Comment another explanation (Score 1) 134
Brooks Moses has some additional explanation which I found helpful: http://notes.dpdx.net/2006/10/06/penny-smiths-proo f-on-the-navier-stokes-equations/
You can tune a piano, but you can't tuna fish. You can tune a filesystem, but you can't tuna fish. -- from the tunefs(8) man page
