I've tried in the past to explain how awesome the sqrt(2) ratio used as the basis of DIN/ISO page sizes is, but there are some very dumb people on HN: https://news.ycombinator.com/item?id=7821947
Correct me if I'm wrong, but the point of the guy you were arguing with in that thread was that the Ax standard was defined in terms of SI units as the US imperial units are?
If you read the parent (by somebody else, not Turing_Machine), it said that the ISO/DIN page sizes are part of the metric system. I corrected him saying that they were only based on it (in that the sizes were defined in terms of metric units) and not part of it, but that what really mattered was the ratio between the long and short edges of the sheets being √2.
Then Turing_Machine came in with this total non sequitur:
> How are factors of 2 and sqrt(2) "based on metric"?
And then things went completely off the rails.
Edit: s/same/came/