}{composition-setup}
{excerpt}Thought to be the building blocks of all matter, the fermionic particles currently believed to be elementary (indivisible) are quarks and leptons. {excerpt} The study of these particles requires physics beyond the scope of Newtonian mechanics. For a (popular level) introduction to the quarks and leptons, see the [Contemporary Physics Education Project's|http://www.cpepweb.org/] [Particle Adventure website|http://particleadventure.org] or [poster of the fundamental particles and interactions|http://www.cpepweb.org/cpep_sm_large.html].
|