Dr. Lia Medeiros is a NSF Postdoctoral Fellow at the Institute for Advanced Study (IAS). She is interested in using computation and theory to better understand compact objects, such as black holes. She is part of the Event Horizon Telescope (EHT) collaboration, contributing to the collaboration’s efforts to image black holes such as the M87 and Sgr A* images. Originally from Brazil, Lia moved around a lot during her younger years, and from a young age she enjoyed learning and studying math because it was the same in every country: “I realized that it was knowledge that would always be transferred to wherever I was”.
In high school, Lia’s interest in math grew even more. “It gave me a sense of wonder that we as humans were able to use this tool called math to make predictions about the universe we live in. It still amazes me how powerful that is”. When learning about special relativity in high school, Lia learned about time dilation and black holes, which sparked her interest in astrophysics and in using math to better understand these objects. She completed her undergraduate degree at UC Berkeley, while doing REUs over the summer to gain more research experience.
Lia went to UC Santa Barbara for her Ph.D. studies, where she aimed to use astrophysical black holes to test fundamental physics. However, when she started her Ph.D, she faced challenges finding an advisor who shared her interests, was accepting new students, and had funding. “When I started my Ph.D, LIGO had not detected gravitational waves yet, and the EHT had not imaged a black hole yet. It was difficult to be part of a field that did not really exist at the time”. One week, she went to a colloquium and became interested in a talk by Prof. Feryal Ozel on her current research involving black holes. Lia mentioned to the professor that she was interested in black holes, and Prof. Ozel asked whether she wanted to join her at the University of Arizona and become her research assistant. “I was really grateful that she was able to take on a student from a different university. I still got my PhD at UCSB, but spent most of my time at the University of Arizona working with the EHT collaboration”.
Current EHT Work
Lia started her postdoc at IAS in June 2019, around two months after EHT published its first black hole image. Most of Lia’s postdoc work has been on Paper 6 of the Sgr A* EHT papers, which aimed to measure the size of the emission ring in the EHT images and used it to test whether Sgr A* is a Kerr black hole (a rotating black hole). “Kerr is a very specific geometry. If the theory of General Relativity is correct, and if a few physically motivated assumptions hold, then black holes in space must be Kerr.” Kerr predicts that there is a specific size for this ring, and a lot of Lia’s work has been on calibrating the measurement of this ring’s size and making sure every uncertainty has been taken into account. “If we were to find that astrophysical black holes are not Kerr, this would have important implications for high energy physics theory”. By better understanding the image of Sgr A*, it is possible not only to make sure it is consistent with Kerr but also to rule out or place constraints on other theoretical alternatives.
Lia’s work on the EHT caught the attention of the Brazilian Senate, who invited her to give a talk on the first black hole image back in 2019: “it was an experience I will never forget. I never imagined this would happen”.
Reaching Out to Students
When asked whether her background has affected her career decisions in any way, Lia mentions that although there is no specific event that made her feel unwelcome in astronomy, coming from Brazil made her very passionate about doing outreach for students from Latin America. “I currently teach astronomy to refugees from South America at a school. Doing outreach is a crucial part of my career. Often it is a cultural shock to move to a different country while growing up, and it is difficult to go through that as a kid. I hope that by meeting someone who went through the same thing I can help these kids in some way”.
When it comes to being a woman in astronomy, Lia finds it very inspiring and motivating that she sees many women who look to the future: “I see it in my colleagues, in women who are younger and older than me. We work very hard to make the field more inclusive and to mentor and support the next generation. We still have some work to do, but there is currently a great effort to make the experiences of the next generation of women better than our own”.
Lia advises that in order to succeed in astrophysics when you are just starting out, you do not have to be a genius. “It creates distance between students and the field, in a way that I do not think is productive for either of them. Making it seem like science is this incredibly difficult and impossible field systematically excludes minority students”. She adds that you have to be willing to work hard to persevere. “I had many things that did not go as planned. My career path wasn’t exactly typical. But I just wasn’t willing to give up”. Lia describes research as a ‘series of failures’: you fail, and you keep going, solving one problem after another. She asks students to remind themselves that doing research is doing something that has never been done before, so problems that you did not predict can happen. “Remember, it is important to be kind to yourself”.
Edited by: Mark Popinchalk
Featured Image Credit: Event Horizon Telescope Collaboration