Science Friday

When it comes to the eventual end of our universe, cosmologists have a few classic theories: the Big Crunch, where the universe reverses its expansion and contracts again, setting the stars themselves on fire in the process. Or the Big Rip, where the universe expands forever—but in a fundamentally unstable way that tears matter itself apart. Or it might be heat death, in which matter and energy become equally distributed in a cold, eventless soup.These theories have continued to evolve as we gain new understandings from particle accelerators and astronomical observations. As our understanding of fundamental physics advances, new ideas about the ending are joining the list. Take vacuum decay, a theory that’s been around since the 1970s, but which gained new support when CERN confirmed detection of the Higgs Boson particle. The nice thing about vacuum decay, writes cosmologist Dr. Katie Mack in her book The End of Everything: (Astrophysically Speaking), is that it could happen at any time, and would be almost i