explain xkcd - User contributions [en]

1643: Degrees

2016-03-02T11:41:01Z

162.158.90.217: /* Explanation */ formula

{{comic
| number = 1643
| date = February 15, 2016
| title = Degrees
| image = degrees.png
| titletext = "Radians Fahrenheit or radians Celsius?" "Uh, sorry, gotta go!"
}}

==Explanation==
[[Cueball]] is being asked by a friend for the {{w|temperature}}. While he is checking his smartphone for the weather, he begins pondering what unit he should use when answering the question. (See below for [[#Cueball's reasoning|Cueball's reasoning]]).

In the US (where Cueball and [[Randall]] are from), the {{w|Conversion of units of temperature|temperature scale}} used in daily life is {{w|Fahrenheit}}. However, {{w|Celsius}} is commonly used for science, even in the US. Most of the rest of the world also uses Celsius in daily life.

:'''The Celsius scale''' is from the {{w|metric system}}. Though this system has been officially sanctioned for use in the US since 1866, it is not frequently used in daily American life, although it is the preferred system for trade and commerce according to the {{w|Metric Conversion Act}} of 1975. The US remains the only industrialized country that has not adopted the metric system as its official system of measurement. The unit ''degree Celsius'' or °C is an accepted {{w|International System of Units#Derived units|derived unit}} from the {{w|International System of Units}} (SI units) used in science (which again is the modern form of the metric system). The SI unit of temperature is the {{w|Kelvin}}, but this temperature scale is linearly related to the Celsius scale, which is why Celsius can be derived from it.
:'''The Fahrenheit scale''' is from the {{w|United States customary units|US Customary system}}, also known internationally as the (British) {{w|Imperial units|Imperial system}}. The unit is ''degree Fahrenheit'' or °F, and the relation to the Celsius scale is not easy to find in a mental calculation. The relations are: [°F] = [°C]*9⁄5 + 32 or [°C] = ([°F] − 32)×5⁄9. (For this exact reason Randall has previously made a helpful table for these situations in [[526: Converting to Metric]]).

Cueball weighs up the benefits of both scales, but fails to find a solution he can live with, and since he feels he has to give his friend an answer now, he panics and gives the answer 0.173 {{w|radians}}.
:'''Radian''' is the standard unit of angular measure, used in many areas of mathematics. An angle's measurement in radians is numerically equal to the length of a corresponding arc of a {{w|unit circle}}. It has no units and is denoted with the superscript c, but more commonly rad, lest it be confused with {{w|Degree (angle)|angular degrees}}.
:'''Angular degrees''' is a system used to measure {{w|angles}} in {{w|geometry}}, and although it used the unit ° it has nothing to do with temperature gradations of whichever scale.

Thus, this answer is unhelpful and the joke is that traditionally both geometrical angles and temperature is measured in degrees, but there is not the slightest degree of correlation between the two.

The title text indicates that Cueball's friend still wants to know whether the answer is in radians Fahrenheit or radians Celsius, which, despite being a silly way to express temperature would actually enable the friend to get some meaning out of the reply. But this just takes Cueball back to the problem he failed to solve in the first place of choosing one scale above the other, so suddenly he has to go, and he runs off without ever clarifying what he meant. This result is probably because he is afraid of being a bad friend according to his very last point regarding Fahrenheit: ''Valuing unit standardization over being helpful possibly makes me a bad friend.''

The answer Cueball gives of 0.173 radians corresponds to a geometric angle 9.91° (0.173 × 360°/2π). If this were "radians Celsius" it would be 9.91 °C corresponding to 49.8 °F and if it were "radians Fahrenheit" it would be 9.91 °F corresponding to -12.3 °C. [http://boston.cbslocal.com/2016/02/13/new-england-freezing-temperatures-valentines-day-weekend/ Given the temperatures] in {{w|Massachusetts}} (where Randall lives) when this comic came out, the day after Valentines day 2016, Cueball was probably giving his answer in radians Fahrenheit.

=== Cueball's reasoning ===
==== Degrees Celsius ====
;International standard
:Degrees Celsius is derived unit in the SI system of units used to measure temperature in most countries today. Using the SI system would allow Cueball to be easily understood in most countries and is by far the most recognized system, but it is not the most commonly used in the United States, his actual location in the comic.
;Helps reduce America's weird isolationism
:The United States uses its own set of units, including degrees Fahrenheit, called the United States Customary system and similar but not equal to the Imperial system, in contrast to most of the rest of the world which uses the SI system. The US's system of units is therefore considered "weird" as it makes the US different from most of the world, but previous efforts to convert the US to the SI system have failed. Cueball evidently believes that by using SI units he will help to eventually convert the US to the SI system, bringing considerable trade and tourism benefits and reducing confusion when dealing with foreigners.
;Nice how "negative" means below freezing
:On the Celsius scale, the freezing point of water at standard atmospheric pressure (101.325 kilopascals) is very close to 0 °C, and any temperature below that is "below" the freezing point. The Fahrenheit scale uses different points of reference (using a water/ammonium chloride chemical reaction for the lower calibration, while the upper calibration is set such that water freezing and water boiling are 180 degrees apart), and as a result the freezing point of water is a less memorable 32 °F.
;Physics major loyalty
:Cueball is apparently a physics major, like Randall, and SI units are more commonly used for scientific work (as the Kelvin scale is sometimes used in advanced Physics), even in the US. By using the Celsius scale in casual conversation he would show his loyalty to the system used by actual physicists.
;Easier to spell
:"Celsius" is generally considered to be an easier word to spell than the German surname "Fahrenheit" (At least this is the case for Cueball, but not necessarily for those who more commonly use Fahrenheit than Celsius). In this case the word is being spoken and the point is not immediately relevant, but part of the joke is that Cueball is overthinking things and worrying about the general use of the word when an answer is needed in this specific case.
;We lost a Mars probe over this crap
:The {{w|Mars Climate Orbiter|Mars Climate Orbiter}} disintegrated in Mars' atmosphere because Lockheed used US Customary units instead of the contractually specified metric units. Note that this had nothing to do with temperature scales, but was the use of the unit pound-seconds where newton-seconds should have been used. This was a great and tragic loss for science in general, Mars exploration in particular, and thus also for Randall who has shown deep interest in any kind of space exploration, especially regarding Mars (more or less mentioning all Mars rovers in his comics so far).

====Degrees Fahrenheit====
;0°F to 100°F good match for temperature range in which most humans live
:In the context of air temperature, 0 °F and 100 °F correspond to "just about as cold as it gets" and "just about as hot as it gets" in temperate zones, thereby making Fahrenheit a useful temperature scale for weather reporting where most people live. By contrast, in Celsius a range of common temperatures in temperate zones is -20 °C to 40 °C, which is a less intuitive range for those used to the Fahrenheit scale.
;Rounds more usefully (70's, 90's)
:An argument sometimes heard for the continued use of Fahrenheit temperatures is that each 10 degrees change is meaningful in how we feel the temperature. Thus, it is convenient to talk about the temperature being in the 70's today, or in the 90's, etc. Since the Celsius degrees are almost twice as large, a similar statement about the temperature being in the 20's or 30's is not as useful, unless more precision is added by using phrases like low 20's or high 30's. However, this seems likely to be more a matter of which scale you are used to using than anything inherent in one scale or the other.
;Unit-aware computing makes Imperial less annoying
:If you need to constantly convert between Imperial and SI measurements in your head, or even between different Imperial units (e.g., ounces and pounds), it gets annoying and is a strong argument for everyone using metric measurements all the time. But, when it is easy to get the temperature - or any other measurement - reported in whatever units you want just by selecting the units you want your computer to report, then the annoyance is minimized, and the arguments for why we should stop using a familiar scale are weakened. Note that Cueball is looking at his smart-phone to get the current temperature.
:As many Americans, Randall is confusing the {{w|United States customary units|United States customary system}} with the {{w|Imperial system}} used in most of the rest of the English speaking world. In both systems temperature is measured in degrees Fahrenheit.
;SI prefixes are less relevant for temperatures
:One of the nice things about SI measurements is how the same basic unit scales by factors of 10 with common prefixes - e.g., kilometer, millimeter, kilogram, milligram, etc. Imperial measurements don't have this feature - you don't talk about long distances as kiloinches or small weights as millipounds. But, we generally don't use multiple units for atmospheric temperature (millidegrees or kilodegrees), so this argument for using SI measurements for length, mass, volume, etc., isn't as applicable for temperature scales.
;Fahrenheit is likely more clear in this context
:Cueball apparently knows that the inquirer is most likely to assume the answer will be in degrees Fahrenheit, so giving the answer that way would be the least likely to be misinterpreted. If he surprisingly gives an answer in Celsius, without explicitly stating he is reporting the temperature in Celsius, then that could be confusing.
;Valuing unit standardization over being helpful possibly makes me a bad friend
:The final thing Cueball considers is to question why he would give an answer that attaches more value to promoting standardization of units when all his friend wants to know is whether it is cold or warm outside. Wouldn't it be more friendly to just answer the question the way his friend will find most convenient? This is probably the reason he ends up not giving any real answer, as giving the answer in Celsius would make him a bad friend. That giving the answer in radians will make him a weird friend might feel better.

==Transcript==
:[Cueball is looking at his smartphone while a friend calls to him from off-panel. Cueball is thinking as indicated with a thought bubble.]
:Off-screen voice: Hey, what's the temperature outside?
:Cueball (thinking): Should I give it in °F or °C?

:[Zoom in on Cueballs head with a list of reason to use Celsius above him:]
:'''Degrees Celsius'''
:* International standard
:* Helps reduce America's weird isolationism
:* Nice how "negative" means below freezing
:* Physics major loyalty
:* Easier to spell
:* We lost a Mars probe over this crap

:[Same view of Cueballs head, but wider frame to accommodate a broader a list of reason to use Fahrenheit:]
:'''Degrees Fahrenheit'''
:* 0°F to 100°F good match for temperature range in which most humans live
:* Rounds more usefully (70's, 90's)
:* Unit-aware computing makes imperial less annoying
:* SI prefixes are less relevant for temperatures
:* Fahrenheit is likely more clear in this context
:* Valuing unit standardization over being helpful possibly makes me a bad friend

:[Cueball is holding his smartphone down while thinking as indicated with another thought bubble floating at the top. He then speaks and gets a reply from his off-panel friend.]
:Cueball (thinking): Crap, gotta pick something. Uhh...
:Cueball: ...0.173 radians.
:Off-screen voice: I'll just go check myself

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Science]]
[[Category:Physics]]
[[Category:Space probes]]

1643: Degrees

2016-03-02T11:39:02Z

162.158.90.217:

{{comic
| number = 1643
| date = February 15, 2016
| title = Degrees
| image = degrees.png
| titletext = "Radians Fahrenheit or radians Celsius?" "Uh, sorry, gotta go!"
}}

==Explanation==
[[Cueball]] is being asked by a friend for the {{w|temperature}}. While he is checking his smartphone for the weather, he begins pondering what unit he should use when answering the question. (See below for [[#Cueball's reasoning|Cueball's reasoning]]).

In the US (where Cueball and [[Randall]] are from), the {{w|Conversion of units of temperature|temperature scale}} used in daily life is {{w|Fahrenheit}}. However, {{w|Celsius}} is commonly used for science, even in the US. Most of the rest of the world also uses Celsius in daily life.

:'''The Celsius scale''' is from the {{w|metric system}}. Though this system has been officially sanctioned for use in the US since 1866, it is not frequently used in daily American life, although it is the preferred system for trade and commerce according to the {{w|Metric Conversion Act}} of 1975. The US remains the only industrialized country that has not adopted the metric system as its official system of measurement. The unit ''degree Celsius'' or °C is an accepted {{w|International System of Units#Derived units|derived unit}} from the {{w|International System of Units}} (SI units) used in science (which again is the modern form of the metric system). The SI unit of temperature is the {{w|Kelvin}}, but this temperature scale is linearly related to the Celsius scale, which is why Celsius can be derived from it.
:'''The Fahrenheit scale''' is from the {{w|United States customary units|US Customary system}}, also known internationally as the (British) {{w|Imperial units|Imperial system}}. The unit is ''degree Fahrenheit'' or °F, and the relation to the Celsius scale is not easy to find in a mental calculation. The relations are: [°F] = [°C]*9⁄5 + 32 or [°C] = ([°F] − 32)×5⁄9. (For this exact reason Randall has previously made a helpful table for these situations in [[526: Converting to Metric]]).

Cueball weighs up the benefits of both scales, but fails to find a solution he can live with, and since he feels he has to give his friend an answer now, he panics and gives the answer 0.173 {{w|radians}}.
:'''Radian''' is the standard unit of angular measure, used in many areas of mathematics. An angle's measurement in radians is numerically equal to the length of a corresponding arc of a {{w|unit circle}}. It has no units and is denoted with the superscript c, but more commonly rad, lest it be confused with {{w|Degree (angle)|angular degrees}}.
:'''Angular degrees''' is a system used to measure {{w|angles}} in {{w|geometry}}, and although it used the unit ° it has nothing to do with temperature gradations of whichever scale.

Thus, this answer is unhelpful and the joke is that traditionally both geometrical angles and temperature is measured in degrees, but there is not the slightest degree of correlation between the two.

The title text indicates that Cueball's friend still wants to know whether the answer is in radians Fahrenheit or radians Celsius, which, despite being a silly way to express temperature would actually enable the friend to get some meaning out of the reply. But this just takes Cueball back to the problem he failed to solve in the first place of choosing one scale above the other, so suddenly he has to go, and he runs off without ever clarifying what he meant. This result is probably because he is afraid of being a bad friend according to his very last point regarding Fahrenheit: ''Valuing unit standardization over being helpful possibly makes me a bad friend.''

The answer Cueball gives of 0.173 radians corresponds to a geometric angle 9.91° (0.173*360°/2π). If this were "radians Celsius" it would be 9.91 °C corresponding to 49.8 °F and if it were "radians Fahrenheit" it would be 9.91 °F corresponding to -12.3 °C. [http://boston.cbslocal.com/2016/02/13/new-england-freezing-temperatures-valentines-day-weekend/ Given the temperatures] in {{w|Massachusetts}} (where Randall lives) when this comic came out, the day after Valentines day 2016, Cueball was probably giving his answer in radians Fahrenheit.

=== Cueball's reasoning ===
==== Degrees Celsius ====
;International standard
:Degrees Celsius is derived unit in the SI system of units used to measure temperature in most countries today. Using the SI system would allow Cueball to be easily understood in most countries and is by far the most recognized system, but it is not the most commonly used in the United States, his actual location in the comic.
;Helps reduce America's weird isolationism
:The United States uses its own set of units, including degrees Fahrenheit, called the United States Customary system and similar but not equal to the Imperial system, in contrast to most of the rest of the world which uses the SI system. The US's system of units is therefore considered "weird" as it makes the US different from most of the world, but previous efforts to convert the US to the SI system have failed. Cueball evidently believes that by using SI units he will help to eventually convert the US to the SI system, bringing considerable trade and tourism benefits and reducing confusion when dealing with foreigners.
;Nice how "negative" means below freezing
:On the Celsius scale, the freezing point of water at standard atmospheric pressure (101.325 kilopascals) is very close to 0 °C, and any temperature below that is "below" the freezing point. The Fahrenheit scale uses different points of reference (using a water/ammonium chloride chemical reaction for the lower calibration, while the upper calibration is set such that water freezing and water boiling are 180 degrees apart), and as a result the freezing point of water is a less memorable 32 °F.
;Physics major loyalty
:Cueball is apparently a physics major, like Randall, and SI units are more commonly used for scientific work (as the Kelvin scale is sometimes used in advanced Physics), even in the US. By using the Celsius scale in casual conversation he would show his loyalty to the system used by actual physicists.
;Easier to spell
:"Celsius" is generally considered to be an easier word to spell than the German surname "Fahrenheit" (At least this is the case for Cueball, but not necessarily for those who more commonly use Fahrenheit than Celsius). In this case the word is being spoken and the point is not immediately relevant, but part of the joke is that Cueball is overthinking things and worrying about the general use of the word when an answer is needed in this specific case.
;We lost a Mars probe over this crap
:The {{w|Mars Climate Orbiter|Mars Climate Orbiter}} disintegrated in Mars' atmosphere because Lockheed used US Customary units instead of the contractually specified metric units. Note that this had nothing to do with temperature scales, but was the use of the unit pound-seconds where newton-seconds should have been used. This was a great and tragic loss for science in general, Mars exploration in particular, and thus also for Randall who has shown deep interest in any kind of space exploration, especially regarding Mars (more or less mentioning all Mars rovers in his comics so far).

====Degrees Fahrenheit====
;0°F to 100°F good match for temperature range in which most humans live
:In the context of air temperature, 0 °F and 100 °F correspond to "just about as cold as it gets" and "just about as hot as it gets" in temperate zones, thereby making Fahrenheit a useful temperature scale for weather reporting where most people live. By contrast, in Celsius a range of common temperatures in temperate zones is -20 °C to 40 °C, which is a less intuitive range for those used to the Fahrenheit scale.
;Rounds more usefully (70's, 90's)
:An argument sometimes heard for the continued use of Fahrenheit temperatures is that each 10 degrees change is meaningful in how we feel the temperature. Thus, it is convenient to talk about the temperature being in the 70's today, or in the 90's, etc. Since the Celsius degrees are almost twice as large, a similar statement about the temperature being in the 20's or 30's is not as useful, unless more precision is added by using phrases like low 20's or high 30's. However, this seems likely to be more a matter of which scale you are used to using than anything inherent in one scale or the other.
;Unit-aware computing makes Imperial less annoying
:If you need to constantly convert between Imperial and SI measurements in your head, or even between different Imperial units (e.g., ounces and pounds), it gets annoying and is a strong argument for everyone using metric measurements all the time. But, when it is easy to get the temperature - or any other measurement - reported in whatever units you want just by selecting the units you want your computer to report, then the annoyance is minimized, and the arguments for why we should stop using a familiar scale are weakened. Note that Cueball is looking at his smart-phone to get the current temperature.
:As many Americans, Randall is confusing the {{w|United States customary units|United States customary system}} with the {{w|Imperial system}} used in most of the rest of the English speaking world. In both systems temperature is measured in degrees Fahrenheit.
;SI prefixes are less relevant for temperatures
:One of the nice things about SI measurements is how the same basic unit scales by factors of 10 with common prefixes - e.g., kilometer, millimeter, kilogram, milligram, etc. Imperial measurements don't have this feature - you don't talk about long distances as kiloinches or small weights as millipounds. But, we generally don't use multiple units for atmospheric temperature (millidegrees or kilodegrees), so this argument for using SI measurements for length, mass, volume, etc., isn't as applicable for temperature scales.
;Fahrenheit is likely more clear in this context
:Cueball apparently knows that the inquirer is most likely to assume the answer will be in degrees Fahrenheit, so giving the answer that way would be the least likely to be misinterpreted. If he surprisingly gives an answer in Celsius, without explicitly stating he is reporting the temperature in Celsius, then that could be confusing.
;Valuing unit standardization over being helpful possibly makes me a bad friend
:The final thing Cueball considers is to question why he would give an answer that attaches more value to promoting standardization of units when all his friend wants to know is whether it is cold or warm outside. Wouldn't it be more friendly to just answer the question the way his friend will find most convenient? This is probably the reason he ends up not giving any real answer, as giving the answer in Celsius would make him a bad friend. That giving the answer in radians will make him a weird friend might feel better.

==Transcript==
:[Cueball is looking at his smartphone while a friend calls to him from off-panel. Cueball is thinking as indicated with a thought bubble.]
:Off-screen voice: Hey, what's the temperature outside?
:Cueball (thinking): Should I give it in °F or °C?

:[Zoom in on Cueballs head with a list of reason to use Celsius above him:]
:'''Degrees Celsius'''
:* International standard
:* Helps reduce America's weird isolationism
:* Nice how "negative" means below freezing
:* Physics major loyalty
:* Easier to spell
:* We lost a Mars probe over this crap

:[Same view of Cueballs head, but wider frame to accommodate a broader a list of reason to use Fahrenheit:]
:'''Degrees Fahrenheit'''
:* 0°F to 100°F good match for temperature range in which most humans live
:* Rounds more usefully (70's, 90's)
:* Unit-aware computing makes imperial less annoying
:* SI prefixes are less relevant for temperatures
:* Fahrenheit is likely more clear in this context
:* Valuing unit standardization over being helpful possibly makes me a bad friend

:[Cueball is holding his smartphone down while thinking as indicated with another thought bubble floating at the top. He then speaks and gets a reply from his off-panel friend.]
:Cueball (thinking): Crap, gotta pick something. Uhh...
:Cueball: ...0.173 radians.
:Off-screen voice: I'll just go check myself

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Science]]
[[Category:Physics]]
[[Category:Space probes]]

1643: Degrees

2016-03-02T11:37:37Z

162.158.90.217: /* Transcript */ semantic markup

{{comic
| number = 1643
| date = February 15, 2016
| title = Degrees
| image = degrees.png
| titletext = "Radians Fahrenheit or radians Celsius?" "Uh, sorry, gotta go!"
}}

==Explanation==
[[Cueball]] is being asked by a friend for the {{w|temperature}}. While he is checking his smartphone for the weather, he begins pondering what unit he should use when answering the question. (See below for [[#Cueball's reasoning|Cueball's reasoning]]).

In the US (where Cueball and [[Randall]] are from), the {{w|Conversion of units of temperature|temperature scale}} used in daily life is {{w|Fahrenheit}}. However, {{w|Celsius}} is commonly used for science, even in the US. Most of the rest of the world also uses Celsius in daily life.

:'''The Celsius scale''' is from the {{w|metric system}}. Though this system has been officially sanctioned for use in the US since 1866, it is not frequently used in daily American life, although it is the preferred system for trade and commerce according to the {{w|Metric Conversion Act}} of 1975. The US remains the only industrialized country that has not adopted the metric system as its official system of measurement. The unit ''degree Celsius'' or °C is an accepted {{w|International System of Units#Derived units|derived unit}} from the {{w|International System of Units}} (SI units) used in science (which again is the modern form of the metric system). The SI unit of temperature is the {{w|Kelvin}}, but this temperature scale is linearly related to the Celsius scale, which is why Celsius can be derived from it.
:'''The Fahrenheit scale''' is from the {{w|United States customary units|US Customary system}}, also known internationally as the (British) {{w|Imperial units|Imperial system}}. The unit is ''degree Fahrenheit'' or °F, and the relation to the Celsius scale is not easy to find in a mental calculation. The relations are: [°F] = [°C]*9⁄5 + 32 or [°C] = ([°F] − 32)×5⁄9. (For this exact reason Randall has previously made a helpful table for these situations in [[526: Converting to Metric]]).

Cueball weighs up the benefits of both scales, but fails to find a solution he can live with, and since he feels he has to give his friend an answer now, he panics and gives the answer 0.173 {{w|radians}}.
:'''Radian''' is the standard unit of angular measure, used in many areas of mathematics. An angle's measurement in radians is numerically equal to the length of a corresponding arc of a {{w|unit circle}}. It has no units and is denoted with the superscript c, but more commonly rad, lest it be confused with {{w|Degree (angle)|angular degrees}}.
:'''Angular degrees''' is a system used to measure {{w|angles}} in {{w|geometry}}, and although it used the unit ° it has nothing to do with temperature gradations of whichever scale.

Thus, this answer is unhelpful and the joke is that traditionally both geometrical angles and temperature is measured in degrees, but there is not the slightest degree of correlation between the two.

The title text indicates that Cueball's friend still wants to know whether the answer is in radians Fahrenheit or radians Celsius, which, despite being a silly way to express temperature would actually enable the friend to get some meaning out of the reply. But this just takes Cueball back to the problem he failed to solve in the first place of choosing one scale above the other, so suddenly he has to go, and he runs off without ever clarifying what he meant. This result is probably because he is afraid of being a bad friend according to his very last point regarding Fahrenheit: ''Valuing unit standardization over being helpful possibly makes me a bad friend.''

The answer Cueball gives of 0.173 radians corresponds to a geometric angle 9.91° (0.173*360°/2π). If this were "radians Celsius" it would be 9.91 °C corresponding to 49.8 °F and if it were "radians Fahrenheit" it would be 9.91 °F corresponding to -12.3 °C. [http://boston.cbslocal.com/2016/02/13/new-england-freezing-temperatures-valentines-day-weekend/ Given the temperatures] in {{w|Massachusetts}} (where Randall lives) when this comic came out, the day after Valentines day 2016, Cueball was probably giving his answer in radians Fahrenheit.

=== Cueball's reasoning ===
==== Degrees Celsius ====
;International standard
:Degrees Celsius is derived unit in the SI system of units used to measure temperature in most countries today. Using the SI system would allow Cueball to be easily understood in most countries and is by far the most recognized system, but it is not the most commonly used in the United States, his actual location in the comic.
;Helps reduce America's weird isolationism
:The United States uses its own set of units, including degrees Fahrenheit, called the United States Customary system and similar but not equal to the Imperial system, in contrast to most of the rest of the world which uses the SI system. The US's system of units is therefore considered "weird" as it makes the US different from most of the world, but previous efforts to convert the US to the SI system have failed. Cueball evidently believes that by using SI units he will help to eventually convert the US to the SI system, bringing considerable trade and tourism benefits and reducing confusion when dealing with foreigners.
;Nice how "negative" means below freezing
:On the Celsius scale, the freezing point of water at standard atmospheric pressure (101.325 kilopascals) is very close to 0 °C, and any temperature below that is "below" the freezing point. The Fahrenheit scale uses different points of reference (using a water/ammonium chloride chemical reaction for the lower calibration, while the upper calibration is set such that water freezing and water boiling are 180 degrees apart), and as a result the freezing point of water is a less memorable 32 °F.
;Physics major loyalty
:Cueball is apparently a physics major, like Randall, and SI units are more commonly used for scientific work (as the Kelvin scale is sometimes used in advanced Physics), even in the US. By using the Celsius scale in casual conversation he would show his loyalty to the system used by actual physicists.
;Easier to spell
:"Celsius" is generally considered to be an easier word to spell than the German surname "Fahrenheit" (At least this is the case for Cueball, but not necessarily for those who more commonly use Fahrenheit than Celsius). In this case the word is being spoken and the point is not immediately relevant, but part of the joke is that Cueball is overthinking things and worrying about the general use of the word when an answer is needed in this specific case.
;We lost a Mars probe over this crap
:The {{w|Mars Climate Orbiter|Mars Climate Orbiter}} disintegrated in Mars' atmosphere because Lockheed used US Customary units instead of the contractually specified metric units. Note that this had nothing to do with temperature scales, but was the use of the unit pound-seconds where newton-seconds should have been used. This was a great and tragic loss for science in general, Mars exploration in particular, and thus also for Randall who has shown deep interest in any kind of space exploration, especially regarding Mars (more or less mentioning all Mars rovers in his comics so far).

====Degrees Fahrenheit====
;0°F to 100°F good match for temperature range in which most humans live
:In the context of air temperature, 0 °F and 100 °F correspond to "just about as cold as it gets" and "just about as hot as it gets" in temperate zones, thereby making Fahrenheit a useful temperature scale for weather reporting where most people live. By contrast, in Celsius a range of common temperatures in temperate zones is -20 °C to 40 °C, which is a less intuitive range for those used to the Fahrenheit scale.
;Rounds more usefully (70's, 90's)
:An argument sometimes heard for the continued use of Fahrenheit temperatures is that each 10 degrees change is meaningful in how we feel the temperature. Thus, it is convenient to talk about the temperature being in the 70's today, or in the 90's, etc. Since the Celsius degrees are almost twice as large, a similar statement about the temperature being in the 20's or 30's is not as useful, unless more precision is added by using phrases like low 20's or high 30's. However, this seems likely to be more a matter of which scale you are used to using than anything inherent in one scale or the other.
;Unit-aware computing makes Imperial less annoying
:If you need to constantly convert between Imperial and SI measurements in your head, or even between different Imperial units (e.g., ounces and pounds), it gets annoying and is a strong argument for everyone using metric measurements all the time. But, when it is easy to get the temperature - or any other measurement - reported in whatever units you want just by selecting the units you want your computer to report, then the annoyance is minimized, and the arguments for why we should stop using a familiar scale are weakened. Note that Cueball is looking at his smart-phone to get the current temperature.
:As many Americans, Randall is confusing the {{w|United States customary units|United States customary system}} with the {{w|Imperial system}} used in most of the rest of the English speaking world. In both systems temperature is measured in degrees Fahrenheit.
;SI prefixes are less relevant for temperatures
:One of the nice things about SI measurements is how the same basic unit scales by factors of 10 with common prefixes - e.g., kilometer, millimeter, kilogram, milligram, etc. Imperial measurements don't have this feature - you don't talk about long distances as kiloinches or small weights as millipounds. But, we generally don't use multiple units for atmospheric temperature (millidegrees or kilodegrees), so this argument for using SI measurements for length, mass, volume, etc., isn't as applicable for temperature scales.
;Fahrenheit is likely more clear in this context
:Cueball apparently knows that the inquirer is most likely to assume the answer will be in degrees Fahrenheit, so giving the answer that way would be the least likely to be misinterpreted. If he surprisingly gives an answer in Celsius, without explicitly stating he is reporting the temperature in Celsius, then that could be confusing.
;Valuing unit standardization over being helpful possibly makes me a bad friend
:The final thing Cueball considers is to question why he would give an answer that attaches more value to promoting standardization of units when all his friend wants to know is whether it is cold or warm outside. Wouldn't it be more friendly to just answer the question the way his friend will find most convenient? This is probably the reason he ends up not giving any real answer, as giving the answer in Celsius would make him a bad friend. That giving the answer in radians will make him a weird friend might feel better.

==Transcript==
:[Cueball is looking at his smartphone while a friend calls to him from off-panel. Cueball is thinking as indicated with a thought bubble.]
:Off-screen voice: Hey, what's the temperature outside?
:Cueball (thinking): Should I give it in °F or °C?

:[Zoom in on Cueballs head with a list of reason to use Celsius above him:]
:'''Degrees Celsius'''
:* International standard
:* Helps reduce America's weird isolationism
:* Nice how "negative" means below freezing
:* Physics major loyalty
:* Easier to spell
:* We lost a Mars probe over this crap

:[Same view of Cueballs head, but wider frame to accommodate a broader a list of reason to use Fahrenheit:]
:'''Degrees Fahrenheit'''
:* 0°F to 100°F good match for temperature range in which most humans live
:* Rounds more usefully (70's, 90's)
:* Unit-aware computing makes imperial less annoying
:* SI prefixes are less relevant for temperatures
:* Fahrenheit is likely more clear in this context
:* Valuing unit standardization over being helpful possibly makes me a bad friend

:[Cueball is holding his smartphone down while thinking as indicated with another thought bubble floating at the top. He then speaks and gets a reply from his off-panel friend.]
:Cueball (thinking): Crap, gotta pick something. Uhh...
:Cueball: ...0.173 radians.
:Off-screen voice: I'll just go check myself

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Science]]
[[Category:Physics]]
[[Category:Space probes]]

Talk:718: The Flake Equation

2015-08-26T13:34:07Z

162.158.90.217: what's up w/ flake?

There was a later comic about our capabilities' precluding of UFO sightings and such. I may find it at some point. --[[User:Quicksilver|Quicksilver]] ([[User talk:Quicksilver|talk]]) 02:51, 20 August 2013 (UTC)

Settled

googlesearch=site:explainxkcd.com ufo

http://www.explainxkcd.com/wiki/index.php/1235:_Settled

[[User:Kevin McCready|Kevin McCready]] ([[User talk:Kevin McCready|talk]]) 13:25, 10 May 2014 (UTC)

Is there any significance to the word "flake"? Urban Dictionary says it stands for "unreliable person", but certainly not in context of alien sightings. --[[Special:Contributions/162.158.90.217|162.158.90.217]] 13:34, 26 August 2015 (UTC)

574: Swine Flu

2015-08-24T18:02:50Z

162.158.90.217: /* Explanation */ what the hell is ACLU.

{{comic
| number = 574
| date = April 27, 2009
| title = Swine Flu
| image = swine flu.png
| titletext = Bad flu epidemics can hit young adults hardest because they provoke their powerful immune systems into overreaction, so to stay healthy spend the next few weeks drunk and sleep-deprived to keep yours suppressed.
}}

==Explanation==
{{w|Swine influenza|Swine flu}} is a strain of the flu which can be transmitted from pigs to humans. In 2009, it was the origin of the {{w|Pandemic H1N1/09 virus}}, which most news stations called either "H1N1" (the subtype name) or "swine flu". Because of the ambiguous name given to it and the somewhat hazy description of the transmittal process and dangers to humans, many people were concerned about the virus in ways that weren't going to be threats. This comic pokes a bit of fun at the overreaction by users on {{w|Twitter}}.

[[Randall]] (or someone else) seems to have created Twitter accounts for all referenced handles (that may not have already existed). Some of the handles continue their interactions with each other in later tweets.

[https://twitter.com/SKEEVE37 SKEEVE37] is a self-described {{w|Hypochondriasis|hypochondriac}}. The tweet exemplifies the general populace's over-concern with the "animal themed" pandemics. Similarly after the "bird flu" scare, people avoided eating chicken.

[https://twitter.com/hanneloreEC HANNELOREEC] is a self-described "young lady who is concerned about many things". She is a reoccurring character in the webcomic "Questionable Content" by Jeph Jacques, who also manages her twitter handle.

[https://twitter.com/PAULYSHOREFAN PAULYSHOREFAN]'s tweet is a reference to the flash game "[http://www.crazymonkeygames.com/Pandemic-2.html Pandemic 2]", in which players try to create a disease that infects the whole world. [http://www.urbandictionary.com/define.php?term=madagascar Madagascar] is the most difficult country to infect, as it only has 1 port and often closes it at the slightest hint of an infection. The difficulty of infecting Madagascar has caused it to become a [http://knowyourmeme.com/memes/shut-down-everything meme].

[https://twitter.com/CrackMonkey74 CrackMonkey74]'s tweet is a parody of viral Christian(?) messages that say that current tragedies are God's punishment, [http://bible.cc/mark/13-7.htm despite the fact that the Bible says that the end is not yet to come.] More specifically, Crackmonkey74 blames the {{w|American Civil Liberties Union|ACLU}}, lesbians (a reference to the current culture wars that give big press towards proponents of gay marriage against fundamentalist Christians), {{w|September 11 attacks|9/11}} (the day when the Twin Towers fell, causing controversy on whether Muslim terrorists crashed their planes on the towers or whether the government staged this by purposefully demolishing the towers) and {{w|Nanorobotics|nanobots}} (possibly a reference towards the highly promising but still relatively not understood field of nanotechnology, plus another reference towards the phrase "playing God").

[https://twitter.com/Twilight7531 Twilight7531]'s tweet implies that she got a {{w|Bone fracture#Orthopedic|bone fracture}} which ended up protruding from her arm. However, she seems to lack medical knowledge (or intelligence in general, given that her name carries both something that may be a reference toward the infamous {{w|Twilight (series)|Twilight books}} and a "gimmicky" naming scheme (7531 has the numerals of every odd number that is less than 9)), so she is worried that her fracture is actually swine flu (though how can she be typing with a broken arm is confusing).

[https://twitter.com/Wigu Wigu]'s tweet is a reply towards [https://twitter.com/Untoward Untoward]'s. Given the context, Untoward seems to have "gotten intimate" with a pig (since {{w|syphilis}} is a venereal disease). Given the fact that Untoward got sick because of a pig, Untoward seems to have concluded that he got swine flu. (In light of the fact that [[471: Aversion Fads|Randall considers furries in general to have an animal fetish]], to consider Untoward a furry would be a safe assumption here.)

The last comment by [https://twitter.com/2011SENIORSRULE 2011SENIORSRULE] references a medical paper published by the journal The Lancet, in which it is proposed that autism is caused by vaccination. Since then, the paper was partially retracted in 2004, and fully retracted in 2010 because of conflicts of interest. The entire incident has been defined as the {{w|MMR vaccine controversy}} and more details can be found on the Wikipedia page. This stance has still been seen since the retraction of the paper, and still holds some popularity. The most famous figure in support of it is {{w|Jenny McCarthy}}. Also, fear of germs is common among autistic people, so "licking an autistic kid" would be a difficult and possibly painful experience.

The title text refers to the common notion that young adults are hard-drinking individuals who get little sleep.

CrackMonkey74 has appeared in two earlier comics, them being [[202: YouTube]] and [[406: Venting]].

==Transcript==
:Twitter is great for watching uninformed panics unfold live.
:[Twitter search results page with "Swine flu" in the search box.]
:Realtime results for '''Swine flu'''
:1,918 more results since you started searching. Refresh to see.
:[All tweets are "Less than 10 seconds ago from web"]
:SKEEVE37: Oh god I ate pork yesterday before I knew about swine flu!
:HANNELOREEC: Without duct tape I can't seal the door to keep out swine flu but I can't get duct tape without going outside! Help!
:PAULYSHOREFAN: How long until the swine flu reaches me here in Madagascar?
:CrackMonkey74: Swine flu is God's punishment for the ACLU and lesbians and 9/11 and nanobots!
:Twilight7531: I fell down the stairs and there was a crack and a jagged white thing is sticking out of my arm guys is this swine flu?
:Wigu: @Untoward: No, that sounds like syphilis, not swine flu. What did you say you did with a pig?
:2011SENIORSRULE: My Dad said flu vaccines are linked to autism, so to be safe from swine flu I'm trying to lick an autistic kid.

{{comic discussion}}
[[Category:Comics with color]]
[[Category:Social networking]]
[[Category:Video games]]
[[Category:Religion]]