Milk is more than just a food for babies. Breast milk has evolved to deliver thousands of diverse molecules including growth factors, hormones and antibodies, as well as microbes.

Elizabeth Johnson, a molecular nutritionist at Cornell University, studies the effects of infants’ diet on the gut microbiome. These studies could hold clues to hard questions in public health for children and adults alike. In this episode of “The Joy of Why” podcast, co-host Steven Strogatz interviews Johnson about the microbial components that make breast milk one of the most wondrous biofluids found in nature.

Listen on Apple Podcasts, Spotify, TuneIn or your favorite podcasting app, or you can stream it from Quanta.

Nothing escapes a black hole … or does it? In the 1970s, the physicist Stephen Hawking described a subtle process by which black holes can “evaporate,” with some particles evading gravitational oblivion. That phenomenon, now dubbed Hawking radiation, seems at odds with general relativity, and it raises an even weirder question: If particles can escape, do they preserve any information about the matter that was obliterated?

Leonard Susskind, a physicist at Stanford University, found himself at odds with Hawking over the answer. In this episode, co-host Janna Levin speaks with Susskind about the “black hole war” that ensued and the powerful scientific lessons to be drawn from one of the most famous paradoxes in physics.

Listen on Apple Podcasts, Spotify, TuneIn or your favorite podcasting app, or you can stream it from Quanta.

Birds flock. Locusts swarm. Fish school. Within assemblies of organisms that seem as though they could get chaotic, order somehow emerges. The collective behaviors of animals differ in their details from one species to another, but they largely adhere to principles of collective motion that physicists have worked out over centuries. Now, using technologies that only recently became available, researchers have been able to study these patterns of behavior more closely than ever before.

In this episode, the evolutionary ecologist Iain Couzin talks with co-host Steven Strogatz about how and why animals exhibit collective behaviors, flocking as a form of biological computation, and some of the hidden fitness advantages of living as part of a self-organized group rather than as an individual. They also discuss how an improved understanding of swarming pests such as locusts could help to protect global food security.

Listen on Apple Podcasts, Spotify, Google Podcasts, TuneIn or your favorite podcasting app, or you can stream it from Quanta.