# Physics How risky is doing a PhD in theoretical Physics?

#### Phys12

Hello everyone!

Apologies if this question has been asked and answered before, please feel free to direct me to that post and delete this one, if needed and if it has been asked before and this post is, hence, redundant.

I looked up some of the earlier posts such as:

But they typically seemed to go into topics about what would happen if you left Physics after your PhD in Physics, or your prospects outside Physics (such as engineering) and that kind of thing. What I am interested in knowing, however, is, the difference in career prospects in Physics after a PhD in experimental Physics vs. one in theoretical Physics. Are the number of theoretical Physicists wanted in theoretical Physics positions (be it at universities as professors or research scientists or in national labs) considerably less than experimental Physicists wanted in experimental Physics positions? I've also heard that if you do a PhD in theoretical Physics and cannot get an academic position, you'll have to leave Physics, is that true? If I get a PhD in theoretical Physics, can I then switch to doing experiment for post-doc and beyond?

Thanks!

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#### Gigaz

I guess it depends on the field. If you're going for something popular like solid state or quantum optics it's not very risky. You should become a good programmer it's even less risky because there's always money and research tasks for people who can simulate nasty stuff. For cosmology, particle physics or other exotic stuff it's probably more risky.

#### mfb

Mentor
Leaving academia is the default case both in theoretical and experimental physics. You might be lucky and the probability will depend a bit on the field, but it should never be what you expect to do later. Take a project that also gives you something you can sell outside of academia. Programming skills, data analysis, lab experience, ...
I've also heard that if you do a PhD in theoretical Physics and cannot get an academic position, you'll have to leave Physics, is that true?
There is physics outside of academia, although it won't be the same as in academia, and some experience with the more experimental side is usually advisable.
If I get a PhD in theoretical Physics, can I then switch to doing experiment for post-doc and beyond?
Depends on the field and your specific topic. Physics is not binary, there is a smooth transition region between experiment and theory.

#### jtbell

Mentor
In the US at least, I expect that there are far more college/university faculty in experimental physics than in theoretical physics. I don't have specific statistics at hand, but there's probably something on the AIP web site. As mfb mentioned, there is some "blurriness". For example, someone who sits at a computer analyzing data and writing code for a high-energy physics experiment would usually be considered an "experimentalist" even though he seldom or never actually enters a laboratory.

#### Dr. Courtney

Gold Member
2018 Award
I mentor lots of aspiring scientists, including my own two sons, who are undergraduate physics majors. I would not steer any of them away from doing a PhD in theoretical physics from a concern that PhDs in theoretical physics are somehow less employable than PhDs in experimental physics. (Though I myself am primarily an experimentalist.)

But my attitude and approach to employment is more informed by the book, "What Color is Your Parachute?" than by the unfortunate and archaic notion that a degree in any specific field either promises or constrains a narrow career path. Every field of both experimental and theoretical physics is producing many more PhDs than there are available faculty openings at R1 universities. But the skills gained completing a PhD in theoretical physics are useful in a broad array of career paths in industry, in government labs, and in many physics faculty jobs where teaching is emphasized more than research.

My advice to students I mentor is to work hard, get really good at a few things, and don't constrain your career possibilities nearly as narrowly as your PhD path.

#### mfb

Mentor
For example, someone who sits at a computer analyzing data and writing code for a high-energy physics experiment would usually be considered an "experimentalist" even though he seldom or never actually enters a laboratory.
I made my master (well, its German equivalent at that time) in experimental physics without working on any hardware related to the experiment, and without seeing the experiment I was working for. There are some people getting a PhD in experimental physics without working on any hardware and without seeing the experiment.

#### jtbell

Mentor
I made my master (well, its German equivalent at that time) in experimental physics without working on any hardware related to the experiment, and without seeing the experiment I was working for.
Almost the same thing happened to me with my PhD. Shortly after I joined my research group, I was scheduled to go to Fermilab to participate in what was going to be our experiment's final data-collecting run. A few days before the beginning of the run, the bigwigs at Fermilab decided we had enough data and cancelled it.

I did get to see the apparatus later (the 15-foot bubble chamber and neutrino beam line) on a visit to Fermilab for a collaboration meeting.

#### DEvens

Gold Member
When I was in my PhD program, my prof had 4 other PhD candidates. All of them eventually got their degrees. As they graduated out, other students came on board, though usually not as many as 5. So a prof might have as many as 20 or 30 students get PhDs under their supervision. But in the ordinary course of things, you only expect one of them to be needed, on average.

Additionally, what will tend to happen is that Pareto distributions apply to physics PhDs as to many things. A few profs will graduate many students who themselves become profs. Often these are profs at "ivy league" schools, or profs that have some special kind of prestige. Most profs will have none or very few of their students become profs.

This is, to some extent, a self reinforcing process. A prof who has some brilliant success will tend to get more support. That will tend to give them more success. And so on. Success get you brilliant students. Brilliant students get you success.

Others have mentioned that you should be sure to acquire additional skills. Learn as much as you can cram into your head during your time in university. Computer programming is a possibility. It will be useful in your own research, supposing you do become a prof. And it will make you a stack of money in industry. There are lots of other possible skills. How to find the needle in a data haystack. How to build a theoretical model. How to explain all of this stuff to somebody who is new to the topic.

These lovely objects are silos. They get filled from the top by blowing material up through those white pipes you see. Usually it's chopped up corn called "silage." During the filling process there is the job of packing down the material and being sure there is no waste space. That means somebody goes inside and stamps down the material as it is blown in. You should think of your brain as one of these silos. Your job during uni is to stamp as much information and as many skills into your brain as you can.

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#### Phys12

[academica] but it should never be what you expect to do later.
Why is that? Is it because the chances are so low?

Take a project that also gives you something you can sell outside of academia. Programming skills, data analysis, lab experience, ...There is physics outside of academia, although it won't be the same as in academia, and some experience with the more experimental side is usually advisable.Depends on the field and your specific topic. Physics is not binary, there is a smooth transition region between experiment and theory.
I see, so I can probably get experience of doing both while I'm doing my PhD and getting some skills of an experimentalist like working in a lab will come in handy later. Out of curiosity, does my lab experience during my undergrad years count or not?

#### Phys12

In addition, I found this list of theoretical Physics job openings:
As of September 5, midnight, there are about 14 faculty position openings that I see there. That doesn't sound too small of a number, does it? I'm sure you'll be competing with the best of the best of the best in the world, but based on how much hype I've seen about the scarcity of faculty positions, I think I had my expectations very low and was expecting to see like 1-2 openings only

#### Phys12

I mentor lots of aspiring scientists, including my own two sons, who are undergraduate physics majors. I would not steer any of them away from doing a PhD in theoretical physics from a concern that PhDs in theoretical physics are somehow less employable than PhDs in experimental physics. (Though I myself am primarily an experimentalist.)

But my attitude and approach to employment is more informed by the book, "What Color is Your Parachute?" than by the unfortunate and archaic notion that a degree in any specific field either promises or constrains a narrow career path. Every field of both experimental and theoretical physics is producing many more PhDs than there are available faculty openings at R1 universities. But the skills gained completing a PhD in theoretical physics are useful in a broad array of career paths in industry, in government labs, and in many physics faculty jobs where teaching is emphasized more than research.

My advice to students I mentor is to work hard, get really good at a few things, and don't constrain your career possibilities nearly as narrowly as your PhD path.
I see, thanks so much for that response. I think I agree; I feel like I want to do Physics for the rest of my life right now, but I do not know how I may feel 4-6 years from now, I should keep my options open. Thank you!

#### mfb

Mentor
Why is that? Is it because the chances are so low?
Yes.
I see, so I can probably get experience of doing both while I'm doing my PhD and getting some skills of an experimentalist like working in a lab will come in handy later. Out of curiosity, does my lab experience during my undergrad years count or not?
Difficult to tell from your description, and it will depend on what exactly you apply to and so on.
As of September 5, midnight, there are about 14 faculty position openings that I see there. That doesn't sound too small of a number, does it? I'm sure you'll be competing with the best of the best of the best in the world, but based on how much hype I've seen about the scarcity of faculty positions, I think I had my expectations very low and was expecting to see like 1-2 openings only
You didn't specify which field of physics. Pick one and see how the number of positions shrinks.
And then consider that they will all get tens of applications. With overlap, sure, but the number of people trying to get a job is much larger than the number of jobs.

#### Dr. Courtney

Gold Member
2018 Award
I see, thanks so much for that response. I think I agree; I feel like I want to do Physics for the rest of my life right now, but I do not know how I may feel 4-6 years from now, I should keep my options open. Thank you!
I've never held a faculty position at an R1 university, but I do feel like I've been doing Physics for most of my career. Some jobs I've had - engineer at wireless communications company, engineer at scientific instrument company, Physics faculty at community college, Physics faculty at second tier state university, high school Physics teacher, math faculty at USAFA, consulting scientist for Department of Defense related business (armor and weapons systems).

Yes, a few of those jobs was more engineering or math or teaching in the day to day of it all. But there was always enough Physics to satisfy me and keep it interesting.

#### Phys12

I've never held a faculty position at an R1 university, but I do feel like I've been doing Physics for most of my career. Some jobs I've had - engineer at wireless communications company, engineer at scientific instrument company, Physics faculty at community college, Physics faculty at second tier state university, high school Physics teacher, math faculty at USAFA, consulting scientist for Department of Defense related business (armor and weapons systems).

Yes, a few of those jobs was more engineering or math or teaching in the day to day of it all. But there was always enough Physics to satisfy me and keep it interesting.
I see...if I may, is that by choice? Or did you want to get a faculty position?

#### Dr. Courtney

Gold Member
2018 Award
I see...if I may, is that by choice? Or did you want to get a faculty position?
I was never really interested in a Physics faculty position at an R1 institution. My view is that these positions put too much weight on maintaining high levels of funding for research and supporting graduate students. As an undergrad Physics major and then a grad student at R1 institutions, I saw my faculty mentors spending too much of their time worried about funding - writing grant proposals, etc. - and not enough time actually being scientists, doing the research, and engaging with students. I respect folks who take that path, but it was not what I wanted.

My career has also been shaped by geographical constraints that come mostly from the priority of my family in my life. I am married to another PhD level physicist, and it has not been uncommon for us to make geographical choices based on my wife's career opportunities. We decided early in our marriage never to live apart and pursue careers in separate locations. Geographical constraints require some career compromises along the way. I wouldn't be opposed to a faculty position at an R1 institution if it didn't put me on the funding treadmill, but these are few and far between and opportunities have never fit my geographical constraints of staying close to my wife.

#### Phys12

I was never really interested in a Physics faculty position at an R1 institution. My view is that these positions put too much weight on maintaining high levels of funding for research and supporting graduate students. As an undergrad Physics major and then a grad student at R1 institutions, I saw my faculty mentors spending too much of their time worried about funding - writing grant proposals, etc. - and not enough time actually being scientists, doing the research
That's interesting because I've felt that too. It makes sense why they would do this, they need continued funding in order to continue the Science they want to do. But wouldn't it be the same case regardless of whether you're at an R1 institution or not? In order to do research, you will need funding for which you'll need to write grant proposals? Or did you mean that you wanted to put more emphasis on engaging with and working with students than doing a lot of research and publishing?

#### Dr. Courtney

Gold Member
2018 Award
That's interesting because I've felt that too. It makes sense why they would do this, they need continued funding in order to continue the Science they want to do. But wouldn't it be the same case regardless of whether you're at an R1 institution or not? In order to do research, you will need funding for which you'll need to write grant proposals? Or did you mean that you wanted to put more emphasis on engaging with and working with students than doing a lot of research and publishing?

My google scholar page shows that I've published over 100 papers since 2005. The median expense for the research represented is less than $1000 per paper. The few grant proposals I have written amount to less than$10k per year in research funding. I doubt I could have supported any grad students or if this level of funding would have retained employment at most R1 universities. Yet, the modest level of funding has been adequate for the science I wanted to do, and I am satisfied with my research productivity and career.

"How risky is doing a PhD in theoretical Physics?"

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