In the night sky, the past and the present are one. If you glance up to catch the twinkle of V762 Cas, the farthest star visible to the human eye, the light you’re witnessing was created more than 16,000 years ago. But visible light is only a fraction of what scientists can see.
The current model of the Universe suggests that space and time are interlocked into a fabric, and the presence of any kind of matter — be it a galaxy, a star or a planet — creates a divot in it. According to Einstein’s theory of general relativity, the greater the mass of the object, the larger that divot will be. Light emitted from stars traverses this fabric, cascading up and down these divots on its way to us. By bending the light, these pockmarks act like a lens, magnifying and bringing into view distant, faint objects that would otherwise never be visible to us on Earth.. Scientists use this property — called gravitational lensing — to map out the contours of the universe and identify objects that are sources of light that existed billions of years ago.
Astrophysicist Dr. Priyamvada Natarajan uses gravitational lensing to transform our understanding of our cosmos and its history. In 2006, she proposed a radical new idea about how the gigantic black holes found at the center of galaxies today, including the Milky Way, could have formed in the very early Universe. In 2023, gravitational lensing helped validate Natarajan’s ideas and distant object UHZ1, an actively growing black hole from more than 13 billion years ago was seen by the James Webb Space Telescope. This object had all the properties that she had predicted, suggesting that it had formed via a new pathway, from the direct collapse of gas into a heavy black hole seed.
A scientist working at the research frontier, Chair of the Yale University Astronomy Department, author of Mapping the Heavens: The Radical Scientific Ideas That Reveal the Cosmos, and lifelong STEM and STEAM advocate, Natarajan’s work is driven by her curiosity about and deep fascination with space and exploration of the invisible Universe. During her July 2023 residency at The Rockefeller Foundation Bellagio Center (Bellagio Center), she worked on an upcoming book tracing the process by which radical scientific ideas find acceptance over time.
In February 2025, just a few weeks after being awarded the prestigious Dannie Heineman Prize for Astrophysics, Dr. Natarajan spoke to us about what sparked her love of space, the power of interdisciplinary environments and how to rebuild public trust in the sciences.
To propose a radical scientific idea and, within your lifetime, have the instrumentation, computation, and tools to see it validated, is wonderful.
Dr. Priyamvada NatarajanWinner, 2025 Dannie Heineman Prize for Astrophysics
How did you become interested in astrophysics research?
It all started when my parents bought me a telescope when I was a kid. Looking through it at the night sky filled me with a sense of awe. You could see the moon or the rings of Saturn, but you couldn’t touch them. There was something about exploring the mystery of this cosmic drama while not being able to engage directly that made me excited to learn more.
When I was in high school, my dad got me a Commodore 64, which I was itching to put to use. I pestered the Director of our local planetarium in New Delhi, where I grew up, to see if I could do a calculation to help them. She asked me to write a program that would let you predict what stars would be visible in the night sky over New Delhi at any given time. It was a tough problem, but I managed to crack it. When I showed her my star map, she tested me, asking, “What would the night sky look like if you were in Boston?” I told her had written the program in such a way that you could input any latitude and longitude on Earth, and it would draw up the star map from that point of view. That was when she apparently decided, “I want to mentor this kid.” She gave me other problems to work on, and I was just hooked. I knew by then that I wanted to do research.
That idea of mentorship is something that is still very much a part of my own work. My career has not been without challenges that are particular to being who I am. When I was coming through the early stages of my career, 20-25 years ago, there wasn’t as much awareness of mentorship and sponsorship — terms that early career researchers are totally familiar with today. Pathways into a career in science are better supported, and I do my bit to expand mentoring opportunities and make sure that the doors are to anyone who has an interest and passion for science.
Your work is influenced by a wide range of interdisciplinary influences beyond the hard sciences. Why is that, and how does it impact what you do?
I love mathematics, physics, history, philosophy, writing, and lots of other subjects. So after I earned my undergraduate degrees in math and physics, I wasn’t sure what was next. This was the time in the 1990s when the new field of science studies, with scholars like Michelle Foucault, Bruno Latour and others were interrogating and challenging science. I had it in my head that to write about things like epistemology, knowledge creation and the scientific process, you had to have credentials in the humanities, so I applied, got into the PhD program in the history and philosophy of science at MIT and finished all the coursework. I was poised to begin my thesis work, but a twist of fate led me back to science and astrophysics and to Cambridge, England, where I enrolled as a PhD student at the Institute of Astronomy.
Later, I had the privilege of being the first woman to be elected a fellow in astrophysics as a fellow of Trinity College, Cambridge. For someone with my interdisciplinary bent, Trinity was heaven. It was a lot like my Bellagio Center residency. You’re in this beautiful place, and all around you, at every meal, you’re meeting and engaging with these great minds that are experts in many different academic fields. It was one of the best times of my life.
That kind of intellectually vibrant environment builds confidence — about yourself, but also confidence about exploring big ideas. You get this permission to dream and to speculate, to do something more daring and bold. One thing that I found so inspiring in my first Bellagio Center residency was how good the other members of my cohort were at clearly explaining their work, which prompted me to start thinking about writing for the broader public. Afterwards, I wrote my first essay for the New York Review of Books, called What Scientists Really Do, about demystifying science and the scientific process — how it’s rigorous, yet also subjective in very particular ways. Those concepts are at the core of what will eventually be my second book, which focuses on how radical scientific ideas go from proposal to acceptance.
What does it feel like to see an idea of yours go from speculation to validated discovery?
People don’t realize the importance of perseverance in science. It took decades for Subrahmanyan Chandrasekhar’s ideas on how black holes formed as the end states of stars to be accepted. By the time he won the Nobel Prize in his eighties, they were seen as scientific facts — but it took 30 years before others in the field were persuaded.
As I was starting my own research on black holes, observations motivated me and others to explore further potential new ways to make the first black holes. There just wasn’t enough time for the earliest black holes that were beginning to be seen to grow to supermassive size — 1,000,000 times the mass of our sun or larger — starting from a stellar corpse. So I started looking for ways they could have formed outsized at birth.
The most likely explanation was direct collapse, when a black hole is formed by a large gas cloud collapsing in upon itself. Along with one of my postdoc collaborators, I identified physics that could make that happen in the early Universe. But the question remained: do those conditions needed to form a direct-collapse black hole actually exist? Answering that took many years.
I was also researching dark matter, which is invisible, but we know it’s there because of the way that matter bends space time around it. It bends and focuses light, a cosmic lens, allowing you to infer and map out the distribution of dark matter. Black holes are similar in that they can’t be seen because light can’t escape them. You have to infer their presence indirectly by what’s happening in their vicinity. In 2017, we realized we could use this property to test our assumptions about how supermassive black holes could form from heavy direct-collapse seeds. We made concrete predictions of signs that would indicate that an object is likely a direct-collapse black hole, including that the superheated gas around the black hole would also be visible in X-rays. I collaborated with a team led by an X-ray astronomer to map out a patch of sky replete with lensing that would magnify faint distant objects using the Chandra X-ray Observatory. With nature’s telescopes augmenting the ones engineered by us humans — the James Webb Space Telescope and Chandra — we found two growing black holes in the very distant Universe that satisfied all our predictions.
I’ve always loved the feeling of figuring something out by myself and identifying how to understand or calculate or solve a problem. There is a simple, childlike joy that comes with that moment of clarity. For me, It’s often about my relationship to a beautiful piece of mathematics and physics. As a practicing scientist, however, when one is in the job of making testable predictions, it’s next-level happiness when your idea gets validated.
What worries you or makes you hopeful about science at this moment in time?
I’m very hopeful — it helps that I am optimistic by nature. I have to be, because we have so many complex problems, and all of them have scientific and technological facets that we can do something about to solve.
It’s critical that we help people understand the science’s process and rigor, as well as how scientists as domain experts contest new claims amongst themselves and reach a consensus, despite some subjective elements. I truly believe that if we can find ways to clearly explain the process of science and illuminate the practice of science to people, that would go a long way in restoring trust in it.
Part of demystifying science is showing that there is no absolute certainty. Any scientific finding that we report is provisional — in the sense that it represents the best of what we know currently and that future data is likely to improve our understanding. But the things we consider to be scientific facts are based on extensive data and validation, so they’re not just opinions that can change at any minute.
It’s important to be able to grasp both possibility and probability — to have a mind that is flexible and open enough to adapt to new data, while still realizing that good data and current knowledge are driving our understanding. Understanding what scientists really do is key.
Imagine that one day, you see a story about a study saying coffee is good for you, and three months later, a different study says it’s not. Which is right? You have to go beyond the headline. How big was their study? What was their methodology? If we can explain how to interrogate which findings are reliable and provide critical-thinking tools to the public in a way that they can understand — people will learn to be their own fact-checkers to catch disinformation and misinformation.
Science is the shared language of the cosmos, distilling our best ideas to create a vision of how our universe works and how we can thrive within it. To Dr. Priyamvada Natarajan, there’s never been a better time to be a part of it. “To be able to propose a radical idea and, within your lifetime, have the instrumentation, computation, and tools to see it validated, is wonderful,” she said. “To be alive and have the opportunity to do science in such a time is a dream come true.”
While The Rockefeller Foundation provided support to the authors to create this project, the Foundation is not responsible for the project and does not recommend or endorse the contents of the article.
Learn More:
- Check out Natarajan’s essay What Scientists Really Do in the New York Review of Books.
- Learn about how radical ideas and discoveries that are transforming our knowledge of the universe in Natarajan’s bookMapping the Heavens: The Radical Scientific Ideas That Reveal the Cosmos.
- Watch Natarajan talk about how understanding black holes can change our sense of the cosmos in this video from the Institute for Arts and Ideas.