Editing 2292: Thermometer

{{comic
| number    = 2292
| date      = April 10, 2020
| title     = Thermometer
| image     = thermometer.png
| titletext = I hate how many times you have to press it to get to the system normal people use, degrees Rømer.
}}

==Explanation==
This comic is the 17th comic in a row (not counting the [[2288: Collector's Edition|April Fools' comic]]) in a [[:Category:COVID-19|series of comics]] related to the {{w|COVID-19 pandemic}}.

This comic expresses frustration at the multitude of {{w|temperature}} scales. [[Randall]], as a former engineer, has strong opinions about units, as unit conversion is often a gripe for many engineers. (In a special preface in the UK edition of Randall's book ''What If'', he mentions that one does not appreciate the metric system unless they have had to go through a bunch of scientific papers using really unusual units like "kilocubic feet per second" or "acre-feet".) As elevated body temperature is a symptom of COVID-19, the comic is thus also concerning the virus.

[[Cueball]] is holding what appears to be a medical thermometer, implying that he's trying to check his {{w|Human body temperature|body temperature}}. He mentions that the thermometer is in Celsius, and asks how to change it.  Many thermometers sold in the United States have settings for both Fahrenheit and Celsius, with an option to change between the two. Americans are almost always more familiar with body temperatures in Fahrenheit, so Cueball presumably expects to change to that scale. However, he finds that the thermometer provides measurements in a series of scales that are increasingly unhelpful. Human body temperature in Celsius is 37 °C.

*Degrees {{w|Celsius}} are used in most of the world. The Celsius scale sets 0 degrees to water's freezing point and 100 degrees to water's boiling point. Few Americans have a clear idea of what normal and elevated ranges of human body temperature are in Celsius.
*{{w|Kelvin}} is a unit often used in scientific fields. It is calibrated on the same scale as degrees Celsius, but 0 K is set at {{w|absolute zero}} or -273.15 °C. This is used in scientific or engineering contexts requiring a thermodynamically absolute temperature, such as {{w|Charles's law}}, but almost never in a medical context, making the report of little use.
*The {{w|Rankine scale}} is another absolute scale, with its zero set at absolute zero, but degrees identical to degrees Fahrenheit. While this scale is still occasionally used in some industrial and scientific settings (being more convenient for absolute temperatures in a system including Fahrenheit), it's essentially never used in medicine, and most people have never heard of it.
*Thermodynamically, temperature is the average translational {{w|kinetic energy}} of a group of particles. ''Translational'' kinetic energy means it doesn’t include rotational and vibrational kinetic energy. The relation between a gas’s translational kinetic energy E and its temperature T is
::<math>E=\frac32 k_B T,</math>
:where k<sub>B</sub> is the {{w|Boltzmann constant}}, 1.380649×10<sup>−23</sup> J⋅K<sup>-1</sup>. So if this thermometer told you a translational kinetic energy measurement in joules, you could get the measured temperature in the Kelvin scale by dividing by the Boltzmann constant and multiplying by 2/3. Somebody who actually wanted to use this measure of temperature might then find it useful to have Boltzmann's constant printed on the thermometer.

Using these last three units for home temperature gauging would be ridiculous, as Kelvin and Rankine measurements of body temperature are unfamiliar to the average user and even those familiar with them would need to do calculations to translate normal body temperature.  Kinetic energy is obscure enough that only physicists, engineers and thermodynamicists, a relative handful of the potential buyers, would likely know what it refers to. Those that do could make use of the value printed on the thermometer, but such would add a great deal of unnecessary complexity to what should be a simple and intuitive task. 

In the last frame Cueball calls the thermometer the worst. It seems to lack {{w|Fahrenheit}} entirely, frustrating its American consumer base, including Cueball. From a nerd's perspective this would be an extraordinary device, offering even exotic temperature scales. However, a "normal person" would find this thermometer terribly difficult to use for everyday purposes when set on any of the non-Celsius scales, like checking their body temperature or the temperature of food. As an item of consumer electronics, especially one sold in the United States, it would be almost completely useless. 

Deliberately lacking Fahrenheit is a jab against the {{w|Imperial system of units}}, and against the similar but distinct system of {{w|United States customary units}}. Although Imperial units and local traditional units are still used for various limited purposes (and/or by older generations) in different countries, most of the world has switched to using the metric system for most purposes going forward, with the US being relatively unusual in the extent to which it still routinely defaults to the US customary units in daily life.  Many proponents of the metric system have long pushed for the US to change over, arguing that Imperial and US customary units (and degrees Fahrenheit, specifically) are archaic and obsolete. [[Randall]] has dealt with this conflict in [[1643|other strips]]; as a physics major, he's partial to the metric system, and finds it frustrating to maintain multiple different scales (which is the basis of the conflict in this strip). On the other hand, he recognizes certain intuitive advantages to Imperial and US customary measurements, and recognizes that the forces of social inertia in US society make change difficult. 

The title text references an archaic temperature unit, {{w|Rømer scale|Rømer}}, first proposed in 1701. It is the common ancestor of both the Celsius and Fahrenheit scales, defining the freezing point of water as 7.5 degrees and the boiling point of water as 60 degrees. Unlike the other measurements mentioned in this strip, the Rømer scale is no longer used in any context, and only people interested in the history of temperature scales have any idea that it even exists. This is the ultimate form of obscure and outdated temperature measurements.

In [[1643: Degrees]], Cueball struggles with which temperature unit to use, and ultimately tells his friend the temperature in {{w|radian}}s, which is not a valid temperature scale. In [[1923: Felsius]], Randall proposes a combined Fahrenheit/Celsius temperature scale called Felsius.

==Transcript==
:[Cueball stands in the center of the panel holding a thermometer.]
:Cueball: This thermometer is in Celsius. How do you change it?	
:Off-panel voice: Long press the button.

:[Cueball presses the button, and the thermometer beeps]
:''Press''
:''Beep''
:Thermometer: Units: Kelvin	
:Cueball: No...	

:[Cueball presses the button, and the thermometer beeps]
:''Press''
:''Beep''
:Thermometer: Units: Degrees Rankine	
:Cueball: What.	

:[Cueball presses the button, and the thermometer beeps]
:''Press''
:''Beep''
:Thermometer: Units: Average Translational Kinetic Energy
:Cueball: This is the worst thermometer.
:Off-panel voice: Boltzmann's constant is on the side if you need it.

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:COVID-19]]
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[[Category:Physics]]