On the origin and evolution of the world
The physicist Cigdem Issever just moved from Oxford to the HU Berlin
What is dark matter? How does matter obtain mass? The physicist Cigdem Issever, who took up her post at Humboldt-Universität zu Berlin (HU) and the DESY research centre in Zeuthen this summer, is seeking answers to these questions. Her aim is also to strengthen high-energy physics in Germany’s East.
About 27 percent of all the universe’s matter and energy consist of so-called dark matter, 68 percent of dark energy. The matter that all humans, galaxies, and our solar system consist of, the so-called ‘ordinary’ matter, makes up only 5 percent of the entire universe’s matter and energy content. We know this thanks to cosmological experiments such as the observation of rotation speeds of galaxies and solar systems. Experiments conducted at, for example, the Large Hardon Collider (LHC) at CERN in Geneva are hoped to produce new insights into dark matter. Cigdem Issever has been doing research there since 2004. ‘It is a remarkable machine. Whenever I’m working there, every day feels like I’m part of a moon landing,’ she says, waxing lyrical. Until August, the elementary particle physicist was a professor at Oxford University. Based on experiments done at the LHC, she will now continue her research in Berlin and Brandenburg with an additional 2.3 million euros ERC Advanced Grant of the European Union.
The collision of protons within the particle accelerator create unimaginably great energy densities, much like the ones found just fragments of a second after the big bang. This creates many new particles and conditions, and, possibly, dark matter capable of decomposing into ordinary matter. All these events are measured by highly specialised sensors. Issever uses these measurements to look for peculiarities that cannot be explained by the known behaviour of ordinary matter, thus suggesting the presence of dark matter. At DESY in Zeuthen, the physicist aims at refining the forensic methods underlying this quest, for example, using machine learning technology.
Issever’s working group at HU deals with similar approaches and is dedicated to investigating the Higgs particle. Since its spectacular discovery at the LHC in 2012, it has been experimentally shown that elementary particles obtain mass by interacting with so-called Higgs fields. The time has come to measure exactly what happens. To do so, Issever will look at proton-proton collisions that produce two Higgs bosons at the same time. This peculiar process makes possible to experimentally measure the shape of a Higgs field, which is so crucial to nature’s mechanism for producing matter. ‘The LHC is like a time machine that enables us to explore the states of matter, forces of nature, vacuum states, and space time, the way they were just after big bang. We can use that to understand why the universe developed the way it did. In this way, particle physics connects us to our beginnings, which is what makes it so fascinating and inspiring to me.’
Fostered by her parents, two teachers who emigrated from Turkey and valued asking questions, critical thinking, and knowledge, Cigdem Issever was fascinated by fundamental questions even as a child. She decided to study physics because ‘it is the most fundamental of the natural sciences.’ Her teacher at school also played an important role in this by challenging her and supporting her quest for knowledge.
This awareness for the important role of schools is why, back in Oxford, she was committed to working at schools, as she says, ‘particularly at primary schools because interest in children must be sparked early on.’ Working with middle school and high school students, she created a 3D model of the LHC and her ATLAS experiment in Minecraft. This can be downloaded online and lets one move around a virtual version of the accelerator and learn more about the experiments conducted there. Issever plans on continuing these projects in Berlin and Brandenburg.
Whenever Cigdem Issever speaks about her research, she also makes passionate pleas for freedom in basic research. Especially in the English-speaking world, she sees this freedom threatened by funding programmes that are limited to supporting only supposedly useful ideas. However, for research to bring forth truly new things, it needs sandboxes to experiment without asking ‘how is this useful?’ ‘History has shown that basic research has always brought forth revolutionary developments – if societies were open towards them.’ Famous examples include the world wide web, light bulbs, lasers, data processing, and combating cancer. But even beyond that, she says that we need spaces dedicated simply to the quest for knowledge, which is basic need of all humans.
By Dr. Uta Deffke for Adlershof Journal