The LIUniverse with Dr. Charles Liu Podcast By theliuniverse cover art

The LIUniverse with Dr. Charles Liu

The LIUniverse with Dr. Charles Liu

By: theliuniverse
Listen for free

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.Copyright 2022 All rights reserved. Astronomy Astronomy & Space Science Science Science Fiction
Episodes
  • Supernovas and Space Gold with Dr. Ashley Villar

    Supernovas and Space Gold with Dr. Ashley Villar
    Mar 21 2026
    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 81Previous 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 4.0Nazca line “The Condor”. – Credit: Photo by Roger CanalsBlue butterfly wings in an electron microscope. – Credit: Radislav A. Potyrailo et al.Aragonite plates in a shell. – Credit: Fabian HeinemannSN 1987A (Bright central “star”). – Credit: European Southern ObservatoryArtist’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
    Show more Show less
    40 mins
  • Building Worlds with Luke Skywatcher

    Building Worlds with Luke Skywatcher
    Mar 8 2026
    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
    Show more Show less
    44 mins
  • Chuck GPT: Astrotech

    Chuck GPT: Astrotech
    Feb 8 2026
    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 AgencyMap showing locations of ESA tracking (Estrack) stations as of 2017. Credit: European Space AgencyVideo of Perseverance landing on Mars. Credit: NASA/JPL-CaltechIngenuity on the surface of Mars. Credit: NASA/JPL-CaltechAnatomy of the Mars helicopter Ingenuity. Credit: NASA/JPL-CaltechIngenuity’s Test Chamber. Credit: NASA/JPL-CaltechIngenuity in the Test Chamber. Credit: NASA/JPL-CaltechVideo of Ingenuity altimeter data and the first flight as seen from Perseverance. Credit: NASA/JPL-CaltechDragonfly space probe concept art. Credit: NASA/Johns Hopkins-APLTitan’s thick methane atmosphere gives it a fuzzy yellow look. Credit: NASA/JPL-Caltech/Space Science InstituteTuned Mass Damper used to stabilize buildings during earthquakes. Credit: CCJosephson Junction. Credit: Public DomainJosephson 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 #...
    Show more Show less
    55 mins
No reviews yet