The LIUniverse with Dr. Charles Liu

Space Telescopes with Dr. Alexandra Greenbaum

Are we living in a golden age of space telescopes? As our minds are being collectively blown by the images of our universe beginning to come from the JWST, our host Dr. Charles Liu and co-host Allen Liu explore the next space telescope on the horizon, the Nancy Grace Roman Space Telescope, with our guest, astronomer Dr. Alexandra Greenbaum, PhD.
 
Dr. Greenbaum is an astronomer at Caltech working on the NGRST, which is set to launch in 2027. Named after Nancy Roman, who created NASA's space astronomy program and is known to many as the “Mother of Hubble,” it’s a NASA observatory designed to unravel the secrets of dark energy and dark matter, search for and image exoplanets, and explore many topics in infrared astrophysics.
 
As always, though, we jump into the day’s joyfully cool cosmic thing, the incredible first picture of Sagittarius A Star, (Sgr A*), the supermassive black hole at the center of our Milky Way galaxy taken by the Event Horizon Telescope. Dr. Greenbaum explains that the EHT uses signals from many telescopes around the world to gather the data that is combined into images like this stunning photo.
 
Alexandra works at IPAC, the Infrared Processing and Analysis Center at Caltech, on the Roman Telescope’s coronagraph instrument, which is going to pave the way for future space photography of exoplanets. The coronagraph eliminates the glare that stars produce and allows astronomers to directly image planets in orbit around them. It will be far more powerful than any other coronagraph ever flown, seeing planets that are almost a billion times fainter than their host star.
 
Our first question this week comes from Isaac, who asks how the JWST differs from the Hubble. Dr. Greenbaum explains how the JWST’s mirror is made of 18 different mirror segments, whereas Hubble has a single mirror. Also, JWST is an infrared telescope, while Hubble functions primarily with the optical and ultraviolet portions of the spectrum. That means that JWST can see the light from stars stretching back to the earliest periods of our universe.
 
Chuck and Alex also discuss how the NGRST differs from Hubble and the JWST. It primarily features a wide-field instrument that can look at a huge portion of the sky with different kinds of detectors. The coronagraph instrument is actually a technology demonstration that will help us develop the optical systems to see planets that are otherwise obscured by the overpowering light of the sun they orbit. Dr. Greenbaum also worked on the JWST, and she explains how each one worked to remove solar interference from planets or brown dwarfs orbiting stars.
 
For our second question, Jayla from North Andover wants to know what’s most exciting about Alexandra’s job as an astronomer. She describes traveling to telescopes all around the world as an observational astronomer before the pandemic, and how wonderfully open and collaborative the field of astronomy is. 
 
Last but not least, Chuck, Alexandra, and Allen talk about what she’s just read: “Parable of the Sower” by Octavia E. Butler, and how that book helped strengthen her commitment to her career studying the universe.
 
If you’d like to know more about Dr. Greenbaum’s work and keep up on the developments with the Nancy Grace Roman Space Telescope, you can check out roman.ipac.caltech.edu.
 
We hope you enjoy this episode of The LIUniverse, and, if you do, please support us on Patreon. 

Adventures in Science with Geoff Notkin, Dr. Andrew Maynard and Dr. Cady Coleman.

Can your passions for science, science fiction, space, fossils and even opera lead you to a life of adventure and maybe a career in science? 
 
To find out, Dr. Charles Liu and co-host Allen Liu welcome returning guest Geoff Notkin, The Meteorite Man, and the co-hosts of the “Mission: Interplanetary” podcast, physicist/futurist Dr. Andrew Maynard and chemist/astronaut Dr. Cady Coleman. 
 
All three of our guests have had interesting journeys and adventures in their careers. They’re here to discuss how the circuitous paths scientists often take in our lives, in an episode that connects, as Cady so perfectly sums up, pieces of the universe falling to earth, science fiction, real space stations, future space stations, physics, astrophysics and shopping!
 
Chuck starts off the episode talking about… The thrill of the hunt. Geoff describes how he fell in love with exploration and adventure, and spent half his childhood hunting for fossils on the “Jurassic Coast” of Dorset, UK and the other half in the museum looking at meteorites. 
 
Although she’s most famous as an astronaut who flew on two space shuttle missions and was a member of Expedition 27 to the ISS, Cady tells us about her 2 1/2-month long expedition to Antarctica looking for meteorites. You’ll hear how the sheer number of meteorites that have been found there has transformed the study of meteorites. She also shares how living in tents and moving around the Antarctic environment relate to training for space travel. Find out the geologic reason why we’re more likely to find meteorites in Antarctica than anywhere else, and the challenges posed to that search by runny noses, moraines, and apple cores.
 
Next, Charles and Andrew discuss his surprising path, from teenage opera singer (something his co-host Cady discovers for the first time along with the rest of us!) to physicist to futurist, with sojourns in risk analysis, the early days of nanotechnology, synthetic biology, artificial intelligence, and of course, science communication. 
 
Naturally, with this crew, we’d get around to talking about risk and asteroids. We start off with the Chelyabinsk meteor, which airburst over a heavily populated area in Siberia, Russia in 2013 where about a million people live. Andrew explains that calculating the probability of a large meteor hitting Earth isn’t very straightforward, while his co-host Cady talks about how we’re working to have better measurements and more understanding about asteroids and meteors.
 
And then we get to “show and tell.” Geoff shares his favorite find, an elephant’s head-shaped iron meteorite he dug up at one of the 15 Henbury meteor craters from a single event in Australia 4600 years ago. Andrew shows off his set of the original CDs for “The Hitchhiker’s Guide to the Galaxy” radio series by Douglas Adams, after which Cady describes the poster for Expedition 42 to the ISS with its obvious connection. (If you don’t know why the number 42 is important… READ THE BOOKS! They’re sci-fi classics.) Cady shares the stuffed penguin she brought back from her trip to Antarctica that has actually been to the South Pole. (Believe it or not, there’s more than one gift shop in Antarctica!) And finally, Charles shares something that co-host Allen Liu actually got for him from Allen’s trip to Antarctica – to see what, though, you’re going to have to watch the episode.
 
If you’d like to know more about Geoff, check out his YouTube channel, https://www.youtube.com/channel/UCAcGREEGQbQV3x-CnOXcXTg. And you can find out more about Andrew and Cady and the Mission Interplanetary podcast here: https://missioninterplanetary.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:– A glacial moraine in Antarctica – Warren B. Hamilton /USGS, Public Domain– Meteor exploding over Chelyabinsk, Russia – Aleksandr Ivanov, CC-BY 3.0– The largest of the Henbury Craters – Michael Bemmerl, CC-BY 3.0 de– ISS Expedition 42 poster – NASA Space Flight Awareness, Public Domain

Nuclear Fusion with Christina Migliore

NOTE: This episode was recorded in early 2022, before the invasion of Ukraine by Russia and their attack on the Chernobyl nuclear facility, which we discuss.
 
What’s up with nuclear fusion? Dr. Charles Liu dives into the heated subject with the help of MIT Nuclear Physicist Christina Migliore and co-host Allen Liu. 
 
We start with today’s joyfully cool cosmic thing: the JET, or Joint European Torus. JET is a “giant metal donut” in the UK engaged in plasma physics and nuclear fusion. You’ll learn about magnetic containment devices known as “tokamaks,” the most common form of experimental devices with which to create nuclear fusion. Find out about plasma, the fourth state of matter, and how difficult it is to work with. 
 
Speaking of hot balls of plasma, aka stars, Caroline from the Pingree School asks, “What is fusion and why does it occur in stars?” Find out about different forms of fusion, their sources, and their outputs. Learn about the strongest laser in the world, the National Ignition Facility (NIF) at Lawrence Livermore Labs, which is on the cutting edge of generating energy from fusion.
 
Josh, another student at the Pingree School, wants to know how nuclear fusion would be affected by strong gravitational forces. We explore why stars can use strong gravity to sustain their fusion, but we can’t do that here on Earth…yet.  
 
We also delve into the two “hottest” topics in the field of nuclear fusion research. First, Christina tells us about the engineering aspect of building high magnetic field devices, including high temperature superconductors. Next, Christina explains her work studying wall interactions with plasma to minimize the creation of hotspots that generate impurities. (Geek Warning: Chuck and Christina nerd out a bit a wavelengths, energy outputs, rectification, cold plasma, boundary conditions, Maxwell’s Equations, and more!)
 
Pseudoscience rears its ugly head when Chuck and Christina dive into the concept of cold fusion, made famous by Iron Man’s ARC Reactor in the MCU. Before the episode ends, we unpack the difference between nuclear fusion and nuclear fission, the value of each when pursued responsibly, and issues surrounding history, safety and aging infrastructure. And we touch on Chernobyl, the design flaws that led to the situation, and the bureaucratic concerns that pushed it over the edge. Finally, you’ll hear how MIT is developing a new device called SPARC that will create a very strong magnetic field that could eventually let us put fusion generators on the energy grid.
 
Credits for Images Used in this Episode:
 
- Interior of the JET tokamak (2) – Credit: EUROfusion
- National Ignition Facility (NIF) preamplifiers – Credit: Damien Jemison/LLNL
- Interior of the Alcator C-Mod tokamak at MIT – Credit: Bob Mumgaard/Plasma Science and Fusion Center
- The Sun – Credit: NASA/SDO/AIA
- Chernobyl Unit 4 reactor after April 26, 1986. Credit: International Atomic Energy Association (via Creative Commons BY-SA 2.0)
- MIT SPARC – Credit: CAD rendering by T. Henderson, CFS/MIT-PSFC

Black Holes, Galaxies, and The Expanse with Jimmy Negus

Welcome to the first ever episode of the LIUniverse, your happy half hour dose of cosmic conversation and geeky banter with host Dr. Charles Liu! In this episode, we talk quasars, “The Expanse”, and more with our guest Jimmy Negus, PhD candidate at the University of Colorado Boulder, and with our co-host Allen Liu. The trio discuss Jimmy’s research on active galactic nuclei (AGNs), including some that might not even be in a galaxy’s nucleus at all, plus some sci-fi stories that have them hooked, and some in which the science really misses the mark.
You’ll discover how something “only” the size of the orbit of Mercury could outshine an entire galaxy, learn how the highest note on the piano can help examine the atmosphere, and find out how a telescope survey with a tortured acronym is bringing a new dimension to astronomical research. You can also explore how Jimmy helps students understand the truly impressive size of our neighborhood in space – even in his new 10-billion-to-1 scale model.
We also answer questions from students and from our patrons, and we have some great ones to kick us off. Ben asks, what’s the difference between a black hole, an AGN and a quasar? Sadie asks, why choose astronomy over other fields of science? Plus, our patron Walter wonders, is there anything in the universe that doesn’t spin or vibrate?
We’re so glad to finally be able to share the LIUniverse podcast with all of you, and we hope you continue to geek out with us for many episodes to come! If you like the episode, please support The LIUniverse on Patreon.
Credits for Images Used in this Episode:
- B20258+35’s host galaxy, NGC 1167 – Credit: Sloan Digital Sky Survey- Quasar (Artist’s rendering) – Credit: ESO/M. Kornmesser- The Mice, a pair of merging galaxies – Credit: Hubble ACS- The Sun from the Colorado scale model solar system – Credit: Jimmy Negus- The Sloan telescope at Apache Point Observatory – Credit: Sloan Digital Sky Survey- Fiber optics for integral field spectroscopy – Credit: Sloan Digital Sky Survey- Dyson Sphere (Artist’s rendering) – Credit: Kevin Gill- Laser guide star at the Very Large Telescope – Credit: G. Hüdepohl/ESO