Then move through space towards the Earth in successive orders of magnitude until you reach a tall oak tree just outside the buildings of the National High Magnetic Field Laboratory in Tallahassee, Florida. After that, begin to move from the actual size of a leaf into a microscopic world that reveals leaf cell walls, the cell nucleus, chromatin, DNA and finally, into the subatomic universe of electrons and protons.
A quark is one of two currently recognized groups of fundamental particles, which are subatomic, indivisible (at least as far as we know today) particles that represent the smallest known units of matter. Twelve fundamental particles - six quarks and six leptons (the other type) - are the basic building blocks for everything in the universe.
Thought everybody knew that.
In England though Quark is the sound that a posh duck makes.
This site has been in my bookmarks since 1998/99, along with the the old Parc geographic name-mapper, it was one of the early sites that most impressed me --and it still does. I just sent some junior college astronomy students here a week or two ago because they couldn't finish a star-map due to a long spell of inclement weather.