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

Welcome to the third annual Mindscape Holiday Message! Just a chance for me to be a little more chatty and informal than usual, although as it turned out this isn't all that different from a conventional solo episode. With the difference that what I'm talking about — a phenomenon called "cosmic birefringence" — has played a big part in my personal scientific career, so I get to be a bit autobiogra...

Many characteristics go into making human beings special — brain size, opposable thumbs, etc. Surely one of the most important is language, and in particular the ability to learn new sounds and use them for communication. Many other species communicate through sound, but only a very few — humans, elephants, bats, cetaceans, and a handful of bird species — learn new sounds in order to do so. Erich...

Getting into the swing of things here with monthly Ask Me Anything episodes. If you missed the explanation last month, there is  a Patreon page  for people who wish to support Mindscape with a small donation per episode. Benefits include a warm feeling, social status, access to ad-free versions of the podcast, and the ability to ask questions once per month, which I answer over the course of a hil...

Those of us living in democracies tend to take the idea for granted. We forget what an audacious, radical idea it is to put government power into the hands of literally all of the citizens of a country. Where did such an idea come from, and where is it going? Political scientist David Stasavage has written an ambitious history of democracy worldwide, in which he makes a number of unconventional po...

Aristotle conceived of the world in terms of teleological "final causes"; Darwin, or so the story goes, erased purpose and meaning from the world, replacing them with a bloodless scientific algorithm. But should we abandon all talk of meanings and purposes, or instead conceptualize them as emergent rather than fundamental? Philosophers (and former Mindscape guests)  Alex Rosenberg  and  Daniel Den...

Time! It doesn't stop, psychological effects of being under lockdown notwithstanding. How we experience time depends on our situation, but time itself just marches forward. Unless, of course, it's possible to travel to the past, as countless science-fiction scenarios have depicted. But does that really make sense? Couldn't we then change the past, even so dramatically that our own existence would...

As you have likely heard me mention before, I have  an account on Patreon , where people can sign up to donate a dollar or two per episode of Mindscape. In return they get two tangible (if minor) benefits. First, they get to listen to the podcast without any ads. Second, once per month I do an Ask Me Anything episode, where patrons are allowed to ask any question they like, and I do my best to ans...

Emotions are at the same time utterly central to who we are — where would we be without them? — and also seemingly peripheral to the "real" work our brains do, understanding the world and acting within it. Why do we have emotions, anyway? Are they hardwired into the brain? Lisa Feldman Barrett is one of the world's leading experts in the psychology of emotions, and she emphasizes that they are mor...

Imagine you were locked in a sealed room, with no way to access the outside world but a few screens showing a view of what's outside. Seems scary and limited, but that's essentially the situation that our brains find themselves in — locked in our skulls, with only the limited information from a few unreliable sensory modalities to tell them what's going on inside. Neuroscientist David Eagleman has...

This episode is published on November 2, 2020, the day before an historic election in the United States. An election that comes amidst growing worries about the future of democratic governance, as well as explicit claims that democracy is intrinsically unfair, inefficient, or ill-suited to the modern world. What better time to take a step back and think about the foundations of democracy? Cornel W...

Erwin Schrödinger's famous book  What Is Life?  highlighted the connections between physics, and thermodynamics in particular, and the nature of living beings. But the exact connections between living organisms and the flow of heat and entropy remains a topic of ongoing research. Jeremy England is a leader in this field, deriving connections between thermodynamic relations and the processes of lif...

In the service of seeking truth, there would seem to be value in intellectual diversity, both in keeping ourselves honest and in the possibility of new ideas coming from unexpected quarters. That's true in the natural sciences, but even more so in the humanities and social sciences, where the right/wrong distinction is sometimes less clear. But academia isn't always diverse; as an empirical fact,...

Astronomers rocked the cosmological world with the 1998 discovery that the universe is accelerating. Well-deserved Nobel Prizes were awarded to Saul Perlmutter, Brian Schmidt, and today's guest Adam Riess. Adam has continued to push forward on investigating the structure and evolution of the universe. He's been a leader in emphasizing a curious disagreement that threatens to grow into a crisis: in...

Evolution is a messy business, involving as it does selection pressures, mutations, genetic drift, and the effects of random external interventions. So in the end, how much of it is predictable, and how much is in the hands of chance? Today we're thrilled to have as a guest my evil (but more respectable, by most measures) twin, the biologist Sean B. Carroll. Sean is both a leader of the modern  ev...

How can, and should, we talk to each other, especially to people with whom we disagree? "Free speech" is rightfully entrenched as an important value in liberal democratic societies, but implementing it consistently and fairly is a tricky business. Political theorist Teresa Bejan comes to this question from a philosophical and historical perspective, managing to relate broad principles to modern ho...

Stephen Hawking made a number of memorable contributions to physics, but  perhaps his greatest was a puzzle : what happens to information that falls into a black hole? The question sits squarely at the overlap of quantum mechanics and gravitation, an area in which direct experimental input is hard to come by, so a great number of leading theoretical physicists have been thinking about it for decad...

Sexuality is, and always has been, a topic that is endlessly fascinating but also contentious. You might think that  asexuality  would be more straightforward, but you'd be wrong. Asexual people, or "aces," haven't been front and center in the public discussion of gender and sexuality, and as a result there is confusion about such basic issues as what "asexuality" even means. Angela Chen is a scie...

You can't always get what you want, as a wise person once said. But we do try, even when someone else wants the same thing. Our lives as people, and the evolution of other animals over time, are shaped by competition for scarce resources of various kinds. Game theory provides a natural framework for understanding strategies and behaviors in these competitive settings, and thus provides a lens with...

Not too long ago nobody carried a mobile phone; now almost everybody does. That's the kind of rate of rapid progress we're seeing with our ability to directly edit genomes. With the use of  CRISPR-Cas9  and other techniques, gene editing is becoming commonplace. How does that work — and perhaps more importantly, how are we going to put it to use? Fyodor Urnov has worked in this area from its begin...

Human civilization is only a few thousand years old (depending on how we count). So if civilization will ultimately last for millions of years, it could be considered surprising that we've found ourselves so early in history. Should we therefore predict that human civilization will probably disappear within a few thousand years? This "Doomsday Argument" shares a family resemblance to ideas used by...

Physicists have traditionally simplified systems as much as possible, in order to shed light on fundamental properties. But small, simple parts build up into large, complex wholes. Are there new rules and laws of nature that apply specifically to the realm of complexity? This has been a popular question for a few decades now, and we have some answers but not as many as we would like. Neil Johnson...

It's easy to foresee that technological progress will change how we live; it's much harder to anticipate exactly how. Self-driving cars represent an enormous technological challenge, but one that is plausibly on the way to being solved. What will be the unanticipated consequences when autonomous vehicles become commonplace? Jason Torchinsky is a fan of technology, but also a fan of driving, and hi...

We are living, in case you haven't noticed, in a world full of bullshit. It's hard to say whether the amount is truly increasing, but it seems that everywhere you look someone is trying to convince you of something, regardless of whether that something is actually true. Where is this bullshit coming from, how is it disseminated, and what can we do about it? Carl Bergstrom studies information in th...

Despite occasional and important disagreements, most people are in rough agreement about what it means to be moral, to do the right thing. There's much less agreement about  why  we should be moral, or even what kind of answer to that question could be convincing. Philosopher Russ Shafer-Landau is one of the leading proponents of  moral realism  — the view that objective moral truths exist indepen...

Someday, most likely, we will encounter life that is not as we know it. We might find it elsewhere in the universe, we might find it right here on Earth, or we might make it ourselves in a lab. Will we know it when we see it? "Life" isn't a simple unified concept, but rather a collection of a number of life-like properties. I talk with astrobiologist Stuart Bartlett, who (in collaboration with  Mi...