Sometimes, may relatives ask me what I do during a normal day. Somehow, many people can’t quite imagine what a theoretical physicist does all day long. Even though I am often guilty of not answering these questions in much detail, let me give it a try here.
I usually arrive at the office around 8:30, which is rather untypical for my breed (many colleagues show up anytime between 10 am and 2 pm, but then stay until late). I first read my e-mails and some blogs, and finally go through the new preprints on the hep-th (High Energy Physics – THeory) preprint arXiv. With this, I start my work day. We have lunch with our colleagues at twelve, and at 3 pm, we have a cookie break, where we meet with everyone else from IPMU. A few times a week, there are seminars to attend. I leave the office around 6 pm, then often do some sports, and think some more about my projects at home.
How I actually spend the bulk of my time depends largely on which phase I am in with the project I am working on.
In the first phase, which can last several months, I spend most of my time reading earlier works on the subject I am trying to get into, or looking online for suitable references to read. Before you can do something new, you have to know very well what has already been done, and you have to have a very good understanding of the subject matter. When entering into a new subject I previously knew very little about, it takes me usually about three months before I can start doing my own calculations. If my project treats a topic I am already familiar with, this time period is much shorter.
In the second phase, I have a precise problem to solve. I spend time doing calculations, which depending on the type of problem I might do on paper, or using the computer (usually Mathematica). I also spend a lot of time discussing with my collaborators, or colleagues knowledgeable in the particular sub-field. Ideally, this happens in person, but often also via skype, instant messenger, by e-mail, or even using google wave. This phase can take anything from weeks to months.
In the third phase, the results are written down and transformed into a scientific paper (often, there is a partial overlap between phases 2 and 3). Like most others, I use LaTeX to write my papers, which is great for formulae and generally nice-looking typesetting. When several people need to edit the draft, we use a subversion repository, which keeps track of all the changes and merges files that have been edited by different parties. This last phase usually takes several weeks.
The shortest time in which I have finished a paper was two weeks (but after about one year of work on closely related topics), the longest was about two years (but working on other projects in parallel). The rule of thumb is that when I think I am almost done and can submit in one week, it takes about three weeks longer than I thought ;-).
Often, people think I do mostly computer work, but this is only true in phase 3 (or phase 2, if I need to use Mathematica a lot). The reading and calculating parts can often be done on paper.
Of course, one often has more than one ongoing project, so the different types of work can get mixed. It’s useful to have something else to do when one gets stuck on one project, which is another thing that happens regularly. The worst part of the work is when I have a problem and don’t know how to solve it, and I just randomly poke around and read around, without knowing what to do. The easiest is when I know exactly what to do (read this thing, to a straightforward calculation, write down results, etc.), then I can just sit down and do it. The best is the part when I find the solution to a problem I have (but you probably guessed it, these short moments make up a tiny fraction of the time spent working).
Of course, there are also some administrative things, or work that this not directly aimed at a new publication, that need to be taken care of: submitting papers to journals, sometimes reviewing other people’s papers, organizing seminars, organizing business trips to conferences, preparing seminar talks, teaching duties, group meetings, etc. While for postdocs, these things take comparatively little time, many professors do little else! Luckily, I am still able to dedicate most of my time on research!