Incedentally, i don’t know if anyone else has mentioned this story yet but do you know why Farenheit pegged the freezing point of water to an arbitary value of 32F rather than 0F?
The story is (and i freely admit this may be apocryphal) is that Farenheit had a thing against negative numbers. Whether his Prussian soul revolted against such untidiness or he just had an irrational prejudice isn’t clear but he refused to use them.So he pegging the value of waters freezing point to 32. He could then take his measurements throughout the winter, when it was obviously sometimes got colder than that , without having to resort to using negative numbers.
From what I’ve heard, yes, that story is a pack o’ full. I googled, and came up with a version of the story that I heard: he set zero to be the lowest temperature he could attain in his laboratory, a certain combination of water, ice, and salts.
But he may have done it to avoid negative numbers.
He pegged 100 as body temperature. Then later it was discovered that his measurement of average body temperature was somewhat off.
According to the link I gave earlier, he pegged body temperature at 96 degrees. They were a little less hot-blooded then, ya know.
HA!!! You are so WRONG!
0°F is the exact outdoor temperature at which your snot will freeze upon inspiration through the nose.
Hate to resurrect an old thread, but I was wondering about this centigrade Celsius thing this morning & found this one.
The question I have now though, and I hope it’s not too OT, is the triple point of water being absolutely defined. Is it really?
I remember from ground school that way up in the atmosphere you can find absolutely pure water that won’t crystalize until the temperature is well below what most of us would consider water’s freezing point. Pilots need to be aware of this as it causes icing when the water contacts the wings which initializes crystalization. Is this basically correct?
So is the triple point of water based on absolutely pure water, or water with contaminants around which it can crystalize at about 0° C?
Triple point:
That point on a pressure-temperature diagram which is the common meeting point of the liquid-vapour, solid-vapour, and solid-liquid lines for a given substance. The triple point thus represents the presure-temperature conditions, unique for a given substance, at which it may be solid, liquid or gas.
The triple point of water has the co-ordinates p (pressure) = 6.11 mb and T (temperature) = +0.01 deg C
I believe you are referring to freezing rain which is super cooled. Its temperature is a little below 0c but it stays as a liquid until it contacts something which helps it release some latent heat or something. it is a concern when flying because it forms a smooth layer of ice on the aircraft that may be harder to detect visually and harder for the de-icing equipment to dislodge. It’s not necessarily “way up” in the atmosphere. You would normally find it a little above the local freezing level. This is the altitude where the outside air temperature is 0c, in cold places it may be sea level, in hot places it may be as high as 16000-20000’.
Supercooled water droplets can stay in liquid form down to -40 deg C (although ice accretion has been reported at temps as low as -60 deg C).
The rate at which ice forms on the aircraft is also determined by the type of cloud being flown through, and the droplet size, as well as the ambient air temperature.
The risk of airframe icing is actually higher in temperatures of 0 to -12 deg C.
Ok thanks for the info.
Sorry for this late post.
Celsius is a temperature scale. Centigrade was an attempt to measure geometry degrees not temperature degrees. Confusion happened and this mistake was carried over for many (200+?) years.
When metric was being developed, someone thought it would be a good idea to metricize geometric angles. A right angle was defined as a “grade” – a centigrade was therefore 1/100th of a grade. This method didn’t catch on but the other metric measurements did (litres, metres, Celsius, grams)
Officially, metre etc is spelled “re” as a unit but the measuring device ( a meter stick) is spelled “er”. This is true all over the world, except of course, in the U.S. who tweeked the SI (universal) metric system to their liking. Curiously there there appears to be an SI Metric System and a US Metric System.
Someone, somewhere, sometime confused a centigrade degree with a celsius one and the rest is history. Some folks were taught (mistakenly) about the bogus centigrade temperature scale.
eg 50* Centigrade SHOULD be 50/100 of a grade OR 50/100 of a right angle OR 50/100 of 90 degrees (angle) – OR 45 degrees angle measurement !! But nobody uses Centigrade in the way it was intended. 
The Celsius Rap
30 is hot
20 is nice
10 is chilly
0 is ice
The Fahrenheit Rap
86 is hot
68 is nice
50 is chilly
32 is ice
Well, maybe not, but “gradians” has taken over that usage, so the unit still exists under a different name.
There was some reason they couldn’t name it the Caesar scale? Or maybe the Charlemagne scale?
More importantly, what scale is used to measure the temperature of a zombie?