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On the contrary, they found, each including three small particles called quarks - a whimsical name from a passage in the Finnegan the Joyce, from theoretical physicist Murray Gell-Mann, previously speculated that their existence. The experiments confirmed quark own two varieties, which are named and less creative, rise and fall. The two constitute a proton - a quark and the quark; neutron two consecutive down quark and an action quark.           Smaller than the Smallest     In the nineteenth century scientists showed that many familiar substances such as oxygen and carbon had a smallest recognizable constituent; following in the tradition laid down by the Greeks, they called them atoms [‘uncuttable’]... By the early 1930s the collective works of J.J. Thompson, Ernest Rutherford, Niels Bohr, and James Chadwick had established the solar system-like atomic model with which most of us are familiar. Far from being the most elementary material constituent, atoms consist of a nucleus, containing protons and neutrons, that is surrounded by a swarm of orbiting electrons.   For a while many physicists thought that protons, neutrons, and electrons were the Greeks' "atoms." But in 1968 experimenters at the Stanford Linear Accelerator Center, making use of the increased capacity of technology to probe the microscopic depths of matter, found that protons and neutrons are not fundamental, either. Instead they showed that each consists of three smaller particles, called quarks — a whimsical name take from a passage in James Joyce's Finnegan's Wake by the theoretical physicist Murray Gell-Mann, who previously had surmised their existence. The experimenters confirmed that quarks themselves come in two varieties, which were named, a bit less creatively, up and down. A proton consists of two up-quarks and a down-quark; a neutron consists of two down-quarks and an up-quark.   Everything you see in the terrestrial world and the heavens above appears to be made from combinations of electrons, up-quarks, and down-quarks. No experimental evidence indicates that any of these three particles is built up from something smaller. But a great deal of evidence indicates that the universe has additional particulate ingredients. In the mid-1950s, Frederick Reines and Clyce Cowan found conclusive experimental evidence for a fourth kind of fundamental particle called a neutrino — a particle whose existence was predicted in the early 1930s by Wolfgang Pauli. Neutrinos proved very difficult to find because they are ghostly particles that only rarely interact with other matter: an average-energy neutrino can easily pass right through many trillion miles of lead without the slightest effect on its motion. This should give you significant relief, because right now as you read this, billions of neutrinos ejected into space by the sun are passing through your body and the earth as well, as part of their lonely journey through the cosmos. In the 1930s, another particle called a muon — identical to an electron except that a muon is about 200 times heavier — was discovered by physicists studying cosmic rays (showers of particles that bombard earth from outer space.)... And more was to follow.   Using ever more powerful technology, physicists have continued to slam bits of matter together with ever increasing energy, momentarily recreating conditions unseen since the big bang. In the debris they have searched for new fundamental ingredients to add to the growing list of particles. Here is what they have found: four more quarks — charm, strange, bottom, and top — and another even heavier cousin of the electron, called tau, as well as two other particles with properties similar to the neutrino (called the muon-neutrino and tau-neutrino to distinguish them from the original neutrino, now called the electron-neutrino)... Each of these particles has an antiparticle partner...         — Brian Greene, The Elegant Universe - Superstrings, Hidden Dimensions, and the Quest for the Ultimate Theory                 Indexes/10