Imagine a wave of destruction crossing the cosmos at exactly the speed of light, so that the light carrying news of the catastrophe arrives at the same instant you cease to exist. That is the scenario of false vacuum decay, and this episode explains why it is grounded in quantum field theory rather than science fiction. We start by redefining nothing: in quantum field theory a vacuum is simply the lowest energy state of the fields that make up reality, and a false vacuum is a metastable resting place, like a boulder stuck in a valley halfway down a mountain, that could one day tunnel through to the true bottom.

We look at how measurements of the top quark and the Higgs boson at the Large Hadron Collider, including a 2022 re-analysis placing the top quark near 171.77 GeV and the Higgs around 125 GeV, put our universe in the metastable zone,  ...