Invisible, black and extremely attractive - black holes are one of the greatest mysteries of the universe and defy our imagination. dr Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn has been researching the mysterious objects in the universe for almost twenty years. And was instrumental in the scientific sensation of recent years: the first image of a black hole. In zdi-Heldinnen-October she wants to infect girls and young women with her enthusiasm for science.
Do you speak Dr. Silke Britzen on her field of research, her eyes start to light up: “Black holes are the research subject that absolutely fascinates me. In my opinion, black holes are one of the most spectacular predictions of Albert Einstein's theory of relativity.” With sheer enthusiasm and fascination, the scientist begins to talk about invisible objects that swallow everything that approaches them. Compact and super massive, invisible but weighing up to billions of solar masses.
Black holes are truly objects that show you how tiny your world is. A thought that has occupied Silke Britzen since childhood: “I was fascinated by the universe from a very early age. Even as a small child, I had an aesthetic enthusiasm for the starry sky. Later questions came up like: We live here in a small spaceship in the big cosmos and there is so much more out there, how can you investigate that? How did the universe come about in the first place? And why? How can that be explained? I think these are questions that move a lot of people. And these questions were also what drove me.”
The fear of repetition: Silke Britzen's way into research
Her desire to be able to observe with the radio telescope of the Max Planck Institute in Bonn led to Britzen deciding to study astronomy and not art. In 1986 she enrolled in physics, astronomy and mathematics at the Rheinische Friedrich-Wilhelm-Universität in Bonn. “Painting would have been my plan B. If it hadn't worked out with astronomy, I would have studied art.” After successfully completing her studies, Britzen wrote both her diploma and her doctoral thesis at the same renowned Max Planck Institute for Radio Astronomy in Bonn. With her irrepressible thirst for knowledge, Britzen is predestined to be a researcher: “I really dreaded having to do the same thing my whole life. It is my drive to keep learning, finding and examining new things.” Nevertheless, she has remained true to the fine arts and paints part-time – not only, but also stars. She wants to sharpen the view - for the beauty of nature on earth and in the cosmos. Britzen has been researching full-time at the Max Planck Institute in Bonn since 2003 and her wish to be able to observe with the radio telescope – incidentally one of the two largest fully mobile radio telescopes in the world – has become a reality. Today, Britzen observes distant galaxies with this radio telescope. Or rather: the immediate vicinity of supermassive black holes, e.g. in the center of the elliptical galaxy M87.
Stars, comets or light - black holes swallow everything that comes too close
Albert Einstein published his "General Theory of Relativity" more than 100 years ago. From the groundbreaking gravitational equations of Einstein's theory, the existence of objects in the universe can be deduced whose gravitational force is so immense that everything that comes too close to these objects disappears inside them, never to be seen again.
These objects were christened “black holes” because “no information comes out of the inside of the black holes, not even light. These objects are really dark,” Britzen explains. Since the black holes even swallow their own light, they are invisible.
But if no one has ever seen a black hole, where is the certainty that these objects exist?
Beginning of a new era: The first photo of a black hole
Until April 2019, black holes were mostly a theoretical concept. Then the Event Horizon Telescope Collaboration (EHT), a coalition of over 200 scientists from around the world, including Dr. Silke Britzen, accomplished the seemingly impossible. Not only did they image the shadow of a black hole, they also supported Einstein's general theory of relativity. To do this, the researchers used a trick: They linked eight of the most powerful radio telescopes in the world and thus simulated a giant telescope with immense resolution. “Imagine you are sitting in Berlin and reading a newspaper in New York. We are dealing with such a resolution here,” says Britzen.
The scientists use two phenomena as clues for locating a black hole: On the one hand, matter heats up considerably as soon as it is sucked into a black hole and begins to radiate. With a lot of luck, the researchers will be able to see this glow through the radio telescopes. In addition, during this “feeding process”, as Britzen calls the extreme attraction of black holes, so-called jets are created: “These are plasma jets that are thrown outwards. M87's jets are great for studying with radio telescopes. Whenever we've seen such jets, we've followed them towards the center of M87, where the black hole is located."
Last year, the decades-long chase finally paid off, and Britzen and the EHT collaboration team managed to capture the first photograph of a black hole — a groundbreaking achievement. "At first I thought I was doing something wrong. That was an incredible moment in my own work. We've actually managed to image the shadow of a black hole!” Seen in the photo: A glowing orange ring around a jet black circular area inside – embering matter surrounding a black hole at the center of the M87. The research result will be presented simultaneously in April 2019 at six international press conferences. According to EU Research Commissioner Carlos Moedas, the recording is a milestone in astronomy and a breakthrough for all of humanity (Podbregar 2019).
The darkest secret of the universe
Some would think that after such a success the thirst for knowledge should be quenched. Not so with Silke Britzen. She continues to research those objects that are beyond our imagination, with an ambitious goal: "I would like to know how black holes can be described completely and what physical forces are at work inside." Because what happens inside black holes , is completely unknown and represents one of the greatest mysteries of science. What discourages some researchers is particularly appealing to Britzen, because research on black holes eludes the laws of nature known to us: “It is an incredible drive to approach a dark object work that you can't look into. In black hole research, there is this limit that is imposed on us by physics. And so I ask myself the question every day: Is that really a limit? Or is there a gap in the theory? Can't we find out more somehow?" How essential the research of Britzen and her colleagues is becomes apparent in October 2020 at the latest, when three scientists were awarded the world's most important physical award for their research into black holes: the Nobel Price for physics. Silke Britzen is enthusiastic: “There is no question that black holes are fascinating and important research objects. But such a Nobel Prize is something else and gives the research area even more attention and confirmation. My warmest congratulations to the colleagues!” Among the award winners: Andrea Ghez, a research colleague of Britzen. Ghez is the fourth woman to ever receive the Nobel Prize in Physics. After Donna Strickland, only two years later, a woman again appears at the center of scientific activity and becomes visible. Silke Britzen agrees that this is a consistently positive development: “This year, not only Andrea Ghez was awarded the Nobel Prize in Physics, Emmanuelle Charpentier and Jennifer Doudna were also awarded the Nobel Prize in Chemistry. The fact that the number of female award winners is increasing has also been very positively received outside of science. I think the signal that women are doing research that deserves a Nobel Prize is enormously important. I hope that it encourages young women who enjoy science and gives them momentum.”
Times have never been better for women to enter science
Britzen passes on her immense astronomical knowledge as a lecturer at the University of Heidelberg. Her aim is to get young MINT students interested in scientific research. And to take away the students' fear of research institutes: "Many students have great respect for science," says Britzen. “They think that only geniuses do research at a Max Planck Institute and are afraid to apply. But it's just incredibly exciting research that's fun. And if you already experience the everyday life of research during your studies, then the fear of contact is much less later on.” Britzen would like to encourage young women in particular and encourage them to go into research:
“When I started studying physics, 5-10% of the students were female. Things are different now and the gender ratio has improved significantly in recent years, even if there is still a lot of room for improvement. The ratio is 50/50 among our doctoral students at the Max Planck Institute. Significantly more women are also present and giving lectures at international conferences. And that is very important: We researchers have to show ourselves, ask questions, give lectures, submit proposals. The many wonderful women in science must finally become visible.” Because visible role models encourage girls and young women to also pursue a path in research and not to be deterred by prejudices. dr Silke Britzen sets a good example and sums it up: “Times have never been better for women to enter science. Makes it!"
Would you like more role models? Click here for the zdi heroines October page.
Podbregar, Nadja (2019): The first photo of a black hole. In: scinexx – the knowledge magazine, URL: https://www.scinexx.de/news/kosmos/das-erste-foto-eines-schwarzen-lochs/ (Accessed 13.10.2020).