And yet, vacuum-welding is a long known actual thing, and even without vacuum right in ordinary human environment, by good, non-trivial, but not magical surface

And yet, vacuum-welding is a long known actual thing, and even without vacuum right in ordinary human environment, by good, non-trivial, but not magical surface prep. But it's probably more than just proximity. In vacuum there is probably also evaporation and a form of electrolosis.