the smallest things
Scientists and even non-scientists know things today that the great physicists of a century ago couldn't have imagined. For example, physicists in those days believed that the smallest things in the universe,the foundation of all matter,were atoms,a word derived from a Greek word meaning "uncuttable." Nowadays,however,we are simply not sure what the smallest particle in the universe is.
Atoms are made of particles called protons,
neutrons,and electrons. Protons and neutrons (the "hadrons"that give the collider its name) are made of even smaller particles named Quarks and gluons,which have been detected in collider experiments;experimental proof for the existence of quarks came in 1968 and for gluons in 1979.
To date,57 particles have been found,challenging theoretical physicists to come up with a description of reality that incluludes them all.
American physicist Michael Peskin believes that the LHC will be great help in finding even more particles. "It might turn out tobe like the 1950s,when we were dicovering many new particles and had no clue about how they fit into a coherent picture." He adds,"I hope it will turn out like that. this is what makes science fun."
By creating hundreds of thousands of head on particle collisions each second,physicists hope to reproduce the universe near the time of its theoretical beginning, the so-called Big Bang, a massive explosion,resulted in our universe. Among questions scientists hope to learn more about is the riddle of dark matter,the invisible material thought to make up perhaps 80 percent of the universe.Scientists are also optimistic that experiments in the LHC will reveal an intriguing particle called the higgs boson,which theory predicts exists but whose existence has never been confirmed in an experiment.The Higgs is thought to be responsible for giving all matter its mass.