It's not so much 0 that's the problem with Centigrade for weather purposes, it's the 100. 100 F is rather warm. 100 C is DEAD.
I don't have a problem with Centigrade for other stuff, but I think Fahrenheit captures the human ambient environment range better.
Disclaimer: American, where I remember the vain national attempt at metrication as a young child and still have to convert everything mentally when visiting my Australian in-laws
But I still find the 100 a useful demarcation - especially when cooking. I find it handy to know how far away my soup or tea water is away from boiling without doing complicated maths in my head.
The equivalence to the percent scale also makes it easier to conceive - i.e. if I see my kettle on the hotplate registering 75 degrees C, I immediately think "Oh, it is three quarters of the way to boiling".
You could ask: "Three quarters" of the way from WHAT temperature to boiling?
It sounds like the grandparent is trying to measure how far through the task of boiling their water is, by interpreting degrees Celsius as percentage done.
Maybe they usually make soup or tea by boiling ice cubes. (Perhaps they're Siberian?)
Are they saying that 75 degrees mean three quarters of the way from room temperature tap water to boiling water? Or are they talking about boiling an ice cube, so it's three quarters from 0 Celsius freezing?
Interpreting degrees Celsius as a percentages is not an intuitive way of measuring time elapsed to boil tap water, because 75% between freezing and boiling doesn't mean 75% of the time required to boil has elapsed, since you're starting from room temperature when you boil tap water, not freezing.
The point I'm trying to make is that if 0-100 is a useful mental range, and people seem to be arguing that it is given boiling and freezing points, then for the range of temperatures humans can reasonably occupy the scale should be as close to that range as possible.
This is different from an intuition argument. My wife, an Australian, finds nothing intuitive about 72 F as room temperature, just as I don't find anything intuitive about 22 C. You're right I'd adapt if I had to, but no one lives anywhere for very long at 72 C.
> for the range of temperatures humans can reasonably occupy the scale should be as close to that range as possible.
Why? I don't think I'll die at 110 degrees Fahrenheit and that's off the scale. And I routinely make use of things which get hotter than I can live in. I don't live in my kettle or my oven.
Sure, but you will die at 80 C, and that isn't off the scale. So which mapping is closer?
Again, I'm making my argument about weather. Clearly for other arbitrary temperatures this doesn't apply. If you're actually arguing for a single temperature scale for cooking, weather and anything else, then I think most people will end up concluding it'll be what you're most used to working with.
But surely Americans use temperature for cooking too and not just for weather, and then 100°C is boiling which is also at least somewhat useful to know.
When cooking I have never needed to know what temperature boiling water is. The fact that it's boiling is enough. Never mind that water only boils at 100°C at sea level and most Americans don't live at sea level.
I don't have a problem with Centigrade for other stuff, but I think Fahrenheit captures the human ambient environment range better.
Disclaimer: American, where I remember the vain national attempt at metrication as a young child and still have to convert everything mentally when visiting my Australian in-laws