Physics reflection portfolio

Field I am most confident with: analytical techniques

I am most confident with analytical techniques. I am good at analyzing a physics system. With what I have learned over the last couple of years, I have solid background in math and physics. Math skills are particularly useful for analyzing physical systems. For example, to analyze a simple harmonic oscillation, we need to be able to use differential equations swiftly, which I have no trouble doing. I also gained a lot of knowledge in physics in my toolbox. Not only did I know the equations and theorems, but also I can think of a problem like a physicist. These studies make up my analytical techniques. Even in experimental physics, I can analyze the experiment and identify the errors and assumptions made in the experiment. Thus I feel analyzing techniques is the field that I am most confident with.

Besides, I am able to use very advanced math techniques and this also helps me better analyzing the physical systems. Math plays a very important part in physics and I have taken a significant amount of math over my years at Carleton. This prepares me very well for studying physics. When the physical systems are simple, I can write down simple equations that reflect the exact situation of the system. Using my physics knowledge, I am also enabled to derive a complex system from a simple system such as from a quantum state pointing in x direction to one pointing to any arbitrary direction. Thus, my math skills and physics background gives me great capabilities of analyzing a physics situation.

Contributions to my development of my analytical techniques

In terms of developing my analytical techniques, outside of my coursework, which is obvious, I think my research experience should be the most important. I have done multiple research projects on classical mechanics, engineering and computer science. However, most of my work is experimental work on the detection of gravitational waves.

I started doing research on LIGO in April 2016. I analyzed noises using the coherence tool in O1, ER9, ER10 and O2, identifying the noise sources from the coherence between the strain of the arms and signals in auxiliary sensors. I developed software tools that greatly facilitated the analysis workflow, and recently I am planning to automate the process with a machine learning AI. I also read the technical details of the auxiliary channels to understand the results. The experimental concerns impressed me. I had never worried about seismic movements, quantum noises or thermal noises in any lab before, but when we want to measure a strain of $10^{23}$ we must handle them.

After that, I have been working on another project on the signal recycling system. In this project, the configurations of the signal recycling system are optimized for every laser power input at the power recycling mirror and low-frequency cutoffs of 10Hz, 15Hz and 20Hz. We started with a particular laser power and low-frequency cutoff and then generalized to other interferometer designs. We also considered two models for the stochastic background, the flat model and the power law model created by all binary mergers in the history. I learned a lot about the experimental side of LIGO, with relevant applied optics and quantum mechanics. Very interesting results were found in this research and now the paper is being reviewed by LSC members.

These research experience gave me the chance to reflect on how I am actually thinking about physics. The analytical skills developed out of numerous practice, observation and repetitions. For example, when I was analyzing the noises in the interferometers, I need to look at the data and compare it with the historical data. In this process, I think about the physics that might be going on behind the data and this contributes a lot to my analytical skill. Similarly, I need to learn about the optics of the signal recycling system to be able to analyze it for searching the stochastic background. When we got the data the first time, I saw some difference than what I expected and that led me to more interesting questions regarding the system. In these repetitions of questioning and answering, my analytical techniques are developed.

Field I needs to work on: Designing research projects

I need to work on designing a research project. I have done a lot of research under the supervision of a professor or work under a more senior personnel. However, I feel I lack initiation in the process and thus sometimes need a big picture about the direction. This would require me to stand higher, learn widely and think actively about not only “how to do” but also “what to do”. It is a very important ability to become a great scientist, being able to design a research project. Thus in order to improve my ability to design research projects, I should work on this, observing how others operate and thinking about how research can go further.