QCD vacuum

QCD vacuum is like a really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really really quiet room. Instead of people talking and making noise, it's made up of tiny little particles that are all moving very very fast and buzzing around. They don't usually bump into each other though and so it's a very quiet room - like a vacuum.