The Standard Model
20th Century World View The Standard Model of Particle Physics is a theory about the electromagnetic, weak and strong nuclear interactions, developed throughout the mid-to-late 20th century, as a worldwide collaborative effort. Upon experimental confirmation of the existence of quarks, the theory is finalised in the mid-1970s. Ever since that time, further evidence of its validity have been provided by successive discoveries of the other predicted particles, such as the bottom quark ( 1977) , the top quark ( 1995) , the tau neutrino ( 2000) and even more recently, the Higgs boson ( 2012) to complete the whole set.