John David Galt wrote: >defining the kilogram to equal exactly the mass of 1000 cc of >water at 4 deg C.
At what pressure? Why 4 �C instead of the triple point? The triple point is used in the definitions of kelvin (= 273.16 K) and Celsius (= 0.01 �C). To be even more picky, I would expect an SI definition to use kelvin rather than Celsius and m3 (although cm3 might be acceptable) rather than 'cc'. I would have thought that it would be better to define mass in terms of a fixed number atoms (this is effectively what volume at the triple point defines). However, these are all experimental definitions until you get to a fundamental definition of mass based on something like E = mc2 I presume that a better definition of mass is the sort of thing that entertains a lot of physicists.
