If you want to be a physicist, you have to go through graduate school. There’s the enormous application process, flanked by months of preparation for standardized tests beforehand and then trying to decide what community of physicists you would want to spend the next four, five, or six years living with based on a whirlwind three days afterwards. Everyone you see who holds a tenure track position at a research university has the abbreviation “PhD” or the British/European equivalent after their name.

But why do we put our lives on hold for half a decade while everyone else is busy getting a “real job”, getting paid, and getting married? Why do we need another five years of education to learn things that we can’t learn “on the job”? Accountants, real estate agents, and a variety of other professions require maybe another year of certification. Lawyers and medical doctors spend just three, but they can tell you exactly what year, month, and day they will be done the moment they enroll. So why the uncertainty? What are we here for?I can think of a few reasons, but I’m just guessing from the perspective of someone who has just finished his first year.

1. To complete your knowledge of the fundamentals – Textbooks like J.D. Jackson’s Classical Electrodynamics and J.J. Sakurai’s Modern Quantum Mechanics are lightyears ahead of their undergraduate-targeted equivalents. This is your last chance to really “master” the basics, that you will one day be teaching others that come after you. Also, these things are tremendously useful to know to understand the material you’re about to research.
2. To learn what is being studied — With the raw number of papers published every month, it is difficult to figure out what is relevant, what is interesting, and then learn enough about it to contribute on your own initially. Every day hundreds of preprints are put up on arXiv and SPIRES. The only way to really “catch up” is if someone established in a field points you in the right direction.
3. To learn how to research — The research process is involved. I myself feel a little overwhelmed at times thinking about what I am doing. But this is why we have advisors: to show us when we reach a cul de sac in our research, and to suggest how we might get out.
4. To learn that you can research — Coming up with something new is a difficult prospect, even for people that have done it before. Some people just don’t “think the right way”, which is not to say that they aren’t intelligent or capable people. Perhaps they just think differently from what is required of physicists. Maybe they would be better lawyers. It is important to find this out before getting too deep into your career.
5. To show that you can publish — The ultimate end of graduate school comes with a successful thesis. The dissertation, probably the longest writing exercise of each PhD’s career, is like a giant check to make sure that you, the grad student, can write whatever is required of you. Review articles, scientific publications, possibly even textbooks, are all easier than writing a dissertation. In the interim, you and your advisor, and possibly other professors, will publish several times, and it is by doing this that you learn how to write a scientific publication.

I ask myself sometimes “Why did you pass up making three times what you’re paid now to go to grad school?” The only answer I can come to is that I’m doing what I love, and no amount of money makes up for knowing that what I’m about to do will be something that only about 1200 people succeed in doing each year: obtaining a PhD in physics.