by Shawna Hollen
In graduate school, I was working on publishing a paper with my advisor and another graduate student. We had this new data that showed how particles called Cooper pairs act when they are stuck in an insulating film. The 3D plot of the data looks like a giant wave with ripples and we were trying to decide what color to make it. We couldn’t use blue, actually, because blue meant something else in the paper. We needed a color that would stick out and remind people that the data represented an insulator. We ended up picking “magenta,” which was science-language for bright freaking pink. It was gorgeous:
It wasn’t until later that I realized that pink and purple were under-represented in physics. Since the publication of the “magenta peak” I have taken a stealthy joy in incorporating these colors into my scientific presentations and diagrams whenever I can get away with it.
There are so many things in physics that inspire a childish glee. As a postdoc here at OSU, one of my projects involves making rainbows with lethal chemicals. It actually terrifies me that the chemicals are lethal, but check out these rainbows!
Look at the diagram below the picture: the sample is a piece of silicon (that’s what computer chips are made out of) with an oxide layer on top. The oxide is partly transparent, so the light that hits it reflects off of two surfaces and interferes with itself, like so. If you’ve had any optics in physics yet, you’ll remember that light travels differently in different materials. The interference effect that occurs when the light meets back up with itself at the surface causes one color (wavelength) to appear much more strongly than the others. The “selected” color depends on the oxide thickness. So if you change the oxide thickness in steps, like I have with the lethal chemicals, then voila! A rainbow! My wonderful husband, who is going to be a lawyer but also loves physics, pointed out to me that this is the same reason soap bubbles and oil slicks are multicolored. You just need two surfaces and a partly transparent film of varying thickness to make a rainbow. (Science note: in an actual rainbow, the drops of water in the atmosphere cause the interference effect.)
I also get to make sparkly things. Sparkly things are just many reflective surfaces pointing in different directions. The effect is way cooler when the surfaces are smaller than you can see, then you just see the sparkles. I made a sparkly thing by making some very tiny (100 nm wide: close to one billionth of a meter) crossing lines in a grid. All the raised lines reflected the light. Even though I couldn’t see the lines with my naked eye, I sure could see the sparkles. Oh, I also know someone in the department who is growing DIAMONDS! Real ones. Really really really tiny ones. Nanodiamonds. How awesome is that?
I love physics. Part of my job is making things, part of it is prodding those things to see what happens to them, part of it is making pictures, and part of it is telling stories, and part of it is solving puzzles. In some ways, my job is exactly what I wanted to spend all of my time doing when I was eight. Of course, the most important part about being a scientist is that you’re making things and prodding them to answer important questions about how the universe behaves. Your questions have to be good ones if you want to solve the puzzle. Then (you’re not done when you solve the puzzle) your pictures and stories have to be very carefully crafted to tell the world what you learned in the most efficient and least confusing way possible. Sometimes, even the smartest people on the planet can’t understand you unless you show them the right pictures and explain your story in a way that makes sense. Of course, this is also a lesson all children learn about adults.
Solving the puzzles of the natural world turns out to be very hard to do. Scientists have had to come up with new ways to describe what they observe and new tools for taking observations and turning them into more general rules about the way the world works. When you are trained to be a scientist, you’ll learn how to interpret things that look like this:
Without being told where this equation comes from, you’ll already know that it tells a story about electrons hopping from one place to another in a 2D grid. You’ll be able to tell that they prefer to move to sites that are empty because there’s a repulsive force between the electrons. You’ll also be able to tell that there is a random component that makes some sites more attractive than others for hopping. And if you have an imagination like mine, you’ll turn this 2D grid into a pond with slimy lilypads and the electrons into frogs. (Yes, occasionally weird metaphors fall apart, but it’s always more colorful if you try them out anyway.) So, I’d say I became a scientist because when I was eight I loved puzzles, stories, building things, and prodding stuff to see what it would do. I’m just glad I found out (by accident) that all these qualities were those of a scientist.
About Shawna Hollen
I grew up in Oregon (Newport and Bend) and then went to college at Occidental College in LA, where I first got involved in physics research. After college I got a great job at NASA’s Jet Propulsion Lab, but soon decided that I needed to learn more physics. I went to Brown University for graduate school where I studied superconductivity in very thin metal films. While in graduate school, I got the chance to teach science to elementary school kids in Providence, RI. I also taught an upper level physics class at Wheaton College, which was a lot of fun. I recently started a postdoc here at OSU in the Center for Emergent Materials studying spintronics. Outside of physics, I love photography, hiking, and exploring with my family and my dog (Kodiak).