AaS! 20: How Much Light Is in the Universe?

How much light is in the universe? What's a "photon"? What's the brightest thing out there? 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 Watch on YouTube: http://www.youtube.com/PaulMSutter Read a book: https://www.pmsutter.com/books Keep those questions about space, science, astronomy, astrophysics, and cosmology coming to #AskASpaceman on Twitter@PaulMattSutter and Facebook/PaulMattSutter for COMPLETE KNOWLEDGE OF TIME AND SPACE! Music by Jason Grady and Nick Bain.