Ever wanted to know how music affects your brain, what quantum mechanics really is, or how black holes work? Do you wonder why you get emotional each time you see a certain movie, or how on earth video games are designed? Then you’ve come to the right place. Each week, Sean Carroll will host conversations with some of the most interesting thinkers in the world. From neuroscientists and engineers to authors and television producers, Sean and his guests talk about the biggest ideas in science, philosophy, culture and much more.
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 assumptions are reasonable? Niayesh Afshordi and Phil Halper have written a new book, Battle of the...
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 understanding of probability can help us decide when new evidence is actually confirming our bel...
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 Lloyd is a scientist who has traveled around the world studying these organisms, as she explains in h...
Eric Topol discusses AI's role in medicine, including diagnostics and image interpretation, highlighting both its potential and challenges. He also explores evidence-based approaches to longevity, emphasizing the importance of lifestyle, diet, and understanding age-related diseases like cancer, heart disease, and Alzheimer's, along with the role of the immune system and inflammation. The episode also debunks anti-aging myths and discusses societal and individual strategies for healthier living.
Welcome to the May 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 them together if they are about a similar topic. Enjoy! Blog post with AMA questions and tran...
Thomas Levenson discusses the history of germ theory, from the first observations of microbes to the development of vaccines and antibiotics. The episode explores why it took so long for germ theory to be accepted, the social and cultural factors that influenced its acceptance, and the lessons that can be learned from the past to address current challenges in infectious disease. It also touches on vaccine hesitancy and the importance of public health measures.
Questions about consciousness range from the precise and empirical -- what neurons fire when I have some particular experience -- to the deeply profound -- does consciousness emerge from matter, or does matter emerge from consciousness? While it might be straightforward to think that consciousness arises from the collective behavior of atoms in the brain, Annaka Harris and others argue that consciousness could be the fundamental stuff from which matter arises. She talks with a variety of experts...
Welcome to the April 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 them together if they are about a similar topic. Enjoy! Blog post with questions and transc...
Cosmologists were, let us be honest, pretty stunned in 1998 when observations revealed that the universe is accelerating . There was an obvious plausible explanation, the cosmological constant proposed by Einstein, which is equivalent to a constant vacuum energy pervading space. But the cosmological constant was known to be enormously smaller than its "natural" value, and it seems fine-tuned for it to be so small but not yet zero. Once burned, twice shy, and since then we ...
Consciousness is easier to possess than to define. One thing we can do is to look into the brain and see what lights up when conscious awareness is taking place. A complete understanding of this would be known as the "neural correlates of consciousness." Once we have that, we could hopefully make progress on developing a theoretical picture of what consciousness is and why it happens. Today's guest, Christof Koch, is a leader in the search for neural correlates and an advocate of a particular ap...
We often study cognition in other species, in part to learn about modes of thinking that are different from our own. Today's guest, psychologist/philosopher Alison Gopnik, argues that we needn't look that far: human children aren't simply undeveloped adults, they have a way of thinking that is importantly distinct from that of grownups. Children are explorers with ever-expanding neural connections; adults are exploiters who (they think) know how the world works. These studies have important impl...
Welcome to the March 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 them together if they are about a similar topic. Enjoy! Link to the 2012 Moving Natur...
Kevin Peterson discusses the science and art behind crafting perfect cocktails, drawing on physics, engineering, and perfumery. He explores the theory of balance, temperature, and aroma, and shares tips for both home mixologists and bar owners. The episode culminates in the creation of a custom "Mindscape" cocktail, inspired by forest scents after rainfall.
Helen Czerski discusses the complexities of the Earth's oceans, emphasizing their dynamic nature and the interconnectedness of physical, chemical, and biological processes. She highlights the importance of understanding these systems to address human impacts like climate change and pollution. The conversation also explores various methods of ocean exploration and the necessity of maintaining a human connection with the ocean for effective stewardship.
Lilliana Mason and Sean Carroll discuss political polarization, exploring how cultural and social identities now align with political affiliations, leading to increased animosity and potential violence. They examine the historical context, media influences, and psychological factors contributing to this divide, while also considering potential solutions for restoring democratic norms and fostering constructive engagement.
The Trump administration, led by Elon Musk and his Department of Government Efficiency, has proposed sweeping cuts to spending on science research here in the US, in particular at the National Institutes of Health and the National Science Foundation. I explain a little about what is being cut and why these funds are important to scientific progress. I try, for what it's worth, to provide these explanations in a way that would be informative to those who generally favor cutting govern...
It is a feature of many human activities - sports, cooking, music, interpersonal relations - that being able to do them well doesn't necessarily mean you can accurately describe how to do them well. Science is no different. Many successful scientists are not very good at explaining what goes into successful scientific practice. To understand that, it's necessary to study science in a scientific fashion. What kinds of scientists, in what kinds of collaborations, using what kinds of techniques, do...
Welcome to the February 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 them together if they are about a similar topic. Enjoy! Blog post with questions and tra...
A typical human lifespan is approximately three billion heartbeats in duration. Lasting that long requires not only intrinsic stability, but an impressive capacity for self-repair. Nevertheless, things do occasionally break down, and cancer is one of the most dramatic examples of such breakdown. Given that the body is generally so good at protecting itself, can we harness our internal security patrol - the immune system - to fight cancer? This is the hope of Nobel Laureate James Allison, who wor...
Randomness plays an important role in the evolution of life (as my evil twin will tell you). But random doesn't mean arbitrary. Biological organisms are physical objects, after all, and subject to the same laws of physics as non-biological matter is. Those laws place constraints on how organisms can fulfill their basic functions of metabolism, reproduction, motility, and so on. Easy to say, but how can we turn this into quantitative understanding of actual organisms? Today I talk wit...
Big data is ruling, or at least deeply infiltrating, all of modern existence. Unprecedented capacity for collecting and analyzing large amounts of data have given us a new generation of artificial intelligence models, but also everything from medical procedures to recommendation systems that guide our purchases and romantic lives. I talk with computer scientist Tina Elassi-Rad about how we can sift through all this data, make sure it is deployed in ways that align with our values, and how to dea...
A new year, and a new centennial -- 300 (regularly-numbered) episodes of Mindscape! Our tradition is to have a solo episode, and what better topic than the nature of time? Physicists and philosophers have so frequently suggested that time is some kind of illusion that it's become almost passé to believe that it might be fundamental. This is an issue where, despite the form of the question, physics has important things to say that most philosophers haven't yet caught up to. I will talk about idea...
It's the end of the year, and time for our annual holiday break here at Mindscape. But as usual, we wrap up with a Holiday Message. This year, inspired by Joni Mitchell's "Hits" and "Misses" albums, I go through my scientific papers and talk about some of my favorites -- some of which were hits, in terms of making an impact on subsequent research, and some of which were misses by that standard. But I love them all! It's an excuse to talk about process -- how papers come to be, from the initial i...
Living organisms seem exquisitely organized and complex, with features clearly adapted to serving certain functions needed to survive and procreate. Natural selection provides a compelling explanation for why that is so. But is there a bigger picture, a more general framework that explains the origin and evolution of functions and complexity in a world governed by uncaring laws of physics? I talk with planetary scientist and astrobiologist Michael Wong about how we can define what "functions" ar...
The number of neurons in the human brain is comparable to the number of stars in the Milky Way galaxy. Unlike the stars, however, in the case of neurons the real action is in how they are directly connected to each other: receiving signals over synapses via their dendrites, and when appropriately triggered, sending signals down the axon to other neurons (glossing over some complications). So a major step in understanding the brain is to map its wiring diagram, or connectome : the complete ...
Welcome to the December 2024 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 them together if they are about a similar topic. Enjoy! Blog post with AMA questions and...
Not too long ago, Brad Pitt and Eric Bana starred in a (loose) adaptation of Homer's epic poem The Iliad ; next month, Ralph Fiennes and Juliette Binoche will headline a film based on The Odyssey . Given that the originals were written (or at least written down) in the 8th century BCE, that is some impressive staying power. But they were also written in a very different time than ours, with different cultural context and narrative expectations. We talk about t...
Biological evolution via natural selection is a simple idea that becomes enormously complicated in its realization. Populations of organisms are driven toward increased "fitness," a measure of how successfully we reproduce our genetic information. But fitness is a subtle concept, changing with time and environment and interactions with other organisms around us. We talk with biologist Brandon Ogbunu about the best mathematical and conceptual tools for thinking about the messy complexities of evo...
Emergence is a centrally important concept in science and philosophy. Indeed, the existence of higher-level emergent properties helps render the world intelligible to us -- we can sensibly understand the macroscopic world around us without a complete microscopic picture. But there are various different ways in which emergence might happen, and a tendency for definitions of emergence to rely on vague or subjective criteria. Recently Achyuth Parola and I wrote a paper trying to clear up some...
Welcome to the November 2024 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 them together if they are about a similar topic. Enjoy! S upport Mindscape on Patr...
