The LIUniverse with Dr. Charles Liu

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.

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

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

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

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