Thus, by expressing quantum mechanics in phase space ( the same ambit as for classical mechanics ), the relativistic mechanics, with deformation parameter " v " / " c "; or the deformation of Newtonian gravity into General Relativity, with deformation parameter Schwarzschild radius / characteristic-dimension .)
32.
Since does not change from frame to frame, the energy momentum relation is used in relativistic mechanics and particle physics calculations, as energy and momentum are given in a particle's rest frame ( that is, and as an observer moving with the particle would conclude to be ) and measured in the lab frame ( i . e . and as determined by particle physicists in a lab, and not moving with the particles ).
33.
The idea that a theory ( in our previous example, Newtonian mechanics ) that is close to being true ( i . e ., that is verisimil ) converges as a limiting case into a superior theory ( in this example, relativistic mechanics ) can be an argument for scientific realism, as the theoretical entities postulated by the previous theories are still considered existent ( if one assumes semantic realism, they are considered existent because they are referred to ) in the successor theories.
34.
Thus, by expressing quantum mechanics in phase space ( the same ambit as for classical mechanics ), the above Weyl map facilitates recognition of quantum mechanics as a deformation ( generalization, cf . correspondence principle ) of classical mechanics, with deformation parameter . ( Other familiar deformations in physics involve the deformation of classical Newtonian into relativistic mechanics, with deformation parameter " v / c "; or the deformation of Newtonian gravity into General Relativity, with deformation parameter Schwarzschild-radius / characteristic-dimension.
