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

Stephen Hawking's discoveries of black hole radiation, entropy, and the information-loss problem have both taught us an enormous amount about the relationship between quantum mechanics and gravity, and also left us with some knotty puzzles. One major insight is the holographic principle: the information describing a black hole can be thought of as living on the event horizon (the two-dimensional b...

Why do people voluntarily hand over authority to a government? Under what conditions  should  they do so? These questions are both timeless and extremely timely, as modern democratic governments struggle with stability and legitimacy. They also bring questions from moral and political philosophy into conversations with empirically-minded social science. Margaret Levi is a leading political scienti...

Welcome to the November 2022 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...

People have a complicated relationship to mathematics. We all use it in our everyday lives, from calculating a tip at a restaurant to estimating the probability of some future event. But many people find the subject intimidating, if not off-putting. John Allen Paulos has long been working to make mathematics more approachable and encourage people to become more numerate. We talk about how people t...

The founders of statistical mechanics in the 19th century faced an uphill battle to convince their fellow physicists that the laws of thermodynamics could be derived from the random motions of microscopic atoms. This insight turns out to be even more important than they realized: the emergence of patterns characterizing our macroscopic world relies crucially on the increase of entropy over time. B...

It's a big universe we live in, so it comes as no surprise that big numbers are needed to describe it. There are roughly 10^22 stars in the observable universe, and about 10^88 particles altogether. But these numbers are nothing compared to some of the truly ginormous quantities that mathematicians have found to talk about, with inscrutable names like Graham's Number and TREE(3). Could such  immen...

Welcome to the October 2022 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 t...

With communication satellites, weather satellites, GPS, and much more, what happens in space is already important to our lives here on Earth. And the importance of space is only going to grow as we increase the presence of humans, whether in Earth orbit or beyond. So the questions of what laws govern activity in space, and how nations and institutions should practice good governance more generally...

The detection of gravitational waves from inspiraling black holes by the LIGO and Virgo collaborations was rightly celebrated as a landmark achievement in physics and astronomy. But ultra-precise ground-based observatories aren't the only way to detect gravitational waves; we can also search for their imprints on the timing of signals from pulsars scattered throughout our galaxy. Chiara Mingarelli...

My little pandemic-lockdown contribution to the world was a  series of videos  called  The Biggest Ideas in the Universe . The idea was to explain physics in a pedagogical way, concentrating on established ideas rather than speculations, with the twist that I tried to include and explain any equations that seemed useful, even though no prior mathematical knowledge was presumed. I'm in the process...

What's the fastest way to get a human being around a racetrack, if we ignore all the rules of racing? How many pages would you have to read to absorb all of the government laws that apply to you? It's hard to imagine a better person to tackle these kinds of slightly-askew questions than Randall Munroe, creator of the  xkcd  webcomic. He collected some answers in his book  What If? , and has releas...

People throughout history have imagined ideal societies of various sorts. As the twentieth century dawned, advances in manufacturing and communication arguably brought the idea of utopia within our practical reach, at least as far as economic necessities are concerned. But we failed to achieve it, to say the least. Brad DeLong's new book,  Slouching Towards Utopia: An Economic History of the Twent...

Welcome to the September 2022 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 Patrons, 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...

There is no human endeavor that does not have a theory of it — a set of ideas about what makes it work and how to do it well. Music is no exception, popular music included — there are reasons why certain keys, chord changes, and rhythmic structures have proven successful over the years. Nobody has done more to help people understand the theoretical underpinnings of popular music than today's guest...

It's always a little humbling to think about what affects your words and actions might have on other people, not only right now but potentially well into the future. Now take that humble feeling and promote it to all of humanity, and arbitrarily far in time. How do our actions as a society affect all the potential generations to come? William MacAskill is best known as a founder of the  Effective...

Evolution by natural selection is one of the rare scientific theories that resonates within the wider culture as much as it does within science. But as much as people know about evolution, we also find the growth of corresponding myths. Simon Conway Morris is a paleontologist and evolutionary biologist who's new book is  From Extraterrestrials to Animal Minds: Six Myths of Evolution . He is known...

Welcome to the August 2022 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...

The idea of an "interest rate" might seem mundane and practical, in comparison to our usual topics around here, but there is a profound philosophical idea lurking in the background: if you lend me money now against the promise of me paying you back more in the future, I am relating the different values that a certain sum has to me at different moments in time. Traditionally, the interest rates set...

Recent years have seen a revolution in the study of exoplanets, planets that orbit stars other than the Sun (or don't orbit stars at all). After a few tentative detections in the 1990s, dedicated instruments in the 2000s have now pushed the number of known exoplanets into the thousands, enough to begin to categorize their distribution and properties. Today's guest is John Asher Johnson, one of the...

We describe the world using language — we can't help it. And we all know that ordinary language is an imperfect way of communicating rigorous scientific statements, but sometimes it's the best we can do. Linguist N.J. Enfield argues that the difficulties run more deeply than we might ordinarily suppose. We use language as a descriptive tool, but its origins are found in more social practices — com...

Welcome to the July 2022 Ask Me Anything episode of Mindscape! These monthly excursions are funded by  Patreon supporters  (who are also the ones asking the questions). I take the large number of questions asked by Patreons, whittle them down to a more manageable size — based primarily on whether I have anything interesting to say about them, not whether the questions themselves are good — and som...

The United States is suffering from an epidemic of tragic gun violence. While a political debate rages around the topic of gun control, it remains important to understand the causes and possible remedies for gun violence within the current system. Andrew Papachristos is a sociologist who uses applied network science to study patterns of street violence in urban areas. His research shows that such...

All of us construct models of the world, and update them on the basis of evidence brought to us by our senses. Scientists try to be more rigorous about it, but we all do it. It's natural that this process will depend on what form that sensory input takes. We know that animals, for example, are typically better or worse than humans at sight, hearing, and so on. And as Ed Yong points out in his new...

Welcome to the June 2022 Ask Me Anything episode of Mindscape! We are inaugurating a slightly different publication schedule, in which these monthly AMA will take the place of one of the regular Monday episodes, rather than being in addition to all of them. A slight tweak that will hopefully make my obligations a little more manageable. These monthly excursions are funded by  Patreon supporters  (...

The 200th episode of Mindscape! Thanks to everyone for sticking around for this long. To celebrate, a solo episode discussing a set of issues naturally arising at the intersection of philosophy and physics: how to think about probabilities and expectations in a multiverse. Here I am more about explaining the issues than offering correct answers, although I try to do a bit of that as well. Support...