What is "empty space" composed of?

I'm trying to sketch out what empty space is composed of and I'm drawing a blank (pun intended). http://ift.tt/yFYBbr



No, really though, I'm trying to wrap my head around just what exists in this newly-modeled seething foam we used to call "nothing." From what I understand, within the vacuum there is a continuous "boil" of quantum fluctuations whereby virtual particles pop in and out of existence in a process called "pair production." That's about all I'm fairly confident of at this point. I have scoured several Wiki pages trying to get a better picture of what is going on. Here are a few of those:



http://ift.tt/1k9rCzB

http://ift.tt/1gQsuoL

http://ift.tt/W2xKPX

http://ift.tt/RFuvVu

http://ift.tt/14ZkqYN

http://ift.tt/1nJEfmv



One main question I have that I didn't get from reviewing these is whether or not anything besides electrons-positrons are involved in the pair production/quantum fluctuation process. Most specifically, do quark and anti-quark pairs pop in and out of the vacuum. None of these articles say. The closest I could get was this statement from the pair production article:

Quote:

Pair production is the creation of an elementary particle and its antiparticle, for example an electron and its antiparticle, the positron, a muon and anti-muon, or a tau and anti-tau.

From this statement it looks as though it's just leptons? Am I wrong? What about neutrinos? They are electrically neutral leptons, do they pair produce in the vacuum?