[stephencanon]

0 is uncomfortably cold. 100 is uncomfortably hot. The temperatures that non-STEM people (“humans”) deal with on a day-to-day basis can be represented with satisfactory precision using two digits (OK, three in Australia), no negative numbers, no decimals. It’s a great system for casual temperatures.

Whereas “reasonable” temperatures in C run from what, -18ish to 38ish? Where’s the sense in that?

If you want to defend a unit of temperature, defend Kelvin. Don’t pretend that ˚C is significantly more reasonable than ˚F. They’re both bonkers in their own way (mysticism about the vitality of water is not a real justification).

If (more likely) you just want to make fun of Americans for being rubes, use distances or weights or volumes as your example.

[bcj]

There are a lot of humans that live places where we regularly see negative temperatures. Where I live the temperature range is roughly -40–85ºF.

Choosing the freezing point of water isn't really mystic. It lets you know whether it will rain or snow. It also means that any negative temperature is capable of causing frostbite.

[mpyne]

> It lets you know whether it will rain or snow.

Not really, since it depends upon temperature at the clouds, not at the ground level. Oh, and it also depends on atmosphere pressure, and on time (since a phase change requires latent heat transfer in addition to merely being at the right temperature).

And as baddox mentions, 32 is hardly harder to memorize than 0, especially if you know anything at all about computers.

[baddox]

> Choosing the freezing point of water isn't really mystic. It lets you know whether it will rain or snow.

Fahrenheit also has a chosen freezing point of water: 32 degrees. This is no more difficult to remember than Celsius' zero degree freezing point.

[scott_karana]

"Uncomfortably cold" is quite an understatement, when talking about allegedly "human" temperatures.

Sure, at 100, healthy humans can survive as long as their increased water needs are met. (Sun is another matter, but I'm just talking temperature.)

However, at 0F, permanent tissue damage onset is within 30 minutes, with almost any wind speed. (http://www.nws.noaa.gov/os/windchill/images/windchillchart3....)

[stephencanon]

Humans have developed clothing, which allows us to stay alive in cold weather. There’s very little we can do (short of going into a building with AC) to survive hot weather — 100 is tolerable (just), but heat gets deadly very quickly when you go above it. You don’t want to be outdoors for extended stretches in either condition (the analogy is imperfect; realistically my experience of 10F is subjectively similar to 100F, and 0F is more like 110F).

[scott_karana]

How does that change the fact that 0F is more than "uncomfortably cold" for most people?

I'm not disputing the 0F to 100F (or -18C to 40C) range in terms of being "regularly seen".

EDIT: I suppose the core of the misunderstanding is that I was addressing the "human centric" advantage and relation to brine, where you were just arguing (quite reasonably) the convenient representation of the range?

[stephencanon]

It doesn’t, but I’m being slightly approximate. Keep in mind that perception of (and physical effects of) temperature is hugely nonlinear. 0F is more dangerous than 100F, but when you go outside of that range, heat becomes far more deadly very quickly. I shovel my driveway in -20F, but I would never consider doing that sort of outdoor labor at 120F. Many people live in regions where -40F occurs from time to time, but if its 140F, you will die (actually, I think the highest recorded surface temperature is 13xF).

To your edit: yes, I think that’s the real thing. I certainly don’t think the brine thing is reasonable, just that 0-100F is a nice range.

[scott_karana]

I agree that the smaller degrees, and lack of fractions, is more convenient for casual usage.

However, I'd argue that being water-based is hardly mystical: if water is boiling, or frozen, survival is more difficult. It's also a pragmatic system for any nation that regularly drops below freezing. (Eg, could it snow today? Could there be ice to slide on?)

[saraid216]

> (mysticism about the vitality of water is not a real justification)

Water was also used in the original definition of a gram, which is a fairly good reason to reuse it in another definition.