The LIUniverse with Dr. Charles Liu

theliuniverse

A half-hour dose of cosmic conversation with scientists, educators and students about the cosmos, scientific frontiers, scifi, comics, and more. Hosted by Dr. Charles Liu, PhD, an astrophysicist at the American Museum of Natural History. Support us on Patreon.

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78 episodes
Updated June 13

Episodes78

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June 13 · 38 min
ChuckGPT - Patreon Question Edition
It’s time for the Season 5 finale of The LIUniverse, which means another episode of ChuckGPT where we answer our audience’s most vexing questions – this time via video from our Patreon Patrons. And to help us answer those questions, Dr. Charles Liu and co-host Allen Liu welcome back fan favorite guest and expert on ancient civilizations, author and educator Hannah Liu, M.Ed. As always, though, we start off with the day’s joyfully cool cosmic thing: the completion of DESI’s 5-year survey mapping millions of objects in the universe. The Dark Energy Spectroscopic Instrument completed the survey ahead of schedule, so there’s still time to map millions more. Hannah tells us about mapping the universe in antiquity, starting with the first star catalog created by the Babylonians about 3,000 years ago. You’ll hear about the Venus tablet from the first millennium BC, Chinese star charts from the Tang dynasty, and Atlas, the mythological Titan who was the “first astrologer.” Returning to the DESI survey, Chuck talks about the change in the dark energy content of the universe that we didn’t really expect. Allen, our resident mathematician, talks about the velocity of universal expansion and a concept called “the jerk.” Then it’s time for audience questions, and for this episode, we’re doing something new. Both audience questions come from Patreon Patrons, and both are in video format so you can actually see our fans asking Chuck the questions – if you’re watching rather than listening, that is. Our first question comes from Patron Lee Dubey, who asks, “Since atoms are mostly empty space, could all matter, including measuring devices, almost undetectably consume minimal space, warping the space around it? If so, could that cause gravity, and could the shrinkage cause a redshift related to dark energy?” We’re not even going to try and summarize the explanation from Allen and Chuck here, except to say that the ensuing conversation includes the physics concept of “unparticles.” Hannah brings up Democritus, who, along with his teacher Leucippus in ancient Greece, first theorized the existence of atoms. Our next question comes from our Patreon Patron Lee Williams, who asks, “If we live in a simulation, is it correct to assume that there’s an architect? Could there be a simulation without an architect?” Given that there’s no scientific answer to either of these questions, Chuck turns to Hannah for enlightenment. While she explains that the question of whether we live in a simulation is a modern concept, Hanna discusses how humanity grapples with the questions of existence and higher powers, and why people engage with religion, magic, or quantum entanglement in the first place. In the free-wheeling, far-ranging conversation that follows, Allen brings up how we create simulations now, by creating processes and letting them run, to offer some perspective on the role of the architect. And yes, H.P. Lovecraft, “The Devil and Daniel Webster,” “Frankenstein: The Modern Prometheus,” and even Spider-Man somehow make it into the discussion. And that’s it for this season of The LIUniverse. We want to thank all of you for your questions, your curiosity, and your help in keeping this experiment going. As Chuck always says, “Thank you for being a part of The LIUniverse.” We hope you enjoyed this episode, and this season, of The LIUniverse. If you do, please support us on Patreon. Credits for Images Used in this Episode: Map of DESI’s 5-year survey. – Credit: Claire Lamman/DESI collaboration. Roman statue of Atlas (2nd century AD). Credit: Lalupa / Creative Commons The Venus tablet recording astronomical positions for Venus dating from the first millennium BC. – Credit: FAI / Creative Commons Chinese Tang dynasty star map made around the year 700. – Credit: Public Domain. CHAPTERS 00:00 - We Welcome Back Archaeology Expert, Author and Educator Hannah Liu, M.Ed. 02:28 - Joyfully Cool Cosmic Thing: DESI Completes Its 5-Year Survey of the Universe 04:33 - Mapping the Universe in Antiquity 12:06 - The Empty Space in Atoms, Gravity, Shrinkage, and Dark Energy 16:42 - What Are Unparticles? 22:53 - Do We Live in a Simulation? Is There an Architect?
May 30 · 43 min
Our Weird, Wondrous Universe with Erika Hamden
How do distant galaxies form? If you have two distant clouds of hydrogen, why does one turn into a star and another doesn’t? To find out, Dr. Charles Liu and co-host Allen Liu welcome Dr. Erika Hamden, Professor of Astrophysics at the University of Arizona. If Erika looks familiar, that might be because her TED Talk or “New Frontiers,” the TV show she hosts on Arizona Public Media. As always, though, we start off with the day’s joyfully cool cosmic thing, Artemis II, our first manned mission around the moon since 1972. Chuck, Allen and Erika share their excitement watching the mission, and especially the landing, while we watch the “only good video of the moon ever taken with a phone” that Reid Wiseman shot on his iPhone. Dr. Hamden tells us about her research into how distant stars and galaxies form. To fill in the blanks of this cosmic puzzle, she observes hydrogen in its elemental or molecular form – not looking at the stars themselves, but the emissions from hydrogen atoms. You’ll learn about star formation in our galaxy and how Erika discerns the moment that a new star “first turns on.” Then it’s time for our first audience question. Emma B. asks, “How many galaxies are there?” Erika says that in the observable universe, it’s an outrageously large number, probably hundreds of billions or more. We take a look at the Hubble Ultra Deep Field image, which reflects a “tiny, tiny part of the sky,” where every dot except for the 3 stars is a galaxy. And that’s just the universe we can see. Chuck asks Erika to tell us about her book, “Weird Universe: Everything We Don’t Know about Space (and why it’s important).” Professor Hamden shares her belief that anyone can understand anything if it’s explained the right way to them. She talks about a poem by Rebecca Elson called “Responsibility to Awe” and the responsibility scientists have to share the wonders of the world with everybody. For our next audience question, Ava asks, “What is the craziest job in Astronomy that you have seen AI take over from humans?” Erika talks about using LLMs to review the digitized photographic plates of stars and the massive amount of data from the Vera Rubin Observatory, and also which activities still require human creativity. Speaking of creativity, it turns out that before becoming an astrophysicist, Erika got a diploma at Le Cordon Bleu in London and had a career as a professional chef. She still loves to cook and shares her recipe (below) for the Swedish-style cardamom buns she shows us in the episode. Finally, before we go, we congratulate Emily on recently being awarded a Guggenheim Fellowship. She shares some wisdom and advice she’s learned on her journey that she also tells her students, but according to her it’s a bit “cheesy” so we’ll let her tell you in the show. If you’d like to know more about Dr. Hamden, you can keep up with her research, follow her on her social media accounts, and find out about her book by visiting her website. We hope you enjoy this episode of The LIUniverse, and, if you do, please support us on Patreon. Erika’s Cardamom Bun Recipe You can find the original recipe here on Cecilia Tolone’s Substack. Erika’s Modifications: “My changes are that I add more milk- about 75 grams more, because American flour is drier and Tucson is especially dry! And I played around with adding chiltipin flakes (a local, very spicy pepper) to the filling to make it kind of spicy. It’s great! Finally, I use whole cardamom seeds from Penzey’s that I grind before putting in.” Credits for Images Used in this Episode: Artemis II end of mission splashdown. – Credit: NASA/ Bill Ingalls. Artemis II astronaut Reid Wiseman’s iPhone video of the Earth and the Moon with his iPhone 17 ProMax, using 8x zoom, which he said is comparable to what he was seeing from the Artemis II capsule. – Credit: NASA /Reid Wiseman Hydrogen observed in the Milky Way Galaxy. – Credit: HI4PI Collaboration The Hubble Ultra Deep Field. – Credit: NASA/ESA Example of a photographic plate of stars, including notation marks, aka a Schmidt ammonia-sensitized, near-IR (Kodak I-N) objective-prism plate exposed for 1 hr. – Credit: STScI/ESO/Carnegie. Additional Credits: A Responsibility to Awe, by Rebecca Elson CHAPTERS 00:00 - We welcome University of Arizona Astrophysics Prof. Dr. Erika Hamden 02:43 - Joyfully Cool Cosmic Thing: Artemis II Mission and Return 08:14 - How Do Distant Stars and Galaxies Form? 15:46 -How Many Galaxies Are There? 18:25 - Weird Universe and Scientists’ Responsibility to Awe 24:06 - What Jobs in Astronomy Has AI Taken Over from Humans? 31:33 - Chef Erika and her Swedish-style Cardamom Buns 39:10 - Parting Advice and Wisdom from Professor Erika Hamden #LIUniverse #CharlesLiu #AstronomyPodcast #ErikaHamden #GalaxyFormation
May 16 · 45 min
Ruby Raindrops and Painted Peacocks with Munazza Alam
Are there really exoplanets with where it rains ruby and emerald raindrops? How do we measure the atmospheres of exoplanets light years away? To find out, Dr. Charles Liu and co-host Allen Liu welcome Dr. Munazza Alam of the Space Telescope Science Institute. The STScI performs science operations for the Hubble Space Telescope, the James Webb Space Telescope, and the Nancy Grace Roman Space Telescope when it launches in 2026. As always, though, we start off with the day’s joyfully cool cosmic thing. On Feb 24, 2026, the Vera C. Rubin Observatory activated the alert system it will use to notify astronomers of noteworthy events and sent out 800,000 alerts on that single day! Munazza tells us about how she studies the atmospheres of exoplanets like Wasp 121-b, a gas giant thought to have ruby and sapphire rain. Dr. Alam describes exoplanets with surface oceans made of magma, and she and Chuck talk about the importance of plate tectonics. You’ll hear about Hot Jupiters, Super-Earths, and Sub-Neptunes – and the theories about why we don’t have any of them in our solar system despite the fact that they’re incredibly common in the Milky Way galaxy. Then it’s time for audience questions, which for this episode come from students at Notre Dame Academy on Staten Island, where Munazza is an alum. Not only does past guest Dr. Betty Jensen teach there, as well, but she was a critical influence on Munazza’s career path. (You can listen to our episode with Dr. Jensen here.) The first question is from Charlotte, who asks, “How far have we gone in space?” Munazza, Allen, and Chuck discuss Voyager 1, which at a current distance of nearly 16 billion miles is the man-made object that has gone furthest from Earth. Next up, Gabby asks, “What was the best advice you were given when you were preparing for college?” Dr. Alam’s answer: Pick something you enjoy and are good at - in spite of any pressure you might get from friends, family, and others. A second piece of advice Munazza got was to maintain your breadth, i.e., developing other interests besides your primary focus. For Munazza, that was art and writing, and she shares some of her art later in the show. Finally, Gisella asks if it was hard picking a college. Dr. Alam shares her process, with the caveat that it might not be good advice for everyone. Charles and Munazza reflect on the tradition of scientific exploration, observation, discovery and analysis of which she’s part. Munazza recounts the excitement when JWST observations of transmission spectra of the exoplanet Wasp 39b confirmed their predictions – and also detected something unexpected: sulfur dioxide in the atmosphere of the planet which is a by-product of photochemistry between light from its star and water molecules in the atmosphere of the planet. Finally, Chuck asks Munazza to share some of her art. She shows us one of the first paintings she ever did, a peacock, and tells us a little about it and a portrait she has displayed at the Lowell Observatory. If you’d like to know more about what Dr. Alam is up to, you can follower her on LinkedIn or visit her website . We hope you enjoy this episode of The LIUniverse, and, if you do, please support us on Patreon. Credits for Images Used in this Episode: Artist impression of Wasp 121-b, an exoplanet thought to have ruby and sapphire rain. – Credit: NASA, ESA, Q. Changeat et al., M. Zamani (ESA/Hubble) Quake epicenters Digital Tectonic Activity Map of the Earth (DTAM). – Credit: NASA/Goddard Space Flight Center Illustration comparing the sizes of sub-Neptune exoplanets TOI-421 b and GJ 1214 b to Earth and Neptune. – Credit: NASA, ESA, CSA, Dani Player (STScI) Illustration of the inferred size of the super-Earth CoRoT-7b (center) in comparison with Earth and Neptune. – Credit: Creative Commons / Aldaron Location of the Voyager 1 and Voyager 2 spacecraft. – Credit: NASA/JPL-Caltech JWST transmission spectra of the exoplanet Wasp 39b. – Credit: NASA, ESA, CSA, Joseph Olmsted (STScI) Radial velocity method to detect exoplanets. – Credit::ESA Transit method for discovering exoplanets (animation). – Credit: NASA PlanetQuest Artist's concept of WASP-107b, a gas giant, orbiting a highly active K-type star about 200 light-years from Earth. – Credit: ESA/Hubble, NASA, M. Kornmesser CHAPTERS 00:00 - We welcome Dr. Munazza Alam of the Space Telescope Science Institute 02:50 - Joyfully cool cosmic thing: Vera C. Rubin Observatory Alert System 07:00 - How Do We Know What Exoplanets Are Like? 10:37 - The Importance of Plate Tectonics 11:45 - Hot Jupiters, Super Earths, and Sub-Neptunes 19:56 - How Far Have We Gone In Space, i.e., Where is Voyager now? 22:44 - Best advice when preparing for college? 25:32 - Was it hard picking a college? 31:00 - Confirming Theories and Discovering the Unexpected 36:33 - Munazza Alam Shares Her Painting of a Peacock 38:49 - What data and measurements are used to study exoplanets?
May 2 · 47 min
Astrophotography with Astronaut Don Pettit
Can the physics you learned in High School take you to the stars? Who is behind many of your favorite pictures of space? What is it actually like to live and work in space? You might be surprised to know how much of it comes down to the physics you probably learned in class and thought to yourself, “When will this ever be useful?” To answer those questions and more, Dr. Charles Liu and co-host Allen Liu welcome Dr. Don Pettit –NASA astronaut, astrophotographer, chemical engineer, and genuinely one of the most interesting people alive, who was also a science consultant for the movie Project Hail Mary. As you’ll see, the complex physics of space could be critical to your future endeavors in the world of tech, space, and astrophysics. As always, though, we start off with the day’s joyfully cool cosmic thing, which was the famous DART mission (Double Asteroid Redirection Test). It’s a mission where NASA crashed a spacecraft into a small asteroid (Dimorphos) to see if they could literally change the orbit of an asteroid in space. This mission was successful, changing the asteroid’s orbit by nearly 30 mins. This is certainly joyfully cool, as it shows we can take planetary defense measures to change the path of an impending asteroid. Throughout the episode, Don, Chuck, and Allen ping pong back and forth with the following topics: Why he chose chemical engineering (and how that led to becoming an astronaut by consistently choosing passion and innovation over money) Whether being an astronaut is even worth it financially How cities look different from orbit over time (yes, you can literally see lighting technology evolve) The physics behind astrophotography from space (and why those images look so insane) How astronauts drink coffee in zero gravity! Just wait, there is even more that we dive into: from lunar bases, to Antarctica meteorite hunts, to a casual mention of driving a lunar rover simulator like it’s nothing. There’s a lot here that feels huge and abstract, but also weirdly human, like choosing passion over money, or just wanting your morning espresso in space. While Don always had a love for chemistry, he ultimately pursued chemical engineering because he thought he wouldn't be able to get a good job without higher ed (relatable or what?). Then he got a PhD anyway, following his passion. Don also discusses the coffee cup he invented, which is widely used in space and lets you drink espresso like normal. He designed a cup that lets astronauts drink normally in zero gravity using fluid physics. Toward the end of the episode, he talks about going to Antarctica to collect meteorites and what that tells us about the chemistry of space. During this episode, Don’s intrinsic love for creation and scientific innovation shines through. If you like physics, space, or just hearing someone explain complicated things in a way that actually makes sense, you’ll absolutely love this. If you want to know more about Dr. Don Pettit, you can find him on NASA’s website. For the latest updates on his many projects and dazzling astrophotography, check out his Instagram @astro_pettit. (We’ve included some of those photos in the episode - just another reason to watch on YouTube!) We hope you enjoy this episode of The LIUniverse, and, if you do, please support us on Patreon. Credits for Images Used in this Episode: Photo of asteroids Didymos and Dimorphus, NASA’s DART mission target. Credit: NASA/Johns Hopkins APL Lunar map depicting craters on the south pole of the Moon. Credit: USGS Don Pettit taking photos on the International Space Station. Credit: NASA Chicago as seen from the ISS. Credit: NASA/Don Pettit Burj Khalifa, the world’s tallest building, as seen from the ISS. Credit: NASA/Don Pettit Sao Paulo, Brazil, at Night, April 12, 2003 as seen from the ISS. Credit: NASA/Don Pettit Star trail time exposure, taken for approximately 30 minutes during orbital night, assembled from multiple 30 second exposures. Credit: NASA/Don Pettit/Babak Tafreshi The first prototype of Don Pettit’s capillary cup. Credit :NASA Astronaut Samantha Cristoforetti drinking from Don Pettit’s cup on the ISS. Credit: NASA ANSMET meteorite hunters in Antarctica. Credit: NASA Cross-section of a carbonaceous chondrite, the 4.5-billion-year-old Allende meteorite formed along with the solar system. Credit: AMNH/Creative Commons Spaceborne - Don Pettit’s photography book. Credit: Don Pettit / Press Syndication Group Special thanks to Eleanor Adams for writing this episode description. CHAPTERS 0:00 - Introduction of Astronaut Don Pettit 3:19 - Asteroid Defense Explained (DART Mission & Saving Earth) 10:49 - Don Pettit’s Early Life 14:50 - How Much Does It Pay to Be an Astronaut? 17:11 - What It’s Really Like Living in Space for Months 19:49 - Physics Behind Astrophotography: LEDs and Light Pollution 30:00 - Space Coffee Cup Invention 41:00 - Astrochemistry and Antarctica
April 11 · 47 min
Finding the “Bubbles” Exoplanet and Crocheting Dinosaurs with Victoria DiTomasso
How do we find exoplanets? What is the Milky Way’s “Thick Disk” and what makes it so special? To find out, Dr. Charles Liu and co-host Allen Liu welcome Harvard astronomer Dr. Victoria DiTomasso, who has discovered an exoplanet system that includes exoplanet HD60079 b, which she sometimes calls “Bubbles.” As always, though, we start off with the day’s joyfully cool cosmic thing, a paper just recently published about the exoplanet Teegarden Star b. Dr. DiTomasso explains the difference in exoplanet research between the observational studies she does and the theoretical modeling represented in the paper. She goes on to discuss recent, exciting theoretical work coming out of UCLA that posits that rather than have our water brought to Earth by comets, we started out as a larger, sub-Neptune planet with a larger hydrogen-helium envelope that we’ve lost over time. This is a pattern seen in some exoplanets, especially given the fact that Super Earth and sub-Neptune planets are the most common types of planets we’ve found, yet we have none in our solar system. After we find out why a planet Chuck studied was called Flagellan, it’s time to find out how Victoria goes looking for exoplanets, and how she found Bubbles – with an assist from a team of citizen scientists. You’ll learn about using the transit method for discovering exoplanets and identifying potential targets with TESS, the Transiting Exoplanets Survey Satellite and other instruments. Dr. DiTomasso explains the differences between the Milky Way’s younger “Thin Disk,” the older “Thick Disk,” and the oldest of all, the Milky Way’s “Halo.” Victoria studies the chemistry of stars to categorize them and their planets by age. She’s found 4 stars in the thick disk that have “Hot Jupiters” so far, which is more impressive when you learn that we only knew about one before her work. Then it’s time for a question from the audience. Grace asks, “Has the environment ever been as bad as it is now, and can it heal by itself?” Chuck, Allen and Victoria discuss changing environments on exoplanets and on Earth, the difference between long and short term change, and the possibility of recovery. Finally, Chuck asks Victoria what she does outside of astronomy, and we learn all about her new hobby, crocheting. Don’t miss her show and tell, which includes Fred, the cutest crocheted dinosaur to ever appear on The LIUniverse. Victoria also talks about her other hobby, visiting museums – especially art museums. If you’re watching this episode on YouTube, you get to see one of her current favorite exhibits, which consists of semi-abstracted felted wool sculptures of creatures and supernatural beings (yōkai) at the MassArt Museum (MAAM) in Boston. If you’d like to know more about Dr. Victoria DiTomasso, you can find her on LinkedIn . But to see her latest telescope photos that she took during her observing trip to the Canary Islands, check out her Instagram @victoriaditomasso. (We’ve included some of those photos in the episode - just another reason to watch on YouTube!) We hope you enjoy this episode of The LIUniverse, and, if you do, please support us on Patreon. Credits for Images Used in this Episode: Radial velocity measurements graphic depicting the Radial velocity method to detect exoplanets. – Credit: ESA. Artist concept of the exoplanet Teegarden's Star b, also known as Teegarden b. – Creative Commons/ Bubblesong. Illustration comparing sizes of sub-Neptune exoplanets with Earth and Neptune. – Credit: NASA, ESA, CSA, Dani Player (STScI). Transit method for discovering exoplanets (animation). – Credit: NASA PlanetQuest. All-sky image showing the flat plane of the Milky Way galaxy. – Credit: E. L. Wright/UCLA, The COBE Project, DIRBE, NASA. Illustration of the Milky Way’s halo. – Credit: Halo stars: ESA/Gaia/DPAC, T Donlon et al. 2024; Background Milky Way and Magellanic Clouds: Stefan Payne-Wardenaar. Masako Miki's "Midnight March" features semi-abstracted felted wool sculptures of creatures and supernatural beings (yōkai) at the MassArt Museum (MAAM) in Boston. – Credit: Masako Miki/MAAM Photos from Victoria DiTomasso’s observing trip to the Canary Islands. – Credit: @victoriaditomasso on Instagram. CHAPTERS 00:00 - Intro and Let’s Meet Dr. Victoria DiTomasso 03:53 - Joyfully Cool Cosmic Thing of the Day: Exoplanet Teegarden Star B 06:20 - Super Earth and Sub-Neptune Exoplanets 12:46 - The Discovery and Naming of Bubbles the Exoplanet 20:32 - The Difference Between Milky Way’s Thin Disk, Thick Disk, and Halo 27:58 - Audience Question: Has the Environment Ever Been this Bad? 36:51 - Crocheted Dinosaurs and Giant Felt Museum Creatures 45:14 - Victoria DiTomasso’s Observing Trip to the Canary Islands #LIUniverse #CharlesLiu #AstronomyPodcast #VictoriaDiTomasso #Exoplanets
March 21 · 40 min
Supernovas and Space Gold with Dr. Ashley Villar
How do stars die? And what happens when they do? To find out, Dr. Charles Liu and co-host Allen Liu welcome Dr. Ashley Villar, who teaches astronomy at Harvard and whose team studies supernovas as they happen. As always, though, we start off with the day’s joyfully cool cosmic thing, the release of a set of new Hubble Space Telescope images of the Crab Nebula and the pulsar at its center. Needless to say, it’s a great start to an episode about a team of scientists who actually study the moment a star explodes and the immediate aftermath. Ashley explains how they have been able to use LIGO, the gravitational wave detector, as a sort of early warning detector that twice gave them enough time to set up their instruments to observe the explosion over the next few hours and days as it unfolds. Professor Villar talks about how neutron star mergers and magnetars may be the source of heavy elements like gold and uranium. Or, as Chuck says, “A gold-filled smoke ring puffing off of a highly spinning, highly magnetic neutron star - what a great picture that would be.” Ashley is looking forward to how the Vera Rubin Observatory is going to change the observation of these events. In the process of explaining, Professor Villar answers an audience question from Jamison, who asks how often stars explode in space. It turns out, in our observable universe, there’s a supernova every 2 seconds! We currently detect about 10,000 of these explosions every year - Vera Rubin will be able to detect 10,000 of these explosions in just two weeks. In order to get a handle on this flood of data, Dr. Villar and her team will be looking for these exotic physics needles in a haystack using machine learning models to look for patterns and abnormalities and “go fishing.” Charles asks Ashley for her take on AI and whether we should be afraid of it or not.(And yes, take the opportunity to plug co-host Allen Liu’s forthcoming book, “The Handy Artificial Intelligence Answer Book.”) Allen and Ashley discuss the difference between how a chatbot like ChatGPT operates and how she trains her models. There was a second part to Jamison’s question about exploding stars: Are we in any danger. Dr. Villar explains that when we just look at our Milky Way, supernovas occur only once a century, so we’re not in any danger. Next, Jessie asks, “How do we know the universe is infinite?” Our answer is, we don’t. That doesn’t stop us from discussing it, though, and the conversation takes us to, among other places, the Nazca lines in Peru and the quantum effect that creates iridescent blue butterfly wings. (You can read the scientific research mentioned in the episode here: https://www.nature.com/articles/ncomms8959) We end with a discussion about supernovas, neutrinos, space dust, gamma ray bursts, and what kind of event it would take to interrupt the normal activities of space telescopes like the James Webb Space Telescope or the Vera Rubin and hijack them for a disruptive observation. And we get a book recommendation from Ashley, “Katabasis” by R. F. Kuang, about a grad student who journeys to hell to get a letter of reference from her deceased advisor. If you’d like to know more about what Professor Villar is up to, you can check out her lab’s website at http://astrotimelab.com/. We hope you enjoy this episode of The LIUniverse, and, if you do, please support us on Patreon. Credits for Images Used in this Episode: New Hubble mosaic of the Crab Nebula. – Credit: William P. Blair et al 2026 ApJ 997 81 Previous Hubble photo of the Crab Nebula. – Credit: NASA, ESA, J. Hester and A. Loll (Arizona State University) The Vera Rubin Observatory. – Credit: RubinObs/NOIRLab/SLAC/NSF/DOE/AURA/P. Horálek (Institute of Physics in Opava), CC BY 4.0 Nazca line “The Condor”. – Credit: Photo by Roger Canals Blue butterfly wings in an electron microscope. – Credit: Radislav A. Potyrailo et al. Aragonite plates in a shell. – Credit: Fabian Heinemann SN 1987A (Bright central “star”). – Credit: European Southern Observatory Artist’s illustration of Gamma Ray Burst jets. – Credit: International Gemini Observatory/NOIRLab/NSF/AURA/J. da Silva; Image processing: M. Zamani (NSF's NOIRLab) CHAPTERS: 00:00 - Welcome to The LIUniverse 02:14 - Joyfully Cool Cosmic Thing of the Day - Hubble Crab Nebula Images 07:06 - Neutron Star Mergers, Magnetars, and Space Gold 09:18 - How Often Do Stars Explode? 12:35 - Can AI Help Us Find Supernovas? 17:11 - Are We In Danger From Exploding Stars? 19:48 - How Do We Know the Universe Is Infinite? 24:01 - How Does Quantum Physics Impact Color in Butterflies and Supernovas? 31:16 - How to Hijack a Space Telescope
March 8 · 43 min
Building Worlds with Luke Skywatcher
How do planetary systems form? If you wanted to observe them, where would you look and what would you look for? To find out, Dr. Charles Liu and co-host Allen Liu welcome Luke Keller, professor of Astronomy and Physics at Ithaca College, who together with his team has identified 9 of these early solar systems. As always, though, we start off with the day’s joyfully cool cosmic thing: a recently published paper that determined that at any given time, it is likely that a couple of extrasolar objects like 3I/ATLAS and Oumuamua would be present in our solar system. The real issue is detecting them. For context, Luke, whose science has focused over the years on finding debris from solar systems, explains how protoplanetary discs can eject matter that ends up orbiting that star. He’s especially fond of cosmic dust, “the catalyst for the formation of planets and asteroids and comets…” Then it’s time for a question for Luke from the audience, from Elisa: “I heard that the James Webb Space Telescope sees infrared light. How does that work? Does that mean it couldn't see the Sun?” Luke breaks down the various wavelengths of light and our Sun. He also explains how the JWST works and why it never looks at the sun. It turns out that Luke has built a variety of astronomical instruments including imaging and spectroscopic tools with for large observatories. He’s also used information from instruments like JWST in his studies of the formation of stars and solar systems. Luke explains how his teams search for preplanetary solar systems, what they’re looking for, and where they’re currently looking: associations of stars in the direction of the constellations Taurus, Scorpius and Chamaeleon. All told so far Luke and his team have identified 9 of these early solar systems. He then breaks down the current thinking on how planetary systems form from clouds of dust. He explains some of the processes that involves, along with the types of planets that may form. For our next audience question, Joan asks, “What do you think is the most interesting constellation?” Luke picks two: first, Ursa Major, aka “The Big Dipper,” because he grew up in Alaska and saw it all the time – along with “auroras all the time.” The second constellation he picks is Orion, aka “The Hunter,” because it contains some of the closest star forming regions of our galaxy. Luke unpacks the difference between “watching the sky” and “observing the sky” – and why he encourages the latter to both his students and the general public. And before the episode is over, we get to hear about Luke’s live show, Spacetime, where he collaborates with poet David Gonzalez and guitarist Álvaro Domene in a stage performance that’s equal parts astrophysics, poetry, and music. If you’d like to know more about Luke’s show, Spacetime, check it out at https://spacetimeshow.org/. We hope you enjoy this episode of The LIUniverse, and, if you do, please support us on Patreon. Credits for Images Used in this Episode: Image of a young sun-like star encircled by its planet-forming disk of gas and dust. – Credit: NASA/JPL-Caltech edited by Invader Xan. Artist's impression of the interstellar interloper 1I/ʻOumuamua making a visit to our solar system. – Credit: NASA, ESA, and J. Olmsted and F. Summers (STScI). Spectral distribution of sunlight. – Credit: Creative Commons / Rhwentworth. The Taurus-Auriga association, also known as the Taurus-Auriga molecular clouds, is a stellar association located around 140 parsecs (420 ly) from Earth in the constellation of Taurus. It is the nearest large star formation region to Earth. – Credit: ESA/Herschel/NASA/JPL-Caltech; acknowledgement: R. Hurt (JPL-Caltech) The constellation Taurus as seen by the naked eye. The constellation lines have been added for clarity. – Credit: Creative Commons/ Till Credner - Own work, A Visual Guide to the Constellations. Artist’s impression of a young star surrounded by a protoplanetary disk in which planets are forming. – Credit: European Southern Observatory. Illustration comparing the sizes of various exoplanets with Earth, Mercury and the Moon. – Credit: NASA's Goddard Space Flight Center. The constellation Ursa Major as it can be seen by the unaided eye.– Credit: Creative Commons / Till Credner - Own work: AlltheSky.com. Composite image comparing infrared and visible views of the famous Orion nebula and its surrounding cloud, an industrious star-making region located near the hunter constellation's sword. The picture at left was taken with the Infrared Array Camera on board NASA's Spitzer Space Telescope, and the picture at right is from the National Optical Astronomy Observatory, headquartered in Tucson, Ariz. – Credit: NASA/JPL-Caltech/Univ. of Toledo/NOAO. Image showing Betelgeuse (top left) and the dense nebulae of the Orion molecular cloud complex. – Credit: Creative Commons / Rogelio Bernal Andreo
February 8 · 55 min
Chuck GPT: Astrotech
How can a helicopter fly in space? How does LIGO detect gravitational waves? How do quantum electronic devices like Josephson junctions work? Could AI turn evil and destroy humanity? What about those grabby aliens? In this episode of Chuck GPT, Dr. Charles Liu and co-host Allen Liu answer audience questions about the technology of astronomy, astrophysics, and the future. To read those questions, we welcome back our executive producer Leslie Mullen, community director Stacey Severn, and intern Eleanor Adams. As always, though, we start off with the day’s joyfully cool cosmic thing: the ESA’s new Deep Space Antenna in Australia. This fourth antenna in ESA’s network will be used to manage communications for their slate of upcoming missions. For our first audience question, Anna asks, “How is it possible that a helicopter can work in space? I heard that NASA launched a helicopter to Mars and is going to send one to Saturn in a few years.” Leslie, who worked at JPL, talks about the Perseverance Rover and its helicopter, Ingenuity. She explains that they’re not actually flying in space, but in the atmospheres of a planet or a moon. Even so, the thin atmosphere of Mars (less than 1% of Earth’s) created unique problems that don’t exist on Earth. Leslie got to interview the inventor of Ingenuity, Bob Balaram, in her JPL podcast episode, “Flying with Ingenuity.” She describes how JPL tested the helicopter here on Earth, and what it was like the moment Ingenuity actually took flight. The team discusses Dragonfly, the helicopter that will be flying on Saturn’s moon Titan, and how Titan’s thick methane atmosphere creates an entirely different set of engineering problems than Ingenuity faced on Mars. Stacey reads our next question, from Joe: “Gravitational wave detectors like LIGO are said to detect changes in the length of space by less than the width of a proton. But how is that possible, if all the atoms that make up LIGO are so much bigger than protons?” Chuck explains interferometry (the I in LIGO!) and Allen offers a great analogy using a ruler. Eleanor reads a question from TikTok, which Esmeregildo asked in response to our video about Josephson Junctions and the Nobel Prize in Physics: “What is the purpose of the insulating barrier?” Chuck’s answer takes us down a quantum tunneling rabbit hole, filled with superconductors, insulators, and quantum computing. Diane asks: “Professor, you say that astronomers have used AI for a long time so you're not afraid of AI. But AI isn't being used by just scientists anymore, and corporations are using AI to make money now rather than to make scientific advances. So should we be afraid of AI today? Could AI turn evil soon and destroy humanity?” Allen, co-author of a soon-to-be published book about AI, offers a mostly hopeful answer, although Chuck compares AI to nuclear power and Leslie brings up real world problems AI is already creating. Our last question from our audience is, “Hi Dr. Liu, I heard you talking about grabby aliens recently. Could you explain the concept a little more? For example, would humans be grabby aliens if we explore space and colonize Mars and we find there's life there? Would we have to destroy grabby aliens right away if we find them, or would we have to hide from them?” It’s the perfect way to end this edition of Chuck GPT! We hope you enjoy this episode of The LIUniverse, and, if you do, please support us on Patreon. Image Credits: ESA’s first and fourth Deep Space Antennas. Credit: European Space Agency Map showing locations of ESA tracking (Estrack) stations as of 2017. Credit: European Space Agency Video of Perseverance landing on Mars. Credit: NASA/JPL-Caltech Ingenuity on the surface of Mars. Credit: NASA/JPL-Caltech Anatomy of the Mars helicopter Ingenuity. Credit: NASA/JPL-Caltech Ingenuity’s Test Chamber. Credit: NASA/JPL-Caltech Ingenuity in the Test Chamber. Credit: NASA/JPL-Caltech Video of Ingenuity altimeter data and the first flight as seen from Perseverance. Credit: NASA/JPL-Caltech Dragonfly space probe concept art. Credit: NASA/Johns Hopkins-APL Titan’s thick methane atmosphere gives it a fuzzy yellow look. Credit: NASA/JPL-Caltech/Space Science Institute Tuned Mass Damper used to stabilize buildings during earthquakes. Credit: CC Josephson Junction. Credit: Public Domain Josephson junction array chip developed by the National Institute of Standards & Technology. Credit: Public Domain CHAPTERS 03:08 - Joyfully Cool Cosmic Thing of the Day –New ESA Deep Space Antenna 07:36 - How Can the Ingenuity Helicopter Fly on Mars? 16:26 - How Can the Dragonfly Helicopter Fly on Saturn’s Moon Titan? 19:44 - How does LIGO detect gravitational waves? 26:01 - Josephson Junctions, Quantum Tunneling, and Superconductors Explained 36:00 - Could AI Turn Evil Soon and Destroy Humanity? 44:48 - Would Humans Be Grabby Aliens if We Explore Space and Colonize Mars? #LIUniverse #SciencePodcast #AstronomyPodcast #LIGO #ArtificialIntelligence
January 25 · 46 min
Chuck GPT: Answering Eerie Questions
Is universal expansion slowing? What is the Bubble Universe Theory? Will we control AI, or will AI control us? In this special Chuck GPT episode of The LIUniverse, we answer questions from the Annual Global Summit in Erie, Pennsylvania where Dr. Charles Liu gave a talk on “2050 - The Future of Humanity.” To help ask those questions, Chuck and co-host Allen Liu welcome Stacey Severn, our Social Media Manager/Community Director; and physics student Eleanor Adams, our first intern. As always, though, we start off with the day’s joyfully cool cosmic thing, suggested by Stacey: the recent discovery of one of the most distant and earliest known galaxies observed, existing just 570 million years after the Big Bang. It’s got a supermassive black hole 20 times the mass of ours and was found via gravitational lensing by the Canadian NIRISS Unbiased Cluster Survey (CANUCS) using the James Webb Space Telescope. Then it’s time for the main event. Eleanor reads the first Erie audience question from William W., age 13, who asks, “In Bubble Universe Theory, is the force splitting universes apart the same force causing the expansion of the universe, also known as dark energy?” Chuck explains Bubble Universe Theory, aka “Eternal Inflation,” and then how dark energy is different than the forces that cause expansion. Next question: “Have you seen the latest research from South Korea stating universal expansion is actually slowing, thus reducing greatly the amount of dark matter? If it's correct, what are the implications?” Chuck explains the current state of research around the issue, starting with the Dark Energy Spectroscopic Instrument (DESI) survey at the Kitt Peak National Observatory telescope. DESI gave indications of a change in the amount of dark energy being produced; this new study raises questions about how we measure the expansion of the universe using type 1a Supernova. Next question: “What percentage of our global warming does science attribute to man-created activities vs. a natural progression? Even though the world is getting warmer, wouldn’t it be worse if the temperature were getting colder?” Chuck looks at the natural progression of the increase of carbon dioxide and compares it with the larger and more rapid increase in CO2 levels since the Industrial Revolution began. As to whether warming or cooling is better, Allen says that while it’s a question of magnitude, neither extreme is desirable. Mark M’s question is next: “Will we achieve control or effective management of AI, or will it control, or even define, our daily lives? Allen, whose book on AI is coming out soon, says the answer is far from clear cut. He explains that while there are many efforts to ensure we maintain control, there’s no guarantee that we’ll succeed. Next question from Erie: “How do we prepare our young children to be successful in the Age of AI?” Eleanor talks about how, like social media, you can’t stop or avoid AI, but also, like social media, parents can give their children the tools to help them use it. Next: “Many advanced countries have declining populations, while third world countries are gaining population. How do we get tomorrow’s scientific leaders from third world education systems?” Chuck says the best way to ensure an ongoing stream of scientific leaders is for advanced countries to continue to welcome immigrants, while Allen points out it is also important to improve the educational systems and opportunities for research in those third world countries. Stacey reminds us about the impact the internet is having on this issue. With time running out, we squeeze in one last question from Erie: “How can the average person influence science policy in a positive direction?” Our consensus answer: people need to participate, speak out, and support others when they do, too. We hope you enjoy this episode of The LIUniverse. Please support us on Patreon. Credits for Images Used in this Episode: Location of CANUCS-LRD-z8.6. – Credit: ESA/Webb, NASA & CSA, G. Rihtaršič (University of Ljubljana, FMF), R. Tripodi (University of Ljubljana, FMF) Type 1a Supernova. Shown: G299.2-2.9, a type 1a supernova remnant in the Milky Way. – Credit: NASA/CXC/U.Texas Concentration of atmospheric carbon dioxide over the last 40,000 years, from the Last Glacial Maximum to the present day. – Creative Commons / Renerpho Chapters: 00:00 - Welcome – Call Me Chuck 01:02 - Joyfully Cool Cosmic Thing of the Day – CANUCS-LRD-z8.6 08:25 - Chuck Answers Questions from Annual Global Summit, Erie, PA 09:58 - Bubble Universe Theory and Dark Energy 14:17 - Is Universal Expansion Is Slowing? 19:30 - Global Warming 27:28 - Will We Control AI or It Will Control Us? 30:14 – How Can We Prepare Our Children To Succeed in the Age of AI? 36:28 - Where Will Future Scientific Leaders Come From? 42:09 - How Can Individuals Influence Science Policy?
January 10 · 38 min
Serving Cosmic Brunch with Thresa Kelly
How do supermassive black holes actually form in the early universe? Is the Cosmological Constant not so constant after all? And what would be on the astrophysical menu at a Cosmic Brunch? To find out, Dr. Charles Liu and co-host Allen Liu welcome astrophysicist Thresa Kelly, who is a second year grad student working on her PhD at the Rochester Institute of Technology. As always, though, we start off with the day’s joyfully cool cosmic thing, one of the recent studies made using the Dark Energy Spectroscopic Instrument, aka DESI, located at Kitt Peak National Observatory near Tucson, Arizona. According to the DESI team’s research, there is a about a 95% chance that the dark energy levels in the universe have changed over cosmic time. This “Dynamical Dark Energy model” offers the first, tiny hint that the Cosmological Constant may not be so constant after all. Thresa, who is using DESI and other sources for her work putting together a catalog of AGNs, or active galactic nuclei – the supermassive black holes found at the center of galaxies, tells us about what DESI is trying to do and why it’s so important. The end goal of Thresa’s project is to estimate the black hole masses of AGNs, and she’s gotten spectra data on over 2,000 objects that have been observed using DESI. Thresa can’t get into the details of her catalog, which hasn’t been published yet and includes about 14,000 objects, but Allen and Chuck join her in a discussion of what’s going on with black hole masses, accretion discs, Eddington Luminosity, black hole growth, galactic evolution, and more. Our first audience question comes from Kathryn, who asks, “When we look through a standard telescope looking at "past" versions of planets/stars/etc., how far back in the past are we observing?” Thresa explains how we use red shift to measure how long light from a galaxy takes to reach us to help us determine how far in the past the objects are. For instance, an AGN with a red shift of 7 can reach back to the period of “Cosmic Dawn” or, as Thresa puts it, “Cosmic Brunch” taking place 12 billion years ago. Thresa talks about her experience in an REU, or “Research Experiences for Undergraduates,” funded by the NSF, which enabled her to spend time studying at the University of Hawaii and cemented her desire to go to grad school, get a PhD, and become a “real scientist.” She explains how each step of her career brought her from Kansas to where she is today. Our next audience question comes from Walter: “If a quasar's jets are aimed directly away from Earth, would we then not be able to see the supermassive black hole?” Thresa says that depends on how you define “seeing” a black hole, and that even without visible light, you can discern black holes by looking at other wavelengths like x-rays and ultraviolet rays which are generated by different component areas of the black hole like the corona, accretion disk, or the torus. Chuck notices a shelf of games behind Thresa and asks her about them. She pulls out Stardew Valley, a farming simulator she plays with her fiancé and her fellow grad students. It’s not long until Chuck, Allen and Thresa are geeking out about Dungeons and Dragons. Finally, Chuck asks Thresa to speculate on a specific scientific discovery that may come out of her PhD thesis work. Her answer: figuring out how supermassive black holes actually form in the early universe. If you’d like to know more about Thresa Kelly, you can find her on LinkedIn. We hope you enjoy this episode of The LIUniverse, and, if you do, please support us on Patreon. Credits for Images Used in this Episode: DESI - The Dark Energy Spectroscopic Instrument. – Credit: KPNO/NOIRLab/NSF/AURA/P. Marenfeld DESI data map of celestial objects from Earth to billions of light years away.. – Credit: Claire Lamman/DESI collaboration. Montage of dwarf active galactic nuclei candidates. – Credit: DESI collaboration. Map of galaxies based on redshift data. – Credit: Creative Commons / M. Blanton and Sloan Digital Sky Survey. Quasar PKS 1127-145, a luminous source of X-rays and visible light. – Credit: NASA/CXC/A.Siemiginowska(CfA)/J.Bechtold(U.Arizona). Model of AGN. – Credit: Creative Commons.
Dec 27, 2025 · 34 min
2025 Year-End Special
What were our joyfully cool cosmic things of 2025? To find out, Dr. Charles Liu and co-host Allen Liu welcome three members of The LIUniverse production team: Jon Barnes, our Editor and self-proclaimed “#1 LIUniverse Fan,” Stacey Severn, our Social Media Manager/Community Director, and physics student Eleanor Adams, the show’s first intern. Unlike nearly every episode so far, this time, rather than limit ourselves to one joyfully cool cosmic thing, the team is going to each share their individual joyfully cool cosmic things of 2025. Chuck’s saving his for later, so instead, we’re just going to jump right into everyone’s favorite “cosmic thing of the year”, starting with our co-host, Allen Liu. Allen picks the Vera C. Rubin Observatory and the Legacy Survey of Space and Time (LSST). Allen and Chuck, who is also on the Rubin’s Science Advisory Committee and has been involved in the development of the Observatory for over a quarter century, discuss how truly amazing the images are in terms of detail and resolution. Allen shares that he’s most excited to see images of transients like asteroids and gravitational lensing, since the Rubin will be taking images of the same areas twice with a gap of one week. Chuck talks about the citizen science aspect of the Rubin and encourages each of you in our audience to try and discover something on your own. We hear about some of Allen’s published papers, including one on using VR for scientific research. The group talks about VR (including Beat Saber) and Jon shares his experience using VR technology to record his senior project at the Harold Ramis Film School at Second City, and the difficulty he had with the audio. For Eleanor, this year’s cool cosmic thing was highly personal: her studies in modern physics this year, learning more than ever about what we don’t know, like the gap between classical and quantum physics! As she puts it, “the matter-antimatter asymmetry…broke my mind.” She also shares a little inspiration from Cal Sagan’s Cosmos. Stacey’s cosmically cool thing of the year is relatively current: Comet C/2025 K1 ATLAS, which recently broke into 3 parts. The team compares this with the breakup of all breakups: Comet Shoemaker-Levy 9, which broke up in 1994 on its way to a collision with Jupiter. Jon’s joyfully cool cosmic year end thingamabob is about the new science fiction show Pluribus created by Vince Gilligan (Breaking Bad, Better Call Saul), and he’s got a question for Chuck. How long would it take a signal like the one in Pluribus to travel from a star 600 light years away, like Betelgeuse or Antares? Without dropping any spoilers, the team ponders why an alien race would have reached out to Earth based on what they might have seen around the time of Charlemagne, and whether being subsumed in a hive mind would be good or bad. This is a bittersweet episode, though, because we officially bid farewell to the show’s long time editor, Jon Barnes, who is moving on to a gig as a full-time content creator for a meal prep company that will involve lots of Jon cooking and filming himself while he does. Finally, it’s time to wrap up the episode with Chuck’s Picture of the Year, which is related to the Vera C. Rubin Observatory, but not in a way you might expect. It’s a photo of Vera Rubin when she was 10 years old. As Chuck puts it, “Who would have known that 25 years later, she would change our understanding of the cosmos itself?” Happy New Year from The LIUniverse crew! If you’d like to know more about what Jon’s up to post-LIUniverse, you can check out his TikTok @iheartjonbarnes. We hope you enjoy this episode of The LIUniverse, and, if you do, please support us on Patreon. Credits for Images and Music Used in this Episode: Galaxies imaged by the Vera Rubin Observatory. – Credit: NSF–DOE Vera C. Rubin Observatory Artist illustration of gravitational lensing. – Credit: Public Domain Comet C/2025 K1 ATLAS. – Credit: Creative Commons / Dimitrios Katevainis Comet Shoemaker-Levy 9. – Credit: NASA, ESA, and H. Weaver and E. Smith (STScI) Impacts on Jupiter from the broken-up comet Shoemaker-Levy 9. – Credit: Hubble Space Telescope Comet Team and NASA Image collage of Betelgeuse in the constellation Orion. – Credit: ESO, P.Kervella, Digitized Sky Survey 2 and A. Fujii Image of astronomer Vera Rubin, age 10. – Credit: Vera Rubin family, used with permission Music Used In This Episode: Goin' Home, derived from Dvorak's Symphony No. 9, performed by the United States Air Force Band. – Credit: Public Domain. #LIUniverse #AstronomyPodcast #CometC2025K1ATLAS #CometShoemakerLevy9 #VeraRubin
Dec 14, 2025 · 41 min
Venus, Interstellar Visitors, and Auroras with Dr. David Grinspoon
Are Coronal Mass Ejections dangerous to life on Earth? When are we finally going to plunge through the sulfuric acid clouds to measure the atmosphere of Venus. And what’s up with 'Oumuamua and 3I/Atlas? To find out, Dr. Charles Liu and co-host Allen Liu welcome astrobiologist Dr. David Grinspoon, aka Dr. FunkySpoon. As always, we start with the day’s joyfully cool cosmic thing: the arrival at Earth of two consecutive Coronal Mass Ejections on Nov. 11, 2025, creating an amazing display of Northern and Sothern Lights. In the US, aurora were seen as far south as Texas and even Central America, and yet Chuck, Alan and David were all frustrated by clouds in their own attempts to see them! Luckily, they’ve each already seen auroras with their own eyes, a viewing event David likens to seeing a total solar eclipse. David discusses how solar flares can impact human technology, but that while solar flares from other stars could be dangerous for life on their planets, at this point in our sun’s lifetime, they are unlikely to wipe out life on Earth. Chuck shares aurora images that were taken by our previous guest, astrophotographer Elliot Severn. For our audience questions this week, we’re answering questions given to Chuck while he was presenting at an event in Erie, PA. The first question Chuck asks David is, “When we have interstellar visitors like 'Oumuamua and 3I/Atlas, [1] why are they moving so fast in our space? They seem to defy gravity [2] How can they know what 3I/atlas is made of but not the density or materials?” David explains why the extreme speed at which they are moving is actually proof that they are interstellar objects and not something else. He also discusses how we use spectroscopy to determine what they’re made of the same way we determine what distant stars and exoplanets are made of. Our next question from Erie, PA is, “Is there a mathematical probability or formula to predict the likelihood of life existing int he universe? In other words, has someone developed a model to predict how many unique things need to happen for life to evolve?” David explains the Drake Equation, a series of questions that help astrobiologists assess the probability of intelligent life in the galaxy. Our last question from Erie is, “If humans find life on a different planet, would we actually understand how to coexist with the information, or will world leaders hide the truth from us?” David points out – as someone who has helped devise astrobiology policy – that the response depends in part on the specifics of the discovery, like how far away that life is. But would the government be able to hide it? David says that the scientists who discover it would be shouting it from the rooftops: “How long would it take to type it and hit send?” And as Chuck points out, the very act of the government trying to censor it would turbocharge the speed at which scientists would get the news out. The real problem, David says, is the potential of each discovery being overhyped by journalists, leading to public burnout. He brings up two examples of overhype: the discovery of possible biosignatures in iron nodules on the Martian rock Cheyava Falls in 2024 by the Perseverance Rover, and the presence of dimethyl sulphide in the atmospheric composition of exoplanet K2-18 b. Next, we turn to David’s “second favorite planet,” Venus, which he has studied and written about extensively. David shows us the first book he ever wrote, “Venus Revealed” and talks about upcoming missions to Venus: two from the US, DAVINCI and VERITAS; a European Space Agency mission named EnVision; a Venus Orbiter Mission by India’s ISRO, and a private Rocket Lab mission to Venus. David, who is involved with the DAVINCI mission, tells us about the plan to plunge through the sulfuric acid clouds to measure the Venusian atmosphere and surface with modern instruments for the first time. We end with a discussion of the anti-science cycle we’re going through, and David shares why he thinks this moment is so unusual and scary, but also why there is reason for hope. Chuck talks about why scientists take the long perspective, and David reminds us of the huge worldwide support for the exploration of space. If you’d like to know more about David, you can check out his YouTube channel @DrFunkySpoon, or @DrFunkySpoon on Blue Sky and Instagram. We hope you enjoy this episode, and, if you do, please support us on Patreon. Image Credits: Images of aurora over Connecticut. Credit: Elliot Severn Coronal Mass Ejection. Credit: NASA Orbit of ‘Oumuamua. Credit: CC Orbit of 3I ATLAS. Credit: NASA/JPL-Caltech Radar map of Venus made by NASA’s Magellan spacecraft. Credit: NASA/JPL-Caltech/USGS Nodules on Mars rock Cheyava Falls. Credit: NASA James Webb Space Telescope – Atmospheric composition of exoplanet K2-18 b. Credit: NASA, CSA, ESA, J. Olmstead, N. Madhusudhan Venus viewed from orbit. Credit: NASA/JPL-Caltech #LIUniverse #CharlesLiu #AllenLiu #SciencePodcast #AstronomyPodcast #DavidGrinspoon #DrFunkySpoon #Oumuamua #3IAtlas #InterstellarObjects #CoronalMassEjections #aurora #solarflares #DAVINCI #VERITAS #EnVision #antiscience #spaceexploration
Nov 30, 2025 · 46 min
Rings, Orbits and Space Storms with Dr. Phil Nicholson
How do planetary ring systems rings form, and what keeps them in line? What exactly is the Dragon Cloud of Saturn? And what’s up with quasi moon 2025 PN7? To find out, Dr. Charles Liu and co-host Allen Liu welcome Cornell University’s dynamical astronomer Dr. Phil Nicholson for a refresher course in orbital mechanics. As always, though, we start off with the day’s joyfully cool cosmic thing, which is right up Phil’s alley: the recent discovery of quasi moon 2025 PN7. Phil unpacks the orbital mechanics to explain the critical differences between quasi moons and regular moons, and also 2025 PN7’s strange relationship to Earth’s orbit. He also explains the dynamics of the sun’s tidal forces and Earth’s Hill Sphere. For our first question from the audience, Jameson asks, “Are meteorites smaller copies of planets. Are all of them the same?” Rather than discuss meteorites, which are the tiny survivors that have crashed on Earth, Phil pivots to where many of them come from in the first place: asteroids. Really big asteroids share some characteristics with planets, like being spherical in shape, whereas the smaller ones can be highly irregular, like the dumbbell-shaped asteroid 216 Kleopatra, or Arrokoth, previously known as Ultima Thule. Chuck asks Phil about the different shapes large asteroids can come in, and Phil points out 433 Eros, the second largest Near Earth Object, which is banana shaped. The ensuing brief discussion of the “is it a long, skinny asteroid or an interstellar starship?” debate, like the one sparked by Oumuamua, leads to a conversation about Arthur C. Clarke’s “Rendezvous with Rama”, which described just such a starship back in 1973. Somehow, we end up looking at the “face” on Mars and the “Death Star,” aka, Saturn’s moon Mimus as it was imaged by the Cassini spacecraft. Phil actually worked on the Cassini mission, and Chuck asks him to talk about his experience peering hundreds of miles deep into Saturn’s atmosphere with the spacecraft’s Visible and Infrared Mapping Spectrometer (VIMS). Along with other instruments run by other teams, the mission changed our perception of Saturn’s “boring” atmosphere, documenting aurora, lightning, and giant storms like the “Dragon Cloud of Saturn.” Our next student question comes from Marvin, who asks, “What exactly is a Shepherd moon?” To answer, Phil describes what Saturn’s rings are made of, how they form, and how they’re structured. He explains what happens when particles that make up the rings collide, why some rings spread over time, while others stay very narrow, and the role Shepherd satellites play in the process. We end with Chuck soliciting a few classic sci-fi recommendations from Phil, who suggests anything by Arthur C. Clarke, the Foundation Trilogy by Isaac Asimov, and almost anything by Larry Niven, including Ringworld, his most famous series. We hope you enjoy this episode of The LIUniverse, and, if you do, please support us on Patreon at https://www.patreon.com/theliuniverse. Credits for Images Used in this Episode: Orbit of quasi moon 2025 PN7 – Credit: NASA/JPL Earth’s Hill Sphere extends between the Lagrange Points L1 and L2. – Credit: Creative Commons / Xander89 433 Eros, a banana-shaped asteroid. – Credit: NASA/JPL/JHUAPL 216 Kleopatra, a dumbbell shaped asteroid – Credit: NSSDC, NASA Arrokoth, previously known as Ultima Thule – Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute/Roman Tkachenko The “face” on Mars next to a higher resolution image of the same hill. – Credit: NASA / JPL / University of Arizona Mimus as imaged by the Cassini spacecraft. – Credit: NASA / JPL-Caltech / Space Science Institute Visible and Infrared Mapping Spectrometer (VIMS) image of Saturn – Credit: NASA/JPL/Space Science Institute Dragon Cloud of Saturn – Credit: NASA/JPL/Space Science Institute Shepherd moon animation showing Prometheus (right) and Pandora (left) both orbit near Saturn's F ring. – Credit: NASA/JPL/Space Science Institute Uranus ring schematic, solid lines are rings; dashed lines are moon orbits. – Credit: Public Domain / Ruslik0 #LIUniverse #CharlesLiu #AllenLiu #SciencePodcast #AstronomyPodcast #DynamicalAstronomy #PhilNicholson #OrbitalMechanics #Rings #SpaceStorms #QuasiMoons #2025PN7 #HillSphere #433Eros #Asteroid #216Kleopatra #Arrokoth #UltimaThule #Cassini #VisibleAndInfraredMappingSpectrometer #VIMS #DragonCloudOfSaturn #ShepherdMoon
Nov 15, 2025 · 39 min
Tiny Galaxies and Massive Black Holes with Dr. Matt Taylor
Can an ultra-compact dwarf galaxy have a supermassive black hole at its center? Are there galaxies with supermassive black holes that are offset from their galactic centers? To find out, Dr. Charles Liu and co-host Allen Liu welcome “the other” Dr. Matt Taylor, an Assistant Professor of Astronomy at the University of Calgary, who joins us from the control room of the largest astronomical telescope in Canada, at the Rothney Astrophysical Observatory (RAO) in Alberta, Canada. As always, though, we start off with the day’s joyfully cool cosmic thing, which starts with the discovery of a supermassive black hole in the middle of an ultra-compact dwarf galaxy M60-UCD1 located in the Virgo galaxy cluster. That led to the discovery of more 4 UCDs in the Virgo Galaxy Cluster and 1 in the Fornax galaxy clusters, but then the limits of technology prevented the discovery of any additional UCDs. But now, by using the James Webb Space Telescope, Matt and his fellow researchers (including Dr. Vivienne Baldassare, our former guest for Black Holes and Space Junk with Vivienne Baldassare) have just published a paper about their discovery that in the smallest, lowest mass UCD yet found, they found a roughly 2,000,000 solar mass black hole. Basically, that’s a tiny galaxy to hold a supermassive black hole, and Matt is sure there are many more of these waiting to be discovered. After that Matt tells us about his atypical journey to astronomy, including his first career – as a professional chef. When cooking stopped being fun, Matt enrolled at a local community college and “moved from gastronomy to astronomy” as Allen puts it. Our first audience question comes from our Patreon Patron Taylor L, who asks, “Is it possible dark energy and the acceleration of the universe's expansion could be explained by the idea that the black hole we live in is constantly devouring matter from outside?” Matt passes on determining whether or not we live inside a black hole. But, he explains that while at the galactic level expansion is happening on a really large scale, at a smaller scale like our local group of galaxies (Milky Way, Andromeda, and local dwarf galaxies), our mutual gravitation counteracts that expansion. Matt goes on to discuss how accretion disks are what makes it possible to “see” a black hole, but that ultra-compact dwarf galaxies don’t have gas and dust forming accretion disks. Instead, they use stellar velocities to find black holes in UCDs. Next up, Matt tells us about some of the research he’s doing into archetypal compact elliptical (cE) galaxies, which have the mass of a giant galaxy put into the volume of a dwarf galaxy, and how black holes appear in these systems. And Matt dangles another upcoming paper about galaxies with supermassive black holes that are offset from their galactic centers. For our next audience question, Pshemo asks: “We often say gravity is weak compared to other forces. But in the right regimes, like near black holes and neutron stars, or on large cosmic scales, it dominates every other interaction. Should we stop calling gravity a weak force?” It’s a thought-provoking question with an even better answer, so please watch or listen to the episode to hear it yourself from Matt. If you’d like to know more about Matt, you can check out his website, mataylor5128.github.io. (The 5128 comes from the famous and very cool galaxy NGC 5128, aka Centauras A) We hope you enjoy this episode of The LIUniverse, and, if you do, please support us on Patreon. Credits for Images Used in this Episode: Virgo and Fornax galaxy clusters. – Credit: Creative Commons / Atlas of the Universe/ Richard Powell Southern portion of the Virgo Cluster as imaged by the Vera C. Rubin Observatory in very high resolution, taken on June 5, 2025. – Credit: RubinObs/NOIRLab/SLAC/NSF/DOE/AURA Ultra-compact galaxy M60-UCD1. – Credit: NASA, ESA, CXC, and J. Strader (Michigan State University) Diagram of a black hole accretion disk. – Credit: NASA’s Goddard Space Flight Center/Jeremy Schnittman Hubble image of Messier 32, an archetypal compact elliptical (cE) galaxy. – Credit: NASA/ESA Centaurus A (NGC 5128) – Credit: ESO/WFI (Optical); MPIfR/ESO/APEX/A.Weiss et al. (Submillimetre); NASA/CXC/CfA/R.Kraft et al. (X-ray) #LIUniverse #CharlesLiu #AllenLiu #SciencePodcast #AstronomyPodcast #MattTaylor #UltraCompactDwarfGalaxy #UDC #SupermassiveBlackHole #BlackHole #AccretionDisk #M60UCD1 #ArchetypalCompactEllipticalGalaxy #UltraCompactGalaxy
Nov 1, 2025 · 41 min
Black Holes Colliding with Dr. Charlotte Olsen
How do very small galaxies form? What’s going on inside them? And what happens when black holes collide? To find out, Dr. Charles Liu and co-host Allen Liu welcome astrophysicist and “Galaxy Detective” Dr. Charlotte Olsen from New York City College of Technology – and you can call her Chuck, too! As always, though, we start off with the day’s joyfully cool cosmic thing, the latest announcement from LIGO about the detection of a gravitational wave event in 2023 from the loudest collision we’ve heard so far. In this case, the wave was caused by the collision of two black holes that created one new black hole about 60x the mass of our Sun and released an entire sun’s worth of energy. Charlotte explains why there are many black hole collisions going on, and how LIGO detections are now being combined with data from other gravitational wave detectors to give us more precise measurements. You’ll also hear about Active Galactic Nuclei (AGNs) and their negative impact on Charlotte’s research. Charlotte talks about what she looks for in her research, and why it all comes down to “wanting to see more photons” to better validate her modeling. Our first question from the audience comes from Joe, who asks, “What does it mean for the Milky Way to have a bar? Why does it have a bar? And how can such a long bar form?” It turns out that many spiral galaxies like ours have bars, and Charlotte explains a little about bar structure. She brings up the current debate about the stability of these bars, and points out that they actually come in slightly different configurations and that star formation at the ends of the bar has an impact, too. Unlike previous thinking, these bars can develop earlier in galactic evolution and can last a very long time. In other words, as Charlotte puts it, “The bar is always open.” Next, Chuck asks what got Charlotte into astronomy. She describes the inspiration she drew from both the dark skies of Northern California, where she grew up, and from the science fiction she read. She shares a few of her “million and one jobs” she did, including her stint as a bassist in a band. That tees up our next audience question, from Shivani, who asks, “How do you mix music and science? I can't decide if I want to be a scientist or a musician someday – can I be both?” Yes, Charlotte says, and explains why doing both might actually be better. She talks about the value of music, and passion, and hobbies that are more than just hobbies, as well as some of the live music she’s been seeing in Brooklyn, Long Island and Queens. Finally, Chuck asks Charlotte about the current passion project she’s working on. She tells us how she’s looking at a handful of galaxies in multiple wavelengths and comparing them to each other to figure out “what’s going on under the hood.” If you’d like to know more about Charlotte, you can connect with her on Bluesky at @charlotteeureka.bsky.social or on her GitHub page charlotteolsen.github.io. We hope you enjoy this episode of The LIUniverse, and, if you do, please support us on Patreon. Credits for Images Used in this Episode: Visualization of a binary black hole merger consistent with the gravitational-wave event called GW250114. (Note: this is to illustrate the collision of 2 black holes and the subsequent gravity waves generally, it is not specific to the GW230814 event Chuck mentions in the episode) – Credit: H. Pfeiffer, A. Buonanno (Max Planck Institute for Gravitational Physics), K. Mitman (Cornell University) Animation of an active galactic nucleus. – Credit: NASA, ESA, and the Hubble SM4 ERO Team. Hubble Space Telescope image barred galaxy NGC 1300. – Credit: NASA, ESA, and The Hubble Heritage Team STScI/AURA Data from NASA's Wide-field Infrared Survey Explorer (WISE) used to trace the shape of the Milky Way's spiral arms. – Credit: NASA/JPL-Caltech #liuniverse #charlesliu #allenliu #sciencepodcast #astronomypodcast #charlotteolsen #blackholes #ligo #gravitationalwave #blackholecollisions #activegalacticnuclei #agns #milkyway #spiralgalaxies #barredgalaxies
Oct 18, 2025 · 43 min
Measuring the Stars with Astrostatistician Sabrina Berger
How does a star form? How does the universe form? And how can we use every bit of astronomical data to answer those questions? To find out, Dr. Charles Liu and co-host Allen Liu welcome astrostatistician Sabrina Berger, all the way from Melbourne, Australia, where she’s currently pursuing her PhD. As always, though, we start off with the day’s joyfully cool cosmic thing, the new radioastronomy photographs of Callisto, one of the moons of Jupiter, taken by ALMA. Sabrina talks about her own low-frequency radio astronomy research looking for hydrogen in the very early reionization period of the universe when the first galaxies were forming. (Be warned: we dive into the difficulties ionization poses for trying to discern these early processes, including a side trip into quantum mechanics, the hyperfine transition of neutral hydrogen at 21cm depicted on the plaque attached to the Pioneer spacecraft, and even the Cosmic Background Radiation.) You’ll also hear how Sabrina is innovatively using GPS satellites to help calibrate large radioastronomy telescope arrays. For our first student question, Derek asks, “I heard that black holes can form right after the Big Bang, before stars do. How is that possible?” Sabrina describes these primordial black holes, and, although none have been confirmed yet, that there have been a number of papers published recently on the subject. In fact, one paper suggesting that the as-yet-undiscovered “Planet 9” could even be one of these primordial black holes. And then, finally, we get to the subject of astrostatistics, Sabrina’s area of expertise. She explains that it allows you to harness every piece of information that you’re observing in astronomy and to answer questions like “How does a star form?” or “How does the universe form?” You’ll hear about huge data sets, the use of artificial intelligence, field level inferences… and the MCMC, or the Markov chain Monte Carlo used in statistics. (If you don’t know what that is, you’re not alone, and our own resident mathematician Allen helps Sabrina untangle the complexity with a cotton ball analogy that blew Chuck and Sabrina’s collective minds!) For our next student question, Wally asks, “Why is redshift one like nine billion years ago, bur redshift two only two billion years before that, and redshift three only one billion years before that?” As Chuck says, “that’s a little complicated,” just before he, Allen and Sabrina proceed to explain how we measure universal expansion, the passage of time, and the “stretching” of light. Our next conversation is one of the most controversial we’ve ever had and revolves around who Sabrina thinks makes the best espresso, Australia, Italy or a “Third Wave Coffee Shop” like we have here in the US. You’ll hear about why there’s an ISSpresso machine on the ISS – and how the Italian Space Agency invented a way to make an espresso in zero-g! Plus, you’ll hear a little about the work-life balance in Australia and how wonderful astronomy down under is. (Check out our Patreon for the story behind the Australian Aboriginal "Emu-in-the-sky" constellation.) If you’d like to know more about Sabrina, you can find her on Twitter and Blue Sky @sabrinastronomy or check out her research on her website. We hope you enjoy this episode of The LIUniverse, and, if you do, please support us on Patreon. Credits for Images Used in this Episode: An image of Jupiter's icy moon Callisto, photographed by NASA’s Galileo spacecraft in 2001. – Credit: NASA/Galileo Photograph of Jupiter taken in 2019. The four fainter objects are four of its moons (left to right): Callisto, Ganymede, Io, and Europa. – Credit: Creative Commons / Rehman Abubakr ALMA images of Callisto – Credit: Maria Camarca et al 2025 Planet. Sci. J. 6 183. See the ALMA/Callisto paper: “A Multifrequency Global View of Callisto’s Thermal Properties from ALMA”: https://iopscience.iop.org/article/10.3847/PSJ/ade7ee Timeline of the universe. – Credit: NASA, ESA, CSA, STScI The Pioneer plaques, attached to the Pioneer 10 and 11 spacecraft. – Credit: NASA Sedna orbit with solar system (Sun, Jupiter, Saturn, Uranus, Neptune and Pluto visible) and positions on Jan 1, 2017 – Credit: Creative Commons / Tom Ruen Redshift and universe expansion. As light travels from great distances to Hubble's mirrors, it is stretched to longer and longer red wavelengths, or cosmologically redshifted, as the universe expands. – Credit: NASA, ESA, Leah Hustak (STScI) The ISSpresso machine on the International Space Station.– Credit: NASA Astronaut Samantha Cristoforetti drinking espresso out of the cup on ISS, 2015 – Credit: NASA #liuniverse #charlesliu #allenliu #sciencepodcast #astronomypodcast #sabrinaberger #astrostatistician #astrostatistics #redshift #blackholes #primordialblackholes #callisto #alma #planet9 #sedna #universeexpansion #isspresso
Sep 27, 2025 · 37 min
Cosmic Raspberries and Life on Mars with Dr. Kelly Blumenthal
Have we discovered life on Mars? What does the center of our galaxy taste like? To find out, and to kick off Season 5 of The LIUniverse, Dr. Charles Liu and co-host Allen Liu have reached out all the way to Tokyo to chat with Dr. Kelly Blumenthal, the Director of the International Astronomical Union Office for Astronomy Outreach. As always, though, we start off with the day’s joyfully cool cosmic thing, a rock found in Sapphire Canyon by the Mars Perseverance Rover containing potential biosignatures. Allen explains why this rock is different: iron and sulfur nodules that exhibit indications of layers which, on Earth, could only be formed by bacteria. Kelly points out that there needs to be more investigation before we can say anything for sure. Chuck asks Kelly, who when she was 12 told her dad that she wanted to study galaxy evolution, to describe the research she did at the start of her career. She talks about studying with pioneering astronomer Joshua Barnes in Hawaii during her Masters projects and PhD. For her first project, she studied star formation rates in Jellyfish Galaxies, which are being ram-stripped of their gases and so appear to have tendrils. She ended up looking at the history of merging galaxies through cosmic time using large cosmological simulations. Then it’s time for our first student question of Season 5, from Jeannie, who asks, “Now that we’ve found so many planets outside of our solar system, should Pluto be promoted as a planet again?” (Pluto’s “demotion” nearly 20 years ago was traumatic for some.) According to Kelly, though, the “demotion” was really a reclassification, and at least for the time being, Pluto is going to stay a dwarf planet, a new category of which it was the first of its kind. She contrasts Pluto to the moons of Jupiter and reminds us of the new rules about what’s a planet and what’s not. Kelly brings up Star Trek and therefore gives Chuck permission to geek out over “Devil in the Dark” from the Star Trek: The Original Series, and “Silicon Avatar” from Star Trek: The Next Generation. Kelly talks about bingeing sci-fi in high school including 2001: A Space Odyssey, and the Foundation series, and more recently, The Expanse series, which she’s listened to three times as audio books! Chuck and Kelly discuss communicating about science, and even the role science fiction can play. Kelly talks about the importance of understanding your audience. She uses the example of explaining what nebulas look like through the Chandra X-Ray Observatory to a blind and low-vision audience. Kelly also talks about how you can approach science through poetry, music, dance, theatre and art – even smell. She recalls a talk where someone working with incarcerated kids, who was limited in what props they could bring, made the universe come alive for them using the scent of raspberries, which have a similar chemical signature as the center of our galaxy. For our next audience question, Bridget asks, “So is that comet actually an interstellar spaceship?” Kelly debunks the notion that Comet 3I/ATLAS is anything other than a rock that’s come from outside our solar system and explains why extrasolar asteroids are amazing things. We end with a discussion of the IAU’s upcoming, worldwide “100 Hours of Astronomy” on Oct. 2-5, 2025, including a 24-hour live stream on Oct. 4 from the oldest functioning planetarium in Japan. Watch it live on YouTube via the IAU Office for Astronomy Outreach @IAUoutreach here. You can also visit their website at https://iauoutreach.org/, follow IAU Office for Astronomy Outreach on Facebook and LinkedIn, and on Instagram @oao_iau. If you have any questions, email them at public@oao.iau.org. You can follow Kelly on LinkedIn. We hope you enjoy the Season 5 premiere of The LIUniverse. Please support us on Patreon. Credits for Images Used in this Episode: Observatory History Museum at NAOJ in Mitaka – Credit: おむこさん志望, CC BY 3.0 “Sapphire Canyon” sample – Credit: NASA Perseverance Rover Iron Bacteria in Scotland – Credit: Roger Griffith Jellyfish Galaxy ESO 137-001 – Credit: NASA/ESA/CXC Jellyfish Galaxy JO201 – Credit: ESA/Hubble & NASA, M. Gullieuszik, CC BY 4.0 New Horizons probe before launch – Credit: NASA Pluto’s “Heart”, Tombaugh Regio – Credit: NASA / Johns Hopkins University Applied Physics Laboratory / Southwest Research Institute Chandra X-ray Observatory (Illustration) – Credit: NASA/CXC/NGST Interstellar Comet 3I/Atlas – Credit: International Gemini Observatory/NOIRLab/NSF/AURA/Shadow the Scientist, CC BY 4.0 Artist’s illustration of interstellar asteroid 1I/'Oumuamua – Credit: NASA, ESA, Joseph Olmsted (STScI), Frank Summers (STScI) Interstellar Comet 2I/Borisov – Credit: NASA, ESA, and D. Jewitt (UCLA) 100 hours of Astronomy! – Credit: IAU, CC BY 4.0 #liuniverse #sciencepodcast #astronomypodcast #kellyblumenthal #lifeonmars #bacteria #jellyfishgalaxy #pluto #interstellarasteroid #comet3iatlas #iau #officeforastronomyoutreach #startrek #theoriginalseries #thenextgeneration #theexpanse
Jun 21, 2025 · 24 min
Chuck GPT Apocalypse, Part 2
It’s the end of everything! Welcome back to Part 2 of our season finale featuring Dr. Charles Liu, co-host Allen Liu, and our guest archaeology expert and author, Hannah Liu, MEd. (If you haven’t caught up to Part 1, we highly recommend you do before embarking on the next leg of this journey! Listen here or wherever you get your podcasts!) We pick right up where we left off, with the next question from our audience. Daniela asks, “If a black hole hits the Sun, will Earth be destroyed?” Chuck explains a few ways a black hole can mess with our day, including the fact that long before any actual collision took place, the Sun would start shedding material that would destroy us. He compares that unlikely event to the actual example of cosmic destruction we’re watching in NGC 4676 – aka “The Mice” – which are two galaxies swirling together in a death spiral playing out over hundreds of millions of years. Naturally, this leads Chuck to ponder what happens when civilizations fall apart here on Earth, and Hannah brings up the collapse of the Roman Empire. As she explains, “the fall of Rome happened a lot of times, and also, no time.” From 44 BCE and the assassination of Julius Caesar, to the 476 invasion and conquest of Rome by the Germanic tribes denoted by Edward Gibbon in The History of the Decline and Fall of the Roman Empire, to the fact ever since nations have claimed to be the descendants or inheritors of Rome. Chuck points out the influence of Gibbon’s book on Isaac Asimov’s “Foundation” series, followed by a very quick romp through “Decline and Fall of America” literature including The Handmaid’s Tale, A Canticle for Liebowitz, Man in the High Castle, and the zombie apocalypse tour de force, World War Z. Then it’s time for another question from the audience: Michael says, “I heard that scientists brought back a dire wolf. Could they bring back dinosaurs or animals that could destroy us all?” It turns out, these resurrected animals are just gray wolves that have been engineered to have some characteristics of the extinct predator. It’s still a pretty impressive feat, though, and you’ll hear how they collected bits and pieces of dire wolf DNA to “resurrect them.” Allen also brings up similar modification experiments they’re doing on chickens to make them more dinosaur-like. Allen points out that bioengineered germs are far more likely to cause our destruction than resurrected dinosaurs, regardless of the world envisioned in the Jurassic Park franchise. And speaking of Michael Crichton, Chuck gives us a breakdown of his sci-fi classic, The Andromeda Strain, about bacteria from space that cause a biological outbreak here on Earth. Hannah points out that historically, some of the biggest killers of human beings have been plagues. She gives us a guided tour of the bubonic plagues, from the Black Death, which may have wiped out as much as 60% of the population of Europe, to the Plague of Justinian a thousand years earlier that killed as many as 100 million people, while also name dropping the Antonine Plague and the Spanish Flu!) And that’s it Season 4 of The LIUniverse. Stay tuned for Season 5 after the summer. If you want to find out more about what Hannah’s impending book, check out the Mixed Identity Project We hope you enjoy this episode, and this season, of The LIUniverse. If you did, please support us on Patreon Credits for Images Used in this Episode: NGC 4676, aka “the Mice” are two galaxies swirling together. – Credit: NASA, H. Ford (JHU), G. Illingworth (UCSC/LO), M.Clampin (STScI), G. Hartig (STScI), the ACS Science Team, and ESA; The ACS Science Team: H. Ford, G. Illingworth, M. Clampin, G. Hartig, T. Allen, K. Anderson, F. Bartko, N. Benitez, J. Blakeslee, R. Bouwens, T. Broadhurst, R. Brown, C. Burrows, D. Campbell, E. Cheng, N. Cross, P. Feldman, M. Franx, D. Golimowski, C. Gronwall, R. Kimble, J. Krist, M. Lesser, D. Magee, A. Martel, W. J. McCann, G. Meurer, G. Miley, M. Postman, P. Rosati, M. Sirianni, W. Sparks, P. Sullivan, H. Tran, Z. Tsvetanov, R. White, and R. Woodruff. Plaster replica of Statue of George Washington by Antonio Canova at the North Carolina Museum of History.– Credit: Creative Commons / RadioFan (talk) Dire Wolf Cover of TIME magazine, May 12, 2025. – Credit: TIME magazine Page Museum Display of 404 dire wolf skulls found in the La Brea Tar Pits. – Credit: Creative Commons / Pyry Matikainen The spread of the Black Death in Europe, 1346-1353. – Credit: Creative Commons / Flappiefh - Own work from: Natural Earth ; Cesana, D.; Benedictow O.J., Bianucci R. (2017). Yersinia pestis, the bacterium that causes the Plague. Direct Fluorescent Antibody Stain (DFA), 200x. – Credit: CDC 2057 - US Government public domain image, Courtesy of Larry Stauffer, Oregon State Public Health Laboratory Little Ice Age Temperature Chart. – Credit: Creative Commons / RCraig09 - Own work #liuniverse #charlesliu #allenliu #hannahliu #sciencepodcast #astronomypodcast #hannahliu #apocalypse #armageddon #doomsday #ngc4676 #themice #blackhole #romanempire #direwolf #bubonicplague #blackdeath #yersiniapestis #theandromedastrain #michaelcrichton #jurassicpark #littleiceage
Jun 8, 2025 · 27 min
Chuck GPT Apocalypse, Part 1
As our fourth season draws to a close, we’ve got an apocalyptic, 2-part ending lined up. That’s right, we’re talking Armageddon, and we don’t mean the 1998 Bruce Willis blockbuster. And of course, if we’re going to delve into the end of everything, Dr. Charles Liu and co-host Allen Liu are going to need the help of our ever popular archaeology expert and author, Hannah Liu, MEd. As always, though, we start off with the day’s joyfully cool cosmic thing, the failed Soviet-era Kosmos 482 lander that was designed to withstand entry into the Venus atmosphere but never actually let Earth orbit and finally just came crashing back home on May 10, just a few days after we recorded this episode! Chuck, Allen and Hannah ponder the possibilities of cataclysmic destruction that the more than half-ton object could produce. Then, without missing a beat, Hannah takes us all the way back to Greek mythology and the Titanomachy, the legendary fights between the Gods and the Titans that were possibly inspired by catastrophic volcanic eruptions that laid waste to the ancient Mediterranean. Chuck jumps continents to discuss the Norse apocalypse known as Ragnarök – casually dropping that is inspired the massively popular Baldur’s Gate 3 as he does. Not to be outdone, Hannah brings us all back to the original Armageddon itself: the final battle between good and evil that is foretold in the Book of Revelations to take place at Har Megiddo, the “Hill of Megiddo” in Hebrew. You’ll also hear about where the word apocalypse comes from, and why it’s become associated with the end of the world, as Hannah gives us all a quick lesson in eschatology, or the study of the end of the world. Our first question comes from Ahmed, who asks, “What are the odds that a killer asteroid will kill us all?” Allen gets a little excited about asteroid 2024 YR4, an asteroid the size of a 15-story building, that is predicted to pass safely by Earth in 2032 but at one point had as high a chance of hitting us as 4-5% – and still has about a 3% chance of hitting the Moon. Chuck explains that the odds of a true “dinosaur-killer” extinction event asteroid impact from an object at least a mile across is about 50 million to 1 in any given year. Hannah points out that it’s far more likely that Mount Vesuvius, the volcano that inundated Pompeii, will erupt again. The last one was in 79AD, and since it tends to blow its top every 2,000 years or so, we’re due. Moving back further, Hannah tells us about the Minoan Eruption that devastated the isle of Santorini in the Mediterranean, wiping out the city of Akrotiri, around 1600 BCE and was reported as far away as China. And that’s just a few of the disastrous historic collapses Hannah shares with us, including the Hekla 3 eruption in Iceland that had may have had something to do with the Bronze Age Collapse. It turns out that the apocalypse is too big for a single episode! Join us in two weeks for Part 2 of our journey into all things apocalyptic. We hope you enjoy this episode of The LIUniverse, and, if you do, please support us on Patreon. Credits for Images Used in this Episode: The Kosmos 482 lander probe reentered Earth's atmosphere on May 10 at 06:24 UT over the Indian Ocean. Because the Russian probe was designed to withstand entry into the Venus atmosphere, it is possible it survived reentry, but has landed in the ocean west of Jakarta, Indonesia.– Credit: NASA On March 26, 2025, NASA’s James Webb Space Telescope captured images of asteroid 2024 YR4 that indicate the asteroid is about the size of a 15-story building. – Credit: NASA, ESA, CSA, STScI, Andy Rivkin (APL) Santorini island, Greece. Satellite image of Thera. The bay in the center of the island is the caldera created by the Minoan eruption.– Credit: NASA EOS Excavation of Akrotiri in 2018– Credit: Creative Commons: By Rt44 - Own work The Bull-Leaping Fresco from the Great Palace at Knossos, Crete – Credit: Creative Commons / Gleb Simonov Detail of Abraham Ortelius' 1585 map of Iceland showing Hekla in eruption. The Latin text translates as "The Hekla, perpetually condemned to storms and snow, vomits stones under terrible noise". – Credit: Creative Commons / Abraham Ortelius #liuniverse #charlesliu #allenliu #hannahliu #sciencepodcast #astronomypodcast #hannahliu #apocalypse #armageddon #doomsday #kosmos482lander #asteroid2024yr4 #titanomachy #ragnarak #baldursgate3 #bookofrevelations #harmegiddo #eschatology #mountvesuvius #pompeii #minoaneruption #hekla3 #bronzeagecollapse
May 24, 2025 · 45 min
Finding Your Place in Space with Sadie Coffin
Who are the “Redshift Wranglers” and what can they tell us about the evolution of our universe? To find out, Dr. Charles Liu and co-host Allen Liu welcome back astrophysics PhD candidate Sadie Coffin from the Rochester Institute of Technology whose focus is galactic evolution, and in particular, the spectroscopy of galaxies and their lights. As always, though, we start off with the day’s joyfully cool cosmic thing: the Lucy spacecraft fly-by of asteroid 52246 Donaldjohanson, which was named after the American paleoanthropologist who discovered the Australopithecus afarensis “Lucy” fossil the spacecraft was named after. Then it’s time to learn a little about Sadie, who explains how questioning the unknown is what drove her to study astronomy. Chuck, Allen and Sadie talk about the awe embodied in the study of the universe and the universe itself. Like Chuck, Sadie studies galaxy evolution, but Sadie focuses on a galaxy’s light, spread into spectra, and dissecting different features in that light. You’ll hear about the citizen science project called “Red Shift Wranglers” that helps Sadie sift through all the spectroscopic data, and get an awesome explanation of the doppler effect and the way red shift, which measures speed, can be used to help build better maps of galactic evolution. Find out how you can get involved with the project and join the ranks of the 3,500 Redshift Wranglers who’ve participated so far in “Wrangling galaxies and the universe together.” (See below for links.) You’ll also hear about other citizen science projects on Zooniverse like Galaxy Zoo. Sadie talks about the value of non-experts engaging with experts in a community, and the surprising number of people who want to get involved. For our first audience question, Nina asks, “If nothing can go faster than the speed of light, why can galaxies have Z greater than 1?” Sadie’s explanation gets pretty technical, so we’ll let her do it in the episode. Our next question comes from Jerry, who asks, “Will we someday no longer need scientists and have AI do all our research?” Sadie, who gets similar questions all the time relative to citizen science, believes these two things can be complimentary, and that in the name of improving science we can’t forgo either for the other. We finish with a discussion about what defines an act of science and a work of art, the process of questioning, and the roles of humans and machines in these processes. Plus, Sadie tells us about the science-themed travel posters by Dr. Tyler Nordgren on her walls. Chuck also gets Sadie to talk about rowing and the lessons she’s taken from the sport into other aspects of her life and journey as a scientist. If you’d like to know more about the Redshift Wrangler project on The Zooniverse and get involved, or to reach Sadie, visit https://www.zooniverse.org/projects/jeyhansk/redshift-wrangler or find Redshift Wrangler on Facebook and X (Twitter). Listen to the COSMOS project episode referenced in this show with Dr. Jeyhan Kartaltepe, an astronomer and professor at the Rochester Institute of Technology. Watch Sadie’s previous appearance in this short video shot at the COSMOS Team Meeting 2023. We hope you enjoy this episode of The LIUniverse, and, if you do, please support us on Patreon. Credits for Images Used in this Episode: The inner Solar System, with the Jupiter Trojan asteroids shown in green. – Credit: Mdf at Wikipedia/Public Domain. Lucy skeleton (AL 288-1) Australopithecus afarensis, cast from Museum national d'histoire naturelle, Paris. – Credit: Creative Commons. Absorption lines in the optical spectrum of a supercluster of distant galaxies (BAS11) (right), as compared to those in the optical spectrum of the Sun (left). Arrows indicating Redshift. – Credit: Creative Commons / Georg Wiora (Dr. Schorsch) created this image from the original JPG. Derivative work:Kes47. Color composite JWST NIRCam image of distant galaxy JADES-GS-z13-0. – Credit: NASA, ESA, CSA, and STScI, M. Zamani (ESA/Webb), L. Hustak (STScI). Science: B. Robertson (UCSC), S. Tacchella (Cambridge), E. Curtis-Lake (Hertfordshire), S. Carniani (Scuola Normale Superiore), and the JADES Collaboration. Dr Tyler Nordgren’s VLA NRAO travel poster – Credit: NRAO/Tyler Nordgren. #liuniverse #charlesliu #allenliu #sciencepodcast #astronomypodcast #sadiecoffin #redshiftwranglers #citizenscience #zooniverse #galaxyzoo #spectra #dopplereffect #redshift #galaxyevolution #tylernordgren #jeyhankartaltepe

The LIUniverse with Dr. Charles Liu

ChuckGPT - Patreon Question Edition

Our Weird, Wondrous Universe with Erika Hamden

Ruby Raindrops and Painted Peacocks with Munazza Alam

Astrophotography with Astronaut Don Pettit

Finding the “Bubbles” Exoplanet and Crocheting Dinosaurs with Victoria DiTomasso

Supernovas and Space Gold with Dr. Ashley Villar

Building Worlds with Luke Skywatcher

Chuck GPT: Astrotech

Chuck GPT: Answering Eerie Questions

Serving Cosmic Brunch with Thresa Kelly

2025 Year-End Special

Venus, Interstellar Visitors, and Auroras with Dr. David Grinspoon

Rings, Orbits and Space Storms with Dr. Phil Nicholson

Tiny Galaxies and Massive Black Holes with Dr. Matt Taylor

Black Holes Colliding with Dr. Charlotte Olsen

Measuring the Stars with Astrostatistician Sabrina Berger

Cosmic Raspberries and Life on Mars with Dr. Kelly Blumenthal

Chuck GPT Apocalypse, Part 2

Chuck GPT Apocalypse, Part 1

Finding Your Place in Space with Sadie Coffin