PROFILES
IN SCIENCE
Interview with Keith M. Ashman, Ph.D.
(Photo Credit:
He comes into class in funky shirts covered with suns, moons, and stars or multi-colored cats. He has longish black hair, a British accent, bespectacled black eyes that twinkle mysteriously, and a contagious laugh. Astrophysics (along with music) is his big thing. He carries a brief-case that looks much older than he is.
“Good afternoon, ladies and gentleman, and welcome to the study of astronomy...”
Dr. Keith M. Ashman, astronomy professor at UMKC, proves that the world of science is a world of interesting characters.
He explains astronomical concepts using apples impaled on yard sticks (the only non-metric objects allowed in class), drawings and problems involving his faithful feline companion, Zoot the black cat (apparently an extragalactic explorer extraordinaire). Once he asks the class if anyone has ever seen Junkyard Wars—someone in the class watches Battle Bots. Doc gets a grin on his face—apparently this subject will work even better.
For the rest of class he explains principles of temperature in space using the physical principles of a battle bots tournament.
Day 4 of astronomy class—he comes in, puts a wastebasket on his head. Talks from inside the plastic basket. “I like the metal ones better,” he says. “Better acoustics.”
But somehow, it always relates back to stars.
Dr. Ashman is an astrophysicist and his area of specialty is globular clusters; an important type of star cluster which does not usually draw a good deal of media attention. When I came to his office to interview him I immediately wanted to know what exactly a globular cluster was.
Q (Jenny Nielsen): First off—what exactly is a globular cluster?
A (Dr. Ashman): Just a very dense collection of stars. Turns out most form in clusters...but globulars, one of their defining features is many stars crammed into a small volume. Very pretty. Spectacular through a small telescope.
Q: What can we learn from globular clusters?
A: Well. The first thing that we learn from them is more about the center of the universe.You may think that idea was nixed by Copernicus...but actually, around 1910s, we didn’t know that many nebuli were actually external galaxies. [At that time, the little area of universe where we are was apparently all that existed.] An astronomer named Kapteyn decided that he was gonna figure out where we were in this distribution of stars, by looking at photographic plates of the sky. He believed that as you get to fainter and fainter brightness levels of stars, as you move out, eventually you would find the edge of the universe. In this view, he found that the universe looked like a big blob with us in the middle.
Later on, an American named Shapley noticed that there were loads of globular clusters in the sky, in the direction of Sagittarius. He figured out that these globular clusters pointed the way to the true area of the center. There’s about 200 globular clusters in our Milky Way, and they form a “swarm of bees,” centered upon the center of our galaxy. Shapley figured out we were displaced from the center of galaxy.
Q: I understand you and a colleague have developed a working theory of globular clusters. What’s special about your particular theory?
A: We use them to probe evolution of galaxies. It used to be thought that they were all very old, near the age of the universe. The basis for what we use them for is that when we see violent bursts of star formation (when galaxies smash into each other, we have “starbursts” ---bursts of star formation, not the candy). One of the things we predicted is that when we get these massive bursts of star formation, we also get bursts of creation of globular clusters. A major star forming event can form an entire galaxy or create major evolutionary changes.
The basic idea is that globular clusters are tracers of what’s going on when galaxies form or are going through big changes. We can determine the age of the globular cluster, determine the motion radially, and then determine what they're made of. This gives us a way of dating when galaxies form, how the gas out of which they form is moving, and how many heavy elements were in the gas when the galaxies formed. We couldn't possibly learn any of this from simple stars, because you can't see individual stars that far away. But as you look really far away you're looking back in time—it's a sort of astronomy archaeology! If you think about it, astronomy has a great deal in common with archaeology.
We can’t set up a lab bench, set a star on it and poke at it, but by probing further and further into the universe and looking at the light from objects such as globular clusters, we look back in time.
Q: You’re a bass-playing musician, I understand. (For a rock band, isn’t it?) How does your musical career balance out with your career in astrophysics?
A: In terms of time, it’s really difficult.
One of the things which is
most misunderstood about scientists, is that scientists portrayed in
Writing a song and developing theories are very similar; they both involve the creative process. Every song composed is influenced by the body of work, as is any theory of physics. Very similar process.
Q: Why did you decide to be an
astrophysicist?
A: My grandfather was a major influence. Also—the story I didn’t give the
Pitch—when I was four or five I wanted to be an airline pilot. I was doing very poorly in school. Everyone
thought I was stupid. Then the school had the standard eye tests—it turned out
I was blind. So I couldn’t be an airline pilot. I cried for three days, and
then I decided I would be an astrophysicist.
My mother said if I worked really hard, maybe one day I would be a lab technician. Not because she was evil or anything—because we were working class people.
Q: Being one of your students, I notice you have a very humorous, entertaining approach to teaching. What brought that on?
A: It came from teaching calculus-based physics to engineers who didn’t really care for the culture of the physics classroom. So I developed a teaching style which I hoped would encourage them to pay attention.
And beyond that, I really find this stuff fascinating—it’s important to me that some of the students in any class I teach get turned on to that excitement that I have.
Q: One last thing. What in the universe brought you to KC?
A: I ended up here because of KU and my second wife.
Q: Do you like it here?
A: Yes. [A characteristic pause.] A lot, actually.
And for that, all of the future astronomy students at UMKC can be very thankful!
Links: Dr. Keith M. Ashman at UMKC
Text (c) 2004 Jennifer L. Nielsen, All Rights Reserved