<story><title>Uno – the “unit” for dimensionless quantities</title><url>https://en.wikipedia.org/wiki/Parts-per_notation#Uno</url></story><parent_chain></parent_chain><comment><author>Synaesthesia</author><text>Interesting idea. We generally just say &amp;quot;unit&amp;quot; if necessary.&lt;p&gt;&amp;gt;In 2004, a report to the International Committee for Weights and Measures (CIPM) stated that response to the proposal of the uno &amp;quot;had been almost entirely negative&amp;quot;, and the principal proponent &amp;quot;recommended dropping the idea&amp;quot;.[15] To date, the uno has not been adopted by any standards organization, and it appears unlikely that it will ever become an officially sanctioned way to express low-value (high-ratio) dimensionless quantities. The proposal was instructive, however, as to the perceived shortcomings of the current options for denoting dimensionless quantities.</text></comment>
<story><title>Uno – the “unit” for dimensionless quantities</title><url>https://en.wikipedia.org/wiki/Parts-per_notation#Uno</url></story><parent_chain></parent_chain><comment><author>6gvONxR4sf7o</author><text>I&amp;#x27;ve often felt it to be helpful to treat dimensionless quantities as a smell that the dimensions might be too unspecific. 12 meters &amp;#x2F; 3 meters is just a unitless 4, but 12 meters east &amp;#x2F; 3 meters north is a much more interesting 4 units-east-per-unit-north. Keeping track of these invariant &amp;quot;hidden units&amp;quot; was sometimes helpful to me in physics classes, especially in later classes where nondimensionalizing your equations was so handy.</text></comment>