Tales from Berkeley Undergraduate Physics and Astronomy

After recently having graduated with a physics and astrophysics degree at the University of California, Berkeley, I can finally fulfill a long-awaited desire to write down a reflection of my college experiences with some sort of satisfying completeness. In writing this reflection, I hope to achieve two broad goals: (1) to view my experiences with respect to some overarching lessons in summary of how I have developed as both a researcher and a person, and (2) to provide some anecdotal advice and expectations for students hoping to follow a similar path through undergraduate.

As for the former point, when looking back over a significant chapter of one’s life, a question begs to be asked: “what was it all for?” I find that it can be incredibly rewarding to try to understand what exactly there was to be gleaned out of a personal experience, mistake, or struggle. Under a composition of such meditations, I can hope to learn precisely how my overall college experience has shaped me from the shy, anxious freshman to the graduating senior today.

As for the latter point, when making big decisions in one’s life, one often hopes to optimize over the space of all possible futures. In practice, I have learned that the closest thing one can do to this is to learn from the experiences of mentoring figures. I would characterize my experiences at Berkeley as overwhelmingly positive, but I also must emphasize that this is only one of many perspectives, with a unique combination of privileges and struggles which surely differs from person to person.

Over the years, after every semester/summer, I have attempted to succinctly capture the overarching “lesson” within a single word. This is, of course, extremely reductive, perhaps overly so at times, but I think that such a summarizing “term” can provide some useful context for further insights. For the purposes of actually writing down my experiences, it also yields a very convenient partition of this essay in some vaguely coherent fashion. Sometimes the summarizing term is academic, reflecting some scientific theme, and other times it is a more general lesson about how I interact with others and view the world that I live in.

I started my journey at Berkeley in the fall of 2016, unsure of what to expect.

Freshman Fall 2016: Humanity

Like most students, I had never lived away from my family for any extended period of time, and was nervous about how I was going to adjust to college. Moreover, the pessimistic “depression culture” at Berkeley scared me into believing that, if I were not eternally vigilant about my academic responsibilities, I would inevitably fall further and further behind at the country’s most preeminent public university. Fundamentally, I didn’t really believe that I was the kind of person who could actually put in the work to succeed. Of course, I couldn’t actually know for sure how hard it would actually be to keep up, but luck favors the prepared.

I came to college with the intention of doing astrophysics, an arbitrary dream from seventh grade not backed up by any particular knowledge or especially strong enthusiasm. The truth was that, when I came to Berkeley, I didn’t really know what I wanted to do with my life, only that in high school I was generally enthusiastic about most subjects.

At Calapalooza in the first few weeks of school, I walked around the tables run by clubs trying to recruit members. While I signed up for the mailing list for a lot of miscellaneous clubs, I found myself most enthusiastic about the “physics club.” I really liked AP Physics in high school, and thought that I would love to hang out among other physics enthusiasts. This physics club, the Society of Physics Students (SPS), would meet at some corner of the then brand-new Reading Room in LeConte Hall and, while very casual, was also highly supportive to me as a new student. I look fondly on the awkward but endearing dinner that the SPS officers at the time had invited me to. I don’t think it’s a stretch at all to say that these early experiences were ultimately why I decided to major in physics.

My first Secret Schrödinger gift, which was a stocking full of miscellaneous treats and the books Hyperspace (by Michio Kaku) and QED (by Richard Feynman), which I would later find out was from now former SPS president Sabrina Berger. On the sign-up form, for three years straight, I would simply request “anything physics related,” and was never disappointed.

In my freshman year, I also spent a lot of time with the 3D Modeling Club, which was essentially the 3D printing club. While students in that club were comparably friendly and welcoming, I ended up finding it hard to actually fit in as I found myself less interested in the technical details of printing, and didn’t have too terribly many ideas. Nevertheless, I still cherish the time I spent exploring different clubs this first semester, which I feel gave me a diverse set of experiences and helped me discover what things I would ultimately be interested in.

A group photo of 3D Modeling Club members and other visitors to an Autodesk office at Pier 9 in San Francisco.

In this first semester, I took the normal track mechanics course (Physics 7A) as well as multivariable calculus (Math 53). While physics was moderately interesting as a slightly more in-depth version of AP Physics, I truly enjoyed multivariable. While it was the class I stressed out about the most and spent the most time working on, I was constantly enthusiastic about the content, especially the stuff in the later part of the course. Learning about Stokes’s and Gauss’s theorems as generalizations of the fundamental theorem of calculus was an extremely mind-blowing experience for me. It was also in these two classes that I met a new friend, a civil engineering major, who would become my future housemate.

I also took courses on linguistics and anthropology, the former being an old interest of mine and the latter being a back-up course when I was unwilling to be second-place on the waitlist for a philosophy class. Both ended up being reasonably interesting—I met a very good friend in my anthropology class, and always looked forward to going to linguistics and hearing about interesting quirks of language from Professor Larry Hyman. I would say that, in many ways, the lessons about humanity from these two courses were a large highlight of this first semester, since I had never taken—or even heard of—courses in linguistics and anthropology before coming to college. Learning about humanity’s rich and endless history and culture revealed to me an entirely different perspective on the world and people’s role in it.

Because of how much I worried about my performance in this semester, I would basically study all the time, constantly doing readings and not going to sleep until my homework was done a week early. While this cautious behavior wasn’t necessary in hindsight, I don’t regret the work habit that I established early on (though this was certainly subject to gradual relaxation over the years). And this is not to say that I wouldn’t occasionally hang out with my floor mates in Unit 3. Though I worked incredibly hard this semester, I was truly having the time of my life, and didn’t miss home at all (perhaps to the disappointment of my well-meaning parents).

Me relaxing in the floor lounge in Ida Sproul Hall (my residential hall) playing the ukulele, which was my frequent habit in between studying and doing homework.

Looking back, I would consider the coursework in this semester to have been incredibly light—I was only taking two core classes and some breadth courses. This is not to say that it was easy, but more so that, like in high school, I could definitely finish my homework assignments in a single night if I really wanted to—this would certainly not be the case later on.

Eager to get a head start on my career, I asked a graduate student mentor for advice about which professors would be taking undergraduate student researchers. After throwing out a couple of names of people and projects (including some prescient allusions to the Event Horizon Telescope), he recommended that I reach out to Professor Jessica Lu, a new hire from the University of Hawaii who worked on the Galactic Center. After emailing her three times, she decided to take me on and assigned me to an interesting introductory project on the Quintuplet star cluster under the guidance of fantastic graduate student mentor (now, as of writing, UCLA postdoc) Matt Hosek. I sometimes feel slightly embarrassed to recall exactly how little I actually knew about astronomy back then, but then I remember that those little, “obvious” questions were universal growing pains that people were fantastically understanding about. While I found my way into this project purely by chance, I came to realize that Jessica was maybe the most supportive advisor I could have hoped for—she assigned me to a reasonably interesting and also promising project, and was sure to make time for me when it was needed. Moreover, she stressed not just scientific details but also lessons about being a researcher: to write things down, to investigate curious aspects of the data set, and so on. Ultimately, my research in this first semester purely consisted of reading background material and learning Python from page one, but I was having a lot of fun.

The semester was also incredibly eventful for other reasons. I remember being incredibly upset in the bottom floor of Priestley Hall in the Unit 3 dorms, when I watched the news project Donald Trump as the next president on Election Day. I remember walking through campus the next day and seeing a large crowd of students gathered around the Campanile, in solidarity against a decisively unpopular choice on a historically liberal campus.

A gathering of people around the Campanile on the day after the 2016 Presidential Election, during which Donald Trump was elected to the presidency. A school with a proud liberal tradition, the result was “controversial” (to put it as lightly as is possible).

Some events during this semester also set an overall theme during my college experience of things catching on fire. I remember being woken up by a spurious fire alarm on the morning of my first midterm in linguistics and having to leave the building before haphazardly returning, showering, and heading off to class. Another time, I remember returning to my dorm complex covered in a thick blanket of smoke. I walked into the first floor of my dorm where my room was, seeing that it had entirely cleared out, but realizing that everyone on the floor had gathered in my room looking out the window. The church directly across the street from Unit 3 had caught fire, and my room was the closest room in the entire complex. Needless to say, we were some of the last students allowed to return to the dorms, so I spent the day hanging out with friends and sitting in on a chemistry class for fun.

A picture of the church neighboring our residential hall, which unexpectedly caught fire one day, prompting a day-long evacuation of all students from the area. Upon the fire alarm going off, one of the dozen-or-so students in my room mused that a gathering of so many Berkeley students should not have needed a fire alarm to remind them that it was time to evacuate.

Despite the sudden transition and unusual events, I ended up finding my hard work early on paying off, giving me a little boost of confidence. While high school was not a particularly exciting time from me, Berkeley started to feel like the place where I was meant to be.

Freshman Spring 2017: Approximation

After my first semester went well, I was cautiously optimistic about my abilities. Nevertheless, a large insecurity still loomed large, which was that I was perhaps not as integrated in the physics and astronomy departments as some other students. While I later found that major advisors are treasure troves for advice, College of Letters and Science advisors generally did not seem to know even basic facts about the majors in their college. Realizing that the honors Physics 5 sequence was much more appropriate for me as a physics and astrophysics major, I decided to switch from Physics 7A to Physics 5B. While this incurred some other annoying requirements, I enjoyed the new rigor immensely and found it to be very helpful to my later studies. Moreover, I enjoyed being in an environment with people who were just as enthusiastic about the subject as I was.

In general, this second semester was dominated by much more difficult coursework—all of the classes I took were either physics or astronomy, and I learned very foundational content in electromagnetism (Physics 5B), mathematical physics (Physics 89), and astrophysics (Astronomy 7B) during this semester. One of the things that stuck out to me most was how critical approximation was to physics. While this is unsurprising to any physics veteran, to me the extensive utilization of Taylor expansions in various contexts, order-of-magnitude estimates, and other approximations like the Fraunhofer approximation in optics opened up a lot of powerful analytical techniques that I would later find myself using countless times. My first exposure to experimental physics in Physics 5BL also gave me some preliminary appreciation of uncertainty propagation.

Overall, like in the first semester, I was extremely careful to keep on top of my coursework, but I had a lot of fun learning these new concepts. I still remember marveling when the instructor of my mathematical physics class, Dr. Austin Hedeman, first hinted to us that the complex plane had the same structure as a “vector space,” whatever that is.

This semester was the first semester that I really started working on my research project. Every week, I would be assigned some broad task, and I would meet with my graduate student mentor afterwards. Though at this point I still didn’t really understand much of the broad motivation of the project, I felt like I was learning a lot.

At this point in my college experience, I had been going to SPS meetings regularly, and had mingled with a lot of people in my physics cohort. I felt more and more like I had a home. I volunteered for an outreach event at the science fair at Thousand Oaks Elementary School, and discovered that I really liked to communicate science to the public. Later in the semester, I would decide to run as SPS’s outreach coordinator along with one of my personal mentors, a position which would set the stage for broader involvement in the club.

Most students in the class of 2020 would probably remember this semester for the extensive campus-wide protests of Milo Yiannopoulos’s appearance. One day, after an evening SPS meeting, I walked back down to the dorms through Berkeley’s Sproul Plaza, wading through a large crowd of people, many masked, gathered around a bonfire outside of the Student Union building. The press would later have a field day with sensational claims that Berkeley students had become rabid and violent—my counterpoint to this will always be that the masked intruders were almost all off-campus protestors, as a brick was thrown through the Amazon center, and no Berkeley student would dare harm the only nice thing they have.

During the beginning of this semester’s “dead week” (the week before finals), while hanging out in the dorms, I was again driven out by the fire alarm. By this time, the spurious fire alarms had become frequent enough so that nobody really believed them, but this time I left the building to find a crowd staring at a room on the top floor of our building, completely engulfed in flames. After some damage control, we were allowed back into the building, but our lounges were taken up by student “refugees” from the affected floor.

Freshman-Sophomore Summer 2017: Skepticism

After my freshman year, I went on a two-week trip to Europe with my dad. It was a welcome respite after a stressful but successful first year. I needed the time to catch my breath.

I promptly returned to school to do research. Research would sometimes feel isolating as I spent most of my time in a then-empty undergraduate office, and often felt like I was stuck on very tiny pedantic issues that I didn’t really know how to fix and would spent inordinate amounts of time trying to debug, without really having the technical know-how or patience to really deal with them. Nevertheless, I feel like I made reasonable progress on my project over the summer.

It was during this time that I attended my first group meetings, which in this case were structured around paper discussions and research presentations. It was during this time that I really learned to be skeptical—as silly as it sounds now, it was easy to take the impeccable formatting of a journal article as some kind of authoritative guarantee of validity, but it pays to remember that a large fraction of “surprising result” papers later turn out to be invalid for one reason or another.

I also took a very nice formal logic course (Philosophy 12A) over the summer, which I really enjoyed. It was another one of those classes that I felt that I really should have experienced in high school, as it gave me the semantic tools needed to communicate logical statements in a very systematic way. It ended up not being particularly difficult, but incredibly interesting.

Since Berkeley doesn’t guarantee housing, the previous spring I had gathered together some future housemates and we went apartment-searching. After nabbing a very spacious location about 15 minutes away from campus by walking, I ended up living in my first-ever apartment. During the summer, one of our roommates was replaced by a subletter who had very bad etiquette, and so the home situation was generally not very pleasant.

Towards the end of summer, I headed up to Corvallis, Oregon to hang out with some high school friends and witness the highly Amerocentrically dubbed “Great North American (Solar) Eclipse.” It was a fascinating experience which transcended the pictures I had seen on the Internet, and was moreover a time to reconnect with some friends from before college.

Observing the solar eclipse with Hunter (left) and Sachin (right) in Corvallis, Oregon during the Great North American Eclipse, a much needed respite from a rigorous physics curriculum.

Sophomore Fall 2017: Humility

Despite feeling better about my place at Berkeley, I was still extremely cautious in how I tackled new academic milestones in college. This semester would be the first semester that I would start taking upper division classes of any fashion—whether or not Math 110 (linear algebra) is a “difficult” class seemed to be pretty controversial among people that I heard from, so I erred on the side of caution.

I had approached the final courses in my introductory physics in my physics sequence, Physics 5C and 5CL (on quantum mechanics and statistical physics), where uniquely I was presented with some of the first “new” physics content that I had never heard about in high school. In addition to these risky STEM classes, then, I decided to take some breadth courses which had very “easy” reputations.

This semester, I had decided to myself that I would wake up at 6:30 am every day and walk to the SPS Room in LeConte Hall by 8 am to do more research. As SPS’s newest outreach coordinator, I had just gotten access to this community closet space which tended to be pretty quiet in the early morning. However, as I also insisted on doing all of the readings for my classes, I would often stay up late nights, subsequently arriving at school completely exhausted. Unlike in freshman year, I did not particularly enjoy the content of my breadth classes as much save for interesting tidbits about the culture of my parents’ home country. My physics class was utterly impenetrable, and I would take drastic measures to avoid having to think about it, and my laboratory class, while extraordinarily valuable, was in its first-ever iteration and extremely work-heavy. Both of my lab partners in that class subsequently left the physics major, and I began to see the number of my peers remaining in my major dwindle.

I don’t think it would be an exaggeration to say that this was my most unhappy semester—the one thing I wanted to do in college, physics, was not enjoyable to me, and I found myself spending so much time on things I didn’t want to do.

Really, the only class I actually enjoyed was linear algebra with Zvezda Stankova, who ruled her class with refined precision and strict but charming tact. While I had some informal exposure to linear algebra the semester before, I was finally presented with a math class where logical justification was central. Counterintuitively, this enabled more heuristic, intuitive reasoning about the subject, and it was during this semester that I felt like I truly “understood” what linear algebra was for, not in some pragmatic sense but in the sense that probably keeps proper pure mathematicians interested.

Another solace of mine was the extent to which I was able to be involved in the physics department. Prior to this, I had been living in the dorms during the school year and didn’t really know my way around my home department. This semester, I began to make many friends in my major. Moreover, in accordance with my responsibilities in the SPS officer board, I was able to be involved in organizing outreach events, which I found immensely rewarding. In this capacity, I felt like I was actually making a concrete difference in young students’ lives, and I was thankful for the opportunity to convince students that physics is cool. I think this experience was the beginning of my conviction that almost all physicists/astrophysicists secretly want the ability to convince people outside of their field why, in some very visceral way, what they study is awesome.

(from left to right) Rahul, Adrien, I, and Youqi explain physics to waist-high aspiring scientists at the Bay Area Science Festival, serving also as a reminder for us as to why we decided to study physics.

My research had come a long way over the summer, but I was confronted with the well-known stage of the project where the basic results were mostly there, but I had to go back through the procedure and refine little details here and there. The small loose ends that seemed so disproportionately small compared to the progress I had made previously would take weeks upon weeks, sometimes not resolving themselves at all until months later when I had given up and decided to think about something else. Of research projects, the adage “80% of the work happens in the last 20% of the project” had never hit so hard until I had to start cleaning up details and writing up my work, when I was humbled in awe of the towering wall of tasks to be completed. Despite this barrier, research was very rewarding as I gradually started to gain more of the vocabulary of my field, and I started to understand better and better why I was doing things (as well as, of course, an overall better understanding of what I was doing).

Astronomy as a whole also had a majorly exciting find. It was during this time that the first binary neutron star merger (GW 170817) was detected by LIGO, and this would rapidly evolve into a thriving explosion of multimessenger astronomy in the next few years.

While, by the numbers, I did fine during this semester, I had learned a very fundamental lesson. I shouldn’t be trying to choose my classes “strategically” with the end goal of doing well, because I will be destined to end up miserable. Rather, I should just do what I’m interested in, and that I should rely on that enthusiasm to make myself do well. While I can spend all the time, I want figuring out the path of least resistance to a degree and good graduate school, I wouldn’t be able to have the wonder that had driven me to do physics and astronomy in the first place. Through coursework and research, I had learned some humility, both in theory and in practice.

After declaring my physics major, my hastily taken photograph was included on a wall of Berkeley physics majors. Having one’s picture included on the wall is a personal point of pride for new physics majors, reflecting some sense of accomplishment.

Sophomore Spring 2018: Fields

Having learned my lesson the previous semester, I decided to stack a large number of early upper division physics courses all together. I decided to take quantum mechanics, electrodynamics, cosmology, and a quantum computing special topics class all at once. By this time, I knew that if things turned out to be too much for me, I could still reconsider my decisions. For the present time, though, I was set on learning as much as I could.

By and large, despite the nominally difficult course load, it was actually quite manageable for me. Quantum mechanics and electromagnetism were subjects that I had already learned before at least once, and I felt pretty strong in linear algebra. This is not to say that these classes were purely review—I actually learned so much about these topics during these semesters, seeing previous problems in a more insightful light and learning about powerful new formalisms for these topics. Cosmology, while sort of out of left field, turned out to be a dream come true in the sense that it was one of those classes with strong roots in Carl-Saganesque popular science that I could not believe I actually had the privilege of learning. I felt a bit out of depth in my special topics class on quantum computing but, despite my total lack of quantum mechanics experience relative to my classmates, grading was lenient, and I felt like bits and pieces of the course material would rear their heads again and again throughout later classes.

In all of my classes, for some reason, the unifying concept was thinking about doing physics with “fields,” objects taking on certain (scalar or vector) values at every point in space and time. With every new day and every new problem solved, I felt so happy for the new (astro)physics context that clarified the things that I would previously hear about but never quite understand.

Despite my calendar being more ink than whitespace, I was having the time of my life. This may have been the happiest semester of my college career, since I finally felt like I had what it took to belong in this community. Every semester had felt like a semester of “firsts,” first classes, first in-depth physics classes, first upper divisions, and now first physics upper divisions, and I had gone through it and proven that I could do it.

But I don’t want to make it sound like coursework was the only height of my life. In fact, while continuing to organize volunteers for outreach events (and having an unusually good time talking to new students waiting for physics advising at Cal Day), I also taught the Python DeCal for the first time this semester, after having taken the same course the year before. At Berkeley, DeCals are student-run for-credit courses and, in fact, I had inherited this post from a brilliant senior astrophysics major with whom I briefly overlapped in high school in San Diego. This would be another “first,” my first brush with teaching, and I was hooked.

A picture with Katie Latimer and Rahul Sahay, the preceding and succeeding outreach coordinators, respectively.
A picture with Orion Lyau, my Python DeCal co-facilitator and good friend.

Perhaps the saddest thing to happen this semester was the death of Stephen Hawking on π Day. I had devoured his books as a kid, A Brief History of Time and The Universe in a Nutshell, and was sad that the world had lost such an inspirational part of my childhood. During this semester, the first of two memorable lunar eclipses occurred, and I made my way to the top of Campbell at the early hours of the morning to see it (the first of a number of memorable astronomical events during college).

(from left to right) Frank, Andrew, I, Rahul, and Ivan pose next to our outreach weapon of choice, the van de Graaff generator, which has enthralled some significant subset of the next generation of Bay Area physicists.

Sophomore-Junior Summer 2018: Storytelling

As my project on the Quintuplet cluster was coming to a close (so I thought), I ended up joining an experimental atomic physics laboratory with the intention of exposing myself to a whole new field that I knew nothing about. I figured that, since I still had a lot to learn, it couldn’t hurt to try out different modes of exploring the universe and seeing what stuck. Miraculously, despite my obvious utter inexperience with quantum mechanics at the time, Norman Yao gave me a place with his experimentalists studying nitrogen-vacancy (NV) centers. I spent most of the summer working on measuring the autocorrelation of NV center fluorescence to identify single defects. Basically, as single atom-like structures, NV centers should only ever be able to emit one photon at a time, so I worked on an experimental setup to figure out of a spot we were looking at in a confocal scan was indeed a single NV center (as opposed to, say, a couple all near each other). I found the work reasonably interesting despite the extremely different workflow, but, having joined this new group, I was back at the point where I felt like I didn’t really understand what was going on, or what the motivation for anything was. This time, though, I had some belief that I would be able to slowly but surely climb back up the ladder of understanding.

Over the summer, I decided to take the electronics lab, Physics 111A, which is a notoriously time-consuming class. A slightly sanitized version of a piece of advice was that “you should take Physics 111A over the summer so that at least it doesn’t mess-up the rest of your life.” And, though I did learn some valuable skills in the class, I overall didn’t really enjoy my experience too terribly much for a variety of reasons not purely academic.

Superposed with research and courses was my preparation to take the general Graduate Record Examination, the GRE, which was an unfortunately corporate rite of passage for anyone wishing to apply for graduate school. In my still careful fashion, I had decided to practice extensively, doing a practice exam every Sunday with my roommate. Summer culminated with a trip where my roommate, my friend, and I traveled to San Francisco to take the exam (in the process getting heckled by an intoxicated man calling us “spiritual Chinese with our math and shit”).

(from left to right) Myself, Jackson, and Nijaid, taking the BART back to Berkeley immediately after taking the General GRE in San Francisco.

During this summer, I also sat in on a lot of paper writing meetings for a recent project, and it was the first time I had really heard of serious attention being given to the “story” of a paper. While there is some sense in which science is objective, science is also a lot about communication. I watched as group members gathered together to pore over individual words and plot details, as well as to clarify the overall guiding narrative on which the science is delivered. Despite all the nitpicky details I sorted out during the summer, by far the most important lesson I learned was the importance of “storytelling.”

Once I realized this, I began to see understanding of this fact as one major distinguishing feature between younger and older students—younger students would talk about the nitty gritty details of what they do with no holds barred jargon-wise, whereas older students, equipped with self-awareness about the nicheness of their project, would rather explain why what they do is interesting, and how their work fits into that overall picture. Overall, I began to realize how the latter approach, despite its relative simplicity, is far more effective in communicating scientific information (and is quite honestly the only memorable way of doing so).

At the end of the summer, Professor Robert Littlejohn, a weathered wizard of mathematical physics, retired, and his former graduate students and colleagues decided to hold a conference (Robertfest) in celebration of his lifelong scientific career. After doing some cursory volunteering, I was allowed to watch the talks, most of which were completely impenetrable to me. However, as being puzzled by new physics topics was not an unfamiliar feeling to me as a young undergraduate, and I found myself extremely excited about the topics that I occasionally did understand. I would later find that topics I had heard at Robertfest would slowly creep their way back into my later coursework and readings.

A picture of me with “star clusters” team members Matt (left) and Dongwon (middle), modulo Peter, Siyao, Jessica, and others.

Junior Fall 2018: Symmetry

With some reassurance from the previous semester, I decided again to take a full schedule of interesting topics, mechanics (Physics 105), quantum mechanics II (Physics 137B), particle physics (Physics 129), and planetary astrophysics (Astronomy C249). I think it’s pretty clear that the overall unifying theme for this semester was symmetry—symmetry and its relationship with Noether’s theorem reared their head in mechanics (directly), quantum mechanics, and particle physics (for conserved currents, etc.). Discrete symmetries in the form of symmetry operators in quantum mechanics and symmetry groups in particle physics also took leading roles in my academics.

In general, I loved the topics that I learned in this semester. I was so excited to finally learn action-based mechanics formalisms and was floored at the exciting, albeit heuristic, introduction to quantum field theory. I also appreciated the practical skillset I learned in planets, and the amazing graduate student friends I made. In hindsight I really appreciate what I learned in quantum mechanics II though, at the time, it was hard to be captivated by the superficially disjointed and ad hoc nature of the curriculum.

(from left to right) Rahul, myself, and Adam, fooling around in Quantum II (137B).

Though I had demonstrated over the past semesters that I was able to juggle a course load like this, it definitely took its toll. Having four classes generally means something like four problem sets per week, or one due almost every day of the week. In practice, this is not always the case (and was certainly not the case here), but the fast pace meant I necessarily had to develop the habit of glancing over problem sets as soon as they came out and thinking about them in the background all the time—this may not have been the healthiest thing. Frequently, in my more stressful moments, I would whisper the phrase “I am fireproof” to myself, some kind of personal chant to affirm that I had survived everything that was thrown at me up until that point, and that I would get through this too.

My research and service commitments also reached a forefront during this semester. I worked on cleaning up the Quintuplet cluster project, and additionally combed the literature to figure out how to accurately compare high pressure magnetometers. I also went to my first-ever conference, the San Francisco Bay Area Cold Atoms Meeting (albeit only to see the talks). Service-wise, in addition to being now co-vice president of SPS, I had also joined the physics department’s Major Curriculum Committee, and started grading for upper division electromagnetism. I began to take a very strange role of both representing and grading students that I saw every day and was friends with. One highlight of the semester for me was introducing quantum mechanics and relativity to interested high school students from local schools via Splash at Berkeley. I saw undergraduates, graduates, and postdocs alike come together at this event to bring their own customized lessons to the table, and I saw remarkable enthusiasm for science communication.

A group photo with (from left to right) Chelsea, Charlie, Sam, Jaime, Ethan, myself, and Xuyang, after talking to new and prospective Cal students waiting for physics advising.

In addition, I was applying to NSF REU (Research Experience for Undergraduates) programs for the summer, and constantly found myself researching and emailing people as well as writing. Though I wasn’t too terribly invested in the outcome, I knew that the process of synthesizing my research experiences into succinct personal statements would be excellent practice for graduate school applications (which I had some moderate kind of interest in). Nevertheless, it was a slog, and, when superposed with my other myriad responsibilities for the semester, I rarely found myself focusing much on these applications before winter break.

The semester was also complicated by a series of wildfires which corrupted much of the air of California, frequently causing class to be cancelled. For very long periods of time, people would walk around with masks, and the entire city (particularly outside) would be descended upon by a perpetual, not-so-subtle scent of ash. My second mechanics midterm notoriously being postponed three whole times (sometimes the day of) before a successful examination was conducted. Fall 2018 was also the semester during which the midterm elections took place, and the Democratic Party retook the House of Representatives.

Junior Spring 2019: Continuum

My junior spring semester was, in many ways, very similar to my fall semester. In fact, I went into it with my characteristic apprehension—it was like a copy of the fall semester, but every obligation was replaced with something more difficult. Instead of mechanics, I had statistical mechanics with the same instructor, a topic I was very uncomfortable with. Instead of quantum mechanics, I had atomic physics, a deeper and more applied flavor of the former. Instead of planets, I had fluids, a topic with a much more analytical slant. Instead of particle physics, I had general relativity, which would demand a more mathematically precise workflow.

A group photo with a squad of friends going to see Avengers: Endgame, where my total lack of knowledge about superhero films would be laid bare for all to see (and forgive).

Again, I was able to get through the semester, and, again, I enjoyed myself in the many new things I was learning. My statistical mechanics class was so notoriously demanding that I would meet up with friends multiple times a week to finish the weekly problem set, and, though I knew many of the graduate students in my fluids class, I did all of my work by myself as I did not share the class with many undergraduate friends. One day, in reasoning befitting the fluids class I was taking, I observed that my sleep schedule and motivation has a characteristic decay time that one works to keep much longer than the length of a semester. Later on, I would add that the length of the decay time also has a decay time which one hopes to keep much longer than the length of the four years of undergraduate. I must say that, perhaps also in the spirit of this fluids class, I would often assume I was in this regime even when it was not strictly justified. For my atomic physics class, I pulled my first all-nighters with a group of brand-new friends learning about topics I thought were super interesting.

(from left to right) Rahul, myself, and Adam, hanging out on a couch during an average school day.

Perhaps the unifying transition from the previous semester was a pivot from studying individual particles to studying continuous quantities: mechanics of many instead of few, continuous level structures instead of discrete level schemes, spacetime instead of particles, fluids instead of planets.

At the same time, I was chipping away at my Quintuplet cluster paper during my spring break vacation to New York City to visit a friend, combatting my way through my first-ever referee process (and unnecessarily complicated arXiv submission), and (fortuitously) receiving my first-ever paper acceptance, which contributed much to my sense of belonging in the academic community.

A picture with Arani Acharya, who I ran into at the airport after we were both headed to New York City for spring break.

I had also agreed to co-teach the Python DeCal again, though this posed a unique challenge as we had decided to openly advertise the class to non-majors. As campus-wide pragmatism about the importance of data science was at an all-time high, we ended up getting an extremely large enrollment. While I found the second experience also uniquely insightful, I ended up realizing that the expectation upon me as an instructor was to confer some kind of useful skillset. Though coding has its theoretical nuances and is itself an interesting topic, I often felt like I was a walking syntax dictionary. I often didn’t feel like I could muster the enthusiasm to teach excitedly about a topic people felt like they had to learn.

(from left to right) Chelsea, Cooper, I, Dalila, Adam, Hunter, and Rahul take a photo together after some subset of us ran on a stress-relieving evening run during Dead Week.

At the end of the semester, I was elected to be the SPS president for the following school year. While excited, I was also very afraid that I wouldn’t be able to live up to the work of my predecessors. I remembered having felt very welcomed by students older than me when I came to college, and I remembered the influence they had in my decision about what I wanted to do. I knew that I had to take up that niche.

(from left to right) Debayan, I, and Siddhant have a good time at SPS Prom 2019, an annual tradition capping off the previous year of SPS, and the event where the officer reigns are handed off. This particular prom was the day that I began my term as President of SPS.

Like the previous year, there happened to be a lunar eclipse that again captured the attention of people around me for its brief few days of relevance. Perhaps more excitingly, this was also the semester that the Event Horizon Telescope collaboration released their picture of the supermassive black hole at the center of M87, which was taken using very-long-baseline interferometry. I recall much hype and many talks about the milestone, and it was a further injection of enthusiasm about science to people in my home departments, including myself.

A reunion with my freshman floormates from Ida Sproul Hall, Floor 1, at the well-known Berkeley pizza restaurant Sliver.

Junior-Senior Summer 2019: Synthesis

After some time charting my summer plans, I ultimately decided to go to Northwestern University to work at the Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA) with Fred Rasio on globular cluster simulations. It would be my first foray into a theoretical discipline, and my first summer away from friends and familiarity.

When I arrived in Evanston on the first day of my research appointment, I was struck by how lush and green the town was. I spent the majority of my time in a shared apartment as a subletter, and would regularly walk downtown to get food and groceries. My apartment was fairly close to the building that housed CIERA at the time, the “Technological Institute” or “Tech,” and I was struck by just how closely the department stuck to the principle of interdisciplinary research. Despite working only within star clusters, I would frequently bump into other people in the department. As for my own research, I gradually transitioned to working on my own goal of efficiently comparing star cluster models to real data. I frequently learned from a fantastic graduate mentor, Kyle Kremer, as well as some other awesome graduate students Claire Ye and Newlin Weatherford. It was the first time I wasn’t really given a concrete agenda to fulfill, and also the first time I felt like I had some reasonable background knowledge before starting a new research project, and I would say that it was overall a very enjoyable experience.

A picture with Kyle Kremer, former Northwestern graduate student (now Caltech postdoc) to whom I asked many star cluster-related questions.

Socially, I probably suffered a little bit. As a net introvert, I was slow to make friends and would mostly do things by myself. Though I was technically part of one of Northwestern astronomy’s REU programs, in practice I didn’t spend very much time with other REU students (except for a few events including a group tour to Fermilab and a short end-of-the-semester talk). For most of the summer, I would spend my Saturdays running between eight and twelve miles in some random direction, which I would accomplish without much practice by forcing myself to jog in some direction for an hour, and then give myself unlimited time to run back. On Sundays, when I would be utterly exhausted from the previous day’s run, I would do a practice physics GRE exam.

A picture with Katie Latimer, former physics major and personal mentor who overlapped with me in Evanston during my time there.

Summer was also accompanied by a number of responsibilities outside of CIERA. As the president-elect of SPS, I was tasked with coordinating the annual chapter report to the national organization, a task involving collecting pictures, organizing the report, delegating writing responsibilities. I had also decided that senior year would pose a last opportunity to teach a DeCal about a topic I could get really excited about, and, with Shashank and Shishir Dholakia, we wrote syllabi and problem sets, and compiled the necessary paperwork. I would often do this work during the night, when I was kept up by the suffocating humidity of Chicago north shore summer.

My reflection through “the Bean,” a famous landmark in Chicago which resembles a large, reflective bean structure.

Meanwhile, as I acclimatized to working in a new environment far away from what I was used to, the imminent cloud of graduate applications loomed large. I think, when I was a younger student, I had this idea that, by the time I had spent three-ish years at Berkeley, I would have everything figured out and would be totally prepared for this moment. I now think that picture was a bit naïve, and graduate application season would feel like a clumsy shot in the dark.

Senior Fall 2019: Performance

After coming back from Evanston, I began a semester which was unusual in all respects. It would be the first semester where I went in already having dispensed of the bulk of my two majors (besides some last-minute labs), the semester where I would apply for graduate school, and the first semester where I would take graduate classes in physics. Furthermore, it would be my first semester running the club I had joined as a freshman, SPS, and also the first semester I would be teaching the DeCal I had planned over the summer, the Beginner’s Guide to the Universe. I would also stay on the Major Curriculum Committee for yet another semester.

Over the summer, I had decided to go to Northwestern rather than staying behind and building a new experiment to study silicon-vacancy (SiV) centers. This task was then delegated to another undergraduate from a different institution, whose responsibilities I was assigned once he left. For this semester and some portion of the next semester, I would be the only undergraduate working on the experiment, where I would come into lab whenever I had free time—I would plan weekly updates. At one point, I also went to Argonne National Laboratory to conduct a beamline experiment. While extremely rewarding, research also lied central to maybe my most stressful week in all of college. During this week, I had come out of the weekend having given an outreach presentation at a local public library. This was later followed by a series of private meetings to plan a fairly consequential group meeting presentation, during which time I had taken an evening Uber to Marin to give another presentation, followed by late night studying, a morning midterm, and then later the research talk.

A selfie in front of the computers at a beamline at Argonne National Laboratory.

My own classes in electromagnetism and quantum mechanics were relatively defocused in this semester, though Martin White and Robert Littlejohn gave fascinating presentations about these foundational subjects. I often took these classes as a welcome respite from my other responsibilities, a semblance of “normalcy” and a remarkably educational experience. During these classes, I was able to interact with the new graduate student class. At the end of the semester, I stayed behind as my friends left campus in order to do my oral quantum mechanics final, for which I feverishly prepared but, in retrospect, found profoundly worthwhile. These two course loads were superposed with my final breadth about the Holocaust, which I took with a friend and which (justifiably) put a perpetual damper on my mood. Nevertheless, in all three of these classes, I enjoyed the lessons I was learning.

As the president of SPS, I found myself in a central role in many social and academic initiatives in the department. A lot of the job involved organizing people’s responsibilities and communicating with other organizations, with the periods of heartwarming contact with students interspersed with slightly annoying bureaucracy. To me, despite the stress, it was very worthwhile, and I learned how to take help from others. Moreover, at SPS officer meetings, general meetings, and homework parties, I was able to connect with my friends in a time of looming challenges.

Through the Beginner’s Guide to the Universe, I also deeply enjoyed fulfilling a long-standing desire to communicate physics to people who I thought may not get another chance to see such a broad presentation of the subject. My dream was not that students would get any competency in actually “doing physics,” but rather that students would gain some additional physical context to take with them in their future approach to the world and their personal interpretation of forthcoming scientific developments. It was my passion project, and I was extremely grateful for the overwhelming enthusiasm I felt from students when they posed thoughtful questions or made interesting observations during their assignments.

Shashank, Shishir, and I taking an awkward photograph with Grant Sanderson (3blue1brown) after a public event at the Mathematical Sciences Research Institute.

Of course, this semester was primarily the setting of graduate school applications, which were extremely grueling. I was unexpectedly and impossibly unprepared for the task, not even having a particularly concrete idea of my future plans—how could I be expected to even pretend to be sure about my future interests when, just four years ago, I didn’t even know that I wanted to study physics? I spent a lot of time doing busywork that didn’t even have the benefit of being interesting, seeking out potential advisors and filling out forms. Partway into the semester, I took the PGRE along with some other, comparably anxious friends, at a local high school next to my house (at the cost of an exorbitant amount of money). Perhaps my only comfort was that I was able to go through the process side-by-side with my friends who were in the same boat, and we were able to support each other and reassure each other that our challenges were empathized with.

The “bureaucratic” nature of the semester meant that the biggest theme of the semester was that of performance, the ability to adhere to some expected procedure, to work through existing administrative structures and convince people to go your way. Motivating people towards a common task or persuading them to help you achieve your goals is an oft understated part of science and life alike. The process of portraying myself as somebody who knew what I was doing in all of my responsibilities in this semester was educational but also exhausting—between being the “well put-together researcher” for graduate applications, the “inspiring mentor” for SPS, and the “authoritative teacher” for my class, I found myself constantly switching hats, none of which I felt honestly prepared to wear.

The semester was not only professionally troubling but also personally troubling. One evening, I returned to campus in order to shut a liquid nitrogen flow that I forgot to close before heading home. While walking back home near Wheeler Hall at 8 pm fumbling with my headphones, I was confronted by a number of unknown assailants in ski masks who surrounded me, one of whom jumped in front of me and told me to “give me your shit.” Startled (and mentally exhausted), I panicked and punched him in the face, after which one attacker took off his mask and told me that “it was just a joke.” After yelling at them, I hurriedly powerwalked off of campus, constantly looking behind me. To this day, I still don’t know if the event was actually a prank or not—on the one hand, I couldn’t imagine that a real assailant who had been injured would actually show me his face (though I regrettably was too startled to take a picture), but on the other hand it seems like such a dumb prank to try to pull. I was also keenly aware that, if I had been even slightly less fortunate, my rash self-defense would have gotten me knifed or shot or worse, and in retrospect I’m thankful that nothing worse happened. While I had heard horror stories about crime in Berkeley, I had never in my years at Berkeley been actually afraid to walk home alone at night—since that time I have always been conscious of my surroundings outside, and of what I’m holding in my hands in case I will have to defend myself.

During this semester, in fear that power lines would be affected by wind patterns, the Pacific Gas and Electric Company also decided to cut power to a large number of areas across the Bay Area, prompting several stressful days where we needed to quickly relocate items stored in SPS’s and store them under thick layers of laboratory ice in improvised styrofoam containers. The region-wide event was the subject of some jokes at the annual physics department holiday party.

On a brighter side, Fall 2019 was a rare occasion for a Mercury transit, which was excuse to hang out with some friends on the top of Campbell Hall on an early November morning.

(from left to right) Wendy, Yilun, and I take a cheery photo on the top of Campbell Hall on the day of the Mercury transit. We were accompanied by a large, enthusiastic gathering of astronomers and astronomy students, as well as students in Alex Filippenko’s non-major introductory Astronomy C10 course.

Senior Spring 2020: Change

My last semester was undoubtedly a wild rollercoaster. Quantum mechanics (Physics 221B) was more of the same from the previous semester (in a very positive way), but Physics 111B (physics lab) was undoubtedly much different than anything I had taken before. While I tend to enjoy data analysis, working with my hands is something that I have learned is not my favorite thing to do, and so I spent a fair amount of time adjusting to keeping track of all the details needed to make an experiment work. Astronomy 128 (data lab) was also quite different, but as it was extremely analysis-heavy I had a lot of fun in the class and very much appreciated the new skillset that I trained in the class (despite the very long, frustrating late nights when a seemingly invisible code bug would elude my capture).

However, it’s fair to say that courses were definitely defocused during this semester. I was hearing about my graduate school decisions, and also hearing about my friends hearing about graduate school decisions. I think it’s fair to say that my decision of graduate school was difficult than most—I was stuck between four schools, two in physics and two in astronomy, of which I was able to visit exactly two (both in astronomy) before the COVID-19 pandemic shut everything down. I believe that, for each possible combination of two schools, there’s some point in time where I believed that I had narrowed it down to those. I would obsessively schedule meetings with anyone I could think of, prospective PIs, graduate students from other institutions, personal mentors, in order to figure out what would be the best fit for me. Ultimately, on the very last day, I decided to go to Caltech for physics. A fresh time for a change.

The largest highlight of the semester was, undoubtedly and unfortunately, the COVID-19 pandemic. It started off as a relatively quiet pandemic in rural China and would occasionally break headlines, but things didn’t really seem to come to a head until the APS March Meeting was canceled due to coronavirus fears. From then on, more and more things would shut down—while sitting at the airport flying from one graduate school to the other, I remember a flood of emails coming in indicating the cancellation of my other graduate school visits. I ended up going back home to San Diego early, finishing off the coursework for my baccalaureate during very stress-ridden late nights. Default pass/no pass became the official policy at Berkeley, and I decided to accept DPN grades, not only because it would be less of a burden on me but also because I felt that some equity arguments in favor of total pass/no pass were persuasive.

The COVID-19 pandemic also brought along a set of unique challenges not only as a student but also a community member and educator. It was difficult to try to maintain a sense of social cohesion among physics students through SPS when people didn’t have opportunities to run into each other day to day. In this semester, Yonna Kim had recently joined our Beginner’s Guide to the Universe team, and we had to confront the unique challenge of teaching the course online for the majority of the semester. Despite these challenges, both SPS and the Beginner’s Guide to the Universe provided many opportunities to get involved. Thanks to our fantastic outreach and projects teams at SPS, we were able to host online social events, high school tutoring sessions for AP students, and “squishy circuit” elementary school outreach events.

A screenshot of our biweekly DeStress with SPS event during the COVID-19 pandemic, which took place on zoom amidst shelter-in-place.

Perhaps one of the most salient effects of the pandemic (and perhaps the experience that most other people were sympathetic to) was that our undergraduate cohort would not get a proper graduation experience. Unlike most other college graduates I know, I do not own a single picture of myself in a college graduation robe (nor have I ever worn one), and had the Kafkaesque honor of watching our school’s chancellor deliver our commencement address in front of a greenscreen of a Minecraft landscape while her avatar stood on a virtual stage constructed in the same. Moreover, the pandemic meant that I didn’t feel like I was afforded a proper goodbye with the friends that I whom I had come to know over the course of four years, and who supported me during all the rough times. The lack of closure meant much more to me than the lack of any ceremony.

A graduation photo taken with fellow physics major Timothy Guo during the school-supported commencement ceremony, which took place on Minecraft due to COVID-19.

Nevertheless, in the midst of social distancing and sheltering-in-place, I have a future to look forward and numerous sources of optimism. As I tie up current research projects and steer towards uncharted waters, I cannot help but feel some excitement for my first year of graduate school (in whatever form that may take). Soon after the semester ended, I received a mysterious Amazon package in the mail containing the book The Art of Insight in Science and Engineering: Mastering Complexity by Sanjoy Mahajan. It was a book that I didn’t order but would stay up late nights reading, and detailed methods in problem solving and, specifically, order-of-magnitude estimation (giving some clues as to its origin). I am reminded of the countless stones yet unturned not only in my academic career but also my life proper, and retain hope in a distressing era.

Conclusion

From any perspective, college is some mixture of excitement at new frontiers and struggling against new adversity. All things considered, I feel that studying physics and astronomy at Berkeley has made me both a better academic and a better person in general. When I was making my choice of graduate school in the past semester, I had often worried against the uncertain prospect of potentially regretting my choice. I’m happy to say that, despite some of the personal and scholastic challenges that I’ve faced during my time there, I do not regret the choice that I’ve made. This is in large part not only to my own actions but also to the extraordinary guidance of countless mentoring figures along the way, and unending support from my community. As I look towards my future, I find it helpful to reflect on the change that I have undergone in four years, a complex mnemonic for the potential for positive change in my immediate future.

Goodbye Berkeley! Thanks for everything!

The Squishy Pendulum

Over my two-week vacation before I returned to Berkeley for the summer, I read Leonard Susskind and George Hrabovsky’s The Theoretical Minimum: What You Need to Know to Start Doing Physics. This book was based on the first course in a series of courses called the Theoretical Minimum, taught by Leonard Susskind at Stanford targeted at curious older students who had, in their lives, fallen through the cracks of physics education but wanted to learn.

This book was focused on mechanics, but dived pretty rapidly into more advanced formulations of mechanics that I had never really learned in a class. Coincidentally, I’m scheduled to take that class next semester, so I wanted to dive in to get a brief taste of Lagrangian and Hamiltonian mechanics.

So, to start, I set out to simulate the squishy pendulum.

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Linear Algebra and Quantum Mechanics

When I was younger, I would occasionally hear about higher math classes that one was able to take. To me, then a naïve high schooler, AP Calculus represented an attainable pinnacle of mathematical knowledge beyond which lie a plethora of weird maths to explore. I had heard of multivariable calculus, which sounded like more of the same with more letters, differential equations, which was just calculus with more tricky problems, and so on and so forth.

However one, linear algebra, seemed like a mystery. It’s name evoked, to me, the kinds of problems done in middle school where I was painstakingly asked to grind through systems of three equations to find xy, and zSure, I thought, maybe there’s a use for solving ever bigger systems of equations of ever increasing complexity with bigger and better techniques. But, if multivariable and diff-E.Q. were “more of the same,” jumping back to middle school lines and planes was definitely going be a bore.

Spoiler alert: It wasn’t, and, while related, linear algebra really isn’t about that stuff. It’s actually about a lot of other, cooler stuff, including really cool stuff like quantum mechanics.

Note: This is just a primer on linear algebra. I introduce the axioms, and then paint over the subject with a broad brush that isn’t meant to be comprehensive. Quantum mechanics is inseparable from linear algebra, so I try to get to the meat of linear algebra while not glossing over too much. At the same time, this obviously shouldn’t be taken as a substitute for a more rigorous treatment of linear algebra.

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Vector Calculus and Electromagnetism

Vector calculus is an extremely interesting and important branch of math with very relevant applications in physics. Specifically, vector calculus is the language in which (classical) electromagnetism is written. It is fascinating to me that Maxwell’s equations can so succinctly and elegantly express so many phenomena, from electric and magnetic interactions to light (electromagnetic waves). One popular formulation of Maxwell’s equations is the following:

maxwell-equations

So what does this all mean? Let’s break it down, arduously and tediously, from the nitty-gritty of the vector calculus requisite for understanding the elegance of these equations.

Note: I presume basic knowledge of calculus in this post. Obviously, this is not meant to be a substitute for a more rigorous foundation with more computational practice.

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