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.

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#LIUniverse #CharlesLiu #AllenLiu #SciencePodcast #AstronomyPodcast #MattTaylor #UltraCompactDwarfGalaxy #UDC #SupermassiveBlackHole #BlackHole #AccretionDisk #M60UCD1 #ArchetypalCompactEllipticalGalaxy #UltraCompactGalaxy

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.

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#liuniverse #charlesliu #allenliu #sciencepodcast #astronomypodcast #charlotteolsen #blackholes #ligo #gravitationalwave #blackholecollisions #activegalacticnuclei #agns #milkyway #spiralgalaxies #barredgalaxies

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.

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#liuniverse #charlesliu #allenliu #sciencepodcast #astronomypodcast #sabrinaberger #astrostatistician #astrostatistics #redshift #blackholes #primordialblackholes #callisto #alma #planet9 #sedna #universeexpansion #isspresso

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 [email protected].

You can follow Kelly on LinkedIn. 

We hope you enjoy the Season 5 premiere of The LIUniverse. Please support us on Patreon.

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#liuniverse #sciencepodcast #astronomypodcast #kellyblumenthal #lifeonmars #bacteria #jellyfishgalaxy #pluto #interstellarasteroid #comet3iatlas #iau #officeforastronomyoutreach #startrek #theoriginalseries #thenextgeneration #theexpanse

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

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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.

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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.

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#liuniverse #charlesliu #allenliu #sciencepodcast #astronomypodcast #sadiecoffin #redshiftwranglers #citizenscience #zooniverse #galaxyzoo #spectra #dopplereffect #redshift #galaxyevolution #tylernordgren #jeyhankartaltepe

If a black hole shreds a star and nobody is around to hear it, does it make a sound? To find out, Dr. Charles Liu and co-host Allen Liu welcome Professor Yvette Cendes, (aka u/Andromeda321 on Reddit), a Radio Astronomer studying transient radio signals from space.

As always, though, we start off with the day’s joyfully cool cosmic thing, a report by the Dark Energy Survey that seems to show that the amount of dark energy originally described as the cosmological constant by Albert Einstein might in fact be variable. As Prof. Cendes explains, the data indicates that universal expansion is still accelerating but the rate might be changing.

After Yvette explains what she does, and how radio astronomy works in concert with optical astronomy to deliver a more complete understanding, Chuck asks her to explain Tidal Disruption Events, or TDEs, about which she’s a world expert. A TDE is when a star wanders too close to a supermassive black hole and ends up getting shredded. Yvette prefers to call them “Shredders.”

Our first audience question comes from Nachama, who asks, “When will the black hole in the Milky Way eat the Sun?” The good news, according to Yvette, is that will never happen. As she explains, black holes actually don’t suck any more than anything that massive would, and we’re 25-30,000 light years away from Sagittarius A* – too far away to worry about.

Next, Chuck asks Yvette about one of the most famous transient signals we’ve ever found, the so called “Wow!” signal detected in 1977 by Jerry Ehman at the now-defunct Xavier Observatory in Ohio. Because the signal looked exactly like what might be expected if it were of extraterrestrial origin, Ehman circled it on the printout and wrote, “Wow!” Unfortunately, it never repeated. The most likely explanation, according to Dr. Cendes, is that it was some sort of manmade interference, although the signal is currently being reinvestigated.

Yvette recounts how she ended up ended up as a first-term professor at the University of Oregon after studying in the Netherlands and Toronto and working at Harvard. Then she answers an audience question from Yan Min, who asks, “Where is the best place in the world to study astronomy? I live in New York – Is it New York?” Unfortunately for Yankees fans, Yvette says it would most likely be Cambridge, Massachusetts thanks to Harvard, which has the biggest number of astronomers under one roof and operates the Chandra X-Ray Observatory, and M.I.T. on the other side of town if you get bored.

Chuck asks Yvette what happens after a black hole shreds a star. Shredders, she explains, are rare. In our own Milky Way, they probably happen once every million years. Once a TDE is classified by optical astronomers, Yvette and her team point their radio telescopes at the tidal radius outside of the event horizon to discern the outflows weeks, months and even years after the initial event.

He also asks Yvette if she has any hobbies to help her decompress from thinking about violent events in the universe. She likes to cross stitch, the “original pixel art.” Yvette shows us a cross stitch she made of the James Webb Space Telescope complex mirror, another featuring an 8-bit Mario screen with the words “What doesn’t kill me makes me smaller,” and a third with objects in the Solar System. She also embroiders and shows us a hoop featuring the constellations visible in the northern hemisphere night sky.

We end with Yvette and Allen schooling Chuck about Reddit’s immense reach and value in scientific discourse. One subreddit, called r/Space, has “27 million intelligent lifeforms” subscribed to it. On Reddit, Yvette’s username is u/Andromeda321, and she’s one of the top users on the platform over 1 million karma points. She’s known for starting her posts that explain or comment on recent discoveries with the phrase, “Astronomer here!”

If you’d like to follow Dr. Yvette Cendes, you can find her on Reddit, where she’s u/Andromeda321, and her dedicated subreddit, reddit.com/r/Andromeda321. You can also follow her on Bluesky @whereisyvette.bsky.social.

Links to the astronomy cross stitch kits shown in the episode:

We hope you enjoy this episode of The LIUniverse, and, if you do, please support us on Patreon.

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#liuniverse #charlesliu #allenliu #sciencepodcast #astronomypodcast #yvettecendes #andromeda321 #astronomerhere #radioastronomer #transientradiosignals #darkenergysurvey #cosmologicalconstant #universalacceleration #wow!signal #6equj5 #tde #tidaldisruptionevents #supermassiveblackhole #shredders #sagittariusa #milkyway #crossstitch

Why is it so difficult to study the evolution of early galaxies? Are metallic D&D dice better than plastic ones? And can you have too many Pokémon tattoos? To find out, Dr. Charles Liu and co-host Allen Liu welcome Justin Cole, who is currently a grad student at Texas A&M studying the evolution of distant galaxies in pursuit of his PhD in Astronomy and Astrophysics.

As always, though, we start off with the day’s joyfully cool cosmic thing – the recent – and remarkable – discovery of four planets orbiting Barnard’s Star, a tiny star not much bigger than Jupiter with the highest measured proper motion of any star in our sky. Chuck and Justin discuss why the discovery of new exoplanets is so challenging, which leads to Justin explaining what he’s studying: galaxies in our universe that developed less than 1.5 billion years after the Big Bang – about 2.5 billion years before the birth of our own Milky Way Galaxy.

We’ve got a handle on what’s going on with our neighbors like the Andromeda Galaxy, but when it comes to early galaxies, we have a very limited range of wavelengths and scant data to study. This makes it harder to derive understandings of galactic evolution and whether they support or conflict with the standard model of physics.

Our first audience question comes from Ricardo, who asks, “What if we discover extraterrestrial plant life and find out it’s intelligent? Actually, what if we discover plants on Earth are intelligent? Would it be unethical to eat them?” After Chuck shares a little about Marvel’s intelligent, telepathic species of plants called the Cotati, and imitates Audrey 2 from Little Shop of Horrors, Justin weighs in on the ethics of eating intelligent plants and asks a critical question: Would we understand them enough to know? What would happen if we bit into a head of alien lettuce and it started screaming? The ensuing discussion is… tasty, albeit a little unsettling.

Our next question is from Thomasina, who asks, “I read that the Big Bang theory is in trouble – what does that mean? And did the Big Bang never happen?” Justin, who is an early universe guy, clarifies what’s going on here. We occasionally find galaxies that seem to be too big for the amount of time that they’ve had to grow. We’re also finding black holes that with our current instruments, also appear to be too big. In each case, we’re finding better ways to simulate these situations, and it’s not that they’re too big, or that the Big Bang isn’t supportable, it’s that we’re using tools that are calibrated to “nearby and today” that aren’t as good at helping us assess early galaxies.

Next up, Justin, who is getting ready to run a Dungeons & Dragons 5th Edition roleplaying session after the podcast recording, talks about using D&D Beyond to create his own campaigns (set in the World of Warcraft universe!). Chuck and Justin discuss the benefits of rolling metal dice, and Justin shows off a couple of his beautiful D20. Not to be outdone, Allen shares his 120-sided die, the largest die allowed by three dimensional Euclidean geometry in conventional space. Meanwhile, Chuck tells us the sad story of his old, worn plastic dice. As Allen points out, Chuck was in the hobby before it was cool! And as we run out of time, Justin shares his intention to get one Pokémon tattoo for every state he and his wife visit.

If you’d like to know more about what Justin’s up to, he suggests you Google “Justin Cole Astronomy” or “Justin Cole A&M.”

We hope you enjoy this episode of The LIUniverse, and, if you do, please support us on Patreon.

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#TheLIUniverse #CharlesLiu #AllenLiu #SciencePodcast #AstronomyPodcast #JustinCole #Astronomy #Astrophysics #BarnardsStar #GalacticEvolution #BigBang #StandardModelofPhysics #ExtraterrestrialPlantLife #IntelligentLife #D&D #Pokemon #Tattoos

What’s it like to stand at the edge of human knowledge, where we don’t know what leap forward in understanding the next technological innovation will herald? To find out, Dr. Charles Liu and co-host Allen Liu welcome Dr. Melodie Kao, resident radio astronomer at the Lowell Observatory in Flagstaff, AZ, where Clyde Tombaugh discovered Pluto back in 1930. (And if you’re scratching your heads saying, “What’s a radio astronomer doing at an optical observatory?” you’re not alone. Short answer: Melodie convinced them they wanted one, and that it should be her!”)

As always, though, we start off with the day’s joyfully cool cosmic thing, the amazing discovery by the NEID Spectrograph at the WIYN telescope at Kitt Peak Observatory of a planet 9 times the mass of Earth orbiting a sun-like star 49 light years away with an orbital period of just 31 days. Melodie explains the precision of the measurement required to discover a planet at that distance, and shares one of her own recent discoveries using a technique called very-long-baseline interferometry (VLBI). In a groundbreaking effort she strung together 39 radio dishes across the northern hemisphere of Earth in a multi-observatory effort to create an Earth-sized telescope (similar to the technique that was used to create the first image of a black hole) and pointed it at a brown dwarf and measured its magnetic fields and radiation belts (like our Van Allen belts). For comparison, the effort was like measuring a pea perched on the Golden Gate Bridge in San Francisco while standing on the Statue of Liberty in NYC.

The trio discusses the importance of the discovery of the Van Allen belts, and how that allowed us to plot trajectories that avoided the worst of that radiation for Apollo astronauts on their journeys to the Moon.

For our first audience question, Ari from North Greene High School in Tennessee asks, “What is the percentage of possible exoplanets that are similar to the earth’s atmosphere, placed in their solar system (within a similar area of their respective Goldilocks zone), gravity, etc.? And how long would it take to hypothetically get to them?”

That turns out to be a very complicated question, and Melodie knows someone who has devoted her entire career to answering it. It’s one of the questions that drove the creation of the James Webb Space Telescope and is the basis of the Drake Equation. The bottom line, though, is that we don’t know yet, and until we find a rocky planet with an Earthlike atmosphere orbiting a sun-like star outside of our solar system, it will remain unanswerable.

Next, Charles asks Melodie how she became an astronomer, especially since she’d always planned on being an architect. She even went to MIT to become one, but she missed studying physics, which she realized she truly loved. MIT had just finished constructing their Center for Theoretical Physics, and Melodie shares the story of how she convinced MIT to bend the rules and let switch her major to Physics while continuing to study architecture. When she attended a lecture by a grad student about galaxy clusters, and learned how you could back out the formation history of a cluster of galaxies by looking at the gradients of colors generated by starlight, she realized astronomy was a way to unlock the secrets of the universe.

Our next question comes from Alex at North Greene: What are the conditions necessary for life in the universe? It’s a question without an easy answer, but the conversation it spawns is worth your time to listen to. It leads Melodie to talk about her love of exploring the natural world and how she co-created a Wilderness Astronomy class. She’s also a guide for off-trail, high route backpacking trips where you don’t know what’s coming next and you need to rely on your instincts, curiosity and bravery as you explore the world, and the universe, around you.

If you’d like to know more about what Melodie is up to, she’s not on social media but you can check out her website. You’ve also got an invitation to visit her at the Lowell Observatory for a personal tour!

We hope you enjoy this episode of The LIUniverse, and, if you do, please support us on Patreon.

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