>OTOH, the only way to get people to use metric is to enforce it. So what to do? Well, you need parallel, dual measurements for a period so people can adjust - which we are now doing on package-labeling etc., and liquids are often only-metric in measures already. So progress is occurring...

I didn't know that, and I am happy to hear that steps are underway to change to metric.

I did see that science books - all the way from elementary to university - have a greater emphasis on SI than on the English system.

>Some of it is the cost-problem, too. For example, we have 47 gazillion signs, maps, etc, all in miles, which is expensive to alter, especially in hard econimic times here. That will be a real challenge, physically and economically, never mind what people think about metric. But we'll get there someday.

Apart from the cost, lets not forget the potential of confusions between the two systems, which may even cause accidents: Let's say the speed limit is 100 km/h, and the car driver goes at 100 mph instead (without looking at his modern instruments; using his sense of speed instead). Or an airplane pilot confusing feet with meters.

This doesn't mean the transition shouldn't be done, of course, but it is a point to consider.