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

The radius of the Earth is over 6,000 kilometers, but the deepest we've ever dug below the surface is only about 12 km. Yet we have a quite reliable idea of the structure of the Earth's interior -- inner core, outer core, mantle, crust -- not to mention pretty good pictures of what's going on inside some other planets. How do we know those things, and what new things are we learning in the exoplanet era? I talk with astrophysicist and planetary scientist Sabine Stanley about how we use gravitation, seismology, magnetic fields, and other tools to learn what's happening inside planets.

Blog post with transcript: https://www.preposterousuniverse.com/podcast/2024/01/29/264-sabine-stanley-on-whats-inside-planets/

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Sabine Stanley received a Ph.D. in geophysics from Harvard University. She is currently a Bloomberg Distinguished Professor at Johns Hopkins University. She has been awarded the William Gilbert Award from the American Geophysical Union. Her recent book is What's Hidden Inside Planets?

• Website
• Johns Hopkins web page
• Publications from Google Scholar
• Wikipedia

Einstein's theory of general relativity is distinguished by its singular simplicity and beauty. The Standard Model of Particle Physics, by contrast, is a bit of a mess. So many particles and interactions, each acting somewhat differently, with a bunch of seemingly random parameters. But lurking beneath the mess are a number of powerful and elegant ideas, many of them stemming from symmetries and how they are broken. I talk about some of these ideas with Chris Quigg, who with collaborator Robert Cahn has written a new book on the development of the Standard Model: Grace in All Simplicity.

Blog post with transcript: https://www.preposterousuniverse.com/podcast/2024/01/22/263-chris-quigg-on-symmetry-and-the-birth-of-the-standard-model/

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Chris Quigg received his Ph.D. in physics from the University of California, Berkeley. He is currently Distinguished Scientist Emeritus at Fermi National Accelerator Laboratory. Among his awards is the J.J. Sakurai Prize in theoretical particle physics from the American Physical Society. He is also the author of Gauge Theories of the Strong, Weak, and Electromagnetic Interactions.

• Website
• Publications
• Amazon author page
• Wikipedia

Scientists and philosophers sometimes advocate pretty outrageous-sounding ideas about the fundamental nature of reality. (Arguably I have been guilty of this.) It shouldn't be surprising that reality, in regimes far away from our everyday experience, fails to conform to common sense. But it's also okay to maintain a bit of skepticism in the face of bizarre claims. Philosopher Eric Schwitzgebel wants us to face up to the weirdness of the world. He claims that there are no non-weird ways to explain some of the most important features of reality, from quantum mechanics to consciousness.

Blog post with transcript: https://www.preposterousuniverse.com/podcast/2024/01/15/262-eric-schwitzgebel-on-the-weirdness-of-the-world/

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Eric Schwitzgebel received his Ph.D. in philosophy from the University of California, Berkeley. He is currently a professor of philosophy at the University of California, Riverside. He is the author of several books, including the new The Weirdness of the World.

• UC Riverside web page
• The Splintered Mind blog
• Google Scholar publications
• PhilPeople profile
• Wikipedia

In mid-20th-century cosmology, there was a debate over the origin of the chemical elements. Some thought that they could be produced in the Big Bang, while others argued that they were made inside stars. The truth turns out to be a combination of both, with additional complications layered in. Some of the elements of the periodic table come all the way from the Big Bang, but others are made inside stars or in stellar explosions. But still others are made by cosmic rays or when neutron stars and black holes merge together. We talk to nuclear astrophysicist Sanjana Curtis about all the different ways that the universe is cleverly able to produce various elements.

Blog post with transcript: https://www.preposterousuniverse.com/podcast/2024/01/08/261-sanjana-curtis-on-the-origins-of-the-elements/

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Sanjana Curtis received her Ph.D. in physics from North Carolina State University. She is currently a National Science Foundation postdoctoral fellow at the University of California, Berkeley. Her research involves nuclear astrophysics, especially the production of heavier elements in supernova explosions and neutron-star/black-hole collisions. She is also active in science communication, including at her TikTok channel.

• Website
• Google Scholar publications

Octopuses, artificial intelligence, and advanced alien civilizations: for many reasons, it's interesting to contemplate ways of thinking other than whatever it is we humans do. How should we think about the space of all possible cognitions? One aspect is simply the physics of the underlying substrate, the physical stuff that is actually doing the thinking. We are used to brains being solid -- squishy, perhaps, but consisting of units in an essentially fixed array. What about liquid brains, where the units can move around? Would an ant colony count? We talk with complexity theorist Ricard Solé about complexity, criticality, and cognition.

Blog post with transcript: https://www.preposterousuniverse.com/podcast/2024/01/01/260-ricard-sole-on-the-space-of-cognitions/

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Ricard Solé received his Ph.D. in physics from the Polytechnic University of Catalonia. He is currently ICREA research professor at the Catalan Institute for research and Advanced Studies, currently working at the Universitat Pompeu Fabra, where he is head of the Complex Systems Lab. He is also an External Professor of the Santa Fe Institute, Fellow of the European centre for Living Technology, external faculty at the Center for Evolution and Cancer at UCSF, and a member of the Vienna Complex Systems Hub. He is the author of several technical books.

• Web site
• Google Scholar publications

The final Mindscape podcast of each year is devoted to a short, reflective Holiday Message. This year the theme is Immortality: whether it's an attractive idea, and whether the laws of physics and cosmology would allow for it in principle. (Spoiler: they do not.) Mindscape will return as usual on January 1, 2024. Happy holidays everyone!

Blog post with transcript: https://www.preposterousuniverse.com/podcast/2023/12/18/holiday-message-2023-reflections-on-immortality/

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Here are some of the stories and papers mentioned in the episode:

• Borges, "The Immortal"
• Barnes, A History of the World in 10 1/2 Chapters
• The Good Place
• Chiang, Stories of Your Life and Others
• Dyson, "Time Without End: Physics and Biology in an Open Universe"

It wasn't that long ago that topics like the nature of consciousness, or the foundations of quantum mechanics, or prospects for extraterrestrial life were considered fringey and disreputable by much of the scientific community. In all these cases, the tide of opinion is gradually changing. Life on other worlds, in particular, has seen a remarkable growth in interest -- how life could start on other worlds, how we can detect it in the solar system and on exoplanets, and even thoughts about advanced alien civilizations. I talk with astrophysicist Adam Frank about some of those thoughts. We also give the inside scoop on what professional scientists think about UFOs.

Blog post with transcript: https://www.preposterousuniverse.com/podcast/2023/12/11/259-adam-frank-on-what-aliens-might-be-like/

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Adam Frank received a Ph.D. in physics from the University of Washington. He is currently the Helen F. and Fred H. Gowen Professor in the Department of Physics and Astronomy and Distinguished Scientist at the Laboratory for Laser Energetics at the University of Rochester. Among his awards are the National Honors Society Best Book in Science award, and the Carl Sagan Medal from the American Astronomical Society. His new book is The Little Book of Aliens.

• Web Site
• U Rochester web page
• Wikipedia
• Amazon author page

Welcome to the December 2023 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 transcript: https://www.preposterousuniverse.com/podcast/2023/12/04/ama-december-2023/

Link to the article referenced about time travel in movies: Ars Technica.

There will be no AMA in January due to holiday break.

Mindscape Big Picture Scholarship.

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The Artificial Intelligence landscape is changing with remarkable speed these days, and the capability of Large Language Models in particular has led to speculation (and hope, and fear) that we could be on the verge of achieving Artificial General Intelligence. I don't think so. Or at least, while what is being achieved is legitimately impressive, it's not anything like the kind of thinking that is done by human beings. LLMs do not model the world in the same way we do, nor are they driven by the same kinds of feelings and motivations. It is therefore extremely misleading to throw around words like "intelligence" and "values" without thinking carefully about what is meant in this new context.

Blog post with transcript: https://www.preposterousuniverse.com/podcast/2023/11/27/258-solo-ai-thinks-different/

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Some relevant references:

• Introduction to LLMs by Andrej Karpathy (video)
• OpenAI's GPT
• Melanie Mitchell: Can Large Language Models Reason?
• Mitchell et al.: Comparing Humans, GPT-4, and GPT-4V On Abstraction and Reasoning Tasks
• Kim et al.: FANToM: A Benchmark for Stress-testing Machine Theory of Mind in Interactions
• Butlin et al.: Consciousness in Artificial Intelligence: Insights from the Science of Consciousness
• Margaret Boden: AI doesn't have feelings

Putting on clothes is one of the most universal human experiences. Inevitably, this involves choices; maybe you just grab the cheapest and most convenient clothing available, or maybe you want to fit seamlessly into your local environment, whatever that might be. But maybe you choose to dress more consciously, putting a bit of effort into crafting a personal style and creating a desired impression in others. Derek Guy has, to his own surprise, become well-known as the menswear guy on Twitter. He has put a lot of thought into both the practicalities of clothing (how to find a suit that fits) and its wider social impact (how fashion acts as a cultural language). We talk about both sides of the coin.

(Picture on right is not Derek, but rather former US Attorney General Elliot Richardson, whose dapper image Derek uses as his avatar.)

Blog post with transcript: https://www.preposterousuniverse.com/podcast/2023/11/20/257-derek-guy-on-the-theory-and-practice-of-dressing-well/

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Derek Guy is a fashion writer living in San Francisco. He blogs at Die, Workwear!, and contributes to a number of publications.

• Twitter (X)
• Wikipedia
• Politico essay on John Fetterman