3001: Temperature Scales

Explain xkcd: It's 'cause you're dumb.
Revision as of 10:36, 25 October 2024 by 172.69.194.227 (talk) (→‎Explanation: Changed the emphasis. Noting that 0, 50 and 100 will always be the relevent current record, but historic records will drift inwards (min/max) or around (mid). That potentially sends out-of-range conversions *wildly* all over the place.)
Jump to: navigation, search
Temperature Scales
In my new scale, °X, 0 is Earths' record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.
Title text: In my new scale, °X, 0 is Earths' record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed.

    Explanation

    Ambox warning blue construction.svg This is one of 54 incomplete explanations:
    Created by an TOTALLY CONFORMING TEMPERATURE SYSTEM. Do NOT delete this tag too soon. If you can fix this issue, edit the page!

    Since the invention of the thermometer, a number of different temperature scales have been proposed. In modern times, most of the world uses the 1742 Celsius scale for everyday temperature measurements. A small number of countries (the USA and its territories, the Bahamas, Belize, the Cayman Islands, Liberia, and Palau) retain the imperial system (or the related US customary system), which uses the 1724 Fahrenheit scale. The other widely used temperature scale is the 1848 kelvin, which uses the same scale as degrees Celsius, but is rooted at absolute zero, making it both useful in scientific calculations and easy to convert to and from °Celsius (which, along with °Fahrenheit, is now officially defined relative to kelvins). Kelvins have been part of the widely adopted official metric system since 1954. Even in countries that use Fahrenheit, scientific measurements are usually made in degrees Celsius or kelvin.

    The comic compares these scales, and a number of others, on Randall's scale of "cursedness." The joke is highlighting how different the temperature scales are, and how impractical most of them are. All of the listed scales are real, but may be considered obsolete to varying degrees. Please see also 1923: Felsius, a combination of degrees Fahrenheit and Celsius.

    Unit Water freezes Water boils Notes Cursedness Explanation
    Celsius 0 100 Used in most of the world 2/10 The Celsius (°C) scale, also known as "centigrade", was devised by Swedish astronomer Anders Celsius in 1742 and revised in 1745, a year after his death. 0°C represents the freezing point of water and 100°C represents the boiling point, both under standard atmospheric pressure. The Celsius scale is now defined in terms of kelvins. By the given "cursedness," it is regarded as one of the least problematic temperature scales.
    Kelvin 273.15 373.15 0K is absolute zero 2/10 Kelvin (plural with a lowercase 'k' as a temperature unit; or as the symbol 'K', without the degrees symbol '°', unlike most other such units) is a unit of temperature devised by Lord Kelvin in 1848. It uses the same scale as Celsius but is shifted by 273.15 to set absolute zero at 0K (based on the Boltzmann constant.)
    Celsius = kelvin - 273.15
    kelvin = Celsius + 273.15

    While kelvin is very useful for calculations in thermodynamics and material physics, it can be unintuitive to laypersons.

    Fahrenheit 32 212 Outdoors in most places is between 0–100 3/10 Fahrenheit (°F) is officially used in a few countries and informally in several others. It originated in a time when factors of 360 were favored in science over powers of ten, which is why the freezing and boiling points of water are set 180° apart. Devised around 1724, Daniel Fahrenheit chose not to base 0° on the freezing point of water, instead ofiginally setting it at the coldest temperature he could achieve: the freezing point of an ammonium chloride brine solution.
    Celsius = (Fahrenheit - 32) × 5/9
    Fahrenheit = Celsius × 9/5 + 32

    Although those reference points are now considered arbitrary and outdated by modern scholars, the scale gained popularity in Anglophone countries because everyday weather conditions usually fall handily all across the range 0–100°F, and 100°F is coincidentally close to normal human body temperature. The Fahrenheit scale remains officially used only in Randall's home country (the U.S., and its territories), the Bahamas, Belize, the Cayman Islands, Liberia and Palau.

    Réaumur 0 80 Like Celsius, but with 80 instead of 100 3/8 Abbreviated as °Ré, this system devised by René Antoine Ferchault de Réaumur in 1730 was used in some places until the early 20th century, mostly for cheese-making.
    Celsius = Réaumur / 0.8
    Réaumur = Celsius × 0.8

    The rating (3/8) is a joke on the boiling point of water in this system being 80 instead of 100 as it is in Celsius; converting this to an out-of-ten scale would give 3.75/10, labeling it as more cursed than Fahrenheit but less so than Rømer.

    Rømer 7.5 60 Fahrenheit precursor with similarly random design 4/10 Abbreviated as °Rø, this scale was created by the Danish astronomer Ole Rømer around 1702. Much like Fahrenheit, it originally used the freezing point of ammonium chloride brine as the benchmark for 0°, and the scale is built with factors of 360 in mind with the boiling point of pure water at 60°. Like the Fahrenheit scale, the freezing point of pure water was not originally considered significant by Rømer, but the scale was later updated to give the value of 7.5 at this point.
    Celsius = (Rømer - 7.5) × 40/21
    Rømer = Celsius × 21/40 + 7.5

    The Rømer scale is considered the predecessor of both the Celsius and Fahrenheit scales, because Réaumur was inspired by Rømer's scale, Celsius based his work on Réaumur and Fahrenheit specifically designed his scale with more divisions than Rømer's to reduce the necessity for fractions.

    Rankine 491.7 671.7 Fahrenheit, but with 0°F [sic; should be 0°Ra] set to absolute zero 6/10 The Rankine scale (°Ra), devised in 1859 by William Rankine, is to Fahrenheit what kelvin is to Celsius, an absolute scale rather than a relative one. The scale is mostly obsolete, but is still occasionally used in legacy industrial operations where absolute temperature scales are required. It is described as more cursed than the otherwise identical Fahrenheit scale, despite being rooted at a more universal zero point.
    Celsius = (Rankine - 491.67) × 5/9
    Rankine = (Celsius + 273.15) × 9/5

    Another comic, 2292: Thermometer, expresses disdain for this scale.

    Newton 0 33-ish Poorly defined, with reference points like "the hottest water you can hold your hand in" 7-ish/10 The famous scientist and mathematician Isaac Newton published this scale in 1701, which was referred to by the the °N symbol. Sadly, the degrees of temperature specified do not correlate exactly with amounts of heat. The cursedness rating (7-ish/10) is a joke about the vagueness of the scale's definition.
    Celsius = Newton × 100/33
    Newton = Celsius × 33/100

    Very few scientists other than Newton ever used this scale,[actual citation needed] but it did appear on commercial thermometers around 1758.[1]

    Wedgwood –8 –6.7 Intended for comparing the melting points of metals, all of which it was very wrong about 9/10 Created by the potter Josiah Wedgwood in 1782, the '°W' scale was based on the shrinking of clay when heated above red heat, but was found to be very inaccurate.
    Celsius = (Wedgwood + 8) × 100/1.3
    Wedgwood = (Celsius × 1.3/100) - 8

    The comic has a typo, as the scale is called Wedgwood, without the second 'e'.

    Galen –4? 4?? Runs from –4 (cold) to 4 (hot). 0 is "normal"(?) 4/–4 The Greek physician Galen suggested a "neutral" temperature around 180 A.D.,[2] when he was a prominent physician in the Roman Empire. Created by mixing equal parts of boiling water and ice, on either side of this neutral point he described four degrees of heat and four degrees of cold.
    Galen = ((Celsius - 22) / 100) × 8
    Celsius = (Galen × 100 / 8) + 22

    This range from +4 to –4 is humorously used as its rating, implying -100% cursedness. Technically this makes it the least cursed of all the listed scales, but the idea of negative cursedness (or cursedness itself) would be Randall's invention. There is no standard modern abbreviation for Galen's scale.

    Real Celsius 100 0 In Anders Celsius's original 1742 specification, bigger numbers are colder; others later flipped it 10/0 Most scales' temperatures can be indefinitely large, but have an absolute minimum temperature. By starting at a maximum value and counting down, this scale is indeed cursed, as nearly all possible temperatures (possibly to the equivalent of 1.42x1032K, considered the maximum attainable physical temperature) will be negative in this implementation. The cursedness rating (10/0) is a joke on the scale "flipping" the fixed points of modern Celsius. Division by zero is strictly undefined (see 2295: Garbage Math) and may be interpreted in a number of counter-intuitive ways.
    Celsius = 100 - real_Celsius
    real_Celsius = 100 - Celsius

    The original logic was that zero could be easily calibrated to the height of a column of mercury at the temperature of boiling water, and further measurements then made of the amount it reduced in height under cooler conditions. This orientation survives in the historic Delisle scale devised in 1732 by French astronomer Joseph-Nicolas Delisle, which arguably inspired the Celsius scale. The scale originally used by Professor Celsius was only changed, after his death, in 1745. Delisle's scale was never reversed.

    Dalton 0 100 A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton 53.9/50 John Dalton proposed a logarithmic temperature scale in 1802 during his work on what became Charles's Law. The scale is defined so that absolute zero is at negative infinity, with the exponent chosen to match Celsius at 0 and 100:
    Dalton = 320.55 × ln( (Celsius + 273.15) / 273.15 )
    Celsius = 273.15 × e(Dalton / 320.55) - 273.15

    There is no standard abbreviation for Dalton's scale. While Dalton temperature is defined for all positive and negative numbers, the nonlinear scale is difficult to work with since the amount of heat represented by a change of one degree Dalton is not constant. Degrees Dalton differs from Celsius by as much as 3.9 degrees between 0 and 100, but diverges much more for more extreme temperatures. The rating (53.9/50) is a joke about the unit, as 53.9 Dalton would be 50 degrees Celsius — i.e., the cursedness could be understood as 50/50, or entirely cursed, but perhaps instead as 107.8% (even more than entirely) cursed.

    °X 42.9 151.4 Title text: "In my new scale, °X, 0 is Earths' [sic] record lowest surface temperature, 50 is the global average, and 100 is the record highest, with a linear scale between each point and adjustment every year as needed." Randall has not stated the cursedness of his new scale The record lowest surface temperature on Earth as of 2024 is –89.2°C (–128.6°F), recorded at the Vostok Research Station in Antarctica on July 21, 1983.[3] The average surface temperature as of 2023, the most recent available, is 14.8°C (58.6°F.)[4] The record highest temperature is 56.7°C (134.1°F), recorded on July 10, 1913 at Furnace Creek Ranch in Death Valley, California.[5]

    "Surface" temperatures are measured at 1.5 meters above ground inside a shaded shelter, to accurately represent the temperature of the air, because temperatures closer to the ground are often quite different due to the heating effects of sunlight (or a lack therof, e.g., at night or under clouds), and the thermal capacity of soil.

    Derivation and graph

    To break the scale into two linear parts (below and above 14.8°C), we define two separate equations for each range:

    1. Below 14.8°C (from –89.2°C to 14.8°C):

    • 0 °X corresponds to –89.2°C
    • 50 °X corresponds to 14.8°C

    We calculate the slope m₁:

    m₁ = (50 – 0) / (14.8 – (–89.2)) = 50 / (14.8 + 89.2) = 50 / 104 ≈ 0.48

    Now, using the point (14.8°C, 50 °X), we calculate the intercept b₁:

    50 = 0.48 × 14.8 + b₁
    50 = 7.1 + b₁
    b₁ = 50 – 7.1 = 42.9

    Thus, the equation for temperatures below 14.8°C is:

    X = 0.48 × C + 42.9

    2. Above 14.8°C (from 14.8°C to 56.7°C):

    • 50 °X corresponds to 14.8°C
    • 100 °X corresponds to 56.7°C

    We calculate the slope m₂:

    m₂ = (100 – 50) / (56.7 – 14.8) = 50 / 41.9 ≈ 1.19

    Now, using the point (14.8°C, 50 °X), we calculate the intercept b₂:

    50 = 1.19 × 14.8 + b₂
    50 = 17.6 + b₂
    b₂ = 50 – 17.6 = 32.4

    Thus, the equation for temperatures above 14.8°C is:

    X = 1.19 × C + 32.4
    Freezing and boiling points of water

    Freezing point of water (0°C): Since 0°C is below 14.8°C, we use the equation X = 0.48 × C + 42.9:

    X = 0.48 × 0 + 42.9 = 42.9

    So, the freezing point is 42.9 °X.

    Boiling point of water (100°C): Since 100°C is above 14.8°C, we use the equation X = 1.19 × C + 32.4:

    X = 1.19 × 100 + 32.4 = 119 + 32.4 = 151.4

    So, the boiling point is 151.4 °X.

    XvsC.png

    See also 2701: Change in Slope for a general discussion of separate linear scales between three points.

    Due to high and average temperature records now increasing almost every year as a result of climate change, Randall's new °X scale must be re-calibrated each year. While the value given to everyday (non-record) temperatures will vary over time, more extreme values like absolute zero or the melting point of tungsten will shift vastly more.

    Trivia

    Here are the room temperature, water freezing and boiling, human body temperature, recommended refridgerator and freezer, warm bath, and hot coffee temperature values for those scales:

    [Warning, not proofread.]
    Unit scale Room temperature Water freezing temperature Water boiling temperature Body temperature Recommended refrigerator temperature Recommended freezer temperature Warm bath temperature Hot coffee temperature
    Celsius 22 °C 0 °C 100 °C 37 °C 2.5 °C -18 °C 39 °C 77 °C
    Kelvin 295 K 273 K 373 K 310 K 276 K 255 K 312 K 350 K
    Fahrenheit 72 °F 32 °F 212 °F 98.6 °F 36.5 °F -0.4 °F 102 °F 171 °F
    Réaumur 17.6 °Ré 0 °Ré 80 °Ré 29.6 °Ré 2 °Ré -14.4 °Ré 31.2 °Ré 61.6 °Ré
    Rømer 19.1 °Rø 7.5 °Rø 60 °Rø 26.9 °Rø 8.8 °Rø -2 °Rø 28 °Rø 47.9 °Rø
    Rankine 531 °Ra 492 °Ra 672 °Ra 558 °Ra 496 °Ra 459 °Ra 562 °Ra 630 °Ra
    Newton 7.3 °N 0 °N 33 °N 12.2 °N 0.8 °N -5.9 °N 12.9 °N 25.4 °N
    Wedgwood -7.71 °W -8.00 °W -6.70 °W -7.52 °W -7.97 °W -8.23 °W -7.49 °W -7.00 °W
    Galen 0.00 -1.76 6.24 1.20 -1.56 -3.20 1.36 4.40
    Real Celsius 78 100 0 63 98 118 61 23
    Dalton 24.8 0 100 40.7 2.9 -21.9 42.8 79.6
    °X 59 °X 43 °X 151 °X 76.4 °X 44.1 °X 34.3 °X 78.8 °X 124 °X

    Transcript

    Ambox warning green construction.svg This is one of 29 incomplete transcripts:
    Do NOT delete this tag too soon. If you can fix this issue, edit the page!
    Temperature Scales
    [A table with five columns, labelled: Unit, water freezing point, water boiling point, notes, cursedness. There are eleven rows below the labels.]
    [Row 1:] Celsius, 0, 100, Used in most of the world, 2/10
    [Row 2:] Kelvin, 273.15, 373.15, 0K is absolute zero, 2/10
    [Row 3:] Fahrenheit, 32, 212, Outdoors in most places is between 0–100, 3/10
    [Row 4:] Réaumur, 0, 80, Like Celsius, but with 80 instead of 100, 3/8
    [Row 5:] Rømer, 7.5, 60, Fahrenheit precursor with similarly random design, 4/10,
    [Row 6:] Rankine, 491.7, 671.7, Fahrenheit, but with 0°F set to absolute zero, 6/10
    [Row 7:] Newton, 0, 33-ish, Poorly defined, with reference points like "the hottest water you can hold your hand in", 7-ish/10
    [Row 8:] Wedgewood, –8, –6.7, Intended for comparing the melting points of metals, all of which it was very wrong about, 9/10
    [Row 9:] Galen, –4?, 4??, Runs from –4 (cold) to 4 (hot). 0 is "normal"(?), 4/–4
    [Row 10:] Real Celsius, 100, 0, In Anders Celsius's original specification, bigger numbers are colder; others later flipped it, 10/0
    [Row 11:] Dalton, 0, 100, A nonlinear scale; 0°C and 100°C are 0 and 100 Dalton, but 50°C is 53.9 Dalton, 53.9/50

    References

    References

    Ambox warning blue construction.svg This is one of 54 incomplete explanations:
    On this, wiki, we do not use references. We only link the cited source in the sentence that needs sourcing itself. For more info, see this section of the Editor FAQ. Please move these links inside the explanation and remove this section. If you can fix this issue, edit the page!
    1. ↑ https://www.scienceandsociety.co.uk/results.asp?image=10413117&wwwflag=&imagepos=43
    2. ↑ https://www.loebclassics.com/view/galen-temperaments/2020/pb_LCL546.3.xml
    3. ↑ https://wmo.asu.edu/content/world-lowest-temperature
    4. ↑ https://climate.copernicus.eu/climate-indicators/temperature
    5. ↑ https://wmo.asu.edu/content/world-highest-temperature

    comment.png  Add comment      new topic.png  Create topic (use sparingly)     refresh discuss.png  Refresh 

    Discussion

    Shouldn't Rankine say "0ºR is set to absolute zero"? 172.70.230.29 (talk) 22:58, 21 October 2024 (UTC) (please sign your comments with ~~~~)

    Yep. 162.158.186.253 04:38, 22 October 2024 (UTC)
    Furthermore, should it be 0°R or just 0R (no °)? I've been told that Kelvin doesn't use degrees because it's an absolute scale, so a) is this true and b) should it apply to Rankine? 172.71.211.54 14:44, 24 October 2024 (UTC)
    Kelvin is rather strange, for reasons never totally explained. It's "the Kelvin scale", but the unit is "kelvin" and I never got on with the official absence of the ° symbol by the "K". I was always taught to say "degrees kelvin" (for temperatures) and "kelvin degrees" (for a change/range of temperature) in order to not cause confusion and technical misunderstandings (perhaps easier to contextualise when down in writing?) but no accounting for taste, or possibly official laziness.
    On the basis that Rankine is not kelvin (whatever the reason for how kelvin is what it is), I would use the degrees, as I would any other absolute scale (whether it be an adjusted form of °Rø or °Ré or whatever else might be invented), because kelvin is just inexplicably (to me, and to others) the exception to absolutely every other reasonably equivalent contemporary measure, including capitalisation. YMMV! 172.70.162.2 19:53, 24 October 2024 (UTC)
    0ºRa, not 0ºR. 172.70.206.157 02:16, 25 October 2024 (UTC)
    Can be either. Perhaps best to use °Ra (in ambiguous context) to avoid possible confusion with °Ré and °Rø, but probably less important when both those two are also listed alongside (except for wondering what, if anything, is a typo, bad handwriting or other error). 172.69.194.12 11:01, 25 October 2024 (UTC)
    It's easy if you think about it like "meter". You usually say "meters" not "the meter scale" although both are correct. Scientists and engineers who use them daily call them "kelvins", not "kelvin" unless following a number. You wouldn't say "We need to measure this room in meter." Someone keeps reverting me on this, and they're wrong, but I don't care much anymore. I'll probably fix it next month or something. Liv2splain (talk) 21:10, 25 October 2024 (UTC)
    "Americans typically measure temperatures in Fahrenheits, whilst Europeans use Celsiusses..." hmm, no, that doesn't sound right at all. (Celciuses? No, wait. Celcii! Masculine Nominative Singular changed to the Plural, if I've got my Latin declensions right. But still doesn't sound right. Maybe I also need to use "Fahrenheiten"..? Wait, wasn't he born Polish, so that means...)
    Seriously, I think that if you talk of "measured in [the scale of] Celsius" you should probably talk of "... in [the scale of] Kelvin" (using the capital for the scale). According to the orthography, you'd be right to specify "50 kelvins" (c.f. "50 degrees [whatever non-Kelvin measure]" or "50 [whatever non-Kelvin measure] degrees" for a range), but talking about the scale would definitely call for a simple "Kelvin". 172.68.205.135 21:39, 25 October 2024 (UTC) (PS., I'd also say "metre(s)", but then I'm British... which might also colour (or 'color') my personal grammatical sensibilities. But oh what fun you lot seem to have had with this whole issue!)
    The units are degrees Celsius or Fahrenheit, but just kelvins, like watts or ohms or amps. It's explained in great detail in the article already. Fun?! Perhaps you should talk to someone who uses kelvins on a regular basis before you impose your imagined usage over the course of a half dozen reverts. 172.70.206.73 23:16, 25 October 2024 (UTC)
    Isn't that what was just said? Though I'd say "It's 50 kelvin", apparently the 'right' way to say that is "It's 50 kelvins" (also "It went up by 50 kelvin"/"it went up by 50 kelvins"... that latter sounds off to me, and isn't how I've ever used it, but the orthography link suggests it's right).
    But then one can talk about measuring temperatures (or temperature ranges) in Celsius or Fahrenheit or Delisle or whatever, because you're saying you're measuring things in the scale of whatever-it-is, so you can equally say you're measuring things in (the scale of) Kelvin. Not too different from saying that you're using the meter or the foot or the kiloparsec or the nanosecond or the coulomb-squared-per-barn or even the fortnight-per-firkin-furlong if you ever so wish. 172.68.205.150 23:32, 25 October 2024 (UTC)
    Tell me you never talk about kelvins in everyday work without telling me you never talk about kelvins in everyday work. 172.68.22.98 13:59, 26 October 2024 (UTC)
    Nonsense. It clearly means "This is what Fahrenheit would be if 0°F were absolute zero." Saying "This is what Fahrenheit would be if 0°R were absolute zero" is wrong on two counts: Fahrenheit wouldn't be affected by changing Rankine, AND 0°R is already absolute zero, which clearly hasn't made Fahrenheit and Rankine identical. I'll admit that Randall's phrasing is ambiguous, but if it's wrong then so is what you're suggesting for the same reason, because the ambiguity hasn't been resolved. Ambiguity isn't the same thing as an error, and adding this as a correction achieves nothing other than making things more confusing.172.70.46.99 23:19, 29 October 2024 (UTC)

    yo,i thought comic 3000 was anticlimactic so randall would make this one COOL but sadly not Same. Hope he does something cool for 3072.172.69.134.225 23:44, 21 October 2024 (UTC)

    really he didn't do anything special for this either? come ON randall if you don't do something cool for comic 3072 i will come to your house personally and yell at you RadiantRainwing (talk) 23:57, 21 October 2024 (UTC)
    What's random about Fahrenheit? (Answer: nothing.) 0F is the freezing point of brine, 100F (or 98.7) is the human body temperature. 172.68.54.65 00:00, 22 October 2024 (UTC)

    What concentration of brine? (And which specific salt... No, not NaCl, as you might presume but NH4Cl!)
    And body temperature varies a lot ('typically' 36.5–37.5°C or 97.7–99.5°F, though even this range is thought to be too small), across genders, individuals, time of day and which orifices/surfaces you try to measure it from. (Originally, it was set so that 90°F was to be the 'best guess' of human body temperature. It gradually changed, including via various compounded misunderstandings so that the best you can say is that 100°F is arbitrarily slightly above most afebrile human body temperature measurements.)
    Celsius might be a bit off (arguments about triple-point or STP freezing, etc), but it still has far more physical logic to it. 172.70.160.188 01:14, 22 October 2024 (UTC)

    Sorry, Randall, for my comfort, Fahrenheit is the least cursed. It's the best scale to use for my personal use, especially when hearing the weather report and deciding what to wear outdoors: temp in the 80's - no jacket. temp in 70's - maybe a windbreaker if it's breezy. 60's - sweater weather. 50's - medium weight coat. 40's - winter coat. 30'3 - winter coat with scarf and gloves. 20's - multiple layers. teens - stay indoors. None of the other scales provide such convenient distinctions for my daily life. Kelvin is great for astro physics or super conductivity, but useless for any common uses. Celsius is great for hanging out with the Euro crowd but still not so useful to scale my home thermostat. I judge Fahrenheit as 1.0 for cursedness. Rtanenbaum (talk) 14:19, 22 October 2024 (UTC)

    I conveniently use Celsius in tens, also. Negative °C: Cold; 0-10°C: Nippy; 10-20°C: Generally pleasant; 20-30°C: Too warm to exert oneself; 30°C+: Definitely too warm. 172.70.86.205 15:24, 22 October 2024 (UTC)

    Personally, I'm most disappointed that Delisle scale was not represented... 172.70.160.188 01:14, 22 October 2024 (UTC)

    I was so hoping for a Planck temperature quip. Like: "Water freezing point: 0; Water boiling point: 0; Notes: 1 = highest possible temperature (1.4E32K) where thermal radiation creates black holes; Cursedness: 0/0" 162.158.164.184 01:27, 22 October 2024 (UTC)
    Same here. Freezing is 0.000000000000000000000000000001928 and boiling is 0.0000000000000000000000000000026338. DanielLC (talk) 03:38, 22 October 2024 (UTC)
    Wow, those are even smaller than the IEEE floating point representations of 1-1.0/3*3! 162.158.90.109 03:59, 22 October 2024 (UTC)
    The Planck temperature quip is definitely well deserved. Good catch! Mumingpo (talk) 17:24, 23 October 2024 (UTC)

    I guess I was wrong in my comment on the last comic. sigh. -P?sych??otic?pot??at???o (talk) 01:16, 22 October 2024 (UTC)

    It's actually spelled Wedgwood scale, not Wedgewood. Wilh3lm (talk) 01:17, 22 October 2024 (UTC)

    I still call the modern version of the "Celsius" scale "centigrade", but if people start nitpicking, I'm happy to switch to "Carolus" to avoid ambiguity. For some reason that tends to annoy people more though. 172.68.22.191 01:32, 22 October 2024 (UTC)

    Every temperature scale is equally "random" as every other scale. People always say that Celsius is so much better because it's defined by the phase changes of water. Okay, cool...why should THAT of all things be what we use as the base for a system of temperature measurement? And, who cares? I'm a Homo sapiens, not a water molecule. If anything we should use the freezing and melting points of humans as our two reference points for temperature (which, I must say, Fahrenheit approximates better than Celsius, assuming 0 and 100 are your points "A" and "B"). Pie Guy (talk) 03:42, 22 October 2024 (UTC)

    Every temperature scale is arbitrary, but since boiling and freezing water is a thing humans have a lot of experience with it makes sense to use that as the reference point. At least it makes more sense than whatever the coldest recorded temperature in Fahrenheit's home town was, because he didn't like negative numbers 172.70.250.23 03:56, 22 October 2024 (UTC)
    Planck temperature (as above) is probably the least arbitrary, and some would say it is to some extent free from arbitrariness. However, it's completely impractical for everyday use (as above.) 172.69.34.138 04:31, 22 October 2024 (UTC)
    Do the physics of black holes or neutron stars involve Planck temperatures greater than 0.0000001? Liv2splain (talk) 07:23, 22 October 2024 (UTC)
    Chat Gippity told me:
    Black holes and neutron stars do not typically involve temperatures reaching the Planck scale. While both objects exhibit extreme physical conditions, their temperatures are far below the Planck temperature, even though they can be incredibly high compared to everyday phenomena.
    - **Neutron stars** have surface temperatures in the range of millions of Kelvin, and the core can reach even higher, possibly up to a few billion Kelvin. These temperatures are still vastly lower than the Planck temperature.
    - **Black holes**, especially the smaller ones, can emit Hawking radiation, with temperatures inversely proportional to their mass. However, the temperature of even a very small black hole is still far below the Planck temperature. Hawking radiation is not expected to reach temperatures close to the Planck scale under normal circumstances.
    The Planck temperature (TP=1) represents an energy scale so extreme that no known physical models, including those describing black holes and neutron stars, operate near or above this threshold. Temperatures reaching **0.0000001 TP** (or 1.416 × 10^26 K) would still be beyond current observational and theoretical frameworks related to these cosmic objects. A quantum theory of gravity would be required to describe physics at or near the Planck temperature, which remains speculative and is far beyond the conditions found in black holes or neutron stars.
    Liv2splain (talk) 08:46, 22 October 2024 (UTC)

    If the °X scale is based on the temperatures of Earth from all time (for some definition of "Earth"), then the scale is very hard to define and highly impractical. The earth appears to have gotten to more than 2,300 Kelvin (hot enough to melt steel and platinum and to boil lead) and while I can't find any sources for the lowest temperature, I imagine it is lower than -100°C. The recorded minimum, maximum and average temperatures appear to be around -89.2 °C, 56.7 °C and 15 °C respectively. This would make the scale somewhat useful, but this would make typical values between 41 °X (cold winter's day) and 68 °X (hot summers day) which I think is pretty cursed. I recommend the clearly superior °Y, based around average temp at 0 °Y, low at -100 °Y and high at 100 °Y. These would be measured by the yearly high, low and mean temperatures averaged per person. Then saying "It's 2 times colder than yesterday" would have some reasonable meaning. --198.41.236.147 04:01, 22 October 2024 (UTC)

    "Record ... surface temperature" implies it was recorded. 172.68.22.9 04:08, 22 October 2024 (UTC)

    How do you all feel about adding an additional column for room temperature 22C/72F?

    Unit Room temperature
    Celsius 22
    Kelvin 295
    Fahrenheit 72
    Réaumur 18
    Rømer 18
    Rankine 531
    Newton 7
    Wedgwood -7
    Galen 0
    Real Celsius 78
    °X 59

    Or 0.00000000000000000000000000000208 °Planck, lol. 108.162.245.211 05:36, 22 October 2024 (UTC)

    I feel like decigalens would be the most practical unit. Who's with me? 162.158.186.5 06:20, 22 October 2024 (UTC)
    It's interesting; calculating the equilibrium temperature (with 2.05 and 4.24 being used for the heat capacities of ice and boiling water) gives 67... If I use water that's about to freeze and steam, I get 31. 172.69.0.178 07:59, 22 October 2024 (UTC)
    Would you please explain in more detail? Liv2splain (talk) 09:03, 22 October 2024 (UTC)
    The equilibrium temperature of a mixture (?) of equal quantities of ice at 0 C and water at 100 C (with the heat capacities 2.05 and 4.24) is 67 C; if I use the data for water at 0 C and steam, I get 31 C. Additionally, if I use equal volumes, I get 68 (which isn't much different.) 172.69.0.178 17:15, 22 October 2024 (UTC)
    One can obtain 0 = 22 C by setting the heat capacity of ice to be 39 and that of water to be 11. For any particular "normal temperature" R °C (that is, the temperature at 0 is R,), I find that x °C = 50R(x+4)/(x(R-50)+200). In particular, for R = 22, we get (1100+275x)/(50-7x). 198.41.236.163 05:58, 23 October 2024 (UTC)
    How about Tnew=0.1694×degC+46.25; degC=(Tnew-46.25)/0.1694, where 0 is absolute zero and 50 is room temperature? (Freezing point of water: 46.25; Boiling point of water: 63.19) 162.158.186.248 05:21, 24 October 2024 (UTC)
    I would absolutely pull the trigger on an additional column if I didn't think it would further screw up what are most probably extremely cursed mobile portrait renderings of the table. How about a Trivia section? Liv2splain (talk) 08:44, 24 October 2024 (UTC)

    Question regarding the X scale - when it‘s defined by *three* (somewhat, implying average is real and not just calculated by (max-min)/2)) independent points, how will linearity be achieved? 162.158.155.76 05:43, 22 October 2024 (UTC)

    Or click "[Expand]" in the bottom right table cell Derivation.
    Please see 2701: Change in Slope. 172.70.206.179 05:50, 22 October 2024 (UTC)
    Sure, "a linear scale between each point":
    Here you go. Liv2splain (talk) 06:33, 22 October 2024 (UTC)

    The reference for the average surface temperature, https://www.space.com/17816-earth-temperature.html, suggests it has increased above 15°C. What value should we use in late 2024? Liv2splain (talk) 07:30, 22 October 2024 (UTC)

    The World Meteorological Organization, Carbon Brief, and Copernicus Climate Change Service suggest 17.16°C. Liv2splain (talk) 07:42, 22 October 2024 (UTC)
    Updated water temperatures, Derivation, and graph. So we've already had more than the +2°C warming we were trying to avoid in 2019? Liv2splain (talk) 08:05, 22 October 2024 (UTC)
    The +2°C (or +1.5°C that we were originally supposed to be avoiding) is over some (undefined) number of years, though, which allows us to ignore the fact that we're cooking ourselves by repeatedly saying 'Oh, but it doesn't count yet.' 172.70.91.62 11:13, 23 October 2024 (UTC)

    Regarding [1], are the average surface temperatures from the sources supposed to be yearly or overall averages? Liv2splain (talk) 09:06, 22 October 2024 (UTC)

    According to https://climate.copernicus.eu/climate-indicators/temperature the global average near-surface temperature in 2023 was 14.4 + 0.4 = 14.8°C. (see Figure 1 and click "Increase above: [1991–2020 reference period].") 172.68.22.8 21:06, 23 October 2024 (UTC)

    where is the interactive epic 3000 comic we should've gotten? This one's cool but 1000 seemed to have more effort in it and 2000 was at least tangetially related. Does Randall just not like making these anymore and is only making more comics as a business? 108.162.238.185 12:14, 22 October 2024 (UTC)

    The comic is free on the website and it doesn't have ads; although the comic is part of his "brand" there are many more profitable things he could be doing with his time, and yet he continues to update it every Monday, Wednesday, and Friday. I just don't like the idea of claiming that a creative person "should" produce any particular thing to satisfy their fans. He's a busy guy! Maybe he's working on a book, or a Scientific American article, or a TV show. He's under no obligation to give us anything, and maybe one day he'll stop making xkcd altogether; that's his choice. Sorry to single you out; I know a lot of people feel the same way as you do, but to me it doesn't make sense. He's not a content machine--he's a guy who started posting sketches on the internet. Dextrous Fred (talk) 15:23, 22 October 2024 (UTC)
    Sorry if I sounded overly brash, I wasn't trying to imply "wahhh no special entry wahhh", I was just wondering if Randall still likes to make these or if he doesn't, mainly because he just didn't do anything special, which feels like he just didn't care. I wasn't trying to imply Randall should just do it for the fans108.162.238.80 17:52, 22 October 2024 (UTC)
    It could be that 3000 (or even 3001) was going to be special but, as fairly frequently with April Fool 'specials', it just wasn't doable on time. (If it's still considered fixablez it might pop up sometime before 3020 or so. Or, if transferable to another occasion (rebranding the obvious "3000!"ness), held over until Haloween, Christmas, April or 4000, perhaps with additional perfections.)
    Hard to know, unless Randall (or his technical collaborators) say anything. And it's probably not worth doing so right now. Maybe "Hey guys, this was going to be #3000!" might accompany its eventual emergence, but also maybe not. Does it really matter? 172.70.85.139 13:03, 23 October 2024 (UTC)

    Is this the first list-style comic where every single entry is real? (Usually he has several joke entries.) 172.70.114.182 14:26, 22 October 2024 (UTC)

    Where would Felsius go on this list?

    One can find a smooth function for °X, namely, (477879x-17634840)/(3341x+197700), which takes °X and returns °C. The inverse is (-197700x-17634840)/(3341x-477879). Should this be included in the wiki article? Or maybe another way of fitting it (like exponential) should be used. 172.69.0.165 06:27, 23 October 2024 (UTC)

    It says "a linear scale between each point". 172.70.210.130 21:09, 23 October 2024 (UTC)

    Should it be noted that in the first _What If?_ book, there's a reference to units and how much Randall loathes rankine? Someone can go take the book and cite it; it's in one of the early pages 172.64.236.10 08:45, 23 October 2024 (UTC)

    I remember it being drummed into us in school physics (admittedly over 50 years ago) that 0 Celsius is defined as the melting point of ice, not the freezing point of water (presumably because of supercooling). 172.70.160.189 08:49, 23 October 2024 (UTC)

    It seems he wrote "Earths'" (plural possessive) instead of "Earth's". 141.101.98.151 08:58, 23 October 2024 (UTC)

    What? No gas mark? It's linear for temperatures over 275°F but inverse powers of 2 below That's pretty cursed, but I still put it in my unit conversion app. It's only used in gas stoves in a few countries, so it doesn't come up very often. By the way, boiling is 1/5.7358 and freezing/melting is 1/843.3572. Interestingly, France has it's own stove temperature scale that seems to be based on °F.

    Also, my understanding is that 7.5 and 32 aren't random. Both Romer and Fahrenheit put numbers on things so that freezing/melting of water and "Normal human body temperature", which was thought to be standard at the time, would be some number X (15 for Romer and 64 for Fahrenheit) and the water thing would be to be X/2 and NHBT would be X/2+X. Pretty nerdy. Sadly, the calibration was off and 212 degrees for boiling was found to be less cursed. But I could be wrong.172.68.54.138 20:39, 23 October 2024 (UTC)

    Re: water/ice point 'random number', I think it's more that it wasn't considered "special", such that "On my scale, that will be zero" (or whatever choice of handily round number, including zero, some scale-setters allocated to the BP of water).
    After all the other messing about ("my zero will be that of brine!", etc), obviously then the ~0°C equivalent would have a number, and perhaps there would then be a slight change to make it a whole (or easy-fraction) number for convenience's sake, but (before the concept of binary computers) there's not much special about landing on the number 32, for what is actually a temperature that is quite significant to the human experience, and less so with 7-and-a-half.
    Maybe landing on 90°F (at one time) for body temperature (and 180 F° between MP and BP) was considered useful as the analogue to angular-degrees where 90 (and 180) indeed features significantly, but I don't think there'd have been too much fuss if the value would have turned out to be 60(/120), also with plenty of handy factors to divide by, 70(/140), without so much, or whatever number(s) happened to depict one realistic real-world measurement that (overall) has no reason to have a factor-based relationship with various quite separate phenomenon measurements.
    And it went through several 'corrective' iterations so that even its handy relationship with 'about 100°F' can be said to be an incidental accident, at best, unless we do something like Randall's °X scale and actively triple-tie the central value of the slope(s) to be exactly something useful by using the "currently accepted mean human body temperature (given various complicated caveats)".
    It's pretty much all random, in the same way that only because of anthropocentric choices of 'standard' time and distance measurements is the speed of light 'pretty much' 3×10⁸ m/s (a handily round value that works well enough for most purposes, even after back-standardising its component SI measurements to make "actually, precisely 299792458" the proper answer, and it could be far worse...). Avagadro's number never had it so good (6.022(+change)×1023...? ...where's the handily mnemonic value in that?), and Pi (in this universe's system of fundemental mathematics) clearly never ever had a chance! And, on at least one occasion, such happenstance numeric roundedness in its exactitude (29,000 ft) was considered actually quite awkward... 172.70.91.90 21:33, 23 October 2024 (UTC)
    My understanding is that the brine thing was an ad-hoc justification when the scale was presented to the Royal Society. It may have seemed less cursed. But yes, there's a BIG reason for using 32 or 64, halving a distance is trivial and as an instument maker, Fahrenheit would have found that attractive. Mind you, I'm getting this from the Straight Dope, so I could be a dope getting it straight. https://www.straightdope.com/21344240/did-cecil-err-in-explaining-the-significance-of-zero-fahrenheit 162.158.10.189 20:04, 24 October 2024 (UTC)

    Ok, then, regarding this edit (and the original IP-led one(s) that even made huge and revert-necessary changes), was it really intended to get rid of whole paragraphs such as "Randall also fails to specify what happens with temperatures[...]" that had nothing to do with the numeric adjustments? When I see that, I see mistakes (especially in light of the "clobber" that happened, where typos reappeared and other things became unexplained/worse-explained once more). — Basically, if your edit summary is nust about updating baseline data, and the resulting maths, I don't expect (maybe good, maybe bad) edits to unrelated bits. Or I may (and have) presumed accidental (or deliberate?) carelessness that I'd rather not try to go back to first principles to re-re-check for the editor concerned. That is all. At least try to justify enough of your edit in its own way, even if it means diving in several times to get enough space to summarise your whole "why" to each tweak. 172.68.186.104 22:44, 23 October 2024 (UTC)

    Yes. I have re-removed the removals piecemeal with individual edit summaries for clarity. Many of them involved detailed obscure technical misunderstandings, such as whether the Vostok and Death Valley measurements were surface temperatures (the WMO says they are, and there are the WMO's photos of the observation stations in the linked references now) which combined with the incorrect yearly average global mean temperature, added five paragraphs unnecessarily. 172.68.23.152 01:46, 24 October 2024 (UTC)
    Definitely some points made (some incorrect, "ne er" was obviously more just a basic typo of "never", not my attempt to use "ne'er" for no good reason, and my attempt to fix that and some other bits ran into a set of Edit Conflicts ...hope I caught all the remaining ones when I finally could try again on the settled-down page) and I've blended answers to your objections in while giving back what useful nuances (from a number of past editors, only a couple of bits even having had my own hand primarilly behind them as they were) really needn't have been removed. I dispute the terms of your objections (as summarised) behind some changes, but have rephrased based upon what I think you mean, giving you should prefer and wouldn't feel the need to be as randomly censorious about. 172.69.195.173 02:54, 24 October 2024 (UTC)
    Figure 1 in https://climate.copernicus.eu/climate-indicators/temperature does not seem like a random walk to me. 172.69.33.118 05:02, 24 October 2024 (UTC)
    Added the "Random Walk" because, ignoring long-term trends, year-on-year the measured average is going to blip up and down for all kinds of reasons (physical and measuring issues, both), so it will be lower than expected or higher than expected compared to the smoother track it actually takes on a rolling average. I think one of the versions I replaced had partial suggestion that the average was effectively constant (in °C, not just °X), and while records adjusted every now and then (or every year!), it all just rather settled down at the °X midpoint. Which it doesn't. (And also that it's possible that Average and Minimum change such that the projected Absolute Zero doesn't move so much, one year, although mostly the fulcrum will be closer to 0°X rather than 0K.)
    But I've yet to see what's been changed (maybe improved) since I was last looking at it. Maybe this is an out-of-date explanation. 172.70.90.202 12:04, 24 October 2024 (UTC)

    When I originally designed my unit conversion app I almost made a unit up that was based on the ideal gas law and one mass pound of said gas in a one cubic foot container. It seemed more quixotic than anything else so I didn't pull the trigger on it. Maybe I should have.172.70.111.33 20:38, 24 October 2024 (UTC)

    Is x based off of elon musk changing twitter to X? 172.71.254.50 23:22, 24 October 2024 (UTC)

    Too many things were already "X" (X marks the spot, Planet X, The X-Men, Xmas...), I see no need to presume that Elon has successfully claimed ownership of one entire letter of the alphabet due to a car-crash business deal and a self-obsessive personality. To paraphrase Freud, "sometimes an X is just an X", and with no references at all to anything Twitter-like I don't see any other intent than just as a traditional placeholder character. 172.70.90.209 09:40, 25 October 2024 (UTC)

    Ummm... why do we have the Explanation give the idea that the record highest global temperature is rising every year (or almost), when the actual reference temperature that the Explanation (and calculation) uses (with supporting reference to wikipedia) was apparently in 1913? I think we've been confused by the average global temperature rising year-on-year, but somewhat hit the buffers on what (non-controversial) highest just-off-the-ground air temperature we can actually currently get (at least without much stranger solar activity starting to dominate).
    Incidentally, plotted against years, this means that the above-average temperature gradient is lessening over time, and the below-average gradient (excepting any future surprises at Vostok) is increasing over time... making me wonder if we had a time when °X was completely linear (50°X was precisely central to 0°X and 100°X, with no inflection point forced). Not going to follow thaat idea up, as probably you'd need a historical record of records that went back to before a reasonable global accuracy/completion of data was available. 162.158.33.224 17:32, 26 October 2024 (UTC)

    Division by zero

    I saw this in an edit summary: "10/0 is not ∞, it's also an error, not NaN according to the IEEE. It's closer to {+∞, -∞} than NaN but it's still neither because you can't make limits work"

    Actually, IEEE floating point 10/0 can be an error, +∞, or NaN depending on the rounding mode. This is one of the reasons why mathemeticians don't appreciate the IEEE as much as they might. Division by zero is strictly undefined because of the problems with limits alluded to in the summary. https://www.youtube.com/watch?v=dHdg1yn1SgE 108.162.245.66 03:48, 24 October 2024 (UTC)

    "When considering division by zero through limits, assigning {+∞, -∞} as potential results is insufficient because limits require consistency and well-defined behavior. In the case of dividing a number by values approaching zero, the results differ depending on whether zero is approached from the positive or negative direction. As a divisor approaches zero from the positive side, the quotient grows towards +∞, and from the negative side, it tends towards -∞. Since limits must converge to a single value for consistency, this disparity leads to an undefined result. Moreover, in many mathematical contexts, infinity is not a number but rather a concept describing unbounded growth, meaning operations involving infinity, like addition or multiplication, are not well-defined in the same way as with finite numbers. This inconsistency in approaching zero prevents {+∞, -∞} from being an adequate solution set for division by zero. Defining division by zero as infinity would create contradictions in both arithmetic and algebraic contexts, as it disrupts fundamental properties like continuity and field structures in mathematics. Hence, division by zero remains undefined to preserve mathematical rigor and coherence."
    [Chat Gippity 4o] Liv2splain (talk) 08:53, 24 October 2024 (UTC)
    https://imgflip.com/i/7yd7gz 172.71.150.131 09:06, 24 October 2024 (UTC)

    Examples section table values?

    Someone please double-check the Trivia Examples section temperatures. I am not convinced they are entirely correct or consistent. I'm least sure about the Galen row. And Wedgwood obviously needs more digits of precision. 162.158.41.28 13:10, 24 October 2024 (UTC)

    LGTM. Liv2splain (talk) 20:55, 25 October 2024 (UTC)

    The Newton scale isn't linear: see https://www.whipplemuseum.cam.ac.uk/explore-whipple-collections/meteorology/early-thermometers-and-temperature-scales and https://instrulearning.com/temperature/temperature-scales/ ... not sure how we should address this in the framework of the explanation. 162.158.42.64 22:43, 26 October 2024 (UTC)

    Fixed for the nonlinearities of Newton and Galen scales. Liv2splain (talk) 23:17, 26 October 2024 (UTC)
          comment.png  Add comment
    Retrieved from "https://www.explainxkcd.com/wiki/index.php?title=3001:_Temperature_Scales&oldid=354327"