Faculty Interview with Dr Girish Kumar Rajan

PS: All the pictures in this article are from Sir's grad school days.

Armed with all the questions they wanted to ask and all the curiosity in the world, two faithful editors from Team Udaan made their way to Girish Sir’s office on a cold, rainy December evening. All set up across his desk, they were ready; ready with all the things they wanted to hear about his life, his experiences and his journey with academia. And thus, began Team Udaan’s faculty interview of the season! From hearing about his dislike towards pizzas and his unique approaches to examinations to hearing about his weekend trips to the movies during his undergrad days, there was a little something interesting in every turn of Girish Sir’s life, and he narrated it all to us. 

Every specialist has a defining moment in their life when they realise, “This is it. This is the field for me.” We were definitely keen to hear about Girish Sir’s. 

He started by recounting his fascination with mathematics, that had taken root at a very young age, just like his interest in teaching. 

"I was always on the lookout for something related to Mathematics. That thought alone would keep my brain occupied all the time during my school days; I liked solving puzzles and equations. People often wonder what I would get by just deriving and solving equations, but that is my bread and butter today. I just can’t thank mathematics enough for whatever I have gotten out of it. As I branched out, I became interested in engineering. In college, I was introduced to this field of fluid mechanics. I was impressed by the level of Mathematics that was employed in this field and decided this was going to be my area of future work and research.”

In the middle of this conversation, he sneaked in a tiny bit about why he likes teaching all the more.

“You get to inspire young minds. I am waiting for the day when someone will come back to me just to say, “I am what I am today because you inspired me back in the day with your lectures, and you are one of the many reasons I am working in this field.” I want to say those words to a few people and thank them for their motivation and inspiration. No award can come close to such acknowledgement, and it is perhaps the one true dream of any educator.’’

Girish Sir then went on to narrate his under-grad days and relive the memories of his first experience with Fluid Mechanics. He told us about his professor, and the course itself, in which scoring the top grade was extremely difficult. Deja vu, fellow Mechanical students! His professor would expect the very best out of them and always push them to think out of the box. Astonishingly, nearly 20% of his class is still working in Fluid Mechanics and its sister fields; a true testament to the ability of that professor to inculcate love for the subject. 

After his Undergraduate Degree, Girish Sir moved abroad to pursue his Masters and PhD Degrees. As he recounted his days at Penn State, he told us about his professors and the unexpected decision to do a Master’s Degree in Mathematics as well, explaining to us the fine differences between mathematicians and engineers.

“I once had the chance to witness a debate between engineers and mathematicians, and I was astounded to see the fervour with which they exchanged arguments. At the end of the debate, I realised that one set was interested in real-world applications, did not mind approximations, but cared about dimensional consistency all the time, while the other was interested in exact solutions, their existence, uniqueness, proofs, theorems and so on. There is a very visible line between the two, and it’s up to us where we want to make our stand. I liked the interface between Applied Mathematics and Engineering, and I decided that is where I wanted to be. I wanted to have a good background in Mathematics and also be an Applied Scientist who could extract the Physics out of raw Mathematics. 

So, my interest in Fluid Mechanics was driven, is being driven and will be driven by my flair for Mathematics. I cannot imagine being in a field without Mathematics; I would consider it to be a rather dry and boring field. I believe my students will know my penchant for equations in particular and  mathematical analyses in general: to push and push and essentially beat the system to death, squeezing out all the physics.”

We sat with him as he narrated his life as a student, reminiscing how his passion for teaching showed up long before he became one. He claimed to be a student who would study hard during his childhood, as his school gave a lot of importance to doing so. They made the students aware of IITs and other prestigious universities right from middle school, preparing them for that journey from a young age. 

It was in college that he started exploring life beyond academics.

“I did not let my interest in academics fade away - I was still the “top dog,” but I was also involved in other things. I was into dramatics, making short films, writing, and a bit of sports. Not to mention the obligatory college trips, watching movies every other week, a bit of social service and so on,” he narrated.

“There was a junior high school nearby, and I used to teach the kids math and science there; that’s where I began my first stint as a teacher. These days, students often complain that they are unable to find time to manage all the things they are interested in. Back in the day, it wasn’t like that - the difference between those days and now is most likely the mobile phone. We had them back then, but we didn’t spend as much time either texting or scrolling as students of today do.”

However, after going abroad for his Masters and PhD, he had to cut back on some extra-curricular activities due to the intensity of his studies and research, as he now had to indulge passionately and give more emphasis to details. Despite the demands of his research and academic journey, he figured out how to keep his sense of adventure alive. After ensuring steady progress in his research, he enrolled as a member of Penn State’s campus recreation club and began participating in outdoor activities.

“I have tried my hand at several adventurous activities, including kayaking, rafting, snowboarding, skiing, caving, rock climbing, and ice skating. These activities, which were frequently organised by the university’s outing club, proved irresistible and turned out to be great stress busters. Come to think of it, words such as stress, strain, pressure, and tension are not uncommon in an engineering college. What is surprising, though, is that these are increasingly being used in a nontechnical context. Outdoor activities are very effective in combating stress, so I recommend that students cut down on screen time and use it for such activities instead.”

He mentions how he found certain aspects of the teaching systems abroad particularly appealing.

“In most cases there, students are governed by an honour system; they would essentially be on their own, be it assignments or exams or learning in general. Most of the professors would be open to the idea of a take-home exam or an open-book exam, especially in grad school, where class sizes are manageable. We had a lot to learn from such exams and assignments. There was no sense of “impending stress” for an exam or an assignment; things were more flexible. We were able to stay relaxed during exams, which helped us think better and eventually brought out the best in us. The lack of dependence on rote learning meant that students did not have to gear up for an exam and just had to show up, ready to think. But you must remember that this model works only for students who are sincere and for those who enjoy being part of the academic system.”

But what of deadlines? Well, deadlines were always there, but the goal of an assignment or an exam was never to “impress the professor” or “obtain good grades.”  Assignments and exams were designed to push us to fall in love with the subject and to make us realise that learning can be enjoyable and effective when there are no restrictions. Back in the USA, students typically follow an informal structure for exams and learning. I loved that experience and approach to learning both as a student and as an instructor. I eagerly await the day when something like that can be implemented in India as well.”

Through and through, Dr Girish K Rajan was a nerdy student in school, an outgoing extrovert in college, and a passionate academician during grad school.

When asked about his dream of professorship coming to reality, and about his earlier career prospects, sir replied, “I don’t know if you will believe me, but I wanted to become a teacher ever since my elementary school days. There was no looking back, and I had no other dreams ever since. That was until I learned about pursuing a PhD, and from that moment on, I decided to become a professor rather than a teacher.” He was also among those students who would naturally find themselves teaching their friends and classmates before exams; the act of teaching seemed to be an innate characteristic of his.

The particular freedom that professorhood provided was also captivating to him. “I decide what I want to do,” he says. His desire to be in touch with books, academics, and young minds who would be up to date with current trends also made it a great place for him to be.

Of course, for all you aspiring professors out there, don’t worry; we've got you covered. We made it a point to ask about his approaches to teaching and how he prepares for lectures.

“It depends largely on what I’m teaching. In case it’s undergraduate level Fluid Mechanics, then I don’t prepare much. I don’t read textbooks as such, but the day before each lecture, I spend time running the lecture in my mind. From the outside, it may appear as if I’m just staring at a wall, and people will find it hard to understand that I’m actually thinking of the things that I should be telling the students during the lecture, the things that I should be emphasising upon. Essentially, I’d be staging the whole play in my mind. There’s a lot of activity going on in my mind ahead of the lecture.”

I’ve been offering this course (Fluid Mechanics) for a long time, and I’m very comfortable with it. But in other courses like Heat Transfer or Compressible Flow or CFD, I do spend a lot of time preparing, although not in the typical sense. I don’t just read books or material. I tend to push for the finer details. There are standard derivations and techniques out there, but I’m constantly on the lookout for other ways and methods to improve how I teach. I also often ponder on questions asked by students from previous batches to analyse how I can teach the material better and what else I can add if I’m handling the course in the future as well."

Long story short,  he simply does not like to be bound; whether by a rigid "script" or presentation for the lecture, which locks the discussion into a fixed order with no room for deviation, or by the constraints of time, such as the typical 50-minute lecture periods, or even by the boundaries of a syllabus, which dictate the limited concepts to be discussed. He believes that lectures must be ever-evolving, depending on students’ reception to a given concept. According to him, this is what contributes to the “liveliness” of a lecture. He notes that in the true spirit of knowledge transfer, there should be no 50-minute time limit, and his love for the subject and the feeling for continuity are what occasionally push him beyond stipulated end times. 

“I think the real deal for me to deliver a good lecture is how different I can be as a Professor in my ways of teaching and conveying concepts. Do I do things that are not in the textbook? Do I add additional pieces of information to help immerse the students in the concept? I’d like to teach in a way that my students come back to me to tell me that those extra details and steps I take are making the course more interesting for them. The students of an IIT wouldn’t really need me if I were to simply repeat what is there in the textbook. They are really brilliant and can easily pick up a book and learn what’s given there. Not to mention the millions of lectures online - so students can learn from wherever they want to really.”

He also made it a point to tell us about his approach and beliefs around examinations and how they should be. 

“With all this said, I should mention that I spend a lot of time thinking about the questions that I want to include in my exams. I often spend days writing, rewriting, and revising my questions, rephrasing words, and adding/removing sentences, eventually ending up with several drafts of the exam before I make up my mind. On average, from the first draft, the exam would have seen at least half a dozen revisions before it gets printed and handed out to students. 

I like to challenge students with questions that are not from a typical textbook or question bank, forcing them to think and analyse on the spot rather than remember or simply regurgitate what was covered in the lectures.”

We then delved deeper into his policy regarding attendance and his keen interest in getting to know each student in his class on a personal level.

“I know students who have truthfully admitted that they are not really interested in my course. In fact, we have also had students who are not interested in Mechanical Engineering as a whole. It is good that students feel free to open up to a professor and tell the truth, especially in such things. Though I do not mind when students confide that they are not interested in academics, I cannot simply let them off the hook. After all, they’re here for a reason. Nevertheless, I am not convinced that forcing someone to attend my lectures or spend additional time on my coursework when they don't really want to will be of any help.  At times, I try to talk some sense into them, but eventually, I leave it to them to decide. When all is said and done, it is their choice if they want to attend my lectures; they are free to bunk off if they feel that this is not their cup of tea, and that’s the truth - but then, the onus is on them to recover the loss, if there’s any.

One of my guiding principles has been to remember the names of all my students. I can say with a fair degree of confidence that I still remember most of my students’ names with the exception of the class of 2023, for whom I offered two core courses, but both from behind a computer screen. The personal connection runs so deep that I can easily tell who is absent (during a lecture) without an attendance list and estimate who is regular to my classes and who is not. This is especially possible because of the student strength we’ve had so far. I have offered courses with about 100 students present in my class, but even then, I got to know all of them - at least by the end of the semester. As the years go by, I may forget some names, but I’ll definitely remember the faces. 

At the end of the day, I don’t want to be a non-living entity in the classroom. I want to do away with fixed sequences. One might choose to disagree with me and follow other models that work for them, but this is what I go by.”

For those who are interested in knowing more about Girish Sir’s research, he and his students explore interesting problems in fluid mechanics. One of the multiple research problems that his group focuses on is waves at the interface of two fluids with different densities and viscosities. One of his students is investigating the various mechanisms by which such waves dissipate energy, additionally attempting to model the damping rates using mathematical techniques. The end goal is to understand how the composition and rheological characteristics of the sea surface microlayer can influence the damping of gravity waves on the ocean. Another student of his is involved in the computational fluid dynamics simulation of sloshing in moving liquid containers to investigate the dynamic loads acting on the walls. Girish Sir is further expanding into other fields, such as non-Newtonian fluid mechanics;  two recent students who joined his research group are attempting to mathematically and numerically model the flow in elastic blood vessels of arbitrary shapes. In the near future, his research group also hopes to collaborate with chemical engineers to investigate the dynamics of surfactant-laden fluid interfaces and the bubble rise phenomena in non-Newtonian slurry mixtures.

We moved to the next question - For a person who has certainly dabbled in a lot of extra-curricular activities in the past, do you try to keep up with them or occasionally get back in the game?

“During my teenage years, I was into reading and writing. I kind of feel like I don’t have time for those now. I do read and write, but it’s always technical stuff, not fiction or anything non-factual. I would like to get back into the habit, though.”

“I cannot really think of anything from that time that has still continued with me. I think the lifestyle and profession I have chosen have kind of made me move away from those activities. It also has something to do with the people I am surrounded by - there are activities that you can do alone and those for which you need a bunch of like-minded people with the same wavelength.” He goes on to say that he would love to get back into dramatics and making short films again; however, not many people his age would be interested in the same. He’d love to watch stage plays and short films and give feedback to students. So we know what we could be doing next time!

An interesting analogy made by Sir:

Students often ask questions such as “What’s the point of learning this? When will I ever use this in my life?” I feel that whatever you learn is like some liquid medicine injected into your bloodstream: you do not know explicitly how it mixes with the blood, where it travels, and how it helps in the healing process. How does it know where to travel and what to heal, what cells to heal, and stuff like that? So that is how things are. You learn things because you like them - they can help you in ways you can’t easily measure or get hold of. For example, they can contribute to improving your critical thinking skills and your logical reasoning ability.  In fact, you can never really single out specific events or things that made you what you are - whatever you are going through contributes to your growth in some way or the other. It is not possible to produce some tangible evidence all the time to show that everything you learn will lend you a helping hand at some point in your life.

In a world increasingly defined by instant gratification and the pervasive influence of smart devices, Girish sir underscores the significance of cultivating patience in the pursuit of knowledge.

“I also get asked about the importance of learning to be patient. I feel that it is becoming increasingly challenging to make students understand that they have to be patient and keep working till they obtain meaningful results. Not that we were really patient as students, but then, the degree of impatience that students of today exude is certainly a matter of concern. I don’t blame them altogether—certainly, the trend has a lot to do with smart devices.

For instance, I keep reiterating during lectures that in many fluid mechanics problems, one has to grind through a lot of math to reach a stage where the physics can be teased out to understand what’s going on. In the end, it will certainly be worth the effort and you won’t feel the pain if you enjoy the journey, so don't despise the journey (math)! I keep talking about fluids and math because of obvious reasons, but I guess the points I am trying to make can certainly be generalised.”

When asked about his hobbies and other interests, he told us about his fondness for movies, of various genres and languages. This sparked an interesting discourse around the things he used to do back in the day, as an undergraduate student who had plenty of time to visit movie theatres and watch movies with friends. 

“The movies that are truly memorable are the ones I watched when I was a student, like you. My attention span has been decreasing over the years. It might look like I'm listening to you, but then you never know. I might just be there, but my ears would be dysfunctional, and my mind would be thinking of so many other things. Nowadays I don't have a good attention span, so the movies that I watch these days do not make an everlasting impression as the ones that I watched during my student days did.

I remember those days when I used to go with friends to watch movies in theatres. Watching a movie on the big screen was a frequent and favourite activity of mine when I was in college. I don't think many of you are doing that right now. You have this direct-to-home OTT culture, and you hardly ever venture out to watch movies. Back in those days, every other weekend, we used to go watch a movie, dine out, and have fun. We got to roam around the city, hang out with friends, and talk endlessly about random things including relationships, food, politics, culture, science, language, art, human behaviour, evolution, philosophy, and history. Ofcourse, we were not really worried if our conversations were meaningful, and if they made any sense—we talked just for the sake of it! It was during such conversations I realised how the things I had learned in school—those that I thought might never be useful to me in my life—helped me in unusual ways. For instance, my limited knowledge in history that I had acquired while in school helped me spark off a conversation with a like-minded classmate—who would then go on to become a great friend because of the camaraderie that such conversations fostered. Little did I know that learning history in high school would help me get a good friend several years later. As I said before, everything that we learn has something in store for us—we have to be patient, vigilant, and mature enough to understand it. My appeal to students is to think well before they decide to trivialise things that do not appear to constitute helpful “life lessons” in the first instance and deem them useless—it might be a while before you realize their importance.”

Probing into these other things, we discovered that he was also an avid debater. He stressed on the importance of such discussions, especially with peers in college and the role they play in widening your perspective on the outside world. 

“We are always stuck in this cobweb, and in the thought that the entire world is simply what constitutes our immediate surroundings. The depth of knowledge and the thought that takes you outside that small sphere is something I developed when I was in college by debating with many people. We had people from different geographical locations, cultures, backgrounds, habits, and there were so many variations. Prior to college, I was oblivious to much of the world around me, whether it be politics or the societal issues at hand. But through these debates and discussions, I came to realise there is so much more to life than what I have been experiencing.”

At this point, we were very well into the interview and not looking forward to it ending. Girish Sir had given us a lot to think about and reflect as we walked through his academic journey, weaving a story that gives aspiring students hope and wonder for what could be of their own futures. But all must soon end, so we turned to a topic most loved by students - sleep.

Sleep is every college student’s blessing and nightmare, and we asked sir for his perspective on this universal experience.

He told us that when he was a student, he had a professor who claimed that a student requires a minimum of 5 hours and a maximum limit of 6.5 hours a day to ensure that the student is neither tired nor lazy. 

“While I did try to implement this in my own life, I was led to a few new learnings. Students wish to do a lot of things with their time. I think it’s a critical age because you are not too old and you don’t carry all that inertia with you. There comes a point wherein other people around you will be interested in settling down rather than trying out new things, and it might be awkward if that is the moment you decide to try out something new. And if you do end up trying out things too young, you may not have the maturity to accept initial failures and be responsible about your learnings. The sheer understanding that everything does not work out from the get go comes after a certain age.”

He said that the age of an engineering student is perfect to match both of these criteria; you have the maturity to approach learning and appreciating failures and you are not burdened with the responsibility of earning. You have the liberty to fall down and get back up without it bringing your life to a grinding halt. 

“In order to do all those things, I think students should certainly cut out on sleep. I remember some of my friends who would come back to the hostel after lectures and just sleep off, then in turn be nocturnal and spend their time playing video games and doing other things that are not really beneficial as time goes by.”

“Rather than sleep, we must quantify rest, which would include sleep as well as free time wherein there’s not much to think about and your nerves and muscles can relax. Something that I would like to call a “free state of mind.” I believe students need both sleep and rest to some extent.”

“Lastly, it’s not about a fixed number of hours of sleep, but how well you use your time effectively to do the things that you want to do as a student. And I think trading your total unproductive hours of screen time for hours of sleep seems like a fair deal.”

As for his own sleep, he averages around 7-8 hours a day, for all of you wondering. He admits that he did not account for weekends while coming up with these numbers.

During our discussion on his journey to become a professor, he told us of this eerie foretelling of his life back in the day. One of his school teachers predicted that he would go on to college, go abroad for his graduate studies, and later return to India to become a professor. He assured us that this was no feat of predictions, horoscopes, or something of the sort. He told us that it was simply close observation and extrapolation. 

“She was able to predict that after observing me for a while. You observe someone, and then you extrapolate. Sometimes that extrapolation may be accurate and sometimes it may not be. In my case, her prediction did turn out to be true.

I had this kind of faculty-office-like setup right from my childhood. I would keep collecting books. I have a huge collection of books at home, on random topics. I can never let go of any book (whether I read it or not is a different story altogether!). I can let go of old clothes or anything else, but not books. So, I had this ambition of teaching right from school. Now, my dream is to simply try and motivate some students to come to this field.”

“I'm waiting, like I said, for the day when someone will come back and tell me that I am one of the many reasons why they chose to be a professor. They need not even come and tell me; it's enough if they think of it for a moment. I think of many people like that. I'm not able to go and tell all of them; sometimes I write emails, sometimes I call them. Some of them are no more; some of them, even if I want to, I cannot go and tell.

There are many people that I want to thank, but I'm not able to. But then I think of them all the time. I’d be happy if I can make at least a few students remember me for my lectures; for my style of teaching. If a student comes back several years later and tells me the same thing - that's when I would call it a dream come true.”

We concluded with an insightful and hopeful question. 

“Dear Sir, looking back, is there any advice you would give to your younger self as you embarked on your academic career?”

“I feel that I should not have procrastinated as much as I did as a student, that I should have worked on the feedback I received from seniors, and that I should have realised many things that I failed to realise at that point in time because I was reluctant to invest my time and energy. I feel that I should have been more composed when I went through trying times.”

With a chuckle and a sense of newfound wisdom, we bid adieu to our enlightening conversation with Dr Girish, armed with invaluable insights to navigate our own academic journeys. Until next time, dear reader. We sincerely hope that you enjoyed this conversation as much as we did.