According to QFT. The quantum vacuum is a particular state of quantum fields; it's not a "place" where quantum fields "exist in.
No problem with that. But does the word "vacuum" without the quantum word before it has the same meaning? I'm asking because in other usages like written in the Scientific American May 2014 edition:
"The Higgs may hold other clues. The discovery of the Higgs boson shows that there is a Higgs energy field turned on everywhere in the universe that gives mass to elementary particles. This means that the vacuum of “empty” space is a busy place, with both Higgs energy and virtual particles producing complicated dynamics. One might then wonder if the vacuum is really stable or if some unlucky quantum event could one day trigger a catastrophic transition from our universe to a clean slate."
Here they describe "vacuum" as a place...
in QFT.. we know quantum vacuum is a state, and not a place.
Is it because the article is a popularization or does "vacuum" has realy another meaning from "quantum vacuum"? What do you think?