John Gertz is a Renaissance Man. One might think that the President of Zorro Productions might be the last person to talk with about the Search for Extraterrestrial Intelligence (SETI), and the last person to chair SETI’s governing board. But as is clear from our discussion, and from the material in his recent book, Reinventing SETI, John has not only mastered all of the relevant technical issues, he has thought deeply about the motivation for SETI, and the likelihood of its success. Treating the issue as a businessman rather than a scientist, he has tried to anticipate what signals other civilizations might send, and what we might listen for. He also takes a realistic view of what we might actually be able to detect. The net result of our conversations is that the prospects are not good for detecting anything out there. Distant aliens are likely not broadcasting in a way we could be sensitive to. And as he points out, we should probably do the same. His great hope is that alien civilizations have instead installed probes in other solar systems, including ours. However, this possibility too, as I emphasized with him, is also rife with difficulties.

I have thought a lot about SETI since I wrote The Physics of Star Trek. I don’t think anyone has affected my thinking on the issue since then more than John. I was pessimistic before. Now I think the whole effort is probably misguided. Though, if someone other than the government is willing to pay for it, what the heck. As I often tell experimentalists. Do what you can do, no matter what us theorists say. We may be wrong.

I hope you find our discussion as informative and provocative as I did. I will be interested to hear if it changes your perspective on SETI as well.

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.

This lecture, recorded before lecture 5, which was released a month ago, actually more naturally follows it, which is why releasing it after lecture 5, while unintended, actually makes sense. In the last lecture I described the most important unification in all of physics, the unification of electricity and magnetism, a unification into electromagnetism by James Clerk Maxwell in the 19th century.

Because of its elegance, and its overpowering utility, the theory of electromagnetism has provided the prototype for all modern physical theories that have followed it. As I show in this lecture, the form of electromagnetism is governed by a new mathematical symmetry in nature, called gauge symmetry. It turns out the existence of this symmetry is profoundly important, and it not only governs the exact form of the theory, it turns out to govern the form of all the known forces of nature.

Before we get to gauge symmetry, I want to explore more generally what is meant by symmetry in physics, and then I want to redo elementary physics by thinking about symmetry. In my mind, the fact that basic physics is introduced without reference to the symmetries of nature is perhaps the greatest failing in the teaching of modern physics. Concepts like energy and momentum have relevance because of fundamental symmetries of space and time. The facts that energy is ‘conserved’, and momentum is ‘conserved’ in systems, which rigorously fix determine the form of Newton’s laws of motion, are often introduced as if they are dictates on high, like the ten commandments. However, once one understands that these arise from symmetries of nature, the fact that these quantities exist and are conserved, becomes immediate, as the remarkable mathematician Emmy Noether showed at the beginning of the 20th century.

Finally, as important as mathematical symmetries are in governing physical laws, it is equally striking that even if these fundamental symmetries exist in nature, they may not be manifest in particular situations. For example, gravity and electromagnetism don’t distinguish between left and right, but if I look around my room, the left side of my room looks very different than the right side. This is an example of what is called ‘broken symmetry’, one of the most subtle and impactful notions at the basis of what is now called The Standard Model of Particle Physics.

In this lecture I review all of these ideas, which are essential if we are to go beyond the physics of the 19th century to understand the physics of the 20th and 21st centuries.

Enjoy.

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.

Happy August! . Heading back to North America as we just concluded our Origin Project Adventure to Cyrpus and Greece, where we felt the heat, and avoided some wildfires while having some amazing positive experiences as well with an amazing group of 26 travelers. Please stay safe and try and stay cool this month.

To help distract you from the heat, I hope you will enjoy this latest conversation about new discoveries in science with Sabine Hossenfelder. As always, we try and deconstruct the facts behind the headlines, and also explore new strange corners of our universe.

This episode begins with some new observations of the Bullet Cluster of galaxies. This cluster contains two galaxies that have collided, and seems to have provided evidence for exotic dark matter that has passed through the collision unscathed. Not so, says a new analysis, which claims evidence for more dark matter in the form of black holes and other less visible normal matter. There are strong reasons to be skeptical however, as both Sabine and I agree.

Speaking of black holes, a new analysis of collisions of black holes at the terrestrial gravitational wave detectors proposes a solution to the mystery of how black holes in a so-called forbidden gap between 10-20 solar masses and more than 50 solar masses have formed. They provide evidence that some of the black holes observed in collisions have been built up from earlier collisions with other black holes. This hierarchical growth could potentially explain how very large black holes in the early universe form, though it is a long way from 50 solar masses to 1 billion solar masses!

Strange goings on at the largest scales of the universe continue to be claimed, as yet another study argues for an unexpected and unexplained cosmic spatial asymmetry. It is hard to reconcile this with the observed uniformity of the universe on the largest scales we can observe via the Cosmic Microwave Background. As a result, it is too early to get excited, even if newspaper reporters love to report on claims that fly in the face of the standard model of cosmology.

The Vera Rubin Space Observatory has started its 10 year project to monitor a huge swath of sky every night looking for things that go bump in the night. On the first night, they found a few hundred thousand possible events. With a 10 year movie of the cosmos who knows what they will discover.

Sabine introduced me to an article about Quantum Batteries. Are they going to be useful, or just another cute example of how quantum mechanics produces strange phenomena? Time will tell.

Finally, I couldn’t resist introducing a story about cockroaches with nervous system implants that allow their motion to be remote controlled by experimenters, with tiny diving suits attached that allow them to breathe underwater for extended periods. It is claimed that they may help in undersea rescue.. Wow! Maybe so… What will they think of next?

Until the next time.. enjoy!

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 remember when my friend, journalist Claire Berlinski, first contacted me about a tragic situation regarding a family trapped in Afghanistan after the Taliban takeover. She knew that I had helped a young girl interested in physics escape to the US to study years earlier and hoped that I might assist in this case. If ever one imagined a family appropriate to bring to safety, this would be the one. The mother was a women’s rights lawyer before the takeover, and the husband worked for a French firm. The Taliban had broken into the Bar Association Office and found records of lawyers, who were being sought for arrest. One older son, and five young daughters in danger of being married off if they were discovered.

Their original escape plan was foiled when the airport was bombed just before their planned departure. Because Claire lives in Frances the older boy had reached out to her for help, and she sent out a call to her followers to provide financial assistance to help the family.

Claire contacted me because she knew I now lived in Canada, which has a well-established refugee program. In spite of this, for two years I was not able to find a single sponsoring agency who had a sufficiently large slot allocation to assist. Finally, after over a year, with five generous individuals who agreed to act as guarantors, Jewish Immigrant Aid Services in Toronto indicated they had the slots and would sponsor a refugee application for the family, provided we raised the necessary funds to guarantee support for family for their first year in Canada—a government requirement. After five months of fundraising, we achieved the goal, and the full application was submitted to the government of Canada.

I have always found it poetic that the organization in Canada that has been willing to help save this Muslim family is a Jewish organization. Perhaps, in the midst of all the horrible antisemitism that has blossomed in the world over the past years, this provide a useful example that religious differences need not always be a source of discord and hatred.

That was 18 months ago. In spite of having fulfilled at the requirements, the backlog of cases is such that we knew it could take up to two years for the application to be processed. In the interim the family was able to travel to Pakistan. But their visas have expired and Pakistan is now deporting Afghan refugees back to Afghanistan.

The family is in hiding in Pakistan, not able to leave their house. The girls are growing and one of them managed to learn enough English to get a prized scholarship to study online at a US university abroad, where she is studying psychology, as the law degree that she really wants is not available.

The family agreed to be interviewed for this podcast. Their images have been washed out for their protection, and their names have been changed as well. We are hoping this podcast will help spur some of you to provide support through Claire’s online site to help provide essentials for the family while they are in hiding, and that it might also help motivate some of you who might live in Canada to help us lobby the government to ensure that their case is resolved as quickly as possible.

Thanks for watching, or listening, and for any help you can provide. Here is a gofundme link to help support them. https://www.gofundme.com/f/please-help-five-afghan-girls-get-to-safety

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 began this lecture by saying I was daunted by what I was about to talk about. There are several reasons for this.

First, I will lead you through the development of what was certainly most important theoretical development in the 19th century, and what could easily be considered the most important mathematical framework in all of physics. Second, this development affected our modern picture of the universe more than almost any other. Next, this development made our modern technological society possible. And finally, it allowed a calculation that ultimately unveiled the true nature of light. A calculation we will perform together during this lecture

I am going to take you through what is often taught in a whole semester course in physics. So hold onto your hats. Take it step by step. I think the reward of understanding will be worth the effort. I hope at the end of this lecture you agree with me.

This month I will be traveling with the Origins Project and a group of 27 intrepid travelers to Cyprus and Greece. So the next Origins podcast will not air until August. I hope your July is enjoyable.

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 think this was one of my most enjoyable dialogues in our What’s new series. Maybe Sabine and I are getting more used to each other’s cadence and interests or maybe it was the subject matter. Either way, I think you will find this to be a fascinating and provocative discussion of science at the forefront, and at the not-so-forefront, because that science is interesting too!

We began our discussion describing a new finding of a Giant Ring of galaxies billions of light years across in the sky. The key questions are: Is it real? And is it surprising? We both have slightly different takes on this.

Next we described a new measurement of the strength of gravity on scales from 80 to 800 million light years in distance. And guess what? Gravity falls off just like Newton predicted! This may seem like a big yawn, but one of the most popular models that claims to do away with dark matter would imply that Gravity would fall off differently on these scales. Does this new result kill that idea? Stay tuned.

Microsoft, which has cried wolf a number of times so far when it comes to something called Majorana qubits as the basis of a new viable quantum computer just published a new paper claiming they finally have it. Sabine and I discuss why we are both still skeptical, but why the effort is worth it.

Next, CERN, the large European particle physics laboratory, and the world particle physics community seem to have converged on plans for building a huge new accelerator in the current CERN site.. this time involving an underground ring 91 km in circumference, in which electrons and positrons would collide to explore the detailed properties of the Higgs particle. Is the effort worth it? Again, Sabine and I have slightly different takes on this.

Fusion power, which we have talked about in a number of earlier episodes, continues to tempt humanity with the promise of unlimited energy. Many people, myself included, have tended to argue that fusion seems to be 25 years in the future, and may always be 25 years in the future. But many new efforts are underway, so who knows. Unfortunately, a group of economists has analyzed fusion in the context of other large energy programs and have argued that even if we can achieve it, it may not be as economically viable as many claim.

Finally, one day Richard Feynman went to a Thai restaurant with his young companion Ralph Leighton, and wondered what he should order. Should it be the same old dish he loved or something new. An equation filled napkin later, and he had the answer. Fifty years later some cognitive scientists resurrected Feynman’s napkin and explained it, and argued it might have important implications in other social situations. Such is the power of science.

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.

Alvin Roth is a Nobel Prizewinning Economist whose work on designing markets has had real world impacts that may have saved thousands of lives around the world, while arousing strong emotions both for and against the programs he has helped put in place. Clearly not one to shy away from controversy, he represents the best of what The Origins Project is trying to promote: applying science and reason to public policy. In short, connecting science and culture!

Roth’s new book, which is fantastic, and comes out the same day this podcast is released deals with issues that often raise the public’s ire, from legalizing prostitution, to assisted suicide, and finally to a rational market for kidney transplants. For example, everywhere there is good date, legalizing prostitution reduces not only incidents of sexually transmitted disease, but also violent sexual assaults. It may also combat illegal human trafficking. As far as kidney transplants are concerned, in the US alone, over 130,000 kidney failures occur each year, and only 20,000-30,000 transplants are performed, because of a lack of suitable kidney donors. Roth has already helped resolve one bottleneck, connecting donors with those in need, through a kidney exchange, which is actually more complicated than it may seem due to medical incompatibilities even within closely related individuals. More generally, not only could lives be saved, but as he shows, it would save considerable money if a rational system of reimbursing prospective donors could be devised.

Beyond his remarkable work tying empirical testing to theoretical ideas, as a human being, Roth is a saint. I have direct knowledge of this. On the day this podcast was recorded, we had an amazing 3 hour dialogue… one of the best I have had. Only problem was, I forgot to press record! We lost it all. With patience and grace that I never expected, Roth agreed to re-record another podcast on the same day. A friend of mine told me was a mensch. But I never expected that. I am eternally grateful, and I hope you will thoroughly enjoy, and have your perspective of the world altered by my conversation with this remarkable gentleman and scholar. Enjoy!

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”. 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 an incredibly wide range of science topics. Sabine opened with reported claim that the CIA used quantum magnetometry to find the downed pilot in Iran. The report, in the NY Post, looked fishy. We explain why it is. Then I described a new discovery in the physics of material that may solve perhaps the biggest problem in AI now: heat generation in computers. Sabine talked about a new claimed Big Bang Theory that might have some relevance to quantum gravity. Then I countered with a discussion of yet a new result that suggests the standard model of cosmology may have troubles, or that observers are wrong.

After that, Sabine introduced a paper describing a possible new way to measure gravitational waves. I think it is a fine piece of work, though it is not clear if it is practical. If it were, then the huge interferometers that are now being used could be replaced by ‘tabletop’ detectors. We will see.

Finally, I described an amazingly interesting news story that might have implications for the future of medicine. It also demonstrates what one person, with determination and wealth, can do to possibly cure their own maladies. Sid Sijbrandij, a billionaire tech CEO of Gitlab, was diagnosed with inoperable spine cancer, and launched an amazing program of diagnostics, AI data mining, and a group of scientists who developed vaccines specific to his genetic makeup. After implementing all the procedures, he has been cancer free for a year. While this is beyond the reach of people without these resources now, Sid’s story demonstrates the potential power of combining AI and genetic medicine in the future.

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.

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.