Those of us who grew up during the Cold War were keenly aware of the space race between the US and USSR. With us to relive the victories and tragedies of the space race is Leroy Chiao. Leroy is a former NASA astronaut and International Space Station commander. A veteran of four space missions, Leroy most recently served as Commander and NASA Science Officer of Expedition 10 aboard the International Space Station. He logged 229 days in space - over 36 hours of which were spent in spacewalks. Leroy flew missions with Russian, Japanese, and European astronauts and their affiliated space agencies. In addition to being a Space Station Commander and Space Shuttle Mission Specialist, Leroy was also a certified co-pilot of the Russian Soyuz spacecraft. Today we discuss his book Dinner with an Astronaut, published in 2026 by Hanover Square Press.

Marie Curie was one of the most remarkable scientists in history. She was the first woman to win a Nobel Prize, the first person to win two, and the only person ever to earn Nobel awards in separate fields of science. Today we explore the life and legacy of Marie Curie with the science writer Dava Sobel. Dava is the author of prominent and best-selling science history books, including Longitude, Galileo's Daughter, The Planets, A More Perfect Heaven, and The Glass Universe. Today's conversation is based on Dava's latest book, entitled, The Elements of Marie Curie, How the Glow of Radium Lit a Path for Women in Science.

On July 9, 1955, mathematician and philosopher Bertrand Russell announced the Russell-Einstein manifesto, which warned the world of the dangers posed by nuclear weapons. The 11 signatories included Albert Einstein, who signed it just before his death. Physicist Joseph Rotblat stated that the manifesto was "the last message from the man who was the symbol of the great heights the human intellect can reach, imploring us not to let all this be destroyed by human folly." Russell and Rotblat then initiated the Pugwash Conferences on Science and World Affairs, with the first one occurring in 1957 in Pugwash, Nova Scotia. Rotblat led the Pugwash Conferences until 1973, and he and the Pugwash Conferences jointly won the Nobel Peace Prize in 1995 "for their efforts to diminish the part played by nuclear arms in international politics and, in the longer run, to eliminate such arms". With us to discuss the history of Pugwash, nuclear disarmament, and public policy related to science is John Holdren. John served as science advisor to President Barack Obama from 2009 to 2017, making him the longest serving presidential science advisor since World War II. He served in many other scientific leadership roles, including as chair of the executive committee of the Pugwash Conferences from 1987-1997. When the group was awarded the Nobel Peace Prize in 1995, John delivered the acceptance lecture, so he is the perfect person to reflect on the history of Pugwash and nuclear disarmament.

What did the ancient world discover about the cosmos? What were the contributions of Copernicus, Kepler, and Galileo? How did the science of astronomy advance under Newton? And how did everything change again with the discoveries of special relativity, general relativity, and quantum mechanics? With us to answer these questions is Sarah Alam Malik. Sarah is an expert on dark matter, and her work on large-scale experiments such as the Large Hadron Collider has placed her at the cutting edge of exploring the universe's mysteries and its fundamental laws. Today we discuss her new book entitled, A Brief History of the Universe (and our place in it).

Chemical exposures in the womb can lead to what biologists call organizational effects - that is, impacts on the developing child that are irreversible. How were developmental problems associated with chemical exposures during pregnancy first discovered? And how did these discoveries influence policy? With me to discuss chemicals and child development is Tracey Woodruff. Tracey is a professor in the Department of Epidemiology and Population Health at Stanford University, where she co-leads the UCSF/Stanford Environmental Research and Translation for Health Center. She is an expert on environmental pollution exposures and impacts on health, with a focus on pregnancy, infancy and childhood, and health equity. Tracey was elected to the National Academy of Medicine in recognition of her pioneering work advancing environmental health and reproductive justice.

The age of exploration altered the course of human history, but how did early explorers find their way? Calculating their latitude at sea was a relatively straightforward proposition, but calculating longitude presented a vexing problem. Given the big power competition for colonies, conquest, and riches, the search to discover an accurate means of assessing longitude became a scramble. A major piece of the puzzle lay in the accurate assessment of time on a rocking vessel, which tested the ingenuity of the most creative clock makers. With me to discuss the history of the technologies associated with the measurement of longitude is Emily Akkermans. Emily is the Curator of Time at Royal Museums Greenwich, which includes the Royal Observatory Greenwich. The observatory is Britain's oldest purpose-built scientific institution, and it just celebrated its 350th anniversary - which is the impetus for this episode. The observatory is the birthplace of modern astronomy and the home of Greenwich Mean Time and the Prime Meridian.

Today we explore the life and legacy of the physicist Niels Bohr through the reflections of his grandson Tomas Bohr. Tomas is an Emeritus Professor at the Technical University of Denmark. He studies fluid dynamics, biophysics, chaos, turbulence and statistical mechanics, and he has a long and distinguished career publishing in these fields. He is a member of the Royal Danish Academy of Sciences and Letters.

Often in the history of science, myths overrun scientific findings and take hold with such force that they are difficult or nearly impossible to dislodge from public understanding. Perhaps no example of this phenomenon is more pronounced than that of the societal collapse of Easter Island, also known as Rapa Nui. With us to unravel the myth from the science is Mike Pitts. Mike is a writer and broadcaster (a frequent voice on BBC radio), archaeologist (directing excavations at Stonehenge), and one-time museum curator. He has written for The Times, Telegraph, Sunday Times, Observer, and Guardian, and many magazines including New Scientist, Archaeology, and BBC History. He edited British Archaeology magazine for 20 years and has written books on topics ranging from the discovery of Richard III's grave to How to Build Stonehenge. His original research has been published in peer-reviewed journals such as Nature, World Archaeology, and Antiquity. He is a Fellow of the Society of Antiquaries.

The Science History Podcast, now in its 9th year, has spanned Trump's first term in office, four years of the Biden Administration, and a year of the second Trump Administration, not to mention a global pandemic, horrific wars around the world, and the emergence of AI. So now seems like the perfect moment for some levity. The master of musical satire, Tom Lehrer, passed away in 2025. Here is my celebration of Lehrer's ability to make us laugh during the even more tumultuous times of the Civil Rights era, the Vietnam War, the Cold War, and political assassinations and violent polarization.

Today's episode is a discussion on the history of PFAS, or forever chemicals, including their accidental development, incorporation into commercial products, concerns about health effects, and environmental contamination and remediation. My guest is Sharon Udasin. Sharon is a Colorado-based environmental journalist and author of Poisoning the Well: How Forever Chemicals Contaminated America. She was a Ted Scripps Fellow in Environmental Journalism at the University of Colorado Boulder in 2019-2020 and received a SEAL Environmental Journalism Award in 2023. A graduate of the University of Pennsylvania and Columbia Journalism School, she has reported for numerous publications over the past two decades — most recently for The Hill.