» This is an article about a collider. For uses of spear, see spear or spear (disambiguation). SPEAR (originally Stanford Positron Electron Asymmetric Ring, now simply a name) is a collider at the Stanford Linear Accelerator Center. It began running in 1972, colliding electrons and positrons with an energy of 3 GeV. During the 1970s, experiments at the accelerator played a key role in particle physics research, including the discovery of the particle and other charmonium states and the discover… (More on Spear)