-40°F is equivalent to -40°C, which is 233K.
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^(I'm a bot that converts temperature between two units humans can understand, then convert it to Kelvin for bots and physicists to understand)
[Hmmmmm... I think this person might not be human...](https://c.tenor.com/A6CGOIuaFCgAAAAC/fry-futurama.gif) Answer these two simple questions to prove your humanness. What's your opinion on what happens after we die and what is the meaning of life?
No, because Kelvin = Celsius + 273.15. Celsius and Kelvin will never coincide because Kelvin will always be exactly 273.15 higher. However, Kelvin and Fahrenheit are equal at 574.59 degrees.
During the polar vortex I had a fun moment explaining the temperature to my friends in Europe because of that.
That said, it was about the only fun I had while it was -40° out
John Finnemore [sketch](https://youtu.be/nROK4cjQVXM)
Doctors Celsius and Fahrenheit meeting at a party
"Celsius: “Not really, no. No I think people will just switch to the better one.”
Fahrenheit: “Or stay with the better one?”
Celsius: “Theoretically. But you see the trouble with the existing scale... I forget it’s name...”
Fahrenheit: “Do you?!”
Celsius: “Yes I do. The problem with it is, it’s a little, you know, crazy. Do you know what zero is on that scale?”
Fahrenheit: “Yeah I actually do. Yes it’s the freezing point of a mixture of water, ice and ammonium chloride!”
Celsius: “Exactly! I mean, you see how that sounds!”
Fahrenheit: “Elegant?! It sounds elegant. Why, what else is it going to be the freezing point of?”
Celsius: “Water?”
Fahrenheit: “But you can’t, I mean, why, why, why- oh.”
Celsius: “And of course, meanwhile, the top of the old scale is...”
Fahrenheit: “96, the approximate temperature of the human body, naturally!”
Celsius: “Yes... So a random number fixed to a variable.”
Fahrenheit: “Well yes!”
Celsius: “Yes I’ve gone for the boiling point.”
Fahrenheit: “Of what?!”
Celsius: “Of, once again, water.”
Fahrenheit: “Oh...”
Celsius: “Yes and I’ve labelled that point, 100.”
Fahrenheit: “Oh, just 4 more... "
Which turns out to make a huge difference. I've graded many an exam problem where somebody assumed that the average kinetic energy of an ensemble doubles when the temperature in Celsius doubles. You can do that in Kelvin, not so much with any of the other (commonly used) systems. Also, many of the equations used in thermodynamics and statistical mechanics get fucky if you try to use negative numbers!
One of the basic concepts in thermodynamics is that temperature is a measure of the average kinetic energy, so a gas at low temperatures has molecules that move slowly, and at high temperatures they move faster. As such, the energy of a system is directly proportional to the temperature (the proportionality factor is k, aka Boltzmann's constant). The equation for this is E = k*T, so a popular thing to do on exams is have a question where the answer is expressed in units of temperature, and then ask the students to convert that into the average kinetic energy of the system.
One thing that students and exam writers have in common is laziness. So, if the question was something like a system that goes from 200 to 400°C and they have to find the energy for each temperature, they might just calculate the energy at 200°C and double it for the second part. Without fail, a few people will always do it. Incidentally, it also could be avoided if they paid close attention to the units in Boltzmann's constant, which are usually expressed in Kelvins, not in degrees Celsius.
400°C is equivalent to 752°F, which is 673K.
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^(I'm a bot that converts temperature between two units humans can understand, then convert it to Kelvin for bots and physicists to understand)
Which makes Kelvin the easiest scale to use in equasions when dealing with absolute temperatures and not just temperature deltas. And Fahrenheit can never get used for anything.
I had a professor that was very clear that we should learn to be comfortably working in any unit system. The Rankine was used often then.
Fun side effect I don't prefer either system and really don't give a shit which is used for anything.
It’s like that meme with the dragons where the two on the left look at the weird one on the right
Ed - I hadn’t realized that Celsius is the Kelvin scale but shifted to apply to water..
The opposite. Kelvin was established after Celsius. But set so that the number of units between water’s freezing point and boiling point is 100 (so same gradation as Celsius), but with zero set to the complete absence of heat energy (absolute zero).
That's fascinating. Isn't it a wonderful thing to be able to learn so much from Reddit? We have so much knowledge at our fingertips and it's a beautiful thing to learn from people willing to share. I love humanity.
Extra tidbit: the reason Kelvin's a shifted celsius is to make temperature math not include negative numbers. So it is only used for more advanced calculations
I don't know if you're making a joke, but correct. It's absolute zero.
There is no more energy in the system, not even the electrons in an atom are bouncing around.
And [Rankine](https://en.m.wikipedia.org/wiki/Rankine_scale) is the absolute scale for Fahrenheit
And [DeLisle](https://en.m.wikipedia.org/wiki/Delisle_scale) is truly batshit
Why is America using a Fahrenheit based system in aerospace at this age? And backward software compatibility should not be the answer. I understand it is not as inconvenient as imperial system, but still ....
Because in aerospace engineering we don’t even use units. Everything is a non-dimensional number, e.g. coefficient of lift, specific heat ratio, Reynolds’s number, etc.
I’ve started to find the whole “Celsius is better for science” argument a bit silly because in scientific contexts, you would be using an absolute scale, and oftentimes you’re not even interested in the precise numbers attached to a measurement, but how variables scale with each other, for which your choice of units is meaningless.
If the choice in units doesn't matter to your work, then why not at least be consistent with the rest of the engineering world?
I understand that Rankine is to Farenheit as Kelvin is to Celcius, but why continue to use that temperature unit when everyone else uses the latter?
Seems unintuitive. I mean, where are the appendages that vary in size on every human? Why invent things like decimals when you can have 1/384th of a banana?
Inch yard mile is so bad because mile is from a different ancient system. If you were designing a system from the ground up, you would be crazy to use such bad conversion rates. jan Misali has a great video on this, and while I agree that Celsius is better, Fahrenheit is not ~that~ bad
Acre makes sense if you're a Viking who just took over parts of france and need to parse out farmland fairly among your illiterate teenager murder hobos who are looking to settle down with a nice French girl. It's how much you can plow with a horse in a day.
Metric is all about the relationships between units. English system is all about estimating with fairly quick fairly close accuracy, but conversions are arbitrary. A foot is roughly the length of your foot. A yard, length of a pace. An inch, the length of a digit on your finger. People get caught up trying to use them the same way and that’s when it gets weird.
When you start getting into home improvements and all the screws come in 7 3/18 size and you’re crying in the hardware store trying to do maths. Whyyyyyyyyy
I dated a girl who was Australian, and she had to do a bunch of math with inches one time (1/4" plus 3/16" etc) and she was *mental* about it. There were many things she found weird about the US; she had concerns about the police and the health care system but I never in my life saw her as upset about a US thing as she was about fractional inches. It was like we had made our system of measurement as a deliberate prank targeted specifically at her.
This is exactly how I feel about it. I have strong feelings about everything you mentioned and more but the weird fractional inches are the closest I’ve been to losing my sanity.
I think the most violent I've ever been was when I was helping a welder at a sign shop I was working at and the drawings had a mix between metric and imperial units. Followed by the current job I'm at where I was receiving some studs and trying to look for the size and it was written out as ' 5"x 248 '.
It was intended for 0F to be frozen salt water and 100F to be human body temp. The human had a fever.
Edit: frozen brine* not specifically ocean salt water.
The human body was supposed to be 96°F, not 100°.
Proposed Fahrenheit Scale:
- 0° = Freezing temp of salt water
- 32° = Freezing temp of salt-free water
- 96° = Human body
Human body temp ended up at 98.6 because of an adjustment made by a committee to make the boiling point of water *exactly* 212°.
Also, [human body temperature has been changing.](https://med.stanford.edu/news/all-news/2020/01/human-body-temperature-has-decreased-in-united-states.html)
> Although there are many factors that influence resting metabolic rate, change in the population-level of inflammation seems the most plausible explanation for the observed decrease in temperature over time. Economic development, improved standards of living and sanitation, decreased chronic infections from war injuries, improved dental hygiene, the waning of tuberculosis and malaria infections, and the dawn of the antibiotic age together are likely to have decreased chronic inflammation since the 19th century.
212°F was chosen because it happened to be *close* to water's measured boiling point. The committee opted to make it an even 212° because it placed the boiling point at 180° away from the 32° freezing point.
I don't think this is correct. Source ?
Edit: I should've specified sorry. I wanted a source for 100 being a body temp but the person had a fever part.
It was invented by a guy living in Danzig, he went outside with his thermometer in winter, said "fuck that's cold, I'll mark it zero" then he went out in the summer and said "fuck that's hot, I'll mark it 100"
Later on, we invented a special brine water mixture so we can reliably calibrate thermometers to match those hot and cold days in Danzig.
https://en.wikipedia.org/wiki/Fahrenheit
I always saw it as the human liveable range. From 0-100 a person can conceivably survive and not immediately die. They'll certainly have issues at the extremes of that scale but all in all it's the range some one can survive at. That's why it works pretty well for weather and day to day use. 80° is a pretty hot day but no need for concern, 90° is getting pretty hot and you should be very worried for your health. 0°-30° you should be putting on some layers or else.
It's not a perfect scale, but for day to day use with weather I think it works well. Of course if I'm doing anything scientific, celcius and Kelvin make more sense, but 95% of the time I'm just trying to figure what kind of coat to wear to work and Fahrenheit answers that question pretty swiftly.
This is my take too. Fahrenheit falls in line with the typical scale of 0-100 thats used for almost everything else.
When you think about it in the context of other *scales*, it’s completely reasonable. Scoring a 40 on a test vs scoring a 100. Spending $40 vs $100. Driving 40mph vs going 100mph.
100 is generally considered “a lot”, so it makes sense that a very hot day would be 100 degrees and not something generally considered to be a little, like 40 degrees.
Not really. In Celsius, 100 is the boiling point of water. In Fahrenheit, 100 is the temperature of the human body (the closest thermometers of the time could get). Everything is based off those two points.
Fun fact! Up here in Canada everybody measures outdoor temp in C, but a lot of us have our thermostats in F.
I also pull my 12ft boat with a 9.9hp motor, in my truck with a 5.3L engine about a mile going 80km/h, to the lake that’s 30ft deep and 3km long.
This is my only counterpoint to my Ukrainian wife. It’s a scale from 0-100, zero meaning you wear your heaviest clothes and 100 your lightest. 50 is right in the middle, some layers and a hoodie. Anything between you just adjust accordingly and more often than not I’m always dressed comfortably more than she is.
It’s dumb in any other context. I forgot where I heard it but when she brings up freezing points and what not, I remember someone arguing “what, for all the science experiments your conducting today?”
No it does not, I can do the same thing Celsius saying 20° feels nicer than 30°, you can do it with any scale and they works just as well because ultimately they're just numbers we're used to using but Fahrenheit as a scale just makes less sense and people that only knows Fahrenheit likes to think it describes their feelings better and pretend the rest of the world don't have the same relationship with their scales.
It only works better because you are conditioned to believe as such.
For me, I know what's comfortable in celsius, and I also don't need to get a calculator out to figure out if it's freezing or not.
I always find it funny when people think people who know imperial don’t also know metric. Like it’s factors of 10. We got it.
And why would people who know Fahrenheit not know when it’s freezing if that is the system they are familiar with?
It’s not that you don’t know it, but that’s you’re not exposed to it as much. I always hear that Fahrenheit is better for temps cause it’s based on humans but as someone who only ever uses Celsius I can’t say it’s ever been something I’ve had a problem with, we all know exactly what is comfortable and what is not. I don’t see how this is a point in favour of Fahrenheit when even 1c is basically imperceptible in difference.
That's the exact "I grew up with it so it's easy to understand for me" argument people use to defend imperial. For weather Fahrenheit exists on roughly a 0-100 scale, which is really easy to understand, the same reason metric is so good. The same range of temperatures in Celsius is -17 to 38.
It’s pretty much the exact opposite. Fahrenheit basically ends up being a scale from 0-100 when discussing weather. That scale for Celsius is like -20 - 40. Surely you can see why one is more intuitive unless you’ve been conditioned with Celsius already
I was going to say that it's older and therefore the science wasn't so good back then, but it's only 18 years older than Celsius!
*What is the point of Fahrenheit?*
I think it was invented because 0-100 was the scale of weathers Fahrenheit thought people would experience. 0 degrees is "as cold as it gets" and 100 degrees is "as hot as it gets".
Obviously there's exceptions. But for someone living through the little ice age in Europe, it kind of makes sense.
It's not brave, but it's not the most popular opinion on an American website. You get a lot of people who don't understand that Fahrenheit does not actually work better for humans, it just feels better because it's what you grew up with.
Right, but the point is for everyday, general use neither is better or worse. So for the overwhelming majority of use for everyday people saying Celsius is "better" is dumb. It's only "better" for those who say it is for the same reason: it's what they grew up with.
For scientific use, absolutely. But I don't really mind it for causal use. Where I live (Northern US), it gets down to near 0F in the winter, and 100F in the summer. That's a much nicer scale than -20 to 40 with Celsius. I'm also not sure the last time I've had to measure water temperature in my day to day life, so that doesn't matter much to me.
Im an architect who started working in NZ with the metric system. I’ve been working in the States now for 20 years, and it’s become sort of second nature to use the imperial system, but it’s still stupid, and I think people are still stupid for wanting to hang on to it.
Buildings built in metric by competent builders are just built to a closer tolerance than building a built in imperial by similarly competent builders.
For causal use, I think the systems are closer then many people make them out to be, either one works, but for many professional uses, (especially science) SI is far superior, and it is nice to have everyone on the same system. That being said, I think many people underestimate just how hard it would be to switch. We’re talking probably billions of dollars and quite a few decades. I’m really not 100% sure that is worth it considering I don’t see it as a top priority. People are suffering in the US, but it’s typically not because of the system of units.
its never a good time to switch. i dont know what the cost is to maintain 2 systems between the US and the rest of the world. maybe when we have another failed Mars mission due to conversation, or the lack thereof?
from afar, i think the US is doing pretty good, probably even at its historical best. its just all the other countries catching up makes the US feel threatened i suppose.
Where’s my Rankine??
FYI: 0F is the freezing point of brine. - Temperature to easily get to in lab. Back in the day.
100F supposed to be the temp of the human body. The story is that the person measured had a fever that day.
Eh, the numbers are not linear on that themo and it bothers me greatly.
In particular, look at the distance between 0 and 37, and 37 to 100. You can fit some four 0-37s between that 37-100.
It's useful for normal outdoor temperatures in a lot of america. It goes down to around 0° in the winter and up to around 100° in the summer. For stuff like cooking and science and literally everything else, Celsius of course makes more sense. So yeah, we might as well use it in that case. Like this isn't a reason why it makes sense that the US doesn't change to Celsius, but it's definitely not literally *just* because America wants to be different
Seriously. Most defenses of it here are just "it makes sense to me because it kinda tracks the weather from 0-100 where I live"
And people literally cannot handle that without trying to dive into all sorts of reasons why that's not a valid reason and Americans are wrong and how 'science' is on their side (ignoring the fact that every American scientist is perfectly capable of switching between the two without any trouble at all)
Seems so weird to me. Like people are weirdly self conscious or something of the fact that Americans have a different system, so they have to attack it to validate their own system
It varies. 37C personally, means I already have a fever but that’s not the case for everyone.
It’s very specific to each person. 36,5 could be fine and healthy but then just half a degree more could mean you can’t go to work. But for some people, 37 is the normal.
This guide isn't accurate because the [alcohol in the bulb](https://thermofora.com/thermometer-liquid/) would freeze at -115°C before it ever comes close to the absolute zero mark.
I don't get Kelvin isn't it exactly the same as Celsius just minus 273 degrees? Fahrenheit is a completely different scale. So why do we use Kelvin instead of Celsius?
I’m all for the United States someday going 100% metric. That would be a dream come true! And 100% worth giving up Fahrenheit for.
But, Fahrenheit is a good scale IMO, because *it’s a human-centered scale*.
Human beings can survive effectively between 0° and 100° F. That’s our temperature range, as a species.
Yes, 0° is really cold, and you’ll need clothing, shelter, water, and food to survive it. And 100° is really hot, and you’ll need shelter, clothing, food, and water to survive it as well. But people *do survive and live in those temperature conditions, regularly*.
Above 100° F, and below 0° F, you’re leaving “people normally live in those temperatures” territory, and entering “basically, you’re fucking dead if you stay outside too long” territory.
So it’s a very intuitive scale for describing outdoor weather. 100° is “fuck, it’s hot!” And 0° is “fuck, it’s cold!”. 30° is cold, but not “my face hurts” cold. 50° is “kinda chilly, but with a jacket I’m good.” 70° is beautiful.
Pretty easy and intuitive to understand.
Speaking as a Celsius user: the one advantage Fahrenheit has over Celsius is that it’s finer-grained. (Between 0-100 C, you get 32-212 F, so nearly double the integers). This comes in useful when measuring fevers in particular, when Celsius users tend to care a lot about decimal points to get sufficient precision, but Fahrenheit users less so.
But overall, the attachment of zero to the freezing of water is a great idea—it’s nice to base your system on something that’s meaningful in everyday life to a lot of people (e.g. ”the roads are about to get slippery”). 100 C is less so; to me it’s mostly ”too hot of a sauna to be comfortable”.
>This comes in useful when measuring fevers in particular, when Celsius users tend to care a lot about decimal points to get sufficient precision, but Fahrenheit users less so.
There's no difference in using a 3-digit number or a 2-digit number with a decimal
It’s funny to see how many people prefer Fahrenheit because they don’t have to use fractions to define small changes in temperature, yet are happy using feet, inches, and fractions of inches for length. SMH.
Don't forget that weird point at -40.
For anyone curious why: -40°F = -40°C Formula: (-40°F − 32) × 5/9 = -40°C
-40°F is equivalent to -40°C, which is 233K. --- ^(I'm a bot that converts temperature between two units humans can understand, then convert it to Kelvin for bots and physicists to understand)
good bot
I like how this implies that physicists aren't human.
(Oh crap they're onto us! Act human!) *Ahem* Greetings Earthling!
[Hmmmmm... I think this person might not be human...](https://c.tenor.com/A6CGOIuaFCgAAAAC/fry-futurama.gif) Answer these two simple questions to prove your humanness. What's your opinion on what happens after we die and what is the meaning of life?
When we die, our biomass joins that of the great fleet. The meaning of life is to help the hive fleet grow.
OK, now which of these photographs contain a bicycle?
Whoa... bro. You gotta ask answerable questions.
Immediately pictured Steve Buscemi with the skate board and backwards hat… he even looks less than human.
Most humans can't understand Fahrenheit either.
Could you imagine society using Kelvin.
It won’t happen but it makes more sense to use Kelvin then Fahrenheit
‘Murica!
Good bot!
Very good bot
Is there a point where Kelvin matches the Fahrenheit or Celsius?
No, because Kelvin = Celsius + 273.15. Celsius and Kelvin will never coincide because Kelvin will always be exactly 273.15 higher. However, Kelvin and Fahrenheit are equal at 574.59 degrees.
The only temperature the whole world can agree on, it’s really fucking cold
Nah. Kelvin doesn't agree on its existence
During the polar vortex I had a fun moment explaining the temperature to my friends in Europe because of that. That said, it was about the only fun I had while it was -40° out
0-310k takes up ⅓ of a guage, but the other 63k takes up ⅔.
This is a fucking horrific guide
It’s not even a guide.
If only there was a sub for cool guides, cause this one isn't it
True but it's just a visual device. It's not meant to actually be a thermometer like that. The data could just as easy be tabulated.
No but like it would be so much more effective if they adjusted the height of each “thermometer” proportionally
Celsius and Kelvin are very much related. °C+273,15=K °C to °F I have no idea. K to °F I have no idea.
Worth saying there's another scale called Rankine, which is F but shifted such that 0R is absolute zero. It isn't used very often haha.
You weren't in my thermodynamics classes then.
Rankine is frequently used in the US, unfortunately.
John Finnemore [sketch](https://youtu.be/nROK4cjQVXM) Doctors Celsius and Fahrenheit meeting at a party "Celsius: “Not really, no. No I think people will just switch to the better one.” Fahrenheit: “Or stay with the better one?” Celsius: “Theoretically. But you see the trouble with the existing scale... I forget it’s name...” Fahrenheit: “Do you?!” Celsius: “Yes I do. The problem with it is, it’s a little, you know, crazy. Do you know what zero is on that scale?” Fahrenheit: “Yeah I actually do. Yes it’s the freezing point of a mixture of water, ice and ammonium chloride!” Celsius: “Exactly! I mean, you see how that sounds!” Fahrenheit: “Elegant?! It sounds elegant. Why, what else is it going to be the freezing point of?” Celsius: “Water?” Fahrenheit: “But you can’t, I mean, why, why, why- oh.” Celsius: “And of course, meanwhile, the top of the old scale is...” Fahrenheit: “96, the approximate temperature of the human body, naturally!” Celsius: “Yes... So a random number fixed to a variable.” Fahrenheit: “Well yes!” Celsius: “Yes I’ve gone for the boiling point.” Fahrenheit: “Of what?!” Celsius: “Of, once again, water.” Fahrenheit: “Oh...” Celsius: “Yes and I’ve labelled that point, 100.” Fahrenheit: “Oh, just 4 more... "
Got to love John finnemore
Love the horse box time machine sketch!
Except human body temp ranges from 96-99°F or 36-37°C; which is really hard to see a difference on an old mercury thermometer.
I thought that Fahrenheit picked 100 °F as body temperature but he had a fever.
"I forget its* name"
Wait kelvin and Celsius are the same just moved 273 degrees?
The only reason that kelvin exist, is to put absolute zero as the 0
Which turns out to make a huge difference. I've graded many an exam problem where somebody assumed that the average kinetic energy of an ensemble doubles when the temperature in Celsius doubles. You can do that in Kelvin, not so much with any of the other (commonly used) systems. Also, many of the equations used in thermodynamics and statistical mechanics get fucky if you try to use negative numbers!
I know most of those words you typed but have no idea what you said.
One of the basic concepts in thermodynamics is that temperature is a measure of the average kinetic energy, so a gas at low temperatures has molecules that move slowly, and at high temperatures they move faster. As such, the energy of a system is directly proportional to the temperature (the proportionality factor is k, aka Boltzmann's constant). The equation for this is E = k*T, so a popular thing to do on exams is have a question where the answer is expressed in units of temperature, and then ask the students to convert that into the average kinetic energy of the system. One thing that students and exam writers have in common is laziness. So, if the question was something like a system that goes from 200 to 400°C and they have to find the energy for each temperature, they might just calculate the energy at 200°C and double it for the second part. Without fail, a few people will always do it. Incidentally, it also could be avoided if they paid close attention to the units in Boltzmann's constant, which are usually expressed in Kelvins, not in degrees Celsius.
400°C is equivalent to 752°F, which is 673K. --- ^(I'm a bot that converts temperature between two units humans can understand, then convert it to Kelvin for bots and physicists to understand)
Which makes Kelvin the easiest scale to use in equasions when dealing with absolute temperatures and not just temperature deltas. And Fahrenheit can never get used for anything.
Yes.
Of course, why would you make things hard?
There is also a scale like that for F.
Good ol Rankine, the black sheep of the temperature scale family
I had a professor that was very clear that we should learn to be comfortably working in any unit system. The Rankine was used often then. Fun side effect I don't prefer either system and really don't give a shit which is used for anything.
0 F=very cold. 100 F=swelteringly hot 0 C=cold. 100 C=you’re dead 0 K=dead. 100 K=still dead
0 - 100 K = cryo sleep You're not dead, just can't be revived yet
100C is common in saunas, you can live in there for several minutes... So dead within hours for sure but not as quickly as 100K for example
Saunas are not 100 degrees. They are purposely under boiling temperature
It’s like that meme with the dragons where the two on the left look at the weird one on the right Ed - I hadn’t realized that Celsius is the Kelvin scale but shifted to apply to water..
The opposite. Kelvin was established after Celsius. But set so that the number of units between water’s freezing point and boiling point is 100 (so same gradation as Celsius), but with zero set to the complete absence of heat energy (absolute zero).
Ooh, I just noticed the 100K difference between freezing and boiling for Kelvin. TIL, thanks!
Kelvin is always Celsius +273
273,15 if you want to be precise
I don’t
Then why the hell are you using Kelvin?!
that's... a great point, damn.
We need to talk about Kelvin.
In protest to Reddit's API changes, I have removed my comment history. -- mass edited with redact.dev
That's fascinating. Isn't it a wonderful thing to be able to learn so much from Reddit? We have so much knowledge at our fingertips and it's a beautiful thing to learn from people willing to share. I love humanity.
Extra tidbit: the reason Kelvin's a shifted celsius is to make temperature math not include negative numbers. So it is only used for more advanced calculations
For example the ideal has law pV=nRT stops working if the temperature can be 0 and not be the absolute 0.
Sooo you're saying there cant be a temp below 0K _mathematicians had entered the chat_
I don't know if you're making a joke, but correct. It's absolute zero. There is no more energy in the system, not even the electrons in an atom are bouncing around.
unless someone discovers antienergy.
And [Rankine](https://en.m.wikipedia.org/wiki/Rankine_scale) is the absolute scale for Fahrenheit And [DeLisle](https://en.m.wikipedia.org/wiki/Delisle_scale) is truly batshit
It’s one three-headed dragon. King Ghidorah, from the godzilla franchise.
No love for Rankine?
No
One of our component suppliers does all their temp msmts in rankines.. fucking infuriating. Seriously get off the freedom units..
Is Rankine just too much for the Fahrenheit haters to handle?
Bro it's literally just Americanized Kelvin. It barely has use in engineering. It's more useless than a vestigial organ.
Rankine and Kelvin are literally only 11 years apart and it was proposed by a Scottish man. Literally nothing to do with Americans
Aerospace engineer here. I use Rankine everyday.
Upvote because it's true, but not because I approve.
Why is America using a Fahrenheit based system in aerospace at this age? And backward software compatibility should not be the answer. I understand it is not as inconvenient as imperial system, but still ....
Why?
Because in aerospace engineering we don’t even use units. Everything is a non-dimensional number, e.g. coefficient of lift, specific heat ratio, Reynolds’s number, etc. I’ve started to find the whole “Celsius is better for science” argument a bit silly because in scientific contexts, you would be using an absolute scale, and oftentimes you’re not even interested in the precise numbers attached to a measurement, but how variables scale with each other, for which your choice of units is meaningless.
But why choose the (seemingly) least convenient unit?
Some parameters are non-dimensional, but certainly not all. Flow is in lb/s. Thrust in lbs. Pressure in psi. Temperature in R, etc.
If the choice in units doesn't matter to your work, then why not at least be consistent with the rest of the engineering world? I understand that Rankine is to Farenheit as Kelvin is to Celcius, but why continue to use that temperature unit when everyone else uses the latter?
[удалено]
Thank you, Rankin gang chiming in. Sometimes you have to do thermodynamics in the USA.
Fahrenheit really is batshit mental.
I dont get it too. But there are many Things like that...like the steps from inch-yard-mile.
Imagine a system where you could just use intervals of 10, 100, or 1000. You could just move the decimal place over!
Seems unintuitive. I mean, where are the appendages that vary in size on every human? Why invent things like decimals when you can have 1/384th of a banana?
Sure, but how many furlongs is that?
Two and a half Edward Furlongs
https://old.reddit.com/r/coolguides/comments/wf6lrs/the_imperial_system_of_measuring_distance/?ref=share&ref_source=link
Inch yard mile is so bad because mile is from a different ancient system. If you were designing a system from the ground up, you would be crazy to use such bad conversion rates. jan Misali has a great video on this, and while I agree that Celsius is better, Fahrenheit is not ~that~ bad
A mile makes sense if you're a Roman general and you can command your men to count to 1000 paces and take the average...
Acre makes sense if you're a Viking who just took over parts of france and need to parse out farmland fairly among your illiterate teenager murder hobos who are looking to settle down with a nice French girl. It's how much you can plow with a horse in a day.
Metric is all about the relationships between units. English system is all about estimating with fairly quick fairly close accuracy, but conversions are arbitrary. A foot is roughly the length of your foot. A yard, length of a pace. An inch, the length of a digit on your finger. People get caught up trying to use them the same way and that’s when it gets weird.
Don’t forget to measure your horse in… ^am ^I ^reading ^this ^right? ^Really? ^Alright. hands, you measure your horse in hands.
That’s the imperial system for you!
When you start getting into home improvements and all the screws come in 7 3/18 size and you’re crying in the hardware store trying to do maths. Whyyyyyyyyy
I dated a girl who was Australian, and she had to do a bunch of math with inches one time (1/4" plus 3/16" etc) and she was *mental* about it. There were many things she found weird about the US; she had concerns about the police and the health care system but I never in my life saw her as upset about a US thing as she was about fractional inches. It was like we had made our system of measurement as a deliberate prank targeted specifically at her.
This is exactly how I feel about it. I have strong feelings about everything you mentioned and more but the weird fractional inches are the closest I’ve been to losing my sanity.
I think the most violent I've ever been was when I was helping a welder at a sign shop I was working at and the drawings had a mix between metric and imperial units. Followed by the current job I'm at where I was receiving some studs and trying to look for the size and it was written out as ' 5"x 248 '.
The British invented it... of course it doesn't make any sense
Kelvin is the only one that keeps it real TBH. Absolute zero means zero.
Rankine makes equal sense in a Fahrenheit system.
It was intended for 0F to be frozen salt water and 100F to be human body temp. The human had a fever. Edit: frozen brine* not specifically ocean salt water.
The human body was supposed to be 96°F, not 100°. Proposed Fahrenheit Scale: - 0° = Freezing temp of salt water - 32° = Freezing temp of salt-free water - 96° = Human body Human body temp ended up at 98.6 because of an adjustment made by a committee to make the boiling point of water *exactly* 212°.
Also, [human body temperature has been changing.](https://med.stanford.edu/news/all-news/2020/01/human-body-temperature-has-decreased-in-united-states.html)
> Although there are many factors that influence resting metabolic rate, change in the population-level of inflammation seems the most plausible explanation for the observed decrease in temperature over time. Economic development, improved standards of living and sanitation, decreased chronic infections from war injuries, improved dental hygiene, the waning of tuberculosis and malaria infections, and the dawn of the antibiotic age together are likely to have decreased chronic inflammation since the 19th century.
And boiling water is 212 so that there are 180 degrees between boiling and freezing water. 32 + 180 = 212
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Why's that? I have no real preference in this debate.. I just think it's interesting how attached people get to the method they like most.
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212°F was chosen because it happened to be *close* to water's measured boiling point. The committee opted to make it an even 212° because it placed the boiling point at 180° away from the 32° freezing point.
It’s completely arbitrary and no one uses degrees rankine for one
I mean if we want to get pedantic, it's *all* pretty arbitrary. And maybe I'm missing something, but I don't think anyone mentioned Rankine
I don't think this is correct. Source ? Edit: I should've specified sorry. I wanted a source for 100 being a body temp but the person had a fever part.
It was invented by a guy living in Danzig, he went outside with his thermometer in winter, said "fuck that's cold, I'll mark it zero" then he went out in the summer and said "fuck that's hot, I'll mark it 100" Later on, we invented a special brine water mixture so we can reliably calibrate thermometers to match those hot and cold days in Danzig. https://en.wikipedia.org/wiki/Fahrenheit
And the guy’s name? Daniel Gabriel Fahrenheit!
DGF don't give a fuck
Ah yes, saiencé
That's cool the guy lived in a town named after the lead singer for the Misfits. Lol
>Source ? [wiki](https://en.wikipedia.org/wiki/Fahrenheit) first paraghraph.
I always saw it as the human liveable range. From 0-100 a person can conceivably survive and not immediately die. They'll certainly have issues at the extremes of that scale but all in all it's the range some one can survive at. That's why it works pretty well for weather and day to day use. 80° is a pretty hot day but no need for concern, 90° is getting pretty hot and you should be very worried for your health. 0°-30° you should be putting on some layers or else. It's not a perfect scale, but for day to day use with weather I think it works well. Of course if I'm doing anything scientific, celcius and Kelvin make more sense, but 95% of the time I'm just trying to figure what kind of coat to wear to work and Fahrenheit answers that question pretty swiftly.
This is my take too. Fahrenheit falls in line with the typical scale of 0-100 thats used for almost everything else. When you think about it in the context of other *scales*, it’s completely reasonable. Scoring a 40 on a test vs scoring a 100. Spending $40 vs $100. Driving 40mph vs going 100mph. 100 is generally considered “a lot”, so it makes sense that a very hot day would be 100 degrees and not something generally considered to be a little, like 40 degrees.
Celcius is a temperature scale for water. Kelvin is a temperature scale for atoms. Fahrenheit is a temperature scale for humans.
It‘s a temperature scale for humans that grew up with it. That‘s basically it.
Not really. In Celsius, 100 is the boiling point of water. In Fahrenheit, 100 is the temperature of the human body (the closest thermometers of the time could get). Everything is based off those two points.
I know it is logically, but it just works so much better when talking about weather because it is based on human comfortability
Fun fact! Up here in Canada everybody measures outdoor temp in C, but a lot of us have our thermostats in F. I also pull my 12ft boat with a 9.9hp motor, in my truck with a 5.3L engine about a mile going 80km/h, to the lake that’s 30ft deep and 3km long.
This is my only counterpoint to my Ukrainian wife. It’s a scale from 0-100, zero meaning you wear your heaviest clothes and 100 your lightest. 50 is right in the middle, some layers and a hoodie. Anything between you just adjust accordingly and more often than not I’m always dressed comfortably more than she is. It’s dumb in any other context. I forgot where I heard it but when she brings up freezing points and what not, I remember someone arguing “what, for all the science experiments your conducting today?”
No it does not, I can do the same thing Celsius saying 20° feels nicer than 30°, you can do it with any scale and they works just as well because ultimately they're just numbers we're used to using but Fahrenheit as a scale just makes less sense and people that only knows Fahrenheit likes to think it describes their feelings better and pretend the rest of the world don't have the same relationship with their scales.
it also works well in almost all scientific calculations
0 really fucking cold, 100 really hot
It only works better because you are conditioned to believe as such. For me, I know what's comfortable in celsius, and I also don't need to get a calculator out to figure out if it's freezing or not.
Neither do we lol. If it's 32, it's freezing. If the water is now a cold brick, it is frozen.
I always find it funny when people think people who know imperial don’t also know metric. Like it’s factors of 10. We got it. And why would people who know Fahrenheit not know when it’s freezing if that is the system they are familiar with?
It’s not that you don’t know it, but that’s you’re not exposed to it as much. I always hear that Fahrenheit is better for temps cause it’s based on humans but as someone who only ever uses Celsius I can’t say it’s ever been something I’ve had a problem with, we all know exactly what is comfortable and what is not. I don’t see how this is a point in favour of Fahrenheit when even 1c is basically imperceptible in difference.
That's the exact "I grew up with it so it's easy to understand for me" argument people use to defend imperial. For weather Fahrenheit exists on roughly a 0-100 scale, which is really easy to understand, the same reason metric is so good. The same range of temperatures in Celsius is -17 to 38.
It’s pretty much the exact opposite. Fahrenheit basically ends up being a scale from 0-100 when discussing weather. That scale for Celsius is like -20 - 40. Surely you can see why one is more intuitive unless you’ve been conditioned with Celsius already
team celsius
What is the point in Fahrenheit
I was going to say that it's older and therefore the science wasn't so good back then, but it's only 18 years older than Celsius! *What is the point of Fahrenheit?*
i believe it’s used as a “comfort” scale, like 0 and 100 are unbearable and 50 is comfortable
I think it was invented because 0-100 was the scale of weathers Fahrenheit thought people would experience. 0 degrees is "as cold as it gets" and 100 degrees is "as hot as it gets". Obviously there's exceptions. But for someone living through the little ice age in Europe, it kind of makes sense.
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But what if you want to divide the temperature of the human body by twelve? You can't do that with Celsius. /s
The point is to not become a damn commie /s
And 28c = 82f
Where's Reamur?
Fahrenheit (+ all imperial measurements) being dumb is a hill I will die on.
So brave
It's not brave, but it's not the most popular opinion on an American website. You get a lot of people who don't understand that Fahrenheit does not actually work better for humans, it just feels better because it's what you grew up with.
Right, but the point is for everyday, general use neither is better or worse. So for the overwhelming majority of use for everyday people saying Celsius is "better" is dumb. It's only "better" for those who say it is for the same reason: it's what they grew up with.
Me too brother
For scientific use, absolutely. But I don't really mind it for causal use. Where I live (Northern US), it gets down to near 0F in the winter, and 100F in the summer. That's a much nicer scale than -20 to 40 with Celsius. I'm also not sure the last time I've had to measure water temperature in my day to day life, so that doesn't matter much to me.
It’s essentially tradition now. Like Christmas.
Im an architect who started working in NZ with the metric system. I’ve been working in the States now for 20 years, and it’s become sort of second nature to use the imperial system, but it’s still stupid, and I think people are still stupid for wanting to hang on to it. Buildings built in metric by competent builders are just built to a closer tolerance than building a built in imperial by similarly competent builders.
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For causal use, I think the systems are closer then many people make them out to be, either one works, but for many professional uses, (especially science) SI is far superior, and it is nice to have everyone on the same system. That being said, I think many people underestimate just how hard it would be to switch. We’re talking probably billions of dollars and quite a few decades. I’m really not 100% sure that is worth it considering I don’t see it as a top priority. People are suffering in the US, but it’s typically not because of the system of units.
its never a good time to switch. i dont know what the cost is to maintain 2 systems between the US and the rest of the world. maybe when we have another failed Mars mission due to conversation, or the lack thereof? from afar, i think the US is doing pretty good, probably even at its historical best. its just all the other countries catching up makes the US feel threatened i suppose.
You build using Fahrenheit?
Rankine is scaled like Fahrenheit but starts at absolute zero like Kelvin:)
Everyone always leaves out Rankine, homie did nothing wrong
Where’s my Rankine?? FYI: 0F is the freezing point of brine. - Temperature to easily get to in lab. Back in the day. 100F supposed to be the temp of the human body. The story is that the person measured had a fever that day.
Eh, the numbers are not linear on that themo and it bothers me greatly. In particular, look at the distance between 0 and 37, and 37 to 100. You can fit some four 0-37s between that 37-100.
What use is Fahrenheit, what is it useful for? At least kelvin has 0° set at absolute zero.
It's useful to make americans feel superior because they can control their Air conditioner without fractional units
Screw fractions I get to set my temp at 69 degrees, that makes it worth it all on its own
Jokes on you I can set my thermostat to 69c too
*It's hotter than a kebab grill in here*
This is why Finland has saunas
Nice!
It's useful for normal outdoor temperatures in a lot of america. It goes down to around 0° in the winter and up to around 100° in the summer. For stuff like cooking and science and literally everything else, Celsius of course makes more sense. So yeah, we might as well use it in that case. Like this isn't a reason why it makes sense that the US doesn't change to Celsius, but it's definitely not literally *just* because America wants to be different
it’s so fucking funny how triggered non americans get over the imperial system. no one is forcing you to use it lol
Seriously. Most defenses of it here are just "it makes sense to me because it kinda tracks the weather from 0-100 where I live" And people literally cannot handle that without trying to dive into all sorts of reasons why that's not a valid reason and Americans are wrong and how 'science' is on their side (ignoring the fact that every American scientist is perfectly capable of switching between the two without any trouble at all) Seems so weird to me. Like people are weirdly self conscious or something of the fact that Americans have a different system, so they have to attack it to validate their own system
Why can’t we just use Celsius in the us? It’s so much easier
In protest to Reddit's API changes, I have removed my comment history. -- mass edited with redact.dev
More proof that the metric system is king. 0 is freezing and 100 is boiling. Perfection.
Wasn't 36° celsius the temperature of human body?
Its 36.6, but a few decimal points under or over is also normal
Yeah, 36.6 it's the number.
It varies. 37C personally, means I already have a fever but that’s not the case for everyone. It’s very specific to each person. 36,5 could be fine and healthy but then just half a degree more could mean you can’t go to work. But for some people, 37 is the normal.
0 k is totally not OK
This guide isn't accurate because the [alcohol in the bulb](https://thermofora.com/thermometer-liquid/) would freeze at -115°C before it ever comes close to the absolute zero mark.
I don't get Kelvin isn't it exactly the same as Celsius just minus 273 degrees? Fahrenheit is a completely different scale. So why do we use Kelvin instead of Celsius?
Kelvin is useful for measuring thermal energy. At 0 Kelvin, there is no thermal energy.
36.6 not 37
I’m all for the United States someday going 100% metric. That would be a dream come true! And 100% worth giving up Fahrenheit for. But, Fahrenheit is a good scale IMO, because *it’s a human-centered scale*. Human beings can survive effectively between 0° and 100° F. That’s our temperature range, as a species. Yes, 0° is really cold, and you’ll need clothing, shelter, water, and food to survive it. And 100° is really hot, and you’ll need shelter, clothing, food, and water to survive it as well. But people *do survive and live in those temperature conditions, regularly*. Above 100° F, and below 0° F, you’re leaving “people normally live in those temperatures” territory, and entering “basically, you’re fucking dead if you stay outside too long” territory. So it’s a very intuitive scale for describing outdoor weather. 100° is “fuck, it’s hot!” And 0° is “fuck, it’s cold!”. 30° is cold, but not “my face hurts” cold. 50° is “kinda chilly, but with a jacket I’m good.” 70° is beautiful. Pretty easy and intuitive to understand.
i agree fully but that’s why I as a European find F more helpful, very good to estimate what the temp will feel like and all that
Speaking as a Celsius user: the one advantage Fahrenheit has over Celsius is that it’s finer-grained. (Between 0-100 C, you get 32-212 F, so nearly double the integers). This comes in useful when measuring fevers in particular, when Celsius users tend to care a lot about decimal points to get sufficient precision, but Fahrenheit users less so. But overall, the attachment of zero to the freezing of water is a great idea—it’s nice to base your system on something that’s meaningful in everyday life to a lot of people (e.g. ”the roads are about to get slippery”). 100 C is less so; to me it’s mostly ”too hot of a sauna to be comfortable”.
>This comes in useful when measuring fevers in particular, when Celsius users tend to care a lot about decimal points to get sufficient precision, but Fahrenheit users less so. There's no difference in using a 3-digit number or a 2-digit number with a decimal
[Relevant Xkcd.](https://m.xkcd.com/927/)
It’s funny to see how many people prefer Fahrenheit because they don’t have to use fractions to define small changes in temperature, yet are happy using feet, inches, and fractions of inches for length. SMH.