A Personal Approach to Research in AstrophysicsCole MillerThe step from successful coursework to successful research is often a large one, partic-ularly when the research is in astrophysics. There are a number of approaches I’ve pickedup over the years that seem helpful to me. The disclaimer is that there are many differentways to do research, and many people may disagree with me; also, I am speaking from myexperience in theoretical astrophysics, and other techniques may be useful in observationalastronomy.1. Talk to peopleWhen one is doing a homework assignment, the point is often to do it alone. Whendoing research, the point is to solve the problem. If you spend weeks sitting in a cornerbanging your head against a wall because you aren’t making progress, you aren’t usingyour time efficiently.Q: I want to talk to my advisor about my work, but he/she is unapproachable/busy/absent.What then?A: Talk to postdocs or older grad students. When I started doing research as a gradstudent, I was embarrassed to talk to my advisor because he was able to answer all myquestions without appearing to think about it; I felt I was asking low-level questions andmaking a bad impression. I resolved this finally by deciding that when I had a question, Iwould ask some postdocs and if they didn’t know the answer, then I would ask my advisor.This way, the questions that got to him went through a filter.Even if the person you’re talking to doesn’t help you directly, the process of explainingyour problem is often a great help. I can’t stress enough how bad an idea it is to curl upin an extradimensional ball and not interact!This extends to conversations with people outside your university. Down the line, itwill be important that professors at other places know who you are and what your workis. The best way for you to accomplish this is through personal contact. Your advisorshould facilitate this by allowing you to go to conferences and make presentations and, ifpossible, by making personal introductions. You can also initiate this contact by calling ore-mailing experts in your field with various questions. Here you really don’t want to get offto a bad start, so at least at first you should consult with your advisor about such externalquestions, then make contact (e.g., “Hello, Professor Jones, my name is Pat Johnson. I’ma graduate student working with Robin Smith, and I had some questions about axion stars.Do you have a few minutes to talk?”). If you make several such contacts with a professor,the professor will know who you are and will, hopefully, have gained respect for you.2. Don’t begin your research by reading the literatureThere are at least two good reasons to not start a problem by reading the literature.First, you will understand the physics issues much better if you’ve wrangled with themyourself. Second, you have a worse chance of coming up with something really original ifyou contaminate yourself with the thoughts of others.Of course, during your project there will come a time when it is very important tomake a thorough survey of the literature. You can’t think of everything by yourself, so1looking at other people’s work will give you lots of ideas. The other reason an eventualliterature survey is important is that when you write a paper you don’t want to tick peopleoff because you haven’t referenced their papers.Nonetheless, the long-term benefit will be much greater if you spend a while (days,maybe) trying to work things out yourself from first principles. This is one of the bestways to develop intuition: apply it from the start and compare it with what other peoplehave done.3. Don’t believe everything you readWhen you do get around to reading the literature, don’t treat it like holy writ. Thisis another big difference from taking classes. A textbook is often presented as the revealedtruth, which you should learn from but not challenge. Papers are a different story. They arereports on current research and therefore haven’t been tested fully and their argumentsaren’t as crisp as the ones given in textbooks. So, when reading a paper don’t assumeeverything in it is right! One approach is to read just the abstract, then go off and thinkabout things yourself for a while. Then, come back and read the introduction (for context)and conclusion (to see what the authors think they’ve added). If the paper is reallyinteresting to you, read the body, but don’t get bogged down in details. Above all, it isessential to read everything critically! As you read, constantly ask yourself: “Does thismake sense?”, “Does it conform to my previously developed intuition?”, “If the authorsdisagree with me, what is the resolution?”.There are lots of bad papers out there. If you put your brain on autopilot and believeeverything you read, you will mislead yourself.4. Don’t believe everything your computer spits outA large fraction of modern astrophysics involves numerical computations. There aretons of different techniques: Monte Carlo codes, radiative transfer, hydrodynamics andMHD, and so on. The single cardinal rule that applies to all numerical work is GIGO:Garbage In, Garbage Out. The computer only does what you tell it to do, and it willhappily spew out definitive-looking drek. The way around this comes back to intuition:what should the output be? If it doesn’t conform to your expectations, find out why.It could be that your intuition wasn’t developed enough, and that the output is right.However, in the majority of cases I’ve encountered, if the output isn’t what you expect,it’s wrong. I suggest that a productive attitude is that the computer is wrong until it isproven right! The point here is that although you use a computer to explore physics thatyou can’t solve directly, you must run enough test cases that you can solve directly so thatyou trust the final output.The tests you should conduct are both qualitative and quantitative. If you expecta x2dependence and the computer gives you a x4dependence, you need to know why.If you think the computer should give you 7.5000 and it gives you 7.48, you need toknow why. Apparently minor inaccuracies for simple problems can magnify themselves inunpredictable ways in the more complicated problems you really want to solve.25. Learn how the answer to a question depends on what you needOne of the toughest parts of the transition from classroom physics to research astro-physics is that the problems