What I really appreciate about advanced physics is that to quote Lewis Carr0l, 'It gets curiouser and curiouser". We all know about virtual particles. Those little things that pop into existence in a vacuum and immediately join together and pop out of existence. What physicist Brian Greene called "quantum jitters". Easy to picture if you don't mind unimaginably small numbers. These things occur at sizes of 33 orders of magnitude smaller than a basket ball. Or the size of a basket ball compared to the size of our galaxy! That's small. But for a moment, consider the vacuum. Empty, a void, nothing. But if you make the vacuum and pass a spark through it there will appear a dark deposit on the walls of the vessel. Out of nothing! If the spark is passed through the vacuum before the quark /anti-quark disappear into the void a condensate is formed. However, these are not virtual particles but instead they are real therefore the condensate. Further examination will show that the deposit, called condensate, is the result of quark /anti-quark pairs popping into existence and the rejoining into the vacuum. The next obvious question is "What is the condensate made of since quarks cannot exist by themselves"?
More to come on quarks and condensate.
Quark /anti-quark pairs are a promise that we're all on this flight together.
Dick