Is there such a thing as having too broad research interests in a Ph.D application?

Question

First some context. After majoring in astrophysics, I did an MA in philosophy of science before coming back to physics, where I'm currently working on my MSc thesis project. I intend to stay in physics and pursue my PhD in the field, but I want to contribute actively to the philosophy of physics throughout my career.

Recently my supervisor, who is very supportive, referred me to a funded PhD position in the overall ballpark of my current thesis project: gravitational wave astronomy. I have nothing to lose by applying, so I intend to do so. As is customary, the application asks for "a brief description of research interests."

I have some doubts about what to include because my research interests are too broad. I enjoy my current topic tremendously and I see myself capable of investing years refining my knowledge of it. But I am still very passionate about other theoretical and foundational issues in physics. Some of the latter led me to consider radically speculative ideas which have been derided by some physicists as havjng no real scientific basis, at worst, or at best being too esoteric to warrant "serious" scientific attention. I agree to the extent that I wrote my MA thesis on one of these topics as a philosopher of science, not as a physicist, and that community has different standards for what it considers of legitimate interest.

So my question is the following:

• should I include the full list of topics that interest me, including those I am passionate about and have researched academically, in my application? Or
• should I play it more conservatively and list the topics that I know are "safe" and have a direct bearing on the nature of the project I'd be working on in the PhD position?

Thanks!

Answer 1

It is common for people working in cosmic physics to maintain philosophy interests also.

Yet for the purpose of your immediate application, i.e. for funding towards a doctorate in the sub-field of gravitational wave astronomy, I think you should list and elaborate on your Primary Research Interests, then just add another section where you simply list your main Other Interests - and do not add any elaboration on the latter.

And do not raise the subject of your other interests at the interview or phone discussions with faculty of the institution applied to. And if they raise the matter, don't get too carried away into it.

Answer 2

Unless your program is interdisciplinary, it is probably better to focus at the moment. Research normally requires a deep dive into a narrow area, so, unless the program you are entering is special in some way, that is probably best.

That doesn't tie you to that narrow area forever, and it doesn't imply that you give up interest, and modest effort, in the wider realm, but a supervisor will likely want you to focus.

Many people with a reputation of being generalists in a field (thinking of Carl Sagan here) have, at one time, specialized to earn their place in the field. Once you have that place you are more in control of your path.

There is no reason, however, to avoid saying that you are also interested in the wider questions, but make sure you focus on the things that lead to a degree.

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Caveat. In the US, where most beginning doctoral students have only a bachelors degree it is normal to not have a research focus, beyond, perhaps, some fairly broad subfield of the field you enter. Mine was Math Analysis or maybe Topology, but no more focused than that. Admissions committees are used to evaluating candidates who are unfocused. That is much less true in other places and for those who hold masters degrees.