Looking to the left of time

 

The Persistence of Memory, 1931 - Salvador Dali - WikiArt.org

From March to June 2023, I was a postdoctoral visitor at the University of Roskilde in Denmark. Nestled within the very city that shares its name, this experience introduced me to Roskilde's remarkable reputation, previously unknown to me. Renowned for its vibrant and widely acclaimed summer festival, which holds the title of being one of the most popular in northern Europe, the city attracts enthusiastic crowds from near and far, all eager to revel in the lively ambiance it offers. Furthermore, Roskilde also holds deep historical significance as the sacred burial ground for numerous Danish monarchs. Positioned approximately 35 kilometers away from Copenhagen, the Danish capital, Roskilde benefits from an efficient transportation system that makes traveling between the two cities a breeze. Regular train services operate between Roskilde and Copenhagen, providing a convenient mode of transportation for both commuters and explorers. The trains run in both directions every twenty minutes, ensuring a seamless and hassle-free journey for travelers. However, I must clarify that my intention here is not to serve as a promoter of the city (I already hold that position in Warsaw ^_^ ). Instead, my aim is to share the narrative of my academic journey during this period, with the sincere hope that it proves valuable (fingers crossed!) to those embarking on a brief research stay as part of their own scholarly pursuits.

The blessing of having a free will

One of my most prominent characteristics is my uncanny talent for making poor decisions. I possess such a knack for it that even my Polish landlady, who also happens to be one of my closest friends, often advises me, "Bunny please, consult with me before making any life decisions. It will save you time, money, and heartache." Although I've sometimes dismissed her words as an exaggeration, recent events have proven her wisdom to be true. For instance, she managed to secure tickets for both of us to attend the Beyoncé concert in Warsaw. However, I made the ill-fated decision to decline her invitation to go with a guy that just wanted to meet me to said: “I’m not sure if I’m ready to date someone else right now, in fact, I just came today because I didn’t find a ticket to see Beyoncé, I don’t know if you know she has a show today here.” Consequently, I found myself rejected and scrolling through the Instagram stories of my friends and landlady joyfully immersed in the Beyoncé experience.

As you can see, making sound decisions is a skill that consistently eludes me, leaving me to ponder my choices with a sense of frustration and self-reflection.

Now, let's return to Denmark. As I was preparing for my trip, the research center where I am employed graciously provided me with a generous grant to cover the cost of accommodation during my three-month stay. I had the option to reside in the heart of Copenhagen and conveniently commute to Roskilde University each day by train. Considering the university's location outside the city, this arrangement would have made my daily commute even shorter than traveling to Roskilde central station. However, against all logic, I made a different choice. Instead of embracing the convenience, I opted for a place situated outside of Roskilde, but it was in the exact opposite direction of the university. To make matters more challenging, there was only one public bus that passed by the area every two hours. It seemed that my talent for making less-than-ideal decisions persisted, much to my chagrin.

I believe that, as compensation for my tendency to make poor decisions, life has a way of introducing me to wonderful and compassionate individuals who are always willing to lend a helping hand. During my time in Denmark, my landlady (yes, I also made a friendship with my Danish landlady) proved to be one such person. Her kindness and generosity towards me were truly remarkable. Upon my arrival, she went out of her way to greet me at the airport, saving me the hassle of navigating an unfamiliar place alone. Additionally, she loans me some money because my bank block my account when I arrived in Denmark because of suspicious behavior, and I arrived on a Sunday, a day when the bank's services were exclusively available in Polish—a language I had regrettably not found the time to learn–. In addition to her other acts of kindness, she also provided me with a borrowed bike, which became my means of transportation for commuting between the university and my new home. Little did I know at the time that embarking on a 30 km journey each day, especially in a country where rain dominates the weather, would turn out to be a truly unforgettable experience.

The very first day

I already had a scheduled appointment with my Danish supervisor on Monday at 10:00 am (later, I would discover that at the university, people generally arrive between 9:30 and 10:00). Knowing that I have a tendency to get lost easily, I made the decision to leave my place at 7:00 am and bike to the university. According to Google Maps, the estimated travel time was 30 minutes. However, as expected, I ended up getting lost along the way. Eventually, I arrived at the university at 9:20, feeling relieved that I had left my place earlier than planned. Once I arrived at the university, I realized that it would be impractical for me to continue with the one-hour-ish bike commute and then start my work. Recognizing this, I made the decision to cancel my Airbnb reservation and search for a more suitable place to stay. As my mind wandered, contemplating my past poor decisions, my Danish advisor appeared and introduced himself:

"Hej Rene, it's great to meet you. I'm glad you arrived safely. How did you find your way here?" Jeppe greeted me warmly, and in order to make a positive first impression, I concealed any regretful feelings and simply replied, "Hi Jeppe, nice to meet you too. Well, Roskilde is a beautiful city. I rode a bike that my landlady lent me, so I had the opportunity to explore the city on my way here. It's quite charming, and the cathedral is truly impressive." Jeppe seemed surprised by the fact that I had biked just one day after arriving, and he commented, "Well, it seems like you've already embraced the Danish spirit. As you might have noticed, biking is the primary mode of transportation in this country. But where are you living? Is the commute easy?" Determined to make a positive impression, I replied, "Ah, well, it's not very close. Actually, I'm living in the suburbs, about 15 km from here. But I have no complaints. It will be a good workout before and after work." Jeppe's face lit up with excitement. "Oh, don't tell me you live in Lejre! I also live there and commute to work by bike. It's an amazing feeling, and you don't have to worry about exercising separately. What do you think if we ride back together after work? I'll show you the best routes between Roskilde and Lejre."

Now, it's important for me to make a small digression. Jeppe is in his 60s, perhaps even in his 70s, yet he is incredibly energetic and covers over 30 km on his bike every single day. Meanwhile, back in Poland, I had been spending a small fortune on a personal trainer, striving to become a fitness enthusiast. So, after hearing about Jeppe's daily biking routine, I made a firm decision: I would not move from my current house, and for the entire duration of my stay in Denmark, I would bike every single day, come rain or shine. Spoiler alert: I followed through with my plan, and it turned out to be a fantastic experience!

Returning to my meeting with Jeppe, I enthusiastically accepted his invitation for the biking tour from Roskilde to Lejre. In addition to that, he had arranged a lunch gathering with the other professors from the group, followed by a crash course in isomorph theory. A theory developed by them at Roskilde University that happens to be the very subject of my research during my time there.

The heart of the matter

After completing the necessary bureaucratic tasks that one typically encounters when arriving at a new institution—such as obtaining an access card, keys to the buildings, and meeting with the master's and Ph.D. students—it was time for the customary introductory talk. During this session, I had the opportunity to share insights about my research project and articulate the goals I aimed to achieve during my time at the institution. With these formalities behind me, my research journey officially commenced.

Ever since I completed my studies in Colombia and moved to Brazil to pursue my master's and Ph.D., my mom has persistently posed the same question to me: "What are you looking for? You're a researcher, aren't you? What is it that you seek?" Despite my numerous attempts to elucidate the nature of my work, I sense that my mom remains unconvinced and uncertain about what exactly it is that I am "looking for."

I study metallic glasses, which are essentially glasses made from metals. However, when I mention the term "glass," the immediate association that comes to mind for most people is the transparent material used for windows. Then, let me do a second digression, this time about what metallic glasses are

I believe that it is helpful, to begin with an exploration of the different states of matter. While this statement may not capture the complete picture, we are taught in school that matter can exist in three main phases: solid, liquid, or gas, depending on the pressure and temperature conditions. When we observe objects around us like computers, cellphones, soda, or clouds, we can easily categorize them into three phases. However, let's imagine a scenario where we have the ability to take atomic pictures of an object, perceiving the individual atoms that compose it. Taking water as an example, with its chemical formula being H2O, regardless of whether it is in the form of ice, vapor, or liquid if we were to observe a photo of water molecules confined within a box, would we be able to determine the phase solely by examining the H2O molecules in the photo?

The atomic photos of water in a solid and liquid phase are schematically represented in the figure. By examining their microscopic constituents, namely the atoms, it becomes apparent that it is possible to distinguish between a solid and a liquid state. In a solid, the atoms are organized in a well-defined and periodic manner. This orderly arrangement of atoms, displaying a repetitive pattern, is a distinctive feature observed in all elements during their solid phase. In the case of water, the specific rearrangement of H2O atoms can vary depending on temperature and pressure, resulting in different types of solid water with distinct properties. However, all these variations are composed of the same H2O molecules. It is worth noting that researchers have currently identified 19 distinct forms of solid water, each exhibiting atoms arranged periodically. The ice formed when you cool water in the freezer represents only one of these 19 forms, and snow represents another form as well. Now, you might be wondering if all solids possess a periodic atomic-level order. The answer is a big NO. The solids that have this periodic atomic-level order are called crystals. In the fields of physics, chemistry, and material science, the term "crystal" refers to a solid system wherein the atoms are arranged in a specific periodic fashion. Consequently, if a solid lack this ordered arrangement of atoms, what happens to it? How do non-ordered solids form? Furthermore, is it possible to visually differentiate between an ordered solid (crystal) and a non-ordered one? 

Well, the answer to these questions is more or less my research subject. Firstly, non-ordered solids are referred to as glasses. Distinguishing between an ordered solid (crystal) and a non-ordered one (glass) through visual inspection alone can be quite challenging, if not impossible. In many cases, it is not feasible to differentiate them solely by eye. Glasses appear similar to crystalline solids when observed with the naked eye. To give you an idea, I will provide a photograph taken in Jeppe's office, where I am holding two metallic glasses in my hand. As you can see, to the naked eye, they appear as "ordinary solids." By visual examination alone, it is not possible to determine whether they are crystals or glasses.

However, upon closer examination of their atomic structure, a notable distinction becomes evident. The atomic arrangement in glasses bears resemblance to that of liquids, with atoms being dispersed in a disorderly manner. This absence of long-range periodic order is what distinguishes glasses from crystalline solids.

One intriguing aspect of glasses is that they exhibit completely different properties compared to crystals. It becomes the responsibility of scientists to determine the appropriate situations where glasses or crystals should be utilized. This happens to be one of the primary areas of focus at the research center where I work. Our emphasis lies in developing new materials that have direct applications in various industries or medical fields. Therefore, comprehending and controlling the properties of solids is a fundamental undertaking for us. In my specific role, I am responsible for studying the properties of metals under extreme conditions, involving high pressures and temperatures, in both crystalline and glassy phases. In contrast, within my research group based in Denmark, we also delve into the study of glasses. However, our focus primarily revolves around addressing fundamental questions. For instance, we explore the conditions under which liquids transform into glasses and examine the differences in entropy between the glass and liquid states. We investigate whether the current laws of physics accurately describe the properties of a system during a glass transition, and so forth.

I hope this brief digression sheds some light on the nature of my work and what I am currently “looking for”. For those who are interested in delving further into the realm of metallic glasses, I recommend watching a captivating TED video that elucidates their applications, limitations, and historical origins (here is the link).

Who covers a lot, cries in the evenings

The research group I am part of in Denmark is called "glass&time," a name that aptly reflects our primary focus. The group is substantial in size, as evident from their webpage, and is comprised of two major subgroups: experimentalists and theoreticians. I belong to the latter group, which primarily focuses on simulations. Our work entails conducting calculations of physical laws using computers to shed some light on the glass nature of solids. Since is a quite big group dealing with different activities at the same time, it is crucial to maintain a strong connection between experimental work and simulations. To achieve this, we have a weekly gathering every Wednesday that serves as a pivotal meeting point. During this meeting, a designated member shares updates on their work, including conferences, lectures, courses they are involved in, the current progress of their research, as well as any challenges they are encountering. This session typically lasts for about an hour, during which other members provide valuable insights, ideas, or offer assistance in resolving specific issues.

Following this engaging discussion, we take a 15-minute break to refresh our minds. Afterward, another member takes the floor to present an article that they found intriguing and believe would be of great interest to the entire research group. This presentation usually spans around 40 minutes, accompanied by a question-and-answer session that extends for an additional 20 minutes. In addition to these regular gatherings, the simulation group convenes every two weeks specifically to address any potential coding challenges or inconsistencies within ongoing research. The purpose of these meetings is to leverage the expertise of more experienced members, who offer valuable insights into the coding process and suggest alternative solutions for debugging issues. Since I was working with Jeppe, he suggested that we have weekly meetings every Monday for me to provide updates on my research progress and share insights into my daily life in Denmark. I must admit that these Monday meetings became one of the highlights of my week. The reason being that Jeppe and I not only discussed physics but also delved into fascinating topics such as Danish history, which greatly intrigued me as a history enthusiast.

During these meetings, I had the opportunity to learn about various captivating subjects. Jeppe enlightened me on the Viking era, the independence of Norway resulting from Denmark's alliance with Napoleon, the German occupation during World War II, and many other engrossing historical events. It was clear that Jeppe was equally enthusiastic about sharing these stories and insights with me, creating an engaging and enriching environment during our discussions.

To my surprise, all the activities I was already engaged in were not enough to satisfy my curiosity. During my first Wednesday meeting, the professor assigned to present his report was the only member of the simulation group who couldn't attend the introductory lunch organized by Jeppe upon my arrival. If I were to describe him in a single sentence, I would say that he is a devoted physics student who has never lost his passion for learning.

During his presentation, he focused on the thermodynamics of simple liquids and the statistical mechanics models employed to predict their properties. His primary goal is to discover a universal connection between inert gases and metals. I must admit, I was completely captivated by his presentation. In that moment, two thoughts crossed my mind: first, I knew I had to collaborate with this remarkable individual, and secondly, I aspired to become a professor like him one day. After the meeting concluded, I approached him and initiated a conversation regarding our shared research interests. It didn't take long for us to identify a project that we could collaborate on. As a result, we scheduled regular meetings every Friday to discuss and compare our respective results. His focus would be on computing the properties of inert gases, while I would undertake the same for metals. Consequently, Thursdays became the only "free-meeting" days in my schedule.

I was undoubtedly thrilled to have the opportunity to work on multiple projects. However, the challenge arose when I realized I still had ongoing research projects in Poland that needed my attention while I was also working on new ones in Denmark. Each new research endeavor presented its own set of difficulties and problems, and anyone involved in research knows the resilience required to overcome frustrations when things don't go as planned.

In my case, it became a regular occurrence that I couldn't complete all my tasks within a given week. This forced me to make difficult decisions regarding which project to prioritize: the one in Poland, the one with Jeppe, or the one concerning metals and gases. Consequently, every week, there would be someone satisfied with my results while others expressed dissatisfaction with my lack of progress. This made me feel like an inefficient physicist, despite having studied for 13 years. My impostor syndrome reached an all-time high, leaving me feeling inadequate in my ability to fulfill my tasks. 

I vividly recall the days following my first month in Denmark, when I would come home from work in tears, plagued by the belief that I was an inefficient researcher. However, amidst the stress and demanding work, I began to realize that this experience was pushing me towards what I had been striving for. As my time in Denmark drew to a close, I couldn't help but notice how much I had learned during my stay. Even now, back in Warsaw, I am pleasantly surprised by how swiftly I can accomplish tasks that previously would have taken me a month or two, and with results that surpass my own expectations.

I returned from Denmark as a better physicist, armed with newfound confidence in my research abilities. Although there are still weeks when some individuals are satisfied while others are disappointed, I have come to accept this as an inherent aspect of my research journey. As for whether I will become a professor like the inspiring individual I met during my first Wednesday meeting, I cannot say for certain. However, I am deeply convinced that my time in Denmark has brought me closer to that goal.

In tranquillo mors - in fluctu vita

That was a brief summary of my three months in Denmark. I am now back in Warsaw, but happily, I am still in contact with my research group in Denmark, continuously learning and working hard to improve as a physicist each day. I genuinely love my job and feel incredibly fortunate to have had the opportunity to meet amazing individuals in Denmark who have made significant contributions to my journey in physics.

In closing, I would like to share the motto of the University of Roskilde, "In tranquillo mors - in fluctu vita" (In silence, death; in the surge, life). This motto resonates deeply with me, as it reminds me that it is in the face of adversity and frustration that a researcher truly emerges and thrives.