A common argument against free will is that human behavior is not freely chosen, but rather determined by a number of factors. So what are those factors, anyway? There’s no one better equipped to answer this question than Robert Sapolsky, a leading psychoneurobiologist who has studied human behavior from a variety of angles. In this conversation we follow the path Sapolsky sets out in his bestselling book Behave , where he examines the influences on our behavior from a variety of timescales, fro...
Feb 15, 2021•1 hr 29 min•Ep. 134
It’s a truism that what we see about the world is a small fraction of all that exists. At the simplest level of physics and biology, our senses are drastically limited; we only see a narrow spectrum of electromagnetic waves, and we only hear a narrow band of sound. We don’t feel neutrinos or dark matter at all, even as they pass through our bodies, and we can’t perceive microscopic objects. While science can help us overcome some of these limitations, they do shape how we think about the world. ...
Feb 08, 2021•1 hr 38 min•Ep. 133
Here is a special bonus punishment treat for Mindscape listeners: an interview of me, by David Zierler of the American Institute of Physics’s Oral History project. This is a fantastic project that collects interviews with influential physicists of all ages, and apparently sometimes less-influential physicists. So if you’d like to hear my (academic) life story boiled down to a mere four hours, here you go! Support Mindscape on Patreon . It’s well worth checking out the AIP Oral History Project we...
Feb 04, 2021•4 hr 2 min
As a semi-outsider, it’s fun for me to watch as a new era dawns in biology: one that adds ideas from physics, big data, computer science, and information theory to the usual biological toolkit. One of the big areas of study in this burgeoning field is the relationship between the basic bioinformatic building blocks (genes and proteins) to the macroscopic organism that eventually results. That relationship is not a simple one, as we’re discovering. Standard metaphors notwithstanding, an organism ...
Feb 01, 2021•1 hr 22 min•Ep. 132
The possible existence of technologically advanced extraterrestrial civilizations — not just alien microbes, but cultures as advanced (or much more) than our own — is one of the most provocative questions in modern science. So provocative that it’s difficult to talk about the idea in a rational, dispassionate way; there are those who loudly insist that the probability of advanced alien cultures existing is essentially one, even without direct evidence, and others are so exhausted by overblown cl...
Jan 25, 2021•1 hr 41 min•Ep. 131
What is the world made of? How does it behave? These questions, aimed at the most basic level of reality, are the subject of fundamental physics. What counts as fundamental is somewhat contestable, but it includes our best understanding of matter and energy, space and time, and dynamical laws, as well as complex emergent structures and the sweep of the cosmos. Few people are better positioned to talk about fundamental physics than Frank Wilczek, a Nobel Laureate who has made significant contribu...
Jan 18, 2021•1 hr 16 min•Ep. 130
The first full week of 2021 has been action-packed for those of us in the United States of America, for reasons you’re probably aware of, including a riotous mob storming the US Capitol. The situation has spurred me to take the unusual step of doing a solo podcast in response to current events. But never fear, I’m not actually trying to analyze current events for their own sakes. Rather, I’m using them as a jumping-off point for a more general discussion of how democracy is supposed to work and ...
Jan 11, 2021•1 hr 44 min•Ep. 129
We all know stereotypes about people from different countries; but we also recognize that there really are broad cultural differences between people who grow up in different societies. This raises a challenge when most psychological research is performed on a narrow and unrepresentative slice of the world’s population — a subset that has accurately been labeled as WEIRD (Western, Educated, Industrialized, Rich, and Democratic). Joseph Henrich has argued that focusing on this group has led to sys...
Jan 04, 2021•1 hr 27 min•Ep. 128
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 autobiographical. Every photon has a direction of polarization, which generally remains fixed as the photon tr...
Dec 21, 2020•1 hr 31 min
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 Jarvis has been shedding enormous light on the process of vocal learning, by studying birds and comp...
Dec 14, 2020•1 hr 16 min•Ep. 127
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 hilariously long podcast. Thanks to the generosity of Patreon supporters, we are now making the fruits of...
Dec 09, 2020•3 hr 24 min
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 points. The roots of democracy go much further back than we often think; the idea wasn’t invented in A...
Dec 07, 2020•1 hr 26 min•Ep. 126
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 Dennett recently had an exchange on just this subject , and today we’re going to hear from a working scien...
Nov 30, 2020•1 hr 15 min•Ep. 125
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 never have happened? In this solo podcast I talk about both the physics and fiction of time travel. ...
Nov 23, 2020•2 hr 42 min•Ep. 124
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 answer as many as I can. Patreon supporters have kindly agreed to let these monthly AMA episodes be rele...
Nov 20, 2020•3 hr 12 min
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 more constructed and less hard-wired than you might think. How we feel and express emotions can vary fr...
Nov 16, 2020•1 hr 17 min•Ep. 123
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 long been interested in how the brain processes that sensory input, and also how we might train it ...
Nov 09, 2020•1 hr 17 min•Ep. 122
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 West is a well-known philosopher and public intellectual who has written extensively about race and c...
Nov 02, 2020•1 hr 22 min•Ep. 121
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 life. He is also an ordained rabbi who finds resonances between modern science and passages in the Hebrew...
Oct 26, 2020•1 hr 29 min•Ep. 120
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, there are a lot more liberals on university faculties than there are conservatives. I talk with Musa...
Oct 19, 2020•1 hr 16 min•Ep. 119
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: incompatible values of the Hubble constant (expansion rate of the universe) obtained from the cosmic m...
Oct 12, 2020•1 hr 18 min•Ep. 118
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 evo-devo revolution , and a wonderful and diverse writer. We talk about the importance of randomness an...
Oct 05, 2020•1 hr 21 min•Ep. 117
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 hot-button issues. We talk about the importance of tolerating disreputable beliefs, the senses in whic...
Sep 28, 2020•1 hr 44 min•Ep. 116
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 decades. Now there is a possibility that physicists might have made some progress, by showing how subtle e...
Sep 21, 2020•1 hr 27 min•Ep. 115
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 science journalist and an ace herself, and she’s written a new book about asexuality and how it fits into ...
Sep 14, 2020•1 hr 9 min•Ep. 114
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 which to analyze evolution and human behavior, up to and including why racial or gender groups are ...
Sep 07, 2020•1 hr 20 min•Ep. 113
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 beginning, having coined the term “gene editing.” We talk about how this new technology can be used to cure...
Aug 31, 2020•1 hr 20 min•Ep. 112
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 many professional cosmologists to judge whether a model of the universe is natural or not. Philosop...
Aug 24, 2020•1 hr 21 min•Ep. 111
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 is an expert on complex systems generally, and information networks in particular. We discuss how se...
Aug 17, 2020•1 hr 24 min•Ep. 110
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 his recent book Robot, Take the Wheel examines how our relationship with cars is likely to change in t...
Aug 10, 2020•1 hr 18 min•Ep. 109
