Arnab Bhattacharya is an Indian physicist and science communicator. He is a research professor at the Tata Institute of Fundamental Research, where he works in semiconductor optoelectronics. Since 2021, he has also served as director of the Homi Bhabha Centre for Science Education. Bhattacharya is an avid proponent of public engagement and science education. Since 2009, he has led and curated Chai and Why, a widely attended science café in Mumbai. In 2017, the Indian National Science Academy honored him with the Indira Gandhi Prize for the Popularization of Science, one of India’s most prestigious science awards, for his contributions to public science communication. In this wide-ranging and insightful InterDialogue, we explore interconnected questions surrounding science communication, education, and outreach in both Indian and global contexts. We also discuss Bhattacharya’s projects during the COVID-19 pandemic, when he helped create low-cost methods for decontaminating N95 masks for reuse by frontline responders. In addition, we talk about his research on nanomaterials and India’s potential for developing domestic industries centered on advanced technologies such as semiconductors, solar energy, and nuclear power. Beyond his scientific research and outreach work, we also touch on the importance of maintaining work-life balance, as well as Bhattacharya’s passion for Indian classical music, nature, and cooking. Timestamps 1:02 – Bhattacharya’s introduction to science and science communication 10:59 – Interventions in science communication in India 16:16 – Hands-on alternatives to theoretical learning 21:34 – Bhattacharya’s involvement in pandemic response in India 27:36 – Public health communication during the pandemic 33:09 – Problems facing public health and science communication in India 41:01 – Bhattacharya’s directorship of the Homi Bhabha Center for Science Education 45:04 – Impact of AI on science education in India 50:43 – Bhattacharya’s research on lighting technology 55:54 – India’s potential for a domestic semiconductor industry 1:00:57 –...

Earth’s Memory, Part One Abstract Every rock carries a fragment of Earth’s memory. Collectively, these fragments preserve an extraordinary geological record spanning more than 4.5 billion years of planetary evolution. This article traces that record through the deep-time history of our planet—from the formation of Earth’s earliest crust and the Great Oxidation Event, when microbial life transformed the planet’s atmosphere, to the five great mass extinctions that repeatedly reset the trajectory of life, and the Snowball Earth episodes, when our planet experienced its most extreme glaciation. Drawing on more than two decades of fieldwork across Himalaya and Peninsular India, among ancient rocks, minerals, and fossils that bear direct witness to these planetary transformations, it explores how geologists reconstruct Earth’s early history from evidence preserved in the geological archives. Taken together, these geological events reveal a recurring pattern: Earth is a dynamic system in which every major crisis has also created the conditions for new and often more complex forms of life to evolve. That pattern, written into rocks billions of years old, continues to shape the planet today.    I first learned to listen to rocks long before I had the words to describe what that meant.  It began in the Himalaya, the youngest mountain range on Earth, still rising, still deforming, and still recording the ongoing collision between continents. During my early fieldwork, I spent long days mapping folded strata, tracing fault scarps, and trying to understand how landscapes preserve evidence of processes operating across vastly different geological timescales. At that time, I often felt that the mountains were trying to say something in a language I had not yet learned. Over time, through fieldwork, mapping, and countless hours spent among rocks and sediments, I began to decipher that silent language.  The lesson deepened across many other landscapes of India....

Marta González is a Venezuelan-American physicist and complexity scientist whose research explores the dynamics of human mobility, urban systems, and sustainability through the lens of statistical physics and network science. She is a professor of civil and environmental engineering and city and regional planning at the University of California, Berkeley, where she also serves as associate director of the Transportation Sustainability Research Center. González is internationally recognized for pioneering the use of large-scale mobility data to better understand cities and inform public policy. In this wide-ranging InterDialogue, González reflects on her journey from physics into complexity science and urban research, explaining how statistical physics provides powerful tools for understanding human mobility and the collective dynamics of cities. We discuss the emergence of urban science as an interdisciplinary field, the opportunities and limitations of mobile phone and mobility datasets, and how these data can improve transportation planning, climate adaptation, and the design of more resilient and sustainable cities. González also explores the challenges of translating scientific research into public policy, including questions of data access, privacy, and collaboration between researchers, governments, and industry. We further examine the future of urban mobility, autonomous vehicles, and clean energy, as well as the importance of international collaboration and expanding scientific capacity across the Global South. Finally, she reflects on the broader promise of complexity science for addressing some of the most pressing social and environmental challenges facing rapidly urbanizing societies. Timestamps 0:00 – Introduction and Marta González’s path into complexity science 5:01 – From statistical physics to human mobility research 10:18 – Mobile phone data and the emergence of urban science 15:42 – Sustainable cities, climate adaptation, and resilience 20:24 – Privacy, data access, and international collaboration 25:42 – Using complexity science to inform urban policy 29:32 – Measuring the impact of remote work...

Ram Ramaswamy is an Indian physicist whose work cuts across disciplinary boundaries. A leading complex systems scientist, his research has largely centered on nonlinear dynamics, statistical physics, and computational biology. After earning his PhD from Princeton University, he returned to India, first joining the Tata Institute of Fundamental Research before spending most of his career at Jawaharlal Nehru University, where he was part of both the School of Physical Sciences and the School of Computational and Integrative Sciences until his retirement in 2018. He later served as Vice Chancellor of the University of Hyderabad and has held numerous visiting and honorary professorships. Currently, he is an honorary professor in the Department of Physical Sciences at IISER Berhampur and holds the D. D. Kosambi Chair in Interdisciplinary Studies at the University of Goa. Ramaswamy is a fellow of the World Academy of Sciences and a fellow and former president of the Indian Academy of Sciences, where he also founded the journal Dialogue: Science, Scientists and Society. Across his career, he has consistently championed academic freedom and more inclusive, equitable approaches to science education. In this wide-ranging InterDialogue, we discuss Ramaswamy’s contributions to chaos theory, self-organized criticality, and the synchronization of stochastic systems, along with his influential role in shaping nonlinear science in India. The conversation also explores the broader social responsibilities of scientists, particularly within public universities, including teaching, mentorship, and public communication. We delve into his sustained efforts to advance gender equity in Indian science, beginning with Lilavati’s Daughters, a landmark volume he co-edited featuring the voices of nearly one hundred women scientists. Other topics include improving accessibility in science education for students with disabilities and his current work on a biography of the influential Indian thinker D. D. Kosambi. The discussion opens with reflections on the importance of public...

Sunil Mukhi is an Indian theoretical physicist at the Indian Institute of Science Education and Research (IISER) in Pune, Maharashtra. Mukhi has led a distinguished career in theoretical particle physics. He received his PhD from Stony Brook University before joining the prestigious Tata Institute of Fundamental Research in Mumbai, where he worked for 27 years. In 2012, he joined IISER Pune as chair of the physics department, where he is now an honorary emeritus professor and the Raja Ramanna Chair. Throughout the years, Mukhi has held sabbatical positions at CERN in Geneva, the Institute for Advanced Study at Princeton University, and Trinity College at the University of Cambridge. He is a fellow of the Indian Academy of Sciences, the Indian National Science Academy, and the World Academy of Sciences. In 1999, he received the Shanti Swarup Bhatnagar Prize, one of India’s highest science awards, for his contributions to theoretical physics. In this InterDialogue, we begin by speaking about Mukhi’s advisory work on academic ethics, the structural incentives for academic misconduct, his concerns about AI use in academia and the difficulties of curtailing it, and India’s international scientific standing. We then speak about Mukhi’s research and contributions to theoretical physics, especially in the field of string theory. Mukhi also discusses his personal background, his career trajectory, and his reasons for returning to India after studying in the United States. We conclude by addressing the importance of science outreach, inclusivity in science, responsible behavior in scientific and public discourse, and the importance of extracurricular interests to maintaining a healthy work-life balance. Timestamps 00:00 – Introduction 2:27 – Importance of academic ethics 5:59 – Consequences of academic misconduct 8:24 – Structural incentives for academic misconduct 11:23 – Legal challenges in academic ethics 13:14 – AI and academic ethics 16:46 – Addressing AI use...

Omar Prias is an electrical engineer, professor at the National University of Colombia, and former president of the Colombian Energy and Gas Regulatory Commission (CREG). He has decades of experience in the energy sector working at the intersection between the academy, planning, and politics. This InterDialogue addresses the importance of decentralized energy technologies for sustainable development, the role of intercultural dialogue, national and global energy transition, and the possibilities of introducing advanced nuclear technologies, both new and projected, in non-nuclear countries such as Colombia. We begin by talking about the fundamental role of energy in all sectors of society. Timestamps 00:00 – Introduction 1:50 – Prias’s Background in Energy 7:57 – Industry and Energy Systems in Colombia 15:13 – Historical Development of the Energy Sector in Colombia; Energy and Conflict 22:06 – Geopolitics of Colombian Energy 26:32 – Hydroelectric Power in Colombia 44:40 – Intercultural Considerations and Energy Communities 53:15 – Intercultural Dialogue and Decision-Making 1:03:43 – Energy Transition in Colombia 1:13:41 – Nuclear Energy in Colombia 1:20:11 – Opening Spaces for Adopting New Technologies