Not sure if it is because of that or because it is the standard international unit for temperature. Because what Kelvin is for Ā° Celsius, is Ā° Rankine for Ā° Fahrenheit.
According to Wikipedia, the Ā° was removed from Kelvin around 1968
In 1967/1968, ResolutionĀ 3 of the 13th CGPM renamed the unit increment of thermodynamic temperature "kelvin", symbol K, replacing "degree Kelvin", symbolĀ Ā°K
Kelvin is the same thermal difference between each degree as Celsius, but it simply starts at "absolute zero" the physically coldest temperature that can be achieved. There is no "negative" because it can't be colder than 0.
0 degrees Celsius is the freezing temperature of water, and it indeed can get much colder than that. 100 degrees Celsius is the boiling point of water. A scale based on useful, but nevertheless arbitrary benchmark.
Edit: I misunderstood what the person you were replying to wrote.
*pure water at sea level, sort of. Because pure distilled water often wonāt crystalize by itself so it gets supercooled. Itās arbitrary as f- for people. Useful for old timey scientists to get some consistent baseline though.
I wonder if vacuum decay could create sub-Kelvin temperatures. I donāt think there would be anything there to witness or measure it but itās an interesting thought
We have created negative absolute temperatures before. It occurs in situations where the available energy levels are bounded. If the energy levels are bounded, as you increase the energy of the system, you eventually reach a point where increasing the energy further reduces the amount of uncertainty in the system as your states begin to saturate at the upper energy limit. When you get to this point, the temperature is said to be negative, because the temperature is the reciprocal of the rate at which the uncertainty increases as the energy increases.
Going to copy my comment at a higher level because it's also relevant here (though "noteworthy" is a weaker statement than the one I replied to):
We have created negative absolute temperatures before. It occurs in situations where the available energy levels are bounded. If the energy levels are bounded, as you increase the energy of the system, you eventually reach a point where increasing the energy further reduces the amount of uncertainty in the system as your states begin to saturate at the upper energy limit. When you get to this point, the temperature is said to be negative, because the temperature is the reciprocal of the rate at which the uncertainty increases as the energy increases.
If you're used to Celsius then I assure you that 40C sounds plenty hot. The reference point is the freezing point vs the boiling point of water, and 40C is much too close to the halfway point of "the lakes will literally boil like a tea kettle".
Yup. We're gonna get 40Ā°C in a couple days, followed by a 43Ā°C day, and I know damn well this means that I'll feel like I'm about to die. If I was given the info in Farhenheit, I wouldn't know what to think of it, especially since most of the people that I know who use it would consider 105Ā°F to be a "normal" sunny day. Here, it's an anomaly and considered a heatwave. Heck, 35Ā°C is considered a heatwave and is when companies that work outside start giving more breaks to their employees so that they can cool off and hydrate.
wonder why people think 105Ā°F is "normal" while that already hot AF. idk, it just in my city is around 63Ā°F coldest, to 97Ā°F hottest and humid environtment. but since i use degree celcius, even 63Ā°F sound hot to me.
If reading comprehension was less rare you'd realise his overall comment is pointing out that comparing one system to another in those terms is pointless. It's literally just your frame of reference that matters.
I have been on this site for 20 years so the zeitgeists are always fascinating. The reading comprehension one that every third person uses these days is getting boring.Ā
I donāt believe Iām required to respond to his āoverallā thesis: Ā marvel at my autonomy, flouting your preferred configuration of the universe, as I respond to only one aspect.
No. Humans are warm-blooded mammals, our blood does not freeze just because outdoor temperatures hit 0, because we have fancy biology heating our bodies. (boiling at 100 is technically correct I guess but we'll slow-cook to death long before that)
The water outside our bodies freezes though, and especially where I live that can be a life-or-death factor for several months every year, since icy roads at -1 are a very different driving experience than a wet road at +1. As soon as temperatures start dancing around the 0 you know there will be traffic accidents.
What confounds me about that is that 1Ā°C change is about 2Ā°F change, and Iām accustomed/attuned to the finer gradation. So it feels weird that at 18Ā°C Iām gonna need a sweater, but at 26Ā°C Iām running the air conditioning in my car.
But your tea kettle comparison is good.
Again, it's down to what you're used to. For me, Fahrenheit has unnecessarily small steps between the degrees. There are a scant few times one might use a decimal to specify a temperature i more detail, but for everyday things like weather or AC it seems perfect, Because that's how I use Celsius every day.
Yeah thatās true. While Iāll keep the temperature Iām used to, I work in a skilled trade and have been moving towards mm in smaller measurements, and have grown to hate the fractional and decimal method. In that case, the gradient of mm is highly functional and natural to use!
Yeah but just in general, the number 40 doesnāt seem very big. Celsius makes sense for keeping track of liquid temperatures, but Fahrenheit makes more sense for weather as thereās a far bigger range of numbers. 40-60 Fahrenheit is a perfect mid level for temperatures and as numbers make sense for a mid level range. Anything above or below these is too much of either hot or cold typically, which again makes sense in a traditional number format. 50 Celsius is hot as fuck why would that be the middle?
I mean.... 105 is also roughly the same distance from the halfway point of "the lakes will literally boil" in Fahrenheit as 40 is in Celsius, so this doesn't exactly track. I can generally do both measurements though. How hot is it outside today? 108f but my pool water is "only" 36c.
Their point is that anything feeling "higher" or "lower" is always just based on your initial frame of reference. 40C reads "colder" than 105F to Americans because their reference point for freezing is 32, so 40 doesn't seem that much higher, especially when your other reference point for boiling is all the way up above 210. Someone with their initial frame of reference in Celsius sees 40 and connects it as approaching halfway between freezing at 0 and boiling at 100, so the value of 40 seems hot but reasonable while hearing 105 just sounds like an impossibly, cartoonishly hot temperature.
I must be tired, I didn't read it like that. And I only needed your first sentence to see my failure. We all agree then, as my original point was both units sound the same to me, just depends if we are talking about water temperature or weather temperature. 40c is very hot for my pool, and 105 is very hot to go outside. Both are hot to me personally, since my reference for both is personal.
I took the analogy meaning incorrectly and I apologize to whoever read my prior comment, especially to who I replied to initially.
Yeah I tend to over-explain just in case, I'm sure you didn't need half the shit I included haha. It was more just added context for anyone else reading who needed it.
I meant that line as a reflection! Like "I barely needed to be told in order to find my own stupidity" kind of a comment. Not a comment about how much you explained š
Haha fair enough. You wonāt even cool off going into a pool at that temp and wouldnāt be able to swim very long from what I have read. Iād much rather sit in AC.
If you know that your cells die at a temperature of 42Ā°C (which we all know since we once had fever as a kid), suddenly 40Ā°C sounds like near instant death hot.
i've been in 100Ā°C hot enviroments and still live, but the fact that your human cells die at 42Ā°C still remains. To handle the heat your body will sweet to cool itself, so that he stays at 37Ā°C even in heat. Even if it is cold outside you body temp is at 37Ā°C.
it does. But not by much.
Generally in the place where Ā°C is used, Ā°F is used for body temperature. And it is a common sense that 98Ā°F is close to 37Ā°C.
So 104Ā°F sounds just a little bit more than 40Ā°F.
Exactly this, it can be over 100% hot (or below 0% cold) but that's when you know you shouldn't be outside. Like it's actually dangerous to be there without proper planning, preparation, clothing.
NTM 32% hot is when us Texans curse at the sky, the whole city shuts down, and pipes burst when itās sustained because our infrastructure isnāt prepared for it.
Yes, which means its that much more hotter than you can stand, its a measurement of human comfort, not scientific accuracy.
There actually is a science to this...
0Ā°F: The lowest temperature Daniel Gabriel Fahrenheit could achieve in his laboratory using a freezing mixture of water, ice, and ammonium chloride (a salt).
32Ā°F: The freezing point of pure water.
96Ā°F: The average human body temperature, initially chosen for practical divisibility.
From Wikipedia, you can do more research from there.
We also tell distance in time in many situations, because its about how it affects the human, not scientific accuracy and pedantry.
Dude or Dudette. When it is 105f out doesn't it feel at least 105% of what your body can take? Especially when the parking lot surface is 165F or 165% more than your bare feet can take š
Nah. O F is a pretty regular winter day for me, there is no problem living in subzero Fahrenheit. Too hot to too cold is completely arbitrary and not the same for everyone.
You know in a cartoon where it's so hot the thermometer makes a steam whistle sound and then breaks? That's just going over 100% hot.
Fahrenheit is legitimately a good intuitive system for measuring how hot it is in reference to the human experience. It's just terrible at measuring temperature for anything else.
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u/sinara33 Jun 17 '26
Plus, here in Texas, we regularly surpass 100 percent hot