" Tests and predictions The Standard Model predicted the existence of W and Z bosons, the gluon, the top quark and the charm quark before these particles had been observed. Their predicted properties were experimentally confirmed with good precision . The Large Electron-Positron collider at CERN tested various predictions about the decay of Z bosons, and found them confirmed. To get an idea of the success of the Standard Model a comparison between the measured and the predicted values of some quantities are shown in the following table: Quality Measured (GeV) SM prediction (GeV) Mass of W boson 80,4120±0,0420 80,3900±0,0180 Mass of Z boson 91,1874±0,0021 91,1874±0,0021 Challenges to the Standard Model Although the Standard Model has had great success in explaining experimental results, it has never been accepted as a complete theory of fundamental physics. This is because it has two important defects: The model contains 19 free parameters, such as particle masses, which must be determined experimentally (plus another 10 for neutrino masses). These parameters cannot be independently calculated. The model does not describe the gravitational interaction. Model Airplane Building Since the completion of the Standard Model, many efforts have been made to address these problems. One attempt to address the first defect is known as grand unification. "

"Handlexikon zur Wissenschaftstheorie; Deutscher Taschenbuch Verlag; 1989; pp. 219 - 222. [2] Wieringa, R. J. ; "Algebraic foundations for dynamic conceptual models"; PhD dissertation Free University of Amsterdam; 17 May 1990. [3] Kaschek, R. ; "Modeling ontology use for information systems"; In: Althoff, K. Jet Engine For Model Airplane-D. & Dengel, A. "