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

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 pat...

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...

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 sif...

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...

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. Bu...

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...

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 maj...

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 grou...

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...

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 Ogbu...

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 va...

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 grou...

Erwin Schrödinger said that the important characteristic of life is that it "goes on doing something... for a much longer period than we would expect an inanimate piece of matter to keep going under similar circumstances." Living organisms are in constant motion inside; so where does this stability and persistence come from? Addy Pross points to a novel kind of chemical phenomenon -- "dynamic kine...

A large economy is one of the best examples we have of complex dynamics. There are multiple components arranged in complicated overlapping hierarchies, out-of-equilibrium dynamics, nonlinear coupling and feedback between different levels, and ubiquitous unpredictable and chaotic behavior. Nevertheless, many economic models are based on relatively simple equilibrium principles. Doyne Farmer is amon...

It's not immoral to kick a rock; it is immoral to kick a baby. At what point do we start saying that it is wrong to cause pain to something? This question has less to do with "consciousness" and more to do with "sentience" -- the ability to perceive feelings and sensations. Philosopher Jonathan Birch has embarked on a careful study of the meaning of sentience and how it can be identified in differ...

Welcome to the October 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...

Aging and death happen to the best of us, but there are increasing efforts to do something about it. That effort requires that we have some reasonable understanding of why aging happens, and what processes are involved. You will be unsurprised to learn that it's complicated. Venki Ramakrishnan, who won the Nobel Prize for his work on the ribosome, investigates what we know about aging in his book ...

It's a wonder democracy works at all -- a collection of people with potentially different interests have to agree to abide by majority vote even when it goes against their desires. But as we know, it doesn't always work, and racial and ethnic tensions are one of its biggest challenges. Hahrie Han studies the ground-up workings of democracy, how people can come together to successfully enact change...

As an experimental facility, the Large Hadron Collider at CERN in Geneva has been extraordinarily successful, discovering the Higgs boson and measuring multiple features of particle-physics interactions at unprecedented energies. But to theorists, the results have been somewhat frustrating, as we were hoping to find brand-new phenomena beyond the Standard Model. There is nothing to do but to keep...

It wasn't that long ago, historically speaking, that you might put on your tuxedo or floor-length evening gown to go out and hear a live opera or symphony. But today's world is faster, more technologically connected, and casual. Is there still a place for classical music in the contemporary environment? Max Richter, whose new album  In a Landscape  releases soon, proves that there is. We talk abou...

Welcome to the September 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 gro...

One common feature of complex systems is sensitive dependence on initial conditions: a small change in how systems begin evolving can lead to large differences in their later behavior. In the social sphere, this is a way of saying that history matters. But it can be hard to quantify how much certain specific historical events have affected contemporary conditions, because the number of variables i...

Understanding how life began on Earth involves questions of chemistry, geology, planetary science, physics, and more. But the question of how random processes lead to organized, self-replicating, information-bearing systems is a more general one. That question can be addressed in an idealized world of computer code, initialized with random sequences and left to run. Starting with many such random...

Being rational necessarily involves engagement with probability. Given two possible courses of action, it can be rational to prefer the one that could possibly result in a worse outcome, if there's also a substantial probability for an even better outcome. But one's attitude toward risk -- averse, tolerant, or even seeking -- also matters. Do we work to avoid the worse possible outcome, even if th...

Welcome to the August 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...