The kids crave knowledge—that is my main takeaway from a 7-day intensive workshop on Optics I taught at Ensenada, Mexico, as part of the Club de Ciencias, a nonprofit organization based in Mexico with aims to offer scientific education with a high technological impact to undergraduate Mexican students in STEM fields.
Day zero: Arriving at San Diego
When I stepped out of the airport, I couldn’t believe the weather, as if there was a permanent AC cooling down the environment and each corner of the city (I am sorry Houston, but California weather beats you hard).
Carlos, the local organizer of Club de Ciencias Mexico at Ensenada, picked me up, but before that, I made a small stop to try the local oysters.
It was only a one hour drive to Mexico, and even before I knew it, I was already in Tijuana. We continued driving along the Pacific coast, not without experiencing the mesmerizing and contrasting views this Mexican coast offers. On one side, the rocky mountains filled with desertic beautiful life, such as succulents and cacti, and on the other side, the vast and quasi-infinite Pacific ocean with its hypnotic shade of blue. He gave me a brief tour around Ensenada, a city well known for its delicious seafood cuisine and wine production.
Day one: Meeting my colleague
I prepared alongside my colleague, Adriana Nava PhD and Professor at UABC, an optics workshop focused on the fundamentals of light. After long zoom sessions, I was ready to meet her in person. It's such a statistical anomaly that we are both from the same very well unknown tiny city in central Mexico, Pachuca. We met in the morning and she drove me to the Universidad Autonoma de Baja California (UABC) where the students were already waiting for us. After some initial remarks, Carlos officially initiated this intensive week of theory and experiments for five different science clubs across multiple disciplines—from an astrophysics workshop about preparing an space mission to marine biology, on what makes our DNA different from the fish that we eat, including our workshop: Masters of light, reproducing essential experiments on ray and wave optics. While Dr. Adriana was setting up the projector and getting the materials, I gave the students a brief but needed introduction to the wave nature of light, and more in general, how everything in the universe wiggles. In an initial shock therapy, I justified my previous statement of the wiggly nature of the universe by using some arbitrary potential, expanding it around a critical point, and keeping only the second order term. For any equation of motion with such a potential, one can automatically solve it by the most popular ansatz of all time: A Simple Harmonic Motion. This is the prototypical trick under the hood of any physicist, and its range of validity goes from molecular dynamics to planetary motion.
Then I moved to Quantum 101: If one assumes quantum physics really describes reality, then everything can be effectively modeled by a wave function. But this was no challenge for my students, as some were already familiar with the basics of quantum mechanics. Moreover, one of my students asked me a question I was really not prepared to answer: How does the light know or choose to move in a rectilinear path? I dusted off my knowledge on the Fermat’s principle, but it was useless as I did not know how to explain to junior undergraduates, including two high schoolers without any background in physics, variational principles and actions? It is a question that still haunts me as I don’t consider my explanation satisfactory: Nature is naturally lazy, and always seeks to evolve in such a way to use the least energy and time.
After this lame explanation, we moved forward with the workshop. The first day was for ray optics, starting with the Snell’s and reflection laws.
Day Two: Light is not only rays
After the students proved that Newton was right and light behaves as rays, we moved forward with Huygens. We did a popular favorite: the double slit experiment. Proving that under certain experimental conditions, light behaves as a wave, as proven by the interference pattern produced by shedding a laser into a pair of tiny slits, the image produced in the screen is an interference pattern, a clear signal of the wave nature of light. Because physics serves more than to look pretty, we used this interference pattern to get the wavelength. Then, the students obtained the wavelength of a green laser of 563nm. This is impressive by itself, considering our measurement instruments consisted of cheap plastic rulers and our eyes, we could measure in the order of a millionth of a meter using geometry and assumptions about the wave nature of light. We moved forward by measuring the human hair thickness with this same diffraction principle.
Day Three: A visit to CICESE
We did a tour to the Center for Scientific Research and Higher Education at Ensenada , known for its edge research. In particular, we visited the Applied Physics Institute, hosting interdisciplinary projects in areas such as Ultrafast optics for applications, green roofs and water desalination, microfluidics, among many interesting others.
Day Four: Interferometry and relativity
Don’t let these two words scare you, interferometry is a technique harvesting the wave nature of light, to use the interference patterns of light and forming interesting shapes of stripes on a screen. These patterns are very sensitive to vibrations, material composition and experimental conditions due to the small size of the light wavelength used.
Then, we built a Michelson-Morley interferometer, that we used to disprove the existence of the aether, and furthermore, concluding that only by accepting special relativity can we make sense of what is happening with light while it travels through space and time!
Day Five: Building time & recap
Applying all the concepts we learned so far, we built an stenopeic camera using shoeboxes to imitate the way our eyes capture images. Then, the students summarized all the acquired knowledge on the nature of light by writing a theater play to perform in front of the other clubs, workshop teachers and staff. After that, the organizers took us to a very fancy Italian restaurant, where we tried the local wine from the region, which produces 45% of the total product.
Day Six: Masters of light
The play was a success, with all the public clapping nonstop. It mentioned all the principles of light in a very coherent (pun intended) way in a poetic tone.
The name of the play alludes to all the experience acquired during the five-day span proving that even having some conceptions about light was not enough to fully understand it, yet, many research laboratories, including my lab at Rice, are actively using light as a tool to prove cutting edge physics and engineer new technologies, such as communication channels, and many diverse applications.
Day Seven: Adiós Ensenada!
It is the time to say goodbye to Ensenada—to its beautiful imagery and picturesque city, filled with delicious food on each corner of each street. This was a very packed week filled with experimental results and insights about the nature of light, but at the same time with a lot of connection with my students at Ensenada, as we kept talking about questions that arose during the workshop. Their potential they had, and all of that insatiable hunger for knowledge and discovery, their hard working personality and incredible intuition, I am sure that my students will achieve great things with impactful changes in their communities as well as personal and professional goals. As a PhD Student, this adventure gave me hands-on experience on what is teaching to students from different backgrounds and how to prepare material for them in a way that is easy to grasp but at the same time tackles the fundamental knowledge.
I am grateful for the financial support granted by the GPS Office as an official sponsor of Club de Ciencias Mexico, and I also want to thank my mentor Astrid Campos and Dr. Raul Hernandez for their support during the workshop preparation and application to this incredible project!
About the author:
Alan earned his Bachelor’s Degree in Applied Physics from the Benemérita Universidad Autónoma de Puebla (BUAP) in Mexico in 2023. His previous research focused on computational physics and model simulation of both quantum and classical systems. Currently, Alan is engaged in the realm of engineering quantum vacuum fields to control the properties of quantum materials using terahertz radiation technology. Read more.
Further Reading:
Getting an Internship as a PhD student – Experience and tips