOND theories, standard gravity. You can for sure find some "space between spaces" there. I have find a PhD in nuclear physics and then switched to gravity with no problem, with a good background you can do what you like. However, nothing is easy in theoretical physics/math, it might take a time for someone to understand the field, and this vary from person to person.
    – Nikey Mike
    Commented May 6, 2016 at 15:38

2 Answers 2


Well, he has a point. You are not guaranteed to get a position (no one is), and you should have a backup plan.

Some possible solutions for a physicist are working as a software developer, a quant in finance, or teacher. You may also take a temporary job, hone your skills, and try again the next year. Another pre-emptive option, and what he probably has in mind, is to change to a field you are stronger in, and probably have a better chance of getting a position.

This said, if you really like this field, go for it and give it a shot. Just convince your potential supervisor that you are not delusional, you know the risks, and you are not overcomitting to a wild goose chase.


It may be an implied warning: He thinks you aren't up to snuff to do string theory. Which, since you failed his course, strikes me as reasonable. Many professors are poor teachers: Do blame him, because poor teaching is his fault. However, recognize that the majority of students do not fail his course, which suggests they did something you did not, going above and beyond in some way. (Extra study groups? Tutoring? Visiting him in his office?). How 'deeply motivated and interested' you are is irrelevant, unless it is reflected in your actions.

You are never in 'too deep to discontinue'. Getting a PhD in theoretical physics is hardly your only career option. And it's not a particularly good career option. Getting a PhD is hard. About half of those who start quit. Getting a job with a PhD is no picnic either.

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