"The equation is therefore writing a relationship for one component (a spatial component) of the 4-momentum. IMO, it is a scalar equation and not susceptible to criticism on dimensional grounds. (see the textbook for other assumptions)"
Stating "scalar equation" goes over bounds"; I believe it would have been better to write
"The equation is therefore writing a relationship for one component (a spatial component) of the 4-momentum. IMO, it is therefore not susceptible to criticism on dimensional grounds; in the sense of equating a 4-vector to a 3-vector. (see the textbook for other assumptions)"
_________________________
Joel Rauber, Ph.D
Professor and Head of Physics
Department of Physics
South Dakota State University
Brookings, SD 57007
Joel.Rauber@sdstate.edu<mailto:Joel.Rauber@sdstate.edu>
605.688.5428 (w)
605.688.5878 (fax)