Re:They should redefine a kilogram (Score 2, Insightful)

I agree, redefine...but it seems easier to redefine it by fixing Avogadro's number and then saying that the mass of one mole of C12 divided by 12 equals one gram.

Maybe to a physicist/mathematician it seems inelegant to base the definition of mass on an arbitrary number (Avogadro's) rather than on a physical constant. But are we absolutely, positively sure that physical constants are constant throughout the space-time continuum and that we've got them exactly right?