When I think back to when I was a student roaming the halls and classrooms of UW Physics (let’s be honest, I was playing 500 in Phys Club), there are many people to remember. One of the most notable was professor, ground-breaking astrophysicist, and undergraduate advisor, Gretchen Harris – always busy while always having time for you; always with knitting nearby, always quick to laugh, and always offering good advice.
The things I liked best about Dr. Harris as my undergrad advisor were that she listened, asked follow-up questions, and always gave the straight goods without pulling any punches.
One of my favourite memories was when I showed up one morning to sit a final exam for PHYS 275. I had had a rough night of stress and worry. When I turned up to the exam looking like something the cat had dragged in, she came over to me and announced that I looked awful; why? I told her my story and she told me to leave. There was an alternate writing the next day for some other students, see you then.
There was no questioning it – that was the new plan that I gratefully accepted.
Since I never seemed to build up the escape velocity needed to leave this place, I’m still wandering the halls of the physics building… less 500, though. I came to know and appreciate Gretchen as a colleague and friend. I was sad to see her leave when she retired, and I took this opportunity to catch up with her and find out what she’s been up to for the last ten years.
Some things never change – Gretchen is still busy, still makes time for me to chat, still has knitting near at hand, and is still offering great advice!
What many of us remember most about Gretchen was that she would knit. In every Phys 10, every colloquium, and every 437A/B presentation, she would be sitting quietly, knitting. And then, when she put the knitting aside… the questions that she would ask were the toughest!
I can give you all the inside scoop – she would knit in Department meetings too, and those questions? Just as tough!
I had heard an incorrect account of the origins of her seminar knitting, and Gretchen put me straight. She didn’t start knitting until she began her undergraduate degree at Mount Holyoke College, when she saw other students knitting in class. All you had to do was ask the professor ahead of time if it was okay, “but there were some you knew there was no point in asking”. Her first project was a school scarf – just a basic scarf in Mount Holyoke colours. When she left Mount Holyoke for Wesleyan and then U of T, she carried on the habit of knitting while listening.
For those of you who don’t knit, it basically boils down to a series of small, repeated actions; a meditative type of process. It is a way to keep our hands busy and minds more focused – a lot like fidget gadgets do.
I asked if there was anything that she particularly missed about the Department, and she quickly answered, “the students, of course!” The well-beloved Phys 10 Undergraduate Seminar Series is organized in turn by faculty members. When Gretchen was the organizer, she went out of her way to broaden our horizons and expose us to different subjects and ideas. She brought in authors, philosophers, artists, anyone she could think of to talk about things outside of our narrow scope of field. Those were some of the best Phys 10s, the ones where you came out with your new favourite hobby or maybe even plans for a minor.
Gretchen spent her career studying star clusters: gravitationally bound groups consisting of anywhere from 102 -107 stars that formed from the same gas cloud at about the same time. Because of their common age, chemical composition, and distance from us, we can determine the age of a given cluster and compare the evolution of its member stars with mathematical models. We can also determine cluster distances much more accurately than we can for individual stars. With that information we can map their locations in the galaxy and learn when and where clusters formed in the galaxy. And these are just a few of the things we can learn from star clusters.
She started out studying the young open clusters and how their properties compared with the models that were being developed in the 1960s and 70s. But by the 1980s she became more interested in globular clusters which have ages of 10 billion years or more – nearly the age of the universe – making them the oldest identifiable stellar population and important tools for studying star and galaxy formation in the early universe. In the early 1970s we knew many details about these old clusters in our own Milky Way galaxy and nowhere else. But gradually, with the advent of tools like the Canada France Hawaii Telescope and the Hubble Space Telescope, we learned about globular clusters and globular cluster systems in other galaxies. Her first Hubble Space Telescope project was a study of the globular clusters in the relatively nearby galaxy NGC 5128.
And now we have information on them in hundreds of galaxies. Most of the parent galaxies are too distant to resolve the clusters into individual stars, but properties of their integrated light have told us a great deal. Among the things we have learned (and her work has shown) are that: globular clusters are much the same from one galaxy to another, globular clusters began forming before their parent galaxies were fully assembled, and the total number of globular clusters in a galaxy (or the total mass they contain) is well correlated with the mass of the galaxy’s central black hole and its much larger dark matter halo.
In the 1960s globular clusters were regarded as providing valuable clues to the evolution of the Milky Way, but not much more. Things have changed a lot since then and are still changing. But she is leaving that up to others.
The hardest part about retiring, she said, was sorting through her books, her papers, and her work. What should be kept, what could go, and what had to find the right home? It took some work, but she quickly regained her stride. She has published a dozen articles while still sitting on a handful of NSERC committees and panels and travelled to Europe to work with colleagues in Germany. “After ten years of dabbling,” she says, “I’m about ready to be done with it.” The next words out of her mouth? “I just have one more really interesting research proposal I want to push through.”
I confessed to Gretchen that I was a little apprehensive about my writing project because I’m not a writer. She took a few minutes to put my head on straight, and then asked, “Do you know what the coolest thing is that I’ve done since I retired?”
Mind reeling, trying to guess. Is she going to say skydiving?
“I joined a writing group!”
I would never have guessed that; I was betting on skydiving.
She told me about fast writing, where there is an idea, quote, or poem used as a prompt. Any word or phrase can be chosen as the starting point, and you write. For ten minutes, just write. At first, she was cautious about joining an established group. The writing was unlike anything she had ever written before. The whole premise of fast writing is to begin before you know what you’re going to write about, which is completely backward to scientific writing. With practice, it’s now one of her favourite things to do. In the last year she has also started taking classes in drawing. She is not an expert by any means, but she has learned that this discipline teaches one how to see things in different and subtle ways.
If there was ever someone who personified the Waterloo Spirit of "why not?", it’s got to be Gretchen. Ten years into retirement, she is still pushing the limits of why not.
