Even the field when it's at rest / appears to be at a ground state, it will still be made up of these packets. At the smallest level, these are what is commonly referred to in mainstream physics as 'vacuum fluctuations'.
When you add up the amount of vacuum fluctuations that you find in a cubic centimeter of space, you get 1093 grams.
If you "naively" try to construct a quantum theory of gravity by quantizing the gravitational field like it was any other field, you inevitably get energy contributions from vacuum fluctuations that add up to a truly insane number, that's zillions of times greater than the mass-energy content of the observable universe in even a tiny volume of space. It's one of the motivations for various more out-there type theories that have been developed as attempts to marry quantum mechanics and gravity, such as string theory, M-theory and, more recently, loop quantum gravity.No idea what a lot of this means but it was a nice read.
Where does this come from?