Engineer turned physicist: End of second year PhD physics update-Vaibhav Sharma | Physics After Engineering blog

It’s been two years since I started my PhD program in physics at Cornell University and it’s been quite an eye opening journey so far I must admit. I have always written about going from engineering to physics before this, but I guess it’s time to share experiences from the other side now.

In these two years, there are a lot of things I have discovered and realized. Note that all these things might be more specific to PhD programs in the US, but some things are of course generic.

The Physics

Before entering the PhD program, I felt that I knew quite a bit of physics, knew a lot of buzzwords perhaps and you know, you think you would solve the big unsolved problems in physics. But boy oh boy, wait till the reality hits you hard. It’s quite common for students in their first couple semesters to start attending other professors’ group meetings to know about their research and eventually join their group. I was interested in theoretical condensed matter physics, so I went to those groups. And that’s where I started realizing how little physics I knew.

So many things discussed in research flew right above my head. Not to mention, there was so much technical details that I just didn’t know. At this point, I started attending seminars and colloquia that happen every week. It was pretty much the same. Soon I started finding out that there is so much more to physics than what I knew naively. Every field in physics is interesting and challenging. One starts out thinking that things like the origin of the universe or dark matter is the stuff we don’t understand, but it turns out that we aren’t even sure about the correct equation of motion of an accelerating electron! I feel the more you learn, the more you realize that we don’t properly understand even the most basic things.

There is a lot to learn, and in PhD, you would realize that you have to read and learn a LOT to become a top notch physicist. You can be at the top of your class in your undergrad or masters because you are all taking effectively the same courses, but in PhD, everybody knows more than you about most things. Everyone is an expert in their own thing. And you would regularly get the feeling of being clueless. But I guess that’s the new normal and you have to accept it. And that is one of those things that drive me everyday, the quest to learn more.

Depending on the university, you often have to take some graduate level physics courses. My university had no such requirement but I still took the courses depending on what I wanted to learn like Quantum Field Theory and Advanced Statistical Physics. One big change here is that your grades no longer matter. An A grade doesn’t mean anything if you didn’t understand the physics. Ultimately, it’s your grasp of the physics concepts that matters now. All my grades/ranks in the past are now completely useless. You realize that the only metric you would be judged by is the quality of your research.

Money and Finding an advisor

In the US, this is the biggest thing you have to worry about in your first couple years. For me honestly, it worked out pretty well. I found an advisor at the end of my first semester. But from others’ experiences, I know that it isn’t always smooth. In American programs, your funding either comes from your advisor, or you have to be teaching assistant (TA) in an undergraduate physics course.  All students are TAs in their first year, and then if they find an advisor, they are expected to get their salary from them.

Turns out experimental physics is rich. If you are an experimentalist, you find a professor and your salary is confirmed. No problems. (at least in most cases). For a theorist, things aren’t that rosy. Theory professors tend to get less money as research grants here, and hence they often cannot fund students on their own. So theory students have to be TAs throughout their PhDs to get funded. They still get the same amount of money as experimentalists but of course, this means that you would have to sacrifice some time that you could have spent in research. For me, my professor has got some funds, so I TA in alternate semesters, and in others, I am funded by my professor.

It is important to find a group relatively early. Once you get here, there can be competition where multiple students want to work with a professor while the professor can only take 1-2 students that year. The professors often make you do trial projects, and depending on how good you are, they would accept or reject you. So your research experience and your physics knowledge comes in handy here. It is not uncommon for some students to not be accepted in their group of choice. But if you work hard and plan well, most manage to get in the groups they want. 

PhD life

I think PhD is a great privilege, where you are essentially paid money to learn physics, and you don’t really have a boss (even though your advisor has a lot of power but let’s pretend that it’s not the case), and that means you can decide what to do with your time. I have picked up quite decent cooking skills, and can cook great food for myself. I don’t have to be necessarily dependent on restaurants to have Shahi Paneer. I often play tennis, and actually a lot of physics grad students play sports even though one might think that physics students are dorky. Lots of events are always happening. There are plenty of seminars where you not just listen to people talk about physics, but you get to socialize and hang out with other students. I have a shared office which means there are always people around me to talk. So it doesn’t get too solitary either. Physics is actually more social that one might imagine. In fact, a solitary physicist working alone is a myth. If you are a top physicist, it means you have loads of collaborations.

All in all, I have realized that PhD is a marathon. You don’t have to sprint right now, but if you want to reach the finish line, you have to keep going, come what may. Slowly and steadily, you would gain more skills, and be a competent researcher. And for me, I have still got a long way to go.

Vaibhav Sharma
Second year PhD Student

Cornell University

About the author:

Mr. Vaibhav Sharma is currently pursuing his Ph.D. in the prestigious Cornell University, an ivy league university which is the 14th best university in the world and is among the top 10 universities in the USA!!

The fact that he once was an engineering grad like most the readers of the blog, should give us all enough hope and assurance to pursue our passion for physics after engineering.