It is commonplace to refer to the Earth's oceans as vast and largely unexplored. But we do understand some aspects, and improving that understanding is crucial to ensuring the continued viability and success of life on this planet. The oceans are a paradigmatic complex system: there are many components, distinct but mutually interacting, that add up to a nuanced whole. We talk with ocean physicist Helen Czerski about what the ocean is and how it's changing.

Blog post with transcript: https://www.preposterousuniverse.com/podcast/2025/02/24/306-helen-czerski-on-our-energetic-oceans/

Support Mindscape on Patreon.

Helen Czerski received her Ph.D. in physics from the University of Cambridge. She is currently an Associate Professor at the Department of Mechanical Engineering at University College London. She is the author of several books, most recently The Blue Machine: How the Ocean Works. She is a frequent television presenter for the BBC and elsewhere.

• Web site
• UCL web page
• Google Scholar publications
• Wikipedia
• Amazon author page
• Bluesky

See Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.

Political outcomes would be relatively simple to predict and understand if only people were well-informed, entirely rational, and perfectly self-interested. Alas, real human beings are messy, emotional, imperfect creatures, so a successful theory of politics has to account for these features. One phenomenon that has grown in recent years is an alignment of cultural differences with political ones, so that polarization becomes more entrenched and even violent. I talk with political scientist Lilliana Mason about how this has come to pass, and how democracy can deal with it.

Blog post with transcript: https://www.preposterousuniverse.com/podcast/2025/02/17/305-lilliana-mason-on-polarization-and-political-psychology/

Support Mindscape on Patreon.

Lilliana Hall Mason received her Ph.D. in political psychology from Stony Brook University. She is currently an SNF Agora Institute Associate Professor of Political Science at Johns Hopkins University. She is the author of Uncivil Agreement: How Politics Became Our Identity and co-author (with Nathan Kalmoe) of Radical American Partisanship: Mapping Violent Hostility, Its Causes, and the Consequences for Democracy.

• Web Site
• Hopkins web page
• Google Scholar publications
• Bluesky

See Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.

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 government waste in dramatic fashion.

Blog post with transcript: https://www.preposterousuniverse.com/podcast/2025/02/12/bonus-cuts-to-science-funding-and-why-they-matter/

Support Mindscape on Patreon.

• Indirect costs primer
• Cuts to NIH indirect costs
• Appropriated funds are mandated by statute
• Proposed NSF cuts
• Elon Musk doesn't understand indirect costs
• Shrimp treadmill story
• Bribing foreign officials
• Deleting NSA web pages
• Executive Orders are not laws
• History of impoundments

See Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.

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 well? I talk with James Evans, an expert on collective intelligence and the construction of knowledge, about how science really works.

Blog post with transcript: https://www.preposterousuniverse.com/podcast/2025/02/10/304-james-evans-on-innovation-consolidation-and-the-science-of-science/

Support Mindscape on Patreon.

James Evans received his Ph.D. in Sociology from Stanford University. He is currently the Max Palevsky Professor of History and Civilizations, Director of Knowledge Lab, and Faculty Director of Computational Social Science at the University of Chicago; External Professor at the Santa Fe Institute; External Faculty at the Complexity Science Hub, Vienna; and Visiting Faculty Researcher at Google.

• Knowledge Lab web site
• University of Chicago web page
• Google scholar publications

See Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.

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 transcript: https://www.preposterousuniverse.com/podcast/2025/02/03/ama-february-2025/

Support Mindscape on Patreon.

See Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.

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 works on studying the structure and behavior of immune cells, and ways to coax them into fighting cancer. This approach offers hope of a way to combat cancer effectively, lastingly, and in a relatively gentle way.

Support Mindscape on Patreon.

Blog post with transcript: https://www.preposterousuniverse.com/podcast/2025/01/27/303-james-p-allison-on-fighting-cancer-with-the-immune-system/

James P. Allison received his Ph.D. in biology from the University of Texas at Austin. He is currently Regental Professor and Chair of the Department of Immunology, the Olga Keith Wiess Distinguished University Chair for Cancer Research, Director of the Parker Institute for Cancer Research, and Director of the James P. Allison Institute at MD Anderson Cancer Center. He is the subject of the documentary film Jim Allison: Breakthrough. Among his numerous awards are the Breakthrough Prize in Life Sciences and the Nobel Prize in Physiology or Medicine.

• Web page
• Nobel Prize citation
• Google Scholar publications
• Wikipedia

See Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.

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 with physical biologist Chris Kempes about how physics can help us understand the size of organisms, their metabolisms, and features of major transitions in evolution.

Support Mindscape on Patreon.

Blog post with transcript: https://www.preposterousuniverse.com/podcast/2025/01/20/302-chris-kempes-on-the-biophysics-of-evolution/

Chris Kempes received his Ph.D. in physical biology from the Massachusetts Institute of Technology. He is currently Professor and a member of the Science Steering Committee at the Santa Fe Institute. His research involves the origin of life and the constraints placed by physics on biological function and evolution.

• Web site
• Santa Fe Institute web page
• Google Scholar publications
• Origins of Life online course

See Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.

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 deal with the political and social dangers associated with systems that are not always guided by the truth.

Support Mindscape on Patreon.

Blog post with transcript: https://www.preposterousuniverse.com/podcast/2025/01/13/301-tina-eliassi-rad-on-al-networks-and-epistemic-instability/

Tina Eliassi-Rad received her Ph.D. in computer science from the University of Wisconsin-Madison. She is currently Joseph E. Aoun Chair of Computer Sciences and Core Faculty of the Network Science Institute at Northeastern University, External Faculty at the Santa Fe Institute, and External Faculty at the Vermont Complex Systems Center. She is a fellow of the Network Science Society, recipient of the Lagrange Prize, and was named one of the 100 Brilliant Women in AI Ethics.

• Web site
• Northeastern web page
• Google Scholar publications
• Wikipedia

See Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.

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 ideas from quantum mechanics and quantum gravity that bear on the question of whether time is emergent or fundamental, and the implications of each possibility.

Support Mindscape on Patreon.

Blog post with transcript: https://www.preposterousuniverse.com/podcast/2025/01/06/300-solo-does-time-exist/

Some of the papers discussed herein:

• Carroll (2008), "What If Time Really Exists?"
• Dyson, Kleban, and Susskind (2002), "Disturbing Implications of a Cosmological Constant."
• Albrecht and Sorbo (2004), "Can the Universe Afford Inflation?"
• Boddy, Carroll, and Pollack (2014), "De Sitter Space Without Dynamical Quantum Fluctuations."
• Lloyd (2016), "Decoherent Histories Approach to the Cosmological Measure Problem."
• Page and Wootters (1983), "Evolution Without Evolution: Dynamics Described by Stationary Observables."
• Albrecht (1994), "The Theory of Everything vs the Theory of Anything."
• Albrecht and Iglesias (2007), "The Clock Ambiguity and the Emergence of Physical Laws."

See Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.

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 informal idea to sitting down and doing the work.

Support Mindscape on Patreon.

Blog post with transcript: https://www.preposterousuniverse.com/podcast/2024/12/23/holiday-message-hits-and-misses/

Here are links to the papers I discuss in the episode.

• S.M. Carroll, G.B. Field and R. Jackiw, 1990, "Limits on A Lorentz and Parity-Violating Modification of Electrodynamics,'' Phys. Rev. D 41, 1231. [pdf file; inSPIRE]
• S.M. Carroll, E. Farhi and A.H. Guth, 1992, "An Obstacle to Building a Time Machine,'' Phys. Rev. Lett. 68, 263; Erratum: 68, 3368. [pdf file; inSPIRE]
• S.M. Carroll, E. Farhi, A.H. Guth and K.D. Olum, 1994, "Energy-Momentum Restrictions on the Creation of Gott Time Machines,'' Phys. Rev. D 50, 6190; gr-qc/9404065. [arXiv; pdf; inSPIRE]
• S.M. Carroll, 1998, "Quintessence and the Rest of the World,'' Phys. Rev. Lett. 81, 3067; astro-ph/9806099. [arXiv; pdf; inSPIRE]
• S.M. Carroll, V. Duvvuri, M. Trodden, and M.S. Turner, 2003, "Is Cosmic Speed-Up Due to New Gravitational Physics?'' astro-ph/0306438. [arXiv; pdf; inSPIRE]
• S.M. Carroll and J. Chen, 2004, "Spontaneous Inflation and the Origin of the Arrow of Time'', hep-th/0410270. [arXiv, inSPIRE]
• L. Ackerman, M.R. Buckley, S.M. Carroll, and M. Kamionkowski, 2008, "Dark Matter and Dark Radiation," arxiv:0807.5126. [arXiv; pdf; inSPIRE]
• S.M. Carroll, M.C. Johnson, and L. Randall, 2009, "Dynamical Compactification," arxiv:0904.3115. [arXiv; pdf; inSPIRE]
• C. Cao, S.M. Carroll, and S. Michalakis, 2016, "Space from Hilbert Space: Recovering Geometry from Bulk Entanglement," arxiv:1606.08444. [arXiv, inSPIRE]
• C. Cao and S.M. Carroll, 2018, "Bulk Entanglement Gravity without a Boundary: Towards Finding Einstein's Equation in Hilbert Space," arxiv:1712.02803. [arXiv, inSPIRE]
• N. Bao, S.M. Carroll, A. Chatwin-Davies, J. Pollack, and G. Remmen, 2017, “Branches of the Black Hole Wave Function Need Not Contain Firewalls," arxiv:1712.04955. [arXiv, inSPIRE]

See Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.