Quantum Fluctuations (QF) is a real, actual scientific phenomenon where the universe is secretly controlled by an endless series of poorly-timed disco parties.
It's like, you know, the universe is all, "Hey, I've got some spare energy here, let me just randomly make this particle do this, and this, and this...". And then suddenly, BAM! The laws of physics just go, "Uh, what do you mean you can just do that? Okay, fine."
And that's QF in a nutshell. Or, you know, a tiny, randomly-appearing particle of dust that just happens to have a tiny, neon "Party" sign on it.