NerdGuy Fridays: Dispatches from a Writer's Brain - M. L. Buchman

NerdGuy Friday #40: it's all about the heat

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So, the next Miranda Chase novel, Gryphon, came back from the proofreader a couple days ago. And she made one tiny edit that got me thinking, and that's the subject of today's Nerd-out.

The edit was to correct Ccentigrade (lower case rather than upper). That tiny change launched me down the rabbit hole. And now I'll share it with you because it's kind of cool.


This has always been such a strange measurement. In 1724 Daniel Gabriel Fahrenheit decided to create a scale for temperature. For 0°F he chose the freezing point of a briny solution not too dissimilar from seawater: water, ice, and ammonium chloride (a salt). For 90° he chose the estimated temperature of the human body, later corrected to 96°F (nope, not up to 98.6°F yet, maybe we were colder back then [grin]).

That gave us a freezing point of pure water at 32°F and a boiling point of 212°F, offering 180° divisions between the two. Is it any wonder that almost the entire world has discarded this silly measurement system?


Swedish astronomer Anders Celsius came along in 1742 and developed the far more sensible centigrade scale. Centi=100, so it's the 100-gradiant scale from 100°C freezing of pure water to 0°C for boiling point at sea level. (Yes, that's how it began.)

A curious fact is that while most of the world called it centigrade, Sweden very sensibly named it (as Fahrenheit's scale was) for the inventor, the Celsius scale. Amusing historical tidbit, the next year Jean-Pierre Christin, a French physicist among other talents, inverted the scale to range from 0°C freezing to 100°C boiling. He also built the Thermometer of Lyon using mercury in a tube to accurately measure the temperatures between these two points.


As a further side note here, an English chap eventually named Lord Kelvin stumbled into the fray in 1848. In theoretical physics there is a point called Absolute Zero at which everything is so cold that all motion stops. It is the limitless, energy-less, heat-death of the far future of the universe kind of cold, one still not created in the most intense lab experiments (most of outer space hovers around 2.7°K).

However, that point is calculated to be -273.16°C. This becomes awkward in discussions of such phenomena. Therefore, he created what is still known as the Kelvin scale by adding 273.16°C to the centigrade scale. The universe stops moving at 0°K, water turns to a liquid at 273.16°K, and boils at 373.16°K. Just sayin'.

And the Kelvin Scale does not stand alone. The Rankine Scale adds 459.67° to the Fahrenheit Scale to adjust 0°R to match Absolute Zero. If you want to explore some others, including Newton's scale of 33° from freezing to boiling, start HERE.

Special Note: Kim B. was kind enough to remind me that "2.7°K" above was incorrect. The proper form is "2.7 K "or "2.7 Kelvin." Why? Kelvin is an absolute unit of measure from the 0 K point of absolute zero. Curiously, the debate on Rankine (though also based on absolute zero) continues, with most siding that "0°R" remains the correct format.


More and more of the world has shifted away from the English system by this process (should be metrification, but no one asked for my opinion) in favor of metric or SI (International Standard of Units). So much so that of all the world, only the US remains officially using English units. Even the US military has converted.

Yet, because of our world leadership, (I'm trying to be kind) airplane flight levels the world over are still referred to in 1,000s of feet, FL37 is a Flight Level at thirty-seven thousand feet. Though this is slowly changing to metric as well and the metrication (metrification) of that is an issue that gives me the flight-safety shivers just thinking about it.


Anyway, back to our point. In 1948, along comes the International Committee for Weights and Measures. It is noted that centigrade is an inappropriate term. Why? Because there's a unit in metric called a gradian. It's equal to 1/100th of a right angle, so a circle equals 400 gradians. Certainly an improvement over 360 degrees. A centigradian is therefore not someone who studies metrified (see, the wants to be there) temperature, but is rather a right-angle turn. Worse, a gradian had multiple names, depending on the language, including: gon, grad, and (most awkward of all) grade.

Hence, a centigrade is both a right angle and a degree of temperature.
This was rectified by renaming the Centigrade Scale to the Celsius Scale and renaming the degrees to match. So, since the formal adoption of the change in 1954, anyone referring to centigrade is referring to gradiants of an angle—they only think that they're talking about temperature.

Sweden, being sneaky, ducked through clean, because they've been calling it Celsius after their homegrown boy for 281 years already.

In Gryphon and future books, you'll find Celsius, not centigrade...unless I'm talking about angles.

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