The title suggests that the story is about length units in general, but as I was reading I concluded the story was fixed on screens. So at first I was thinking why would inch be better than cm? Then I thought okaay cones... (following some numbers) yeah..so? I don't know why 32" screen from 7feet away is 0.8 something cn and what does that 0.8 mean? What is a good cn when looking at a monitor?