Sean Carroll's Mindscape: Science, Society, Philosophy, Culture, Arts, and Ideas

Our climate is in the midst of dramatic changes, driven largely by human activity, with potentially enormous consequences for humanity and other species. That's why science tells us, anyway. But there is an influential contingent, especially in the United States, who deny that reality, and work hard to prevent policy action that might ameliorate it. Where did this resistance come from, and what ma...

String theory was originally proposed as a relatively modest attempt to explain some features of strongly-interacting particles, but before too long developed into an ambitious attempt to unite all the forces of nature into a single theory. The great thing about physics is that your theories don't always go where you want them to, and string theory has had some twists and turns along the way. One...

It's hardly news that computers are exerting ever more influence over our lives. And we're beginning to see the first glimmers of some kind of artificial intelligence: computer programs have become much better than humans at well-defined jobs like playing chess and Go, and are increasingly called upon for messier tasks, like driving cars. Once we leave the highly constrained sphere of artificial g...

Sometimes science is asking esoteric questions about the fundamental nature of reality. Other times, it just wants to solve a murder. Today's guest, Raychelle Burks, is an analytical chemist at St. Edward's University in Texas. Before becoming a full-time academic, she worked in a crime lab using chemistry to help police track suspects, and now she does research on building new detectors for use i...

Sir Roger Penrose has had a remarkable life. He has contributed an enormous amount to our understanding of general relativity, perhaps more than anyone since Einstein himself -- Penrose diagrams, singularity theorems, the Penrose process, cosmic censorship, and the list goes on. He has made important contributions to mathematics, including such fun ideas as the Penrose triangle and aperiodic tilin...

There won't be any regular episodes of Mindscape this week or next, as we take a holiday break. Regular service will resume on Monday January 7, 2019. In the meantime, here is a special Holiday Message. Most likely it will be of interest to very few people -- there's no real substantive content, just me talking about the State of the Podcast and some other things I've been doing. Thanks to everyon...

It's a big universe out there, full of an astonishing variety of questions and puzzles. Today's guest, Janna Levin, is a physicist who has delved into some of the trippiest aspects of cosmology and gravitation: the topology of the universe, extra dimensions of space, and the appearance of chaos in orbits around black holes. At the same time, she has been a pioneer in talking about science in inter...

Everywhere around us are things that serve functions. We live in houses, sit on chairs, drive in cars. But these things don't only serve functions, they also come in particular forms, which may be emotionally or aesthetically pleasing as well as functional. The study of how form and function come together in things is what we call "Design." Today's guest, Ge Wang, is a computer scientist and elect...

The "Easy Problems" of consciousness have to do with how the brain takes in information, thinks about it, and turns it into action. The "Hard Problem," on the other hand, is the task of explaining our individual, subjective, first-person experiences of the world. What is it like to be me, rather than someone else? Everyone agrees that the Easy Problems are hard; some people think the Hard Problem...

I remember vividly hosting a colloquium speaker, about fifteen years ago, who talked about the LIGO gravitational-wave observatory, which had just started taking data. Comparing where they were to where they needed to get to in terms of sensitivity, the mumblings in the audience after the talk were clear: "They'll never make it." Of course we now know that they did, and the 2016 announcement of th...

Brains are important things; they're where thinking happens. Or are they? The theory of "embodied cognition" posits that it's better to think of thinking as something that takes place in the body as a whole, not just in the cells of the brain. In some sense this is trivially true; our brains interact with the rest of our bodies, taking in signals and giving back instructions. But it seems bold to...

There's no question that human activity is causing enormous changes on our planet's environment, from deforestation to mass extinction to climate change. But perhaps there is a tiny cause for optimism -- or at least, the prospect of a new equilibrium, if we can manage to ameliorate our most destructive impulses. Wildlife conservationist Joe Walston argues that -- seemingly paradoxically, but not r...

We humans love to tell ourselves stories about why things happened the way they did; if the stories are sufficiently serious, we label this activity "history." Part of getting history right is simply an accurate recounting of the facts, but part of it is generally taken to be some kind of explanation about why. How much should we trust these explanations? This is a question with philosophical impl...

Special Halloween edition? Scott Derrickson is a film-lover first and a director second, but he's been quite successful at the latter -- you may know him as the director and co-writer of Marvel's Doctor Strange. (When I was younger, Doctor Strange was one of my favorite comic characters, along with Green Lantern. At least one of them got a great movie.) Scott was gracious enough to take time from...

Economics, like other sciences (social and otherwise), is about what the world does; but it's natural for economists to occasionally wander out into the question of what we should do as we live in the world. A very good example of this is a new book by economist Tyler Cowen, Stubborn Attachments. Tyler will be well-known to many listeners for his long-running blog Marginal Revolution (co-created w...

String theory is a speculative and highly technical proposal for uniting the known forces of nature, including gravity, under a single quantum-mechanical framework. This doesn't seem like a recipe for creating a lightning rod of controversy, but somehow string theory has become just that. To get to the bottom of why anyone (indeed, a substantial majority of experts in the field) would think that r...

The job of science fiction isn't to predict the future; it's to tell interesting stories in an imaginative setting, exploring the implications of different ways the world could be different from our actual one. Annalee Newitz has carved out a unique career as a writer and thinker, founding the visionary blog io9 and publishing nonfiction in a number of formats, and is now putting her imagination t...

Aging -- everybody does it, very few people actually do something about it. Coleen Murphy is an exception. In her laboratory at Princeton, she and her team study aging in the famous C. Elegans roundworm, with an eye to extending its lifespan as well as figuring out exactly what processes take place when we age. In this episode we contemplate what scientists have learned about aging, and the prospe...

Language comes naturally to us, but is also deeply mysterious. On the one hand, it manifests as a collection of sounds or marks on paper. On the other hand, it also conveys meaning – words and sentences refer to states of affairs in the outside world, or to much more abstract concepts. How do words and meaning come together in the brain? David Poeppel is a leading neuroscientist who works in many...

To paraphrase Ian Malcolm in Jurassic Park, scientists tend to focus on whether they can do something, not whether they should. Questions of what we should do tend to wander away from the pristine beauty of science into the messy worlds of ethics and the law. But with the ongoing revolutions in biology, we can't avoid facing up to some difficult should-questions. Alta Charo is a world expert in a...

For something of such obvious importance, money is kind of mysterious. It can, as Homer Simpson once memorably noted, be exchanged for goods and services. But who decides exactly how many goods/services a given unit of money can buy? And what maintains the social contract that we all agree to go along with it? Technology is changing what money is and how we use it, and Neha Narula is a leader in t...

Jazz occupies a special place in the American cultural landscape. It's played in elegant concert halls and run-down bars, and can feature esoteric harmonic experimentation or good old-fashioned foot-stomping swing. Nobody embodies the scope of modern jazz better than Wynton Marsalis. As a trumpet player, bandleader, composer, educator, and ambassador for the music, he has worked tirelessly to keep...

Few events in recent astronomical history have had the worldwide emotional resonance as the 2006 announcement that Pluto was no longer considered a planet, at least as far as the International Astronomical Union was concerned. The decision was a long time coming, but no person deserves more credit/blame for forcing the astronomical community's hand than Caltech astronomer Michael Brown. He and his...

We're all going to die. But while we are alive, it's up to us how we understand and deal with that fact. In the United States especially, there is a tendency to not face up to the reality of death, and to assume that our goal should be to struggle at all costs to squeeze every last minute out of life. The Death Positive movement aims to change that, helping people to both face up to death on a per...

It's fun to be in the exciting, chaotic, youthful days of the podcast, when anything goes and experimentation is the order of the day. So today's show is something different: a solo effort, featuring just me talking without any guests to cramp my style. This won't be the usual format, but I suspect it will happen from time to time. Feel free to chime in below on how often you think alternative for...