SEA: Space Exploration & Astronomy

SEA
  • 5.0 (8)
  • ASTRONOMY
  • UPDATED WEEKLY

I make chilled-out "info-tainment" videos on all-things space related, from the moment of the Big Bang to the end of the universe itself- and everything in between. No AI, written, recorded and produced by a real human. New episodes every Sunday!

  1. The Largest Star (2021 Version)

    2D AGO

    The Largest Star (2021 Version)

    Stars come in a wide range of sizes, but how do we calculate a star's size to determine which is the largest? In this episode, we will find out how stars are measured to determine their mind-boggling sizes, and above all, which of them are the biggest of all. PLEASE NOTE: This one is an older video of mine, back in 2021 when it was thought that the largest known star was Stephenson 2-18. It has since been reassessed as most likely not a member of the Stephenson-2 Cluster, and thus not amongst the candidates for the largest star. I plan to remake this video some time in 2026. SOUNDTRACK: Two songs in this video were made by Chris Zabriskie. (http://chriszabriskie.com/) - Abandon Babylon (Album from which the songs came: https://chriszabriskie.bandcamp.com/album/abandon-babylon)Dark Fog & Ice Demon by Kevin MacLeod are both licensed under a Creative Commons Attribution 4.0 licence. Source: http://incompetech.com/music/royalty-free/index.html?isrc=USUAN1300031 , http://incompetech.com/music/royalty-free/index.html?isrc=USUAN1200061 Artist: http://incompetech.com/ All other music provided by the YouTube Audio LibraryCHAPTERS: 00:00: Introduction 01:04: What Are Stars? 05:40: How Stars Get Big 09:38: Problems with Direct Measurements 11:31: Parallax 13:01: Indirectly Measuring Stars 15:33: VY Canis Majoris 18:30: UY Scuti 22:59: Stephenson 2-18

    27 min
  2. The Great Attractor

    FEB 8

    The Great Attractor

    No matter where you are, you are always moving. The Earth orbits the sun, while the sun moves round the galaxy. But what makes the galaxy move? That is the topic of our video today. Everything in our local galaxy supercluster, Laniakea, is being dragged towards a high concentration of mass obscured by the opaque clouds of our galaxy, but what is it? It has all the ingredients for an epic cosmic mystery, the mystery of the Great Attractor. Background Songs by CO.AG Music: https://www.youtube.com/channel/UCcavSftXHgxLBWwLDm_bNvA Transcending Ambient Chill Out Music: https://www.youtube.com/watch?v=aAp5ecwlU7MThe Deep: https://www.youtube.com/watch?v=e9TJrLeqnhw All other tracks are from the YouTube Audio Library CHAPTERS: 00:00: Introduction 02:13: Galaxies 04:04: Our Local Universe 06:56: The Laniakea Supercluster 09:00: The Great Attractor 10:03: The Zone of Avoidance 11:45: History of Great Attractor Observations 13:56: Surveying the Great Attractor Region 18:39: Dark Flow 20:27: The Dipole Repeller 22:16: CIZA Search 23:37: The Shapley Supercluster 26:03: The Vela Supercluster 27:30: A Mystery Solved?

    30 min
  3. The Cosmic Scale

    FEB 1

    The Cosmic Scale

    How large is the universe? Where does it begin and end? How does it expand? These are some of the biggest questions of astronomy- and while humanity is so small that we may never be able to fully understand the universe's true scale, advancements in technology are helping us to look ever-deeper into space, towards the edge of our observable universe known as the Cosmic Horizon. Today, we will get to know our universe, its laws, and its awe-inspiring scale above all. SOUNDTRACK: Special thanks to Lombus, who allowed me to use his song Doppler Shores in the title screen: https://lombus.bandcamp.com/track/doppler-shores Songs by Chris Zabriskie are licensed under a Creative Commons Attribution 4.0 licence (https://creativecommons.org/licenses/by/4.0/ ) - The Theatrical Poster...: http://chriszabriskie.com/vendaface/ - Unfoldment, Revealment... http://chriszabriskie.com/reappear/ - Cylinder Five: http://chriszabriskie.com/cylinders/ - Take Off and Shoot a Zero: http://chriszabriskie.com/stuntisland/ - Oxygen Garden: http://chriszabriskie.com/divider/ Artist: http://chriszabriskie.com/ Other songs are from the YouTube Audio Library CHAPTERS: (00:00) Introduction (02:23) Defining the Universe (06:51) The Big Bang (09:12) The Observable Universe (10:53) The Hubble Telescope (11:46) The Hubble Deep Field (16:49) Cosmic Expansion (19:40) Redshift (21:48) The Cosmic Horizon and the Unobservable Universe (25:36) Accelerating Expansion (28:29) Dark Energy (30:14) The End of the Universe

    33 min
  4. Beyond the Observable Universe

    JAN 25

    Beyond the Observable Universe

    What we perceive to be the edge of our universe is not the actual edge of the universe, with most scientists in agreement that more space lies hidden beyond what we're able to see. Last time out, we travelled to the very edge of our observable universe. But today, we will be going even farther, as we wade out into the darkness of the unobservable universe. Soundtrack by CO.AG Music: https://www.youtube.com/@co.agmusic1823 - Taboo-Inspired Intro Track: https://youtu.be/YA3yfPh38mc - Strange Days Ahead: https://youtu.be/QaGsRzO-2EA - The Last Breath: https://youtu.be/AekcHz0ZdjU - The Monolith: https://youtu.be/XK_iQLGpId0 - ESP Background Track: https://youtu.be/rT2ONCrdtVU - Encounter: https://youtu.be/vxdlSXZvxL0 - Direct Space: https://youtu.be/G7-3crlxDDE - Do You Understand: https://youtu.be/BXmPuHqXUzc - Phonon: https://youtu.be/2Mgk6jem7Zg - Dark Enigma 13: https://youtu.be/mGFxASTdnhc - Book of the Dead: https://youtu.be/6X3RYrOy1RE CHAPTERS: (00:00) Welcome Back (01:50) Beyond the Cosmic Horizon (05:42) The Shape of the Universe (07:45) Universal Curvature (12:35) Critically Dense Flat Universe (15:18) Drawing Triangles on the CMB (18:52) The Flatness Problem (22:19) Multiply Connected Universe (27:19) 4D Hyper Torus (29:17) Curved on a Large Scale? (31:50) Cosmic Inflation (37:09) Closing Statements

    39 min
  5. Journey to the Edge of the Universe

    JAN 18

    Journey to the Edge of the Universe

    Ever wonder what it would be like to fly all the way to the edge of space? Well in this video, we'll be doing just that. Using beautiful images snapped by the Hubble and James Webb telescopes, we will embark on a tour of our universe- venturing deep into the darkness, and uncovering the most jaw-dropping landmarks along the way. This is our journey to the edge of the universe. SOUNDTRACK [In order of appearance]: - MindHunter (CO.AG): https://youtu.be/72JbdVDg3q0 - 11:11 at Smith - Ninth Street (Chris Zabriskie) - Catafalque (CO.AG): https://youtu.be/Bf_24aUbaQ4 - Satanic (CO.AG): https://youtu.be/E_gQrAMVK8U - Dark Enigma 11 (CO.AG): https://youtu.be/VVbH2gU8TvA - It Will Make You Feel Better (Chris Zabriskie) - Dark Enigma 9 (CO.AG): https://youtu.be/rkZg2FCRcjg - I Refuse to Accept There's Nothing I Can Do About it (Chris Zabriskie): - Lower Third Hall (Chris Zabriskie) - Omen (CO.AG): https://youtu.be/C_ejkBhmmJE Tracks by CO.AG Music and Chris Zabriskie. Songs by Chris Zabriskie are licensed under a Creative Commons Re-use Licence. Check out his new album, which was featured in this video: https://chriszabriskie.bandcamp.com Check out CO.AG's channel, where he uploads loads of cool ambient tracks: https://www.youtube.com/channel/UCcavSftXHgxLBWwLDm_bNvA FOOTAGE: The space scenes in this video were captured using SpaceEngine Pro, a virtual universe simulator: http://spaceengine.org/ Images of space and scientific visualisations are public domain content, and can be downloaded from NASA's GSFC Visualisation Studio: https://www.nasa.gov/goddard Other visualisations and images of space provided by the European Southern Observatory [ESO]: https://www.eso.org/public/ Graphic of the Virgo Supercluster by Ethylice4: https://www.deviantart.com/ethylice4 Stock footage sequences provided by Vecteezy.com . Pro License Holder: https://www.vecteezy.com/members/sea-media-stock CHAPTERS: (00:00) Welcome (01:32) What is the Observable Universe? (05:15) The Local Volume (10:20) Laniakea Supercluster (14:24) Sloan Great Wall (16:30) Active Galactic Nuclei (19:53) Quasars (23:00) Quasar Groups in the Deep Universe (25:55) Hercules-Corona Borealis Great Wall (28:14) Cosmic High Noon (31:44) Re-ionization (33:35) Farthest Galaxies (36:35) The Dark Age (39:19) The Edge of the Universe

    43 min
  6. The Dark Energy Mystery

    JAN 11

    The Dark Energy Mystery

    In 1998, two teams of scientists measured the universe's rate of expansion, expecting to find it slowing down on route to a collapse. But instead, they found the opposite- the universe's expansion appears to be accelerating, having expanded more in the latter half of its life. In attempting to explain this mysterious behaviour, they revived one Einstein's long-since-forgotten ideas. Thank you to SpaceWave - Cosmic Relaxation for yet another amazing soundtrack! If you liked this video's music, check it out below: Dark Energy Soundtrack: https://www.youtube.com/channel/UCj3460Ylt4JEcEiW6PxCH9Q SpaceWave's Channel: https://youtu.be/XntDsSR38qU CHAPTERS: (00:00) Introduction (02:27) Accelerating Expansion (05:09) Einstein's Greatest Blunder (08:26) How Space Expands (12:11) Redshift & Standard Candles (17:03) Type 1a Supernova Searching (19:25) Λ-CDM (22:08) Baryonic Acoustic Oscillations (26:27) Future Missions to Study Dark Energy (28:46) Vacuum Fluctuations (32:29) Quintessence (34:43) Phantom Energy (37:17) The Big Rip

    41 min
  7. The Dark Matter Mystery

    JAN 4

    The Dark Matter Mystery

    Dark Matter is a theoretical form of invisible mass, which has never been definitively detected. You've probably heard of it before, as it makes up a large part of the physics you find in textbooks. But how can something that's never been seen have so much scientific confidence behind it? Furthermore, if we can't see it, how do we know that it is really there? And if it's not, what are the alternative explanations? These are the questions we will be aiming to answer, as we delve into the Dark Matter mystery. The soundtrack was created by SpaceWave - Cosmic Relaxation.Listen to the full 2-hour Soundtrack: https://youtu.be/ZDjXSOkThzk I listen to his ambient music while I write and was keen to bring him on board. Thank you SpaceWave! Check out his Channel: https://www.youtube.com/channel/UCj3460Ylt4JEcEiW6PxCH9Q CHAPTERS: (00:00) Introduction (01:53) What is Dark Matter? (05:00) Signs of Missing Mass (08:21) Lambda-Cold Dark Matter Model (11:21) The Early Universe (14:12) Dark Matter Structures (20:22) The Bullet Cluster (24:23) Weakly Interacting Massive Particles (26:20) Search for Dark Matter (31:00) Alternative Theories (32:57) Modified Gravity (35:31) Entropic Gravity (38:06) Dark Energy?

    40 min
  8. In Search of the Largest Black Holes

    12/28/2025

    In Search of the Largest Black Holes

    Lately, there has been talk of a new largest black hole, named Phoenix A*, which is said to have a mass greater than 100 billion times the mass of the sun! This is much larger than the previous record holder, TON-618. But can we really rely on this prediction? And if not, then what is the largest black hole out there, and how do we know its true size? These are the questions we will answer in search of the universe's biggest black holes. Soundtrack: CO.AG Music: https://www.youtube.com/@co.agmusic1823 - Old Radio Transmission: https://youtu.be/1O8to3C5rM4 - Oprahme: https://youtu.be/2nliN0RbIyw - Long Relaxation Mix: https://youtu.be/8TRjdzXJ5-M - The Earth is Screaming: https://youtu.be/38P0cv_0z5M - Welcome to Somethink: https://youtu.be/R73ZWEDSiM4 - What’s Left: https://youtu.be/Qlp7DmhU1KM - The Fallen Angel: https://youtu.be/U0YL-4yDKJM - Watch My World Burn: https://youtu.be/ejMf7HtsYWw - A Deep Digital Dream: https://youtu.be/Kou0UzcFd8Q - Advanced Technology Mix: https://youtu.be/dG7J2HZYqpM - A Slow End: https://youtu.be/FVbGDg-pjNE CHAPTERS: 00:00: Start 01:50: Stellar Black Holes 05:00: Intermediate & Supermassive Black Holes 07:09: IC 1101* 09:39: TON-618 12:45: The Phoenix Cluster 15:34: Phoenix A 18:18: X-Ray Cavities & Eruptions 20:28: Phoenix A* Black Hole 22:26: Is Phoenix A* the Largest Black Hole? 25:33: Other Ultramassive Black Hole Candidates

    31 min
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About

I make chilled-out "info-tainment" videos on all-things space related, from the moment of the Big Bang to the end of the universe itself- and everything in between. No AI, written, recorded and produced by a real human. New episodes every Sunday!

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