Astrobiologist Caleb Scharf joins Michael Shermer for a wide-ranging conversation about the past, present, and future of our relationship with space. Drawing on his new book The Giant Leap, Scharf explains why human expansion beyond Earth may be less a choice than an evolutionary development, and he walks through the physics, history, and personalities that shaped our journey off the planet.

Scharf also explains the biological toll of radiation and microgravity, and why terraforming Mars is probably unrealistic and why our future might rely more on building vast rotating habitats in space than on settling other planets.

Caleb Scharf is an astrobiologist and recipient of the 2022 Carl Sagan Medal. He was Director of Astrobiology at Columbia University in New York and is now the Senior Scientist for Astrobiology at the NASA Ames Research Center in Silicon Valley. He is author of more than 120 scientific papers and over 500 popular science articles. His new book is The Giant Leap: Why Space is the Next Frontier in the Evolution of Life.

In this episode, Michel-Yves Bolloré lays out his case for why modern cosmology, fine-tuning, and the limits of materialism point toward a creator. Drawing on physics, thermodynamics, probability, and philosophy, he argues that the Big Bang, the apparent beginning of the universe, and the complexity of life collectively form a compelling body of evidence for God’s existence. Bolloré explains why he believes the universe is not eternal, why “nothing” cannot produce “something,” how moral red lines suggest a transcendent source, and how he reconciles scientific reasoning with his Christian faith, while Michael Shermer gently but rigorously presses him with questions to elicit his strongest arguments.

Michel-Yves Bolloré is an engineer and entrepreneur whose career spans industrial innovation and philanthropic investment in education. He is a graduate of the École Nationale Supérieure d’Ingénieur de Toulouse and Paris-Dauphine University (Master of Science and Doctorate in Business Administration). He founded several schools, including The Laurels in London and Les Vignes in France. He is also a Knight of the Legion of Honor. His new book is God: the Science and the Evidence.

Have you ever thought about the science and history of … wind?

In this episode, Simon Winchester explains why eastbound flights are usually faster than flying west, and how the discovery of the jet stream was almost missed because the original research was published in Esperanto. He also talks about the debate over the Great Terrestrial Stilling—the idea that global wind speeds may be decreasing—and why newer measurements suggest the trend may be reversing.

Winchester describes how and where the highest wind speed ever recorded was measured, the increasing frequency of clear-air turbulence (the kind that causes sudden drops during flights), why only one flag placed on the Moon fell, the techniques used by Polynesian navigators to cross vast stretches of ocean without instruments, and the challenges faced by early wartime pilots who unintentionally flew into the jet stream.

Simon Winchester is the acclaimed author of many books, including The Professor and the Madman, which was adapted into a film starring Mel Gibson and Sean Penn, as well as The Men Who United the United States, The Map That Changed the World, The Man Who Loved China, A Crack in the Edge of the World, and Krakatoa. His books have been New York Times bestsellers and have appeared on numerous best-of-the-year lists. In 2006 he was appointed an Officer of the Order of the British Empire (OBE) by Her Majesty the Queen.