Andrew Post-Zwicker is absolutely fascinated by plasmas. He often likes to stare at the glowing, pinkish, ionized gases in his lab.
Plasmas, hot gases containing a significant number of electrically charged particles, are common in nature, (the solar core, lightning, and the aurora are a few examples) and in manmade devices such as fluorescent light bulbs, fusion reactors, and plasma televisions. But many people don’t even know what a plasma is. Post-Zwicker, a plasma physicist and educator at the Princeton Plasma Physics Laboratory, spends much of his time trying to change that.
Andrew Post-Zwicker debating with student during a special program for high school girls interested in science.
He bemoans the fact that while 99 percent of visible universe is in the plasma state, many schools still teach that there are three states of matter—solid, liquid, and gas-- ignoring plasmas entirely. Because of the predominance of plasma in the universe, Post-Zwicker likes to say, “It’s not the fourth state of matter, it’s the first state.” But textbooks and state and national standards don’t mention plasmas, so many high school teachers don’t teach them.
Post-Zwicker himself didn’t become interested in physics until college, when he kind of wandered into the subject. At Bard College in Annandale-on-Hudson, New York, while he wavered between math and engineering, Post-Zwicker met his mentor, Professor Burt Brody, who adopted him and steered him towards physics.
He did well in his undergraduate physics classes, and went on to grad school at Johns Hopkins University. There he met another mentor, Professor Michael Finkenthal, who led him to plasmas and fusion research. Post-Zwicker conducted post-doctoral research at Oak Ridge National Laboratory, at a fusion laboratory in Julich, Germany, and at the PPPL, but he started to become frustrated with big science, and with sitting in front of a computer all day.
Then he had what he calls a life-changing moment, which brought him into education. Though he comes from a family of teachers, Post-Zwicker never intended to teach, until he took on a summer student from a poor urban high school in Trenton, as part of the Science Education Program at the PPPL.
The girl was clearly being held back by a poor school system. “She was way behind her peers in terms of what she knew,” says Post-Zwicker, “but way ahead in focus, maturity, and ambition.”
Her project was to write a computer program to display data. “It wasn’t particularly difficult if you’d ever used a computer,” recalls Post-Zwicker, “but she’d never touched a computer.”
So Post-Zwicker, who had thought he would be able to just hand the student a manual and tell her the problem, spend a tremendous amount of time with her, helping her to write a program that Post-Zwicker and his colleagues used for a long time after she left.
Unwilling to let this bright young woman go back to her school, Post-Zwicker helped her transfer to a private high school on a full scholarship. She later went on to university and medical school. “I opened the door, she stormed right through it. That was an empowering experience for me. It was life-changing for her, and for me, in ways I didn’t appreciate at the time.”
That experience led Post-Zwicker to get more involved in education. He is now the Lead Scientist for Education and Outreach at the PPPL. Post-Zwicker spends most of his time teaching in the Plasma Science Education Laboratory, where high school students and elementary through high school teachers get to share his passion for plasmas.
Instead of just tacking on plasmas to the already full high school science curriculum, Post-Zwicker wants to integrate them, using plasmas to explore other topics. So at “Plasma Camp,” which Post-Zwicker runs, high school teachers from around the country come to PPPL to learn about plasmas and how they can be used as a tool to teach introductory physics.
Post-Zwicker loves teaching so much he agreed to teach a freshman writing course at Princeton University. The topic was originally “Energy in the 21st Century”, but Post-Zwicker became interested in bioethics, so he changed the topic to the ethics of human experimentation. “I’m the only fool teaching totally out of discipline,” he says. He’s also leading a workshop on writing across the curriculum, especially in physics.
In addition to teaching, Post-Zwicker still does plasma research, but even that he combines with teaching. He uses undergraduates and advanced high school students, rather than graduate students and post-docs, as help in his lab, where he conducts tabletop experiments on plasmas. Many times the students themselves come up with research ideas, and he lets them follow their curiosity. “My mentors gave me the freedom to make my own mistakes. I use that style with my own students.”
One of these experiments studies the properties of dusty plasmas, in which tiny silicon dust particles are suspended in the plasma. Dusty plasmas are important in planet formation and comet tails, and the work could have applications in computer chip manufacturing, where dust can seriously harm the chips, or even in controlling dust in smoke stacks.
Another of Post-Zwicker’s experiments works with plasma processing--studying ways to make plasmas with microwaves and radio waves and use plasmas to coat materials. A third project involves using plasma as a model for ion transport through cell membranes. “No one has tried to build a plasma that models a biological system,” says Post-Zwicker. “We’ve found it’s tough to do.”
Because some of this research is so challenging, Post-Zwicker would like some more advanced students to help him. Though he enjoys working with high school students, he would also like to take some of his experiments to a more sophisticated level, which would require help from graduate students and post-docs. Like many scientists, he says he hasn’t quite figured out a balance between teaching and research. Nonetheless, he says, “I’ve got the best job. No one can top my job.”