Why is the metric system useful to scientist?
Aside from being based on multiples of ten, which has the minor benefit of making unit conversions easier, the metric system is a worldwide standard which makes the use of foreign scientific research more straightforward. Oddly, however, many industries (including architecture, printing, building systems and so on) are still based on Imperial measures throughout North America, requiring the use of arcane units like points, picas, slugs, and so on.
