Letters: April 2018

With redefinitions of certain key units like the mole (Chemistry World March 2018, p5) and the kilogram in the offing, isn’t it perhaps also an appropriate moment to take another look at the very word ‘kilogram’ and find a suitable alternative for it?

One of the key features of the SI system is that ‘there is one and one only SI unit for each physical quantity’. Logically, in sympathy with this definition, the kilogram should ideally have been renamed at the same time. Today we are left with an unsatisfactory fudge: decimal multiples of the kilogram are to be referred as though the gram were the base unit. For examples, 10^-3 kg is not 1mkg but 1g; and 10^-6 kg is not 1µkg but 1mg, and so on.

Presumably this matter was not sorted out in the first place because of competing voices wanting to somehow retain the historically important word gram. The kilogram as used as a base unit is, however, surely a hiccup from the manner in which scientific history has developed so far. Do we really want to be stuck with it for ever?

The SI system is the best one yet devised, but would surely be better still if this issue could be resolved, with any objections considered carefully. Surely, all we need is a suitable alternative word for kilogram. I suggest the ‘Gaul’ (G). It would be a suitable recognition to the French for their historic contribution to their careful custodianship of the metallic kilogram, and it would finally see off the gram whilst remaining comfortingly close to it.