Ask A Spaceman Ep. 244: What’s the Most Important Wavelength in All Astronomy?

What is 21-cm radiation? What (and who) produces it? What causes it, and what does it tell us about the universe? I discuss these questions and more in today’s Ask a Spaceman!   Support the show: http://www.patreon.com/pmsutter All episodes: http://www.AskASpaceman.com Follow on X: https://x.com/PaulMattSutter Read a book: http://www.pmsutter/book   Keep those questions about space, science, astronomy, astrophysics, physics, and cosmology coming to #AskASpaceman for COMPLETE KNOWLEDGE OF TIME AND SPACE!   Big thanks to my top Patreon supporters this month: Justin G, Chris L, Alberto M, Duncan M, Corey D, Michael P, Naila, Sam R, John S, Joshua, Scott M, Rob H, Scott M, Louis M, John W, Alexis, Gilbert M, Rob W, Jessica M, Jules R, Jim L, David S, Scott R, Heather, Mike S, Pete H, Steve S, wahtwahtbird, Lisa R, Couzy, Kevin B, Michael B, Aileen G, Toho Warrior, Steven W, Brian O, Mark R, Alan B, Craig B, Mark F, Richard K, Stace J, Stephen J, Joe R, David P, Robert B, Sean M, Tracy F, Sarah K, Ella F, Thomas K, James C, Syamkumar M, Homer V, Mark D, Bruce A, Bill E, Tim Z, Linda C, The Tired Jedi, Gary K, David W, dhr18, Lode D, Bob C, Red B, Stephen A, James R, Robert O, Lynn D, Allen E, Michael S, Reinaldo A, Sheryl, David W, Sue T, Josephine K, Chris, Michael S, Erlend A, James D, Larry D, Matt K, Charles, Karl W, Den K, George B, Tom B, Edward K, Catherine B, John M, Craig M, and Scott K!   Hosted by Dr. Paul M. Sutter.   We've added a new way to donate to 365 Days of Astronomy to support editing, hosting, and production costs.  Just visit: https://www.patreon.com/365DaysOfAstronomy and donate as much as you can! Share the podcast with your friends and send the Patreon link to them too!  Every bit helps! Thank you! ------------------------------------ Do go visit http://www.redbubble.com/people/CosmoQuestX/shop for cool Astronomy Cast and CosmoQuest t-shirts, coffee mugs and other awesomeness! http://cosmoquest.org/Donate This show is made possible through your donations.  Thank you! (Haven't donated? It's not too late! Just click!) ------------------------------------ The 365 Days of Astronomy Podcast is produced by the Planetary Science Institute. http://www.psi.edu Visit us on the web at 365DaysOfAstronomy.org or email us at [email protected].