In 2012, scientists confirmed the detection of the long-sought Higgs boson, also known by its nickname the “God particle,” at the Large Hadron Collider (LHC), the most powerful particle accelerator on the planet. This particle helps give mass to all elementary particles that have mass, such as electrons and protons. Elementary particles that do not have mass, such as the photons that make up light, do not get mass from the Higgs boson. The experiments that detected the Higgs boson revealed it had a mass of 125 billion electron-volts, or more than 130 times the mass of the proton. However, this discovery led to a mystery — at that mass, the Higgs boson should have destroyed the universe just after the Big Bang. The Higgs boson is part of a theory first proposed by Higgs and others in the 1960s to explain how particles obtain mass. The theory proposes that a so-called Higgs energy field exists everywhere in the universe. As particles zoom around in this field, they interact with and attract Higgs bosons, which cluster around the particles in varying numbers. Imagine the universe like a party. Relatively unknown guests at the party can pass quickly through the room unnoticed; more popular guests will attract groups of people (the Higgs bosons) who will then slow their movement through the room. The speed of particles moving through the Higgs field works much in the same way. Certain particles will attract larger clusters of Higgs bosons — and the more Higgs bosons a particle attracts, the greater its mass will be. How does this all relate to the end of the universe? Before the Higgs boson was discovered, scientists wondered if we live in a stable universe, an unstable one, or one that’s metastable—stable for an extended time period, but not at the absolutely most stable point it could be at. Now that the Higgs boson has been discovered and the first measurements of its mass made, scientists think that we’re probably living in a metastable state. Basically, our universe seems to be comfortably tucked in a valley of energy states, but it’s still not the lowest ground around. If something pushes us up and over the side of our valley (or tunnels through the valley wall), we could fall into new and lower territory. The process of transitioning to a lower energy state is sometimes called “vacuum decay.” If it occurred at any point in the universe, the bubble of this new vacuum state would expand outward at the speed of light. We wouldn’t have any warning until we were obliterated very suddenly. But getting to this new state requires an intense amount of energy—which is one of the reasons why Katie Mack, a theoretical astrophysicist at the University of Melbourne, thinks it’s extremely unlikely that we’ll be swallowed up by a cosmic death bubble any time soon. If the universe was going to fall to that lower energy state, “it would have done that in the very early universe, which was a very energetic time; the energy from inflation would have kicked us into the other vacuum in the tiniest fraction of a second,” Mack says. The gargantuan energy levels thought to be necessary for this transition can also occur in cosmic ray collisions, Mack says, but building a particle collider that packs that kind of power is well beyond human capabilities at this time (Hawking himself notes in Starmus that such a collider would have to be larger than Earth). So discovering the Higgs boson or turning on the Large Hadron Collider makes it no more likely that vacuum decay will occur.