In quatum vacuum fluctuations it's been said that particles will come in and out of existence, correct? But you can state that particles pop in and out of existence all you like, but they aren't really coming from 'nothing' at all. The 'Vacuum' isn't a real 'nothingness' and quantum vaccum fluctuations involve the conversion of pre-existing energy into material form, it isn't a creation ex nihilo. There has to be an existing space-time background for these fluctuations to occur. Am I correct?