Does the Universe Have an Edge? What Scientists Actually Know

Does the universe have an edge, or does it go on forever? Here's what scientists actually know. Does the universe have an edge like a wall at the end of space? We follow the oldest light in the cosmos to find the real answer. In this video: the observable universe vs the whole universe, why the oldest light is 13.8 billion years old but its source is now about 46 billion light-years away, the cosmic microwave background, why the Big Bang was not an explosion and has no centre (raisin-bread and balloon analogies), how galaxies beyond the Hubble radius recede faster than light without breaking any law of physics, how NASA's WMAP and ESA's Planck measured space to be flat, and whether the universe is infinite or finite but wrapped around like a 3-torus. Open questions, labelled in the video: nobody knows yet whether the whole universe is infinite or finite; what dark energy is; and what, if anything, came before the Big Bang (bounce and many-universe ideas are hypotheses). Inflation is the leading idea for the first split second and is still being tested. CHAPTERS 0:00 Intro 0:34 The Universe We Can See 1:51 The Oldest Light 2:57 No Explosion, No Centre 4:21 Faster Than Light? 5:29 Is Space Flat? 6:38 Infinite or Wrapped Around? 7:54 Before the Big Bang? 8:43 3 Facts to Share 9:15 What's Next? 3 FACTS TO SHARE AT DINNER TONIGHT 1. The edge of the observable universe is about 46 billion light-years away, because space kept stretching while the light travelled. 2. The Big Bang wasn't an explosion into space. Space itself has been expanding everywhere, so there's no centre. 3. Space looks flat, but nobody knows yet if the universe is infinite, or finite and wrapped around. Which cosmic mystery should we dig into next: black holes, dark energy, or the hunt for other Earths? Tell us in the comments! Subscribe to Earth & Beyond for more journeys across our planet and beyond, and share this video with your family and friends. Follow us: Instagram   / earthandbeyond.shorts   | Facebook https://www.facebook.com/profile.php?... SOURCES Data: NASA WMAP mission pages, NASA Science, NASA Hubble, ESA Planck, Davis & Lineweaver (2004) Images: @NASA, @NASAWebbTelescope, @EuropeanSpaceAgency (Hubble and Webb are NASA/ESA partnerships; Webb also with CSA) IMAGE CREDITS (public domain, via Wikimedia Commons) Cosmic Cliffs in the Carina Nebula (Webb): NASA, ESA, CSA, STScI (Webb) (Public domain (via Wikimedia Commons)) Pillars of Creation (Webb NIRCam): NASA, ESA, CSA, STScI; J. DePasquale, A. Koekemoer, A. Pagan (STScI) (Public domain (via Wikimedia Commons)) The Blue Marble (Apollo 17): NASA / Apollo 17 crew (Public domain (via Wikimedia Commons)) Webb's First Deep Field (SMACS 0723): NASA, ESA, CSA, STScI (Webb's First Deep Field) (Public domain (via Wikimedia Commons)) Hubble Ultra Deep Field: NASA, ESA (Hubble Ultra Deep Field) (Public domain (via Wikimedia Commons)) Westerlund 2 (Hubble 25th anniversary): NASA, ESA, Hubble Heritage Team (STScI/AURA), A. Nota (ESA/STScI), Westerlund 2 Science Team (Public domain (via Wikimedia Commons)) Cosmic microwave background, WMAP 9-year map: NASA / WMAP Science Team (Public domain (via Wikimedia Commons)) Stephan's Quintet (Webb): NASA, ESA, CSA, STScI (Webb) (Public domain (via Wikimedia Commons)) Hubble eXtreme Deep Field: NASA, ESA, G. Illingworth, D. Magee, P. Oesch (UCSC), R. Bouwens (Leiden) (Public domain (via Wikimedia Commons)) Southern Ring Nebula (Webb): NASA, ESA, CSA, STScI (Webb) (Public domain (via Wikimedia Commons)) Dark clouds of the Carina Nebula (Hubble): NASA, ESA, N. Smith (UC Berkeley), Hubble Heritage Team (STScI/AURA) (Public domain (via Wikimedia Commons)) Mystic Mountain (Hubble): NASA, ESA, M. Livio, Hubble 20th Anniversary Team (STScI) (Public domain (via Wikimedia Commons)) Rho Ophiuchi (Webb NIRCam): NASA, ESA, CSA, STScI, K. Pontoppidan (STScI) (Public domain (via Wikimedia Commons)) Orion Bar (Webb NIRCam and MIRI): NASA, ESA, CSA, PDRs4All ERS Team (Webb) (Public domain (via Wikimedia Commons)) Diagrams and animations: made for Earth & Beyond (schematic, not to scale unless stated). Music: original, made for Earth & Beyond. Narration: AI-generated voice (Microsoft Edge text-to-speech, en-GB-RyanNeural). #universe #space #cosmology #science #astronomy