This rejection of the very possibility of nothingness is captured in the famous medieval dictum ex nihilo nihil fit (nothing comes from nothing), used among other things to prove the existence of God, since the universe, it was thought, could not have sprung from nothing all on its own (never mind where God came from). You probably won't find it surprising that it would be David Hume who would first challenge this notion when he declared that, logically speaking at least, anything could come from anything :)
But the problem isn't merely a logical one: it's also empirical. Since at least the time of Aristotle, attempts to create a vacuum consistently failed for almost two thousand years; that is, until Evangelista Torricelli serendipitously managed to create one when he invented the barometer and proved that we live at the bottom of an invisible ocean of air.
With the creation of a vacuum, and as Professor Jim Al-Khalili shows in this fascinating documentary, scientists have slowly come to understand not only the nature of vacuums and nothingness but that the entire universe may owe its existence, literally, to nothingness... There will be some quantum weirdness here, but of the real kind...
Couldn't those fluctuations be due to something as mundane as neutrinos flying through the tanks?