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

Music is math that you can dance to. The fact that certain notes sound good when played together, or in succession, is related to the mathematical properties of the frequencies to which they correspond, an idea that goes back as far as Pythagoras himself. These days we have a much more intricate understanding of these relationships and how to manipulate them. I talk to composer and music theorist...

Welcome to the October 2025 Ask Me Anything episode of Mindscape! These monthly excursions are funded by  Patreon supporters  (who are also the ones asking the questions). We take questions asked by Patreons, whittle them down to a more manageable number -- based primarily on whether I have anything interesting to say about them, not whether the questions themselves are good -- and sometimes group...

Certain features of our universe seem unnatural to us. These include "constants of nature" such as the cosmological constant and the mass of the Higgs boson, as well as features of the initial conditions like the curvature of space and the initial entropy. But they can't truly be "unnatural" -- they are literally features of Nature itself. Some have turned to the anthropic principle and the multiv...

A characteristic of complex systems is that individual components combine to exhibit large-scale emergent behavior even when the components were not specifically designed for any particular purpose within the collective. Sometimes those individual components are us -- people interacting within societies or online communities. Studying the dynamics of such interactions is interesting both to better...

Getting along in society requires that we mostly adhere to certainly shared norms and customs. Often it's not enough that we all know what the rules are, but also that everyone else knows the rules, and that they know that we know the rules, and so on. Philosophers and game theorists refer to this as  common knowledge . In Steven Pinker's new book,  When Everyone Knows That Everyone Knows... , he...

Like any machine, bodies occasionally break down, and it's natural to go in search of a replacement part. Ancient societies featured simple prosthetics for teeth, noses, and limbs, while modern medicine pursues more advanced ways of replacing internal organs and microbiomes. But what is striking is not just the impressive ingenuity of our attempts to replicate human anatomy, but the surprising lev...

Welcome to the September 2025 Ask Me Anything episode of Mindscape! These monthly excursions are funded by  Patreon supporters  (who are also the ones asking the questions). We take questions asked by Patreons, whittle them down to a more manageable number -- based primarily on whether I have anything interesting to say about them, not whether the questions themselves are good -- and sometimes gro...

"Liberalism," divorced from its particular connotations in this or that modern political context, refers broadly to a philosophy of individual rights, liberties, and responsibilities, coupled with respect for institutions and rule of law over personalized power. As Cass Sunstein construes the term, liberalism encompasses a broad tent, from Ronald Reagan and Margaret Thatcher to Martin Luther King...

In a relatively short period of time, exoplanets (planets around stars other than our Sun) have gone from an intriguing conjecture to an active field of scientific study, with over 5,000 confirmed discoveries. The task now is to move beyond merely accumulating new examples, and embarking on systematic studies of their properties. What fraction of stars have planets, how are they distributed in siz...

The world is becoming pixelated. As computers and other digital devices become ubiquitous, human knowledge and communication and information is gradually being converted into, and manipulated as, strings of bits. What does that really mean, and what are the ramifications going forward? Alvy Ray Smith is a computer scientist, co-founder of Pixar, and author of  A Biography of the Pixel .  We go thr...

It is not manifestly obvious that universities should be where most scholarly research is performed. One could imagine systems that separated out the tasks of "teaching students" and "generating new knowledge." But it turns out that combining them yields spectacular synergies, both from letting students experience cutting-edge research and from keeping researchers inspired by interacting with brig...

Welcome to the August 2025 Ask Me Anything episode of Mindscape! These monthly excursions are funded by  Patreon supporters  (who are also the ones asking the questions). We take questions asked by Patreons, whittle them down to a more manageable number -- based primarily on whether I have anything interesting to say about them, not whether the questions themselves are good -- and sometimes group...

The search for a foundational theory of quantum mechanics that all physicists can agree on remains active. Over the last century a number of contenders have emerged, including Many-Worlds, pilot-wave theories, and others, but all of them have aspects that many people object to. Jacob Barandes has taken up the challenge, proposing  a new formulation of quantum theory  in which there is no wave func...

When we think of the capacities that distinguish humans from other species, we generally turn to intelligence and its byproducts, including our technological prowess. But our intelligence is highly connected to our ability to use language, which is in turn closely related to our capacities as social creatures. Philosopher Philip Pettit would encourage us to think of those social capacities, as ena...

Quantum field theory is the basis for our most successful theories of fundamental physics. And yet, there are things we don't understand about it. Some of these puzzles are relatively well-known, while others are less celebrated. David Tong joins us to talk about some of the more interesting and perplexing aspects of quantum field theory. He also discusses his new project to write a series of text...

Welcome to the July 2025 Ask Me Anything episode of Mindscape! These monthly excursions are funded by  Patreon supporters  (who are also the ones asking the questions). We take questions asked by Patreons, whittle them down to a more manageable number -- based primarily on whether I have anything interesting to say about them, not whether the questions themselves are good -- and sometimes group th...

Our universe started out looking very simple: hot, dense, smooth, rapidly expanding. According to our best current model, it will end up looking simple once again: cold, dark, empty. It's in between -- now, roughly speaking -- that things look complex. I have been working to understand the stages by which complexity comes into existence, thrives, and eventually disappears. Without going into techn...

It is common to refer to philosophy as "a series of footnotes to Plato." But in the original quote, Alfred North Whitehead was more careful: he limited his characterization to "the European philosophical tradition." There are other traditions, both ancient and ongoing: Chinese philosophy, Indian philosophy, Africana philosophy, and various indigenous philosophies. For the most part, these do not g...

Economics is seeing an upsurge in the importance of controlled, reproducible empirical studies. One area where this has had a great impact is on development economics, which studies the economies of low- and middle-income societies. Edward Miguel has been at the forefront of both the revolution in empirical methods, and in applying those techniques to alleviating poverty in sub-Saharan Africa and...

The human brain is extremely complicated, but decades of careful neuroscientific research have revealed quite a bit about how it works, including how certain genes affect particular brain behaviors. Nevertheless, this progress has not led to quite as much improvement in the treatment of brain disorders as we might expect. I talk with neuroscientist Nicole Rust about why this is and how to improve...

Welcome to the June 2025 Ask Me Anything episode of Mindscape! These monthly excursions are funded by  Patreon supporters  (who are also the ones asking the questions). We take questions asked by Patreons, whittle them down to a more manageable number -- based primarily on whether I have anything interesting to say about them, not whether the questions themselves are good -- and sometimes group th...

Einstein's general theory of relativity, plus some reasonable assumptions about the universe and what it's made of, has a remarkable implication: that as we trace cosmic evolution into the far past, we ultimately hit a singularity of infinite density and curvature, the Big Bang. Did that really happen? Einstein's theory is classical, after all, and the world is quantum. And whose to say what assum...

Every time you see an apple spontaneously break away from a tree, it falls downward. You therefore claim that there is a law of physics: apples fall downward from trees. But how can you really  know ? After all, tomorrow you might see an apple that falls upward. How is science possible at all? Philosophers, as you might expect, have thought hard about this. Branden Fitelson explains how a better u...

There are living creatures dwelling deep below the surface of the Earth, as deep as we are able to drill. These hearty microorganisms are related to more familiar life forms on land and under water, but the operate and survive in ways that are quite different from what we're familiar with. They live off of nutrients that have penetrated from the surface, or sometimes off of pure electrons. Karen L...

Medical science is advancing at an astonishing rate. Today we talk with leading expert Eric Topol about two aspects of this story. First, the use of artificial intelligence in medicine, especially in diagnostics. This is an area that is a perfect match between an important question and the capabilities of machine learning, to the point where AI can out-perform human doctors. And second, our unders...