Meet the AAS Keynote Speakers: Dr. Scott Tremaine

In this series of posts, we sit down with a few of the keynote speakers of the 237th AAS meeting to learn more about them and their research. You can see a full schedule of their talks here, and read our other interviews here!

Image credit: Dan Komoda

Dr. Scott Tremaine, an emeritus professor at the Institute for Advanced Study, has had a rich astronomical career, studying everything from dark matter to planet rings. His general area of study of dynamics has allowed him to branch out and explore everything from how planets in our solar system move to how large galaxies interact. “Dynamics is pretty easy, there’s only one constant: gravity, and once you have that, everything is scale-free, [or scales like a power law,] so it’s pretty easy to move around from one topic to another,” he says, describing how he’s been able to study such a vast array of systems during his career.

This Candian-born astrophysicist knew from an early age that he wanted to study science. Though he cannot pinpoint one specific experience that got him interested, he credits the 1957 launch of the Russian satellite Sputnik for launching tremendous public and political interest in science, which improved science education and made science opportunities available. He rode this wave of interest all the way to college, where he studied physics at McMaster University, and further to graduate school at Princeton University. There, he worked with Dr. Jeremiah Ostriker on galactic nuclei and the dynamical evolution of galaxies. Throughout his career, he has witnessed some incredible breakthroughs in the field, from dark matter gaining popularity in the field in the 1970s to the discovery of exoplanets in the 1990s. Dr. Tremaine has done quite a bit of work with dark matter, and cites it as one of the greatest puzzles in astronomy.

“I arrived in the field as a graduate student about the time dark matter was starting to become a subject. What’s remarkable is at the end of my career, we’re still in a situation where we’ve ruled a lot of things out, but there’s still a set of candidates that are very very different and we don’t know which one it will turn out to be. The indirect and cosmological evidence for dark matter has grown impressively and is far far stronger than it was 20 years ago, but we’re still in a position where we have absolutely no idea what it is.”

Lately, Dr. Tremaine has been working on a slew of things, from solar system dynamics to exoplanets to cosmology. He’s spent a lot of time thinking about comets in recent years, and which is what his AAS talk will focus on. 

“Comets are interesting because the story of how they got where they are is a pretty clean story. [They are] something you can model pretty accurately, the models makes definite predictions, [and] most of the predictions are borne out by the observations. Partly it’s that the region where the comets are found (between the Kuiper Belt and the Oort Cloud) is a huge region, […] and the only thing in there is the comets. […] We only see 10^-9 of all the comets that are out there, and nevertheless we can get a pretty good idea of what the general population is like just from a very small sample. It’s a nice detective story.”

Fun fact: Dr. Tremaine is credited with coining the term “Kuiper Belt”!

Though it is difficult to pick a favorite project he has done, Dr. Tremaine says he has a particular passion for work he did on the rings of Saturn and Uranus, which he studied for ~10 years in the 1970s and 1980s. “They’re such beautiful, elegant systems for one thing, and second, it was the incredible experience of having the Voyager spacecraft go by and having everything you knew about the rings completely revolutionized over the space of 48 hours. That’s an experience you just can’t get in almost any area of astrophysics, so the huge overturn in what you knew and what your models had to be was tremendous.”

Dr. Tremaine has had an incredible career in the field, and when asked if he has any words of wisdom for young scientists, his biggest piece of advice focuses on research in graduate school. “The transition from taking courses to doing research is a challenge. A lot of people talk about the transition you have to make from high school to university, but the transition from university to grad school is even bigger because you have to learn to do research.” He says that the transition from taking courses to doing research full time can be tough, and that at first it is going to be stressful. Though a lot of new graduate students are very excited to start research early, he cautions not to jump in too quickly. In graduate school, the courses are there to teach you the physics and astronomy you need to take, and he stresses the importance of focusing on these courses to gain the skills you need. “Having that material makes a difference to whether you can move into a new research field and solve a problem that is slightly different from the kinds you solved before.”

Outside of academia, one of Dr. Tremaine’s favorite activities is traveling and exploring different countries, and enjoys that astrophysics has afforded him those opportunities. “One of the nice things about astrophysics is it gives you access to a worldwide community of colleagues, it gives you lots of reasons (when there’s not a pandemic) to travel…I would have done that anyway but it’s a lot easier when you’re in a community that is spread across the world.” He also enjoys exercising, specifically rowing and climbing.  “The best thing I can do to decompress is get some hard exercise .It forces you to concentrate enough that you can’t keep thinking about your work while you’re doing it.”

You can watch his AAS 237 plenary talk about the dynamics of binary stars near galactic centers next Wednesday, January 13th, at 11:00am ET.

Astrobite edited by: Luna Zagorac

Featured image credit: American Astronomical Society

About Haley Wahl

I'm a PhD candidate West Virginia University and my main research area is pulsars. I'm currently working with the NANOGrav collaboration (a collaboration which is part of a worldwide effort to detect gravitational waves with pulsars) on polarization calibration. In my set of 45 millisecond pulsars, I'm looking at how the rotation measure (how much the light from the star is rotated by the interstellar medium on its way to us) changes over time, which can tell us about the variation of the galactic magnetic field. I'm mainly interested in pulsar emission and the weird things we see pulsars do! In addition to doing research, I'm also a huge fan of running, baking, reading, watching movies, and I LOVE dogs!

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