Every Way the Universe Could End (and Which One We're Getting)

The universe might be ending right now. Probably not. But it could. 🌌 Here's every way scientists think everything could end, from the slow Big Freeze to the violent Big Rip, the comeback Big Crunch and the instant Vacuum Decay, and which ending the newest data points to. Spoiler: you might want a sweater. Doug plays everyone: Einstein, Lemaître, the 1998 supernova astronomers, Hawking, the Super-Kamiokande team, Robert Caldwell, DESI, CERN and a very lonely astronomer from the far future. 0:00 The universe might be ending right now 0:59 Can a universe even end? 3:10 The mystery push (dark energy) 5:17 Ending #1: The Big Freeze 8:16 The Big Freeze, part 2: The long dark 11:57 How long is forever? 13:13 Ending #2: The Big Rip 14:57 Ending #3: The Big Crunch 17:15 Ending #4: Vacuum decay 19:56 The scoreboard 20:58 So... should we worry? Sources: Riess et al. 1998 (AJ 116, 1009) and Perlmutter et al. 1999 (ApJ 517, 565): the universe's expansion is speeding up (Nobel Prize in Physics 2011) Adams & Laughlin 1997, "A dying universe" (Rev. Mod. Phys. 69, 337): the far future of stars, black holes and heat death Sawada et al. 2025 (Nature Astronomy): Milky Way and Andromeda, about a 50/50 chance of merging in the next 10 billion years Super-Kamiokande Collaboration: proton lifetime limits above 10^34 years Hawking 1974 (Nature 248, 30): black hole radiation Falcke, Wondrak & van Suijlekom 2025 (JCAP): dead stars evaporating in about 10^78 years Caldwell, Kamionkowski & Weinberg 2003 (PRL 91, 071301): phantom energy and the Big Rip DESI Collaboration 2025, Data Release 2 results: hints that dark energy is weakening Luu, Qiu & Tye 2025, "The lifespan of our universe": a crunch model with the universe ending at about 33 billion years old Andreassen, Frost & Schwartz 2018 (PRD 97, 056006): vacuum decay lifetime about 10^139 years ESA Euclid and the NSF-DOE Vera C. Rubin Observatory: the next big galaxy surveys Doug Explains: the universe, explained (you're welcome). #space #universe #science