File talk:SI Units definition dependencies.svg

@Norm6669: This diagram is somewhat misleading in that different arrows have different meanings. In particular, the metre is not dependent on the second in the same was as the hertz or the becquerrel is dependent on the second: the metre requires that the speed of light (an independent quantity) be measured before the metre itself can be defined whereas the hertz and the bequerrel do not require any other independent quantities to be identified and measured as a pre-requisite to their definitions. The same applies to other base units. You might like to look at the U.S. Metric Association posters for ideas. Martinvl (talk) 15:10, 14 September 2015 (UTC)