::Ain't my job, bub. Constants for first-order terms are the engineers problem. And they're just going to make up some fudge factors instead of using the theoretical value anyway. Physicsts are a laid-back crowd, man. Off by a factor of c squared and can't find where it went? Here, take mine. Switched an h with an h-bar someewhere? Don't worry about it dude, what's a pi or two beetween friends?