We usually begin the study of physics with a discussion of motion, not because it is easy, or because the modern understanding of motion began with Galileo hundreds of years ago. Rather, Galileo’s groundbreaking work provides a paradigm to understand how physics is done today. Extracting out the fundamental essence of motion from all the distractions associated with what turn out to be irrelevant complexities was a monumental intellectual leap for humankind—a leap we often take for granted.

Without the leap, for example, Newton could never have made his profound discoveries about the relationship between force and movement, nor his discovery of the Universal Law of Gravitation.

But too often we treat these remarkable achievements as something belonging in antiquity.. as if we have moved far beyond them in every way. Nothing could be further from the truth. Applying the very same ideas that Galileo and Newton developed leads us to the cusp of modern physics: the discovery of the dominant mass in the Universe, a vast invisible sea of dark matter. In this episode, we travel over 450 years of physics, from Galileo, to the threshold of our understanding of the cosmos today. Hang onto your hats.

I’m also pleased to share a quick PSA. A reminder of our 2026 Origins expedition through the Greek archipelago (July 24 to 31), with a Cyprus add-on (July 17 to 22). If you’re interested, it’s worth raising your hand early. These trips tend to fill quickly. Express interest at

https://originsproject.org/greek-adventure-2026-application/

As always, an ad-free video version of this podcast is also available to paid Critical Mass subscribers. Your subscriptions support the non-profit Origins Project Foundation, which produces the podcast. The audio version is available free on the Critical Mass site and on all podcast sites, and the video version will also be available on the Origins Project YouTube.

Alcoholism is a scourge on modern society. Every year, 178,000 American die from alcohol abuse, and it has been estimated that over 200 billion dollars is lost from the US economy due to alcoholism, includingcosts of health care, lost productivity, and costs of crime enforcement. Given this immense social cost, it is equally amazing that there is no widely accepted cure. Rather, alcoholics are told they need to abstain from taking a single drink for the rest of their lives, or they are likely to revert to their earlier states of alcohol abuse.

Katie Herzog is a journalist whose work I have enjoyed and I was happy to have a conversation with her in general. But even more so after the publication of her recent book, Drink your Way Sober. She discusses there a fascinating science-based approach that appears to provide a ‘cure’ for many alcoholics that actually allows them to drink, if they wish, in moderation, for the rest of their lives. The idea is to use an opioid blocker, in this case something called naltrexone, that basically removes the pleasure response from drinking. A naltrexone pill can be taken a few hours before drinking, and over time, with the correct behavioral management, it has been shown to be effective for many drinking in removing the craving for alcohol.

What makes Katie’s book, and our discussion, so poignant is that Katie is not just a journalist writing about alcoholism, she was an alcoholic for most of her life, and her discovery of the work of of the so-called Sinclair Method, after the scientist David Sinclair, whose original work on naltrexone in Finland changed the field, changed her life.

Her book intersperses her own experiences with the science underlying this new treatment for alcoholism, and it is thus perfect for our podcast, which connects science and culture. It also makes for a fascinating and informative conversation that I hope will help have a positive impact on treating this international blight. I hope you find it engrossing and as enjoyable to listen to as it was to produce.

And there are still berths available on our Greece and Cyprus adventure. Go to originsproject.org and explore the possibilities!

As always, an ad-free video version of this podcast is also available to paid Critical Mass subscribers. Your subscriptions support the non-profit Origins Project Foundation, which produces the podcast. The audio version is available free on the Critical Mass site and on all podcast sites, and the video version will also be available on the Origins Project YouTube.

I’m back with my friend and colleague Sabine Hossenfelder for another episode of “What’s New in Science”. I think this is one of my favorite dialogues that we have had. Spending time with Sabine was a nice chance to step away from my physics lecture series for a bit. I know many of you have been enjoying the lectures, so don’t worry, they’ll be back soon.

In this episode, we covered the kind of science news I like best: ideas you can argue about and results that make you recalibrate. Sabine opened with describing a clever proposal that future fusion reactors might double as axion dark matter factories, producing a flux of very light, weakly interacting particles through neutron-lithium reactions in the shielding. That led to a discussion about what people mean by “axions,” why particle physicists tend to be more particular about the term, and why I’m always more interested in dark matter candidates that were invented to solve an actual problem, not just to fill a cosmological gap. From there we jumped to quantum mechanics at the edge of common sense, with a Vienna experiment showing interference from a cluster of thousands of atoms, and a friendly disagreement about whether “collapse” is a real physical process or just the wrong way to talk about what quantum mechanics is doing.

We also talked about AI and math, including the recent swirl of claims about machines proving famous open problems, what was hype, what was rediscovery, and what might genuinely be changing in how mathematicians search the landscape. Then we went from equations to extinction, with a fascinating new approach using space dust and helium isotopes to argue that life may have started rebounding after the Chicxulub impact far faster than people had assumed. Sabine brought a surprising example of string theory mathematics finding a practical use in modeling biological networks, and we ended with biology proper in two very different moods: a sobering study in mice suggesting lung tumors can hijack vagus nerve signaling to suppress local immune responses, and then a lighter result about dogs learning words from overheard human conversation at roughly toddler level. My dog Levi, who many of you have seen on the podcast, was asleep next to me while we talked about it, which felt like the right way to end.

As always, thank you for your continued support, and I hope the changing of seasons brings you good time with friends and family.

As always, an ad-free video version of this podcast is also available to paid Critical Mass subscribers. Your subscriptions support the non-profit Origins Project Foundation, which produces the podcast. The audio version is available free on the Critical Mass site and on all podcast sites, and the video version will also be available on the Origins Project YouTube.