Almost all of nature can be described in an equation: you just have to be clever enough. Whether it’s what the weather will do tomorrow, or how atoms behave, most things can be described mathematically. Equations are essential tools that help us to build bridges and computers, and to understand all sorts of possible - and impossible - contexts; from outside the universe to the tiniest particles. And for this we can thank researchers in mathematics like Professor Søren Fournais from Aarhus University.

Søren Fournais' expertise is the equations behind quantum physics such as the now fundamental Schrödinger’s equation. What can we use it for? "You won’t get me to say that my research leads to this or that. I deal with the mathematics behind the physics. It’s basic research; mathematical methods for the toolbox," he says. However, he does mention that quantum physical mathematics is important for modern chemistry, for example in the pharmaceutical industry. "Mathematics is a looking glass through which to see the world, and a language we use to describe it.”

“The challenge for quantum mechanical systems is the same as for a weather forecast," he explains. A weather forecast is made on the basis of complex equations, with many factors that affect the answer. For example, the temperature at different places in the preceding days and other information, the accuracy of which may be uncertain. So even though we have an equation for the weather, we don’t have a precise solution. But often we only want to know whether or not it’s going to rain. An equation - the weather forecast - can tell us this. Usually!

The same applies to equations behind quantum physics. “However, we’ve got a better grip on quantum physics than on the weather," he says, with a twinkle in his eye.

"Physicists know what parameters they’re dealing with much more precisely than meteorologists do in relation to a weather forecast. So actually, we know the correct quantum physical equations really well."

Read the full portrait of Søren Fournais (in Danish only) on the ministry's website

At a ceremony on 1 March 2018, Søren Fournais was presented with the Elite Research Prize by Minister for Higher Education and Science, Søren Pind. (Photo: Ministry of Higher Education and Science.)