In defense of the Pascal


  • Robert H. Bushnell


S. A. Morse (EOS Trans. AGU, 60, April 10, 1979) would rather fight than switch, but the rest of us tend to be more rational. We prefer the pascal to the bar. The pascal is coherent with all the rest of the SI units, while the bar is not. His defense of the bar fails because it does not (and cannot) show this fundamental Quality. He is wrong when he says ‘no such purpose is achieved by the choice of pascal over bars within the SI,’ referring to simplicity. Pascal is simpler than bar because it is defined the way all Sl derived units are defined, that is, with no multiplying constant.