# Jeannette Janssen, professor

# A day in the life

## Jeannette Janssen, professor

Mathematics is the language of technology, the language of science. It will be easier to have a basis in mathematics and then learn the other sciences, rather than vice-versa.

### Discovering where pure and applied mathematics meet

Professor Jeannette Janssen says many people have no idea what mathematicians really do.

“They think you are solving math equations everyday. No. We try to think. Thinking is what we do all day.”

A degree in mathematics teaches you how to think logically. Dr. Janssen remembers how her immersion in mathematics as an undergraduate caused a huge shift in the way she saw the world.

“I noticed that in discussions or reading the newspaper, I had a much more logical way of thinking. It was much easier for me to get the gist of things and see how the logic of the argument flowed.”

Of course, you do practice thinking by doing math problems. And that’s where Dr. Janssen sees the benefits of Dalhousie’s Mathematics Program. Class sizes are small, you get a lot of personal attention, there’s lots of project work, and honour students have opportunities to interact with graduate students all the time.

“It’s a very nice environment. That’s a huge advantage here,” she says.

### Solid education in both pure and applied mathematics

Plus, students get a solid grounding in both pure and applied mathematics. Both are useful. Dr. Janssen cites examples of branches of math of that were considered pure, until suddenly, an application that nobody had thought about was found.

“You need both the general principles and you need to know how to bring it down to a specific problem you are working on,” she explains.

Her field – graph theory – is one example. In the last decade, the Internet broke the field wide open. Now all computer science students take graph theory courses because it applies to everything from routing packets to networks to search algorithms.

“The success of Google is to a high degree due to the fact that its founders Larry Page and Sergei Brin looked at the the world wide web as a graph,” she explains.

That’s what’s exciting about math: theoretical playfulness can shake loose applications that can change the way we look at the world. It happens all the time to math grads.