Lavinia Heisenberg is a theoretical physicist. She is reluctant to accept that General Relativity can be used to describe the universe only on the assumption of exotic materials and energy sources. Her goal is thus to update Einstein’s theory.
Two things immediately come to mind when reading Lavinia Heisenberg’s curriculum vitae: her name and her age. She acknowledges that she’s constantly quizzed whether she is related to the father of quantum mechanics and Nobel prize-winner, Werner Heisenberg. ‘Most of the time I quote Heisenberg’s own words from his Uncertainty Principle: ’It`s uncertain’,’ the young physicist explains. The family tree does not provide a clear answer. For Lavinia Heisenberg, the famous name is mostly an incentive to cast off the shadow of the great man of physics and draw attention to herself through her own ground-breaking research. She is well on course to do so: at the age of 33, Heisenberg has already worked at various prestigious universities in a dozen different countries, her list of publications runs to several pages, and she is currently applying for her first appointment as a professor.
Building interdisciplinary bridges
For the past 18 months, the physicist has been engaged in research at the ETH Institute for Theoretical Studies (ITS), where she works as a postdoc under a junior fellowship. She has come to appreciate her new environment and says: ‘I currently have two big dreams: One of them is to stay in Zurich.’ The enormous freedom of research and the openness of colleagues to interdisciplinary collaboration are especially unique at ETH.
Heisenberg describes her main areas of work as follows: ‘Firstly I’m a theoretical physicist, secondly a cosmologist, and thirdly an astrophysicist.’ She has made it her goal to build bridges between these special fields, including mathematics. ‘This can be a lengthy process, partly because we speak very different languages,’ she says. ‘But at the same time, I am continuously learning new things.’ The first publications co-authored by the ETH professor and astrophysicist Alexandre Refregier have already appeared. She is currently collaborating with the ETH Professor and particle physicist Charalampos Anastasiou.
The titles and abstracts of Heisenberg’s publications make it difficult for the layperson to picture her everyday research. But she is able to clarify her work in a few simple words. Physicists are familiar with two basic models: particle physics (based on quantum mechanics) to describe the microscopic world, and cosmology to describe the macroscopic world, or universe. Lavinia Heisenberg works in the latter field, with a focus on gravitation, one of the four fundamental forces of physics. ‘Einstein’s Theory of General Relativity is still the best for describing gravitation, but it has some gaps,’ says Heisenberg. ‘On small scales, we do not know how to reconcile the theory with quantum mechanics.’ However, the incompleteness is also demonstrated by comparisons on large scales, for example through measurements of the accelerated expansion of the universe and the puzzling behaviour of galaxies. ‘In order for theory to fit with empirical observations, we have to make very singular assumptions,’ Heisenberg explains. ‘For instance: 95 percent of the universe is composed of dark matter and dark energy. So far science has failed to prove either of these assumptions.’
For some years, Heisenberg has therefore been puzzling over how Einstein’s theory could be modified so that no ‘exotic’ materials and energy are required in order to explain gravitation, and thus the evolution of the universe. ‘Try to picture physical theory as a tree with many branches," she explains. ’Any changes in the trunk inevitably have consequences right to the top of the tree.’ It often takes weeks before the trunk, branches and twigs fall back into harmony, Heisenberg reckons. Usually all she needs for her work is pen and paper, and occasionally special software as well. But it’s a time-consuming process. Even so, Heisenberg is unwilling to accept that there are still many unknowns in gravitation theory. ‘I need to understand that - and I won’t rest till I do,’ she says.
Dreaming of the universe
Ever since childhood, Heisenberg has had this thirst for knowledge, combined with a refusal to accept things supposedly inexplicable. She was one of those curious kids who wanted to know why a book falls to the floor from the edge of the table, rather than levitating to the ceiling. Or why, when travelling in a bus, passengers are propelled forward by a hidden force when the brakes are applied. At the same time, one of her childhood dreams was to become an astronaut when she grew up. She has always been fascinated by space and the universe. These were constants during a fairly itinerant childhood. Her father worked for an international company, so her family often moved around and Heisenberg grew up in a number of countries. Her current CV lists a knowledge of eight foreign languages, with fluency in six of them. ‘Every time we moved house, I tried hard to learn the new language,’ the researcher recalls. ‘When you learn a new language, you also see the world through different eyes.’ Today Heisenberg is copying the nomadic career moves of her parents with a succession of international research posts and appointments. Before she came to Zurich, she worked as a postdoc at the Nordic Institute for Theoretical Physics in Stockholm. Over the past four years she has also spent time in research posts in Lisbon, Marseille, Valencia, Pisa, Paris, Cape Town, Tokyo, Waterloo and Cleveland.
Heisenberg still clings on to her childhood dream of becoming an astronaut. She shares this dream with her doctoral supervisor Claudia de Rham, a highly respected cosmologist and Assistant Professor at the University of Geneva at the time. De Rham herself was preparing for a space mission, but in the end was not selected. The last recruitment procedure for the European Space Agency (ESA) was nine years ago. Heisenberg would have liked to apply, but she still hadn’t completed her studies. Since then, she has learned Russian, which is a standard requirement for all applicants. But even then, her chances are slim: in the last round, around 10,000 candidates applied for just five places.
Now Heisenberg is pinning her hopes on the next ESA selection process, which is likely to be some time in the next five years. ‘Wouldn’t it be rather ironic if a scientist who has been researching gravitation for so many years finally gets the chance to experience weightlessness’" Heisenberg asks with a smile. She is confident that a space mission would also look good on her CV. After all, many astronauts take up a university post as professors following a space flight. And what could be more satisfying for physics students than having a professor able to recount her experiences in space?