I have just completed the third year of an integrated master's degree (a three-year undergraduate degree plus an additional year of study at a master's degree level, with the final degree being an MPhys) in Astrophysics at a UK university. This summer I have to decide the topic of my final year dissertation, which counts for 50% of my final year.

I am almost certain I would like to continue in research and hence I am also starting to look for PhD places. I am very interested in cosmology, but with no idea of a specific area I want to go into and so I had thought of doing something in the field for my Master's dissertation, to get an idea of what it would be like to perform cosmology research.

However, the university I am at does not have a research group in this area and no facilities or expertise either. I have approached a potential supervisor (the lecturer who taught my one cosmology module, who is a plasma physicist), but he has told me that it is entirely up to me to decide on a topic/ question, which I am wary of doing due to my complete inexperience and lack of knowledge.

So, my question is this: if I decide to do my Master's dissertation on a different topic (eg solar physics), will I be at a disadvantage when applying for cosmology PhDs?

  • 2
    Just to be clear, you're thinking of staying in the UK for the PhD? The answers might be very different if e.g. you are considering the US.
    – user4512
    Commented Jul 4, 2016 at 18:30
  • 2
    I am almost certainly staying in the UK Commented Jul 5, 2016 at 17:23

3 Answers 3


Don't ask us.

Contact your favourite three prospective universities for your cosmology PhD. Better still, contact your favourite three supervisors for your cosmology PhD. Ask them:

  1. What Master's dissertation topic will prepare me best for my intended cosmology studies?

  2. What Master's dissertation topic will make me most likely to be successful when applying to study a cosmology PhD?

(The first question is much more interesting than the second).

You will find enthusiasm for engaging with your question and your situation, because you are expressing specific interest in their field and because you are not asking them to decide anything about your application – since you have not applied. Quite a lot of people in senior levels in cosmology are interested in cosmology and are glad to find interest in cosmology in other people.


Martin's answer is good, but I'd like to share my experience anyway, which is that the topic of your thesis is less important than the quality of your work.

That is to say, publications, good recommendations, good marks, and awards/accolades are much more valued than the specific topic that you worked on. People don't expect miracles from your master's thesis, rather they want to know whether you have the necessary knowledge/skills to embark on a PhD.

Yes, a thesis topic which aligns perfectly with your interests is ideal, and it may be a minor disadvantage if you can't work on such a topic, but ultimately it's not up to you what topics are available to you, and people in academia recognise this.

  • Off-topic: Nice alias!
    – 1010011010
    Commented Jul 4, 2016 at 21:00

In addition to the above, it depends very much on your funding (we are discussing the UK system here). If you will be self-funded, the supervisor will primarily look at your ability to finish (complete), and second to how open you are to work in an area the supervisor(s) is/are comfortable with. The limit here is how many students the supervisor can practically supervise with sufficient attention to each student.

If however you seek to have some scholarship you will likely be working on a previously specified project with certain targets in mind. You will be competing against more students (it's paid, there is more interest; direction can be helpful; there are less places available). In these cases it depends on the project and supervisor. Sometimes there just is a certain piece of work that must be completed. In other cases, some serendipity is possible and may lead to great research outcomes.

Even in the funded case the quality of your work, and especially thinking is the most important. Where a masters requires some independent, reflective, insightful thought, a PhD requires it absolutely. Working from that perspective, as a supervisor (not in physics though) I would expect you to have considered what would/could be the best solution. That you would not be able to do the project of your first choice would not really be held against you (unless it was for lack of exploring ways to do so anyway), but you should have good reasons for the second choice. Those reasons could be that you want to be broad and love that topic as well, or because it is closely aligned.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .