The Consensus View on Vacuum Decay

In the framework of classical physics, there is only such a thing as the vacuum. If you are stuck in this state that has zero energy and there's no other way like this to minimize the energy then anywhere you go from there, the energy of your state increases. Now that is something that is no longer true in the context of quantum mechanics. And that is where this idea of sort of like tunneling and vacuum decay first makes an appearance.