We have identified thousands of planets just in our neighborhood in the Milky Way, mostly from the way they impact their host stars. Basic calculations suggest that there are countless more across the galaxy, and that billions of them could potentially support life. But what kind of life they host, and how we would be able to detect the presence of those biological processes from Earth, remain big questions in the world of exoplanets and astrobiology. What technologies might lie ahead to help us...
Dec 19, 2024•38 min•Ep 24•Transcript available on Metacast Death might seem like a pure loss, the disappearance of what makes a living thing distinct from everything else on our planet. But zoom in closer, to the cellular level, and death takes on a different, more nuanced meaning. There is a challenge in simply defining what makes an individual cell alive or dead. Scientists today are working to understand the various ways and reasons that cells disappear, and what these processes mean to biological systems. In this episode, cellular biologist Shai Sha...
Dec 05, 2024•39 min•Ep 23•Transcript available on Metacast It’s fair to say that enjoyment of a podcast would be severely limited without the human capacity to create and understand speech. That capacity has often been cited as a defining characteristic of our species, and one that sets us apart in the long history of life on Earth. Yet we know that other species communicate in complex ways. Studies of the neurological foundations of language suggest that birdsong, or communication among bats or elephants, originates with brain structures similar to our...
Nov 21, 2024•42 min•Ep 22•Transcript available on Metacast Scientists routinely build quantitative models — of, say, the weather or an epidemic — and then use them to make predictions, which they can then test against the real thing. This work can reveal how well we understand complex phenomena, and also dictate where research should go next. In recent years, the remarkable successes of “black box” systems such as large language models suggest that it is sometimes possible to make successful predictions without knowing how something works at all. In thi...
Nov 07, 2024•37 min•Ep 21•Transcript available on Metacast The “species” category is almost certainly the best known of all the taxonomic classifications that biologists use to organize life’s vast diversity. It’s a linchpin of both conservation policy and evolutionary theory, though in practice biologists have struggled to find a definition that works across the natural world. In this episode, Kevin de Queiroz, a zoologist and evolutionary biologist, talks with host Janna Levin about the variety of ways to conceive of a species, and ways to understand ...
Oct 24, 2024•30 min•Ep 20•Transcript available on Metacast When we think about medicine’s war on cancer, treatments such as surgery, radiation and chemotherapy spring to mind first. Now there is another potential weapon for defeating tumors: statistics and mathematical models that can optimize the selection, combination or timing of treatment. Building and feeding these models requires accounting for the complexity of the body, and recognizing that cancer cells are constantly evolving. In this episode, host Steven Strogatz hears from Franziska Michor, a...
Oct 10, 2024•43 min•Ep 19•Transcript available on Metacast If instruments do someday detect evidence of life beyond Earth, whether it’s in this solar system or in the farther reaches of space, astrobiologists want to be ready. One of the best ways to learn how alien life might function can be to study the organisms called extremophiles, which live in incredibly challenging environments on or in the Earth. In this episode, Penelope Boston, a microbiologist who has worked for many years with NASA, speaks with Janna Levin about the bizarre life found in ha...
Sep 26, 2024•45 min•Ep 18•Transcript available on Metacast As a treat to our listeners, we are posting a full episode of Sidedoor, a podcast that explores the treasures in the Smithsonian's vaults. Subscribe to Sidedoor from Smithsonian wherever you listen to podcasts! Black holes could unlock the mysteries of creation and live at the heart of nearly every galaxy. But these invisible balls of extremely dense matter have never been fully understood, especially when they were only a theory. We travel through a cosmic wormhole back to the 1930s to learn ho...
Sep 19, 2024•35 min•Transcript available on Metacast The principles of thermodynamics are cornerstones of our understanding of physics. But they were discovered in the era of steam-driven technology, long before anyone dreamed of quantum mechanics. In this episode, theoretical physicist Nicole Yunger Halpern talks to host Steven Strogatz about how physicists today are reinterpreting concepts such as work, energy and information for a quantum world.
Sep 12, 2024•43 min•Ep 17•Transcript available on Metacast Observations of the cosmos suggest that unseen sources of gravity — dark matter — tug at the stars in galaxies, while another mysterious force — dark energy — drives the universe to expand at an ever-increasing rate. The evidence for both of them, however, hinges on assumptions that gravity works the same way at all scales. What if that’s not true? In this episode, theoretical physicist Claudia de Rham explains her work on an alternative explanation called “massive gravity” to host Janna Levin....
Aug 29, 2024•42 min•Ep 16•Transcript available on Metacast Within just a few years, artificial intelligence systems that sometimes seem to display almost human characteristics have gone from science fiction to apps on your phone. But there’s another AI-influenced frontier that is developing rapidly and remains untamed: robotics. Can the technologies that have helped computers get smarter now bring similar improvements to the robots that will work alongside us? In this episode, Daniela Rus, a pioneering roboticist at the Massachusetts Institute of Techno...
Aug 15, 2024•38 min•Ep 15•Transcript available on Metacast Can you keep a secret? Modern techniques for maintaining the confidentiality of information are based on mathematical problems that are inherently too difficult for anyone to solve without the right hints. Yet what does that mean when quantum computers capable of solving many problems astronomically faster are on the horizon? In this episode, host Janna Levin talks with computer scientist Boaz Barak about the cryptographic techniques that keep information confidential, and why “security through ...
Aug 01, 2024•24 min•Ep 14•Transcript available on Metacast Common sense rules our world. This fundamental, sometimes trivial knowledge is inherent to how humans interpret language. Yet, some of these simple human truths are so obvious that they're rarely put into words. And without the data of common sense to train on, large language models such as ChatGPT have bizarre, often humorous blind spots. Yejin Choi, professor and the chair of computer science at the University of Washington, calls common sense the “dark matter” of intelligence. In this week’s ...
Jul 18, 2024•44 min•Ep 13•Transcript available on Metacast In the tiling of wallpaper and bathroom floors, collective repeated patterns often emerge. Mathematicians have long tried to find a tiling shape that never repeats in this way. In 2023, they lauded an unexpected amateur victor. That discovery of the elusive aperiodic monotile propelled the field into new dimensions. The study of tessellation is much more than a fun thought exercise: Peculiar, rare tiling formations can sometimes seem to tell us something about the natural world, from the structu...
Jul 03, 2024•39 min•Ep 12•Transcript available on Metacast The universe seems like it should be unfathomably complex. How then is science able to crack fundamental questions about nature and life? Scientists and philosophers alike have often commented on the “unreasonable” success of mathematics at describing the universe. That success has helped science probe some profound mysteries — but as the physicist Nigel Goldenfeld points out, it also helps that the “hard” physical sciences, where this progress is most evident, are in major ways simpler than the...
Jun 20, 2024•36 min•Ep 11•Transcript available on Metacast During traumatic periods and their aftermath, our brains can fall into habitual ways of thinking that may be helpful in the short run but become maladaptive years later. For the brain to readjust to new situations later in life, it needs to be restored to the malleable state it was in when the habits first formed. That is exactly what Gül Dölen , a neuroscientist and psychiatric researcher at the University of California, Berkeley, is working toward in her lab. What is her surprising tool? Psych...
Jun 06, 2024•40 min•Ep 10•Transcript available on Metacast For decades, the best drug therapies for treating depression, like SSRIs, have been based on the idea that depressed brains don’t have enough of the neurotransmitter serotonin. Yet for almost as long, it’s been clear that simplistic theory is wrong. Recent research into the true causes of depression is finding clues in other neurotransmitters and the realization that the brain is much more adaptable than scientists once imagined. Treatments for depression are being reinvented by drugs like ketam...
May 23, 2024•33 min•Ep 9•Transcript available on Metacast If superconductors — materials that conduct electricity without any resistance — worked at temperatures and pressures close to what we would consider normal, they would be world-changing. They could dramatically amplify power grids, levitate high-speed trains and enable more affordable medical technologies. For more than a century, physicists have tinkered with different compounds and environmental conditions in pursuit of this elusive property, but while success has sometimes been claimed, the ...
May 09, 2024•29 min•Ep 8•Transcript available on Metacast 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 t...
Apr 25, 2024•35 min•Ep 7•Transcript available on Metacast Nothing escapes a black hole… or does it? In the 1970s, Stephen Hawking described a subtle process by which black holes can “evaporate,” with some particles evading gravitational oblivion. This phenomenon, now dubbed “Hawking radiation,” seems inherently at odds with general relativity, but it gets weirder still: If particles can escape, do they preserve some information about the matter that was obliterated? Leonard Susskind, a physicist at Stanford University, found himself at odds with Hawkin...
Apr 11, 2024•29 min•Ep 6•Transcript available on Metacast Birds flock. Locusts swarm. Fish school. In these chaotic assemblies, order somehow emerges. Collective behaviors 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 collective animal behavior more closely than ever before. These new insights are unlocking some of the secret f...
Mar 28, 2024•40 min•Ep 5•Transcript available on Metacast Quantum teleportation isn’t just science fiction; it’s entirely real and happening in laboratories today. But teleporting quantum particles and information is a far cry from beaming people through space. In some ways, it’s even more astonishing. John Preskill, a theoretical physicist at the California Institute of Technology, is one of the leading theoreticians of quantum computing and information. In this episode, co-host Janna Levin interviews him about entanglement, teleporting bits from coas...
Mar 14, 2024•30 min•Ep 4•Transcript available on Metacast Time seems linear to us: We remember the past, experience the present and predict the future, moving consecutively from one moment to the next. But why is it that way, and could time ultimately be a kind of illusion? In this episode, the Nobel Prize-winning physicist Frank Wilczek speaks with host Steven Strogatz about the many “arrows” of time and why most of them seem irreversible, the essence of what a clock is, how Einstein changed our definition of time, and the unexpected connection betwee...
Feb 29, 2024•31 min•Ep 3•Transcript available on Metacast We often talk about evolution as the survival of the fittest. But if it is, then where did the widespread (and widely admired) impulse to help others even at great cost to ourselves come from? In this episode, host Janna Levin speaks with Stephanie Preston , a professor of psychology and head of the Ecological Neuroscience Lab at the University of Michigan, about the evolutionary, neurological and behavioral foundations for altruism.
Feb 15, 2024•34 min•Ep 2•Transcript available on Metacast We tend to think of mathematics as purely logical, but the teaching of math, its usefulness and its workings are packed with nuance. So what is “good” mathematics? In 2007, the mathematician Terence Tao wrote an essay for the “Bulletin of the American Mathematical Society” that sought to answer this question. Today, as the recipient of a Fields Medal, a Breakthrough Prize in Mathematics and a MacArthur Fellowship, Tao is among the most prolific mathematicians alive. In this episode, he joins Ste...
Feb 01, 2024•36 min•Ep 1•Transcript available on Metacast Tune in to the new season of ‘The Joy of Why,’ a podcast from Quanta Magazine and PRX. This season, new co-host cosmologist Janna Levin and mathematician Steven Strogatz will be joined by guests including Terence Tao , the mathematician and Fields Medalist, and Frank Wilczek , the Nobel Prize-winning physicist. New episodes premiere every other Thursday.
Jan 25, 2024•2 min•Transcript available on Metacast Even empty space bubbles with energy, according to quantum mechanics — and that fact affects almost every facet of physical reality. The theoretical physicist Isabel Garcia Garcia explains to Steven Strogatz why it’s so important in modern physics to understand what a true vacuum is. The post Does Nothingness Exist? first appeared on Quanta Magazine...
Jul 26, 2023•45 min•Transcript available on Metacast Abnormal waves of electrical activity can cause a heart’s muscle cells to beat out of sync. In this episode, Flavio Fenton, an expert in cardiac dynamics, talks with Steve Strogatz about ways to treat heart arrhythmias without resorting to painful defibrillators. The post Can Math and Physics Save an Arrhythmic Heart? first appeared on Quanta Magazine...
Jul 12, 2023•46 min•Transcript available on Metacast Jellyfish and other aquatic creatures embody solutions to diverse problems in engineering, medicine and mathematics. John Dabiri, a fluid dynamics expert, talks with Steven Strogatz about what jellyfish can teach us about going with the flow. The post What Can Jellyfish Teach Us About Fluid Dynamics? first appeared on Quanta Magazine...
Jun 28, 2023•44 min•Transcript available on Metacast Wave-science researcher Ton van den Bremer and Steven Strogatz discuss how rogue waves can form in relatively calm seas and whether their threat can be predicted. The post What Causes Giant Rogue Waves? first appeared on Quanta Magazine
Jun 14, 2023•40 min•Transcript available on Metacast 
