Whether or not water freezes has a lot of effects on the weather. When deciding whether to walk about a frozen lake the amount of days that the weather was below 0 matters. For gardering it matters whether the soil freezes.
This is a good point; using 0 as a reference point for freezing, which does have real life applications (is it going to snow? will this morning’s rain cause icy roads? etc.) is much less arbitrary than how it’s used on the Fahrenheit scale. I suppose boiling has cooking applications as well?
The granularity point is interesting; in the US, setting a building’s thermostat to 68 degrees Fahrenheit vs. 66 degrees Fahrenheit is typically considered a pretty non-arbitrary decision as far as saving money vs. gaining comfort goes. Now that I actually stop and think about it though, if you asked me to guess what temperature a building I’m currently in’s thermostat was set at, I’m not sure I’d actually be able to tell you.
In fact, I’m not sure I could even consistently guess what temperature the air around me is without being at least 5 degrees Fahrenheit off. Now that you point it out to me, less granularity probably makes life a bit simpler.
I’m reading through Strategy of Conflict right now and am really enjoying it. I hope he lived a good life.