> but centering on the freezing point of water seems more useful overall
But why? Knowing the freezing point of water (at sea level, mind you) is only rarely useful to me in daily life. I think the eutectic point of salt and water (that is, the lowest point at which it's possible to cause ice on the roads to melt by adding salt to them) is marginally more useful; this happens to be about -6F or about -21 C. Perhaps it's a bit more important for farmers who need to know whether their crops will freeze overnight, but as a lifelong city/suburbs dweller who knows next to nothing about agriculture I couldn't really say. At any rate, most people are not farmers.
I'm asking this somewhat rhetorically: I don't really care about Celsius vs. Fahrenheit. The pros and cons between the two are so vastly outweighed by the utility of having a global standard that I really wish the US would switch. I'm just pointing out that I don't think that one particular physical property of one particular substance makes for a very strong argument either way.
I think water freezing without salt is much more common than freezing with it. For example knowing the freezing point of water is useful for setting your fridge/freezer temperature.
But why? Knowing the freezing point of water (at sea level, mind you) is only rarely useful to me in daily life. I think the eutectic point of salt and water (that is, the lowest point at which it's possible to cause ice on the roads to melt by adding salt to them) is marginally more useful; this happens to be about -6F or about -21 C. Perhaps it's a bit more important for farmers who need to know whether their crops will freeze overnight, but as a lifelong city/suburbs dweller who knows next to nothing about agriculture I couldn't really say. At any rate, most people are not farmers.
I'm asking this somewhat rhetorically: I don't really care about Celsius vs. Fahrenheit. The pros and cons between the two are so vastly outweighed by the utility of having a global standard that I really wish the US would switch. I'm just pointing out that I don't think that one particular physical property of one particular substance makes for a very strong argument either way.