76 points

Fahrenheit: how hot humans feel

Celsius: how hot water feels

Kelvin & Rankine: how hot atoms feel

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45 points

I don’t think how hot humans feel works at all, it’s just arbitrary

Can humans survive 100 degree heat? Yes so it doesn’t represent 100%

150 for 3rd degree burns (almost instant), does Fahrenheit go off base 150? Also no

What about cold? Well -40 requires a lot of layers, so then +40 should be pretty hot for humans right? Nope, because it’s not related to humans at all

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-4 points

No one said it represents “100%”, whatever that is even supposed to mean. 100F is really hot outside. 0 F is really cold. Doesn’t have to make 100% sense. Celsius doesn’t make perfect sense either. There is no perfect magical scale that works completely.

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3 points

It’s pointing out multiple ways that it doesn’t represent people

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4 points
*

Fahrenheit only works like that if ur used to extreme cold tempature. Anything under 10c (50f) is cold af to me and 38c (100f) is hot sure but nowhere near as cold as -17c (0f) is

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1 point

“really hot” and “really cold” are supremely useless terms in this context though.

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1 point
*

Can humans survive 100 degree heat? Yes so it doesn’t represent 100%

I have no idea what this means.

150 for 3rd degree burns (almost instant), does Fahrenheit go off base 150? Also no

What about cold? Well -40 requires a lot of layers, so then +40 should be pretty hot for humans right? Nope, because it’s not related to humans at all

Why do these matter? What percentage of humans live where it’s regularly -40 degrees? Why does the scale need to be perfect in your opinion? And how is Celsius better?

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4 points

I have no idea what this means.

Humans can survive 100 F so it’s not a scale of 0-100, which you would expect for a system based on humans

Why does the scale need to be perfect in your opinion?

The person I responded to said it was based off humans, I was arguing that it wasn’t because no patterns exist in relation to humans

And how is Celsius better?

Well the person claimed it’s based on the temperature of water at sea level with 0 being freezing and 100 being boiling. This would be the 0-100% for water

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3 points
*

I don’t think how hot humans feel works at all, it’s just arbitrary

Fahrenheit was originally calculated to be 64 even divisions between water freezing temp and human body temp, then 32 more units below freezing.

Then ambient human body temp was recalculated from 96F to 98.6F.

So it’s not exactly arbitrary. It’s based on powers of 2, based upon an inaccurate measurement.

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6 points

I mean, the temperature 0 was assigned because it was the lowest temperature that winter in Fahrenheit’s town, and the “powers of two” was only chosen because it was simple to mark degree lines on his instrument. Feels quite arbitrary to me…

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12 points

If farenheit represents how humans feel then 50 is the most comfortable temperature right?

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7 points

0 should be the most comfortable, with less being cold and more being hot.

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4 points

In human terms, only 65 and above is passable.

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25 points

100°F was supposed to be average human body temp. Guy who made the scale fucked up his math and we ended up actually at 98.6°F

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12 points

Nah, that’s a myth. It’s actually a little more complicated than that, and the actual measurements changed over time.

https://en.m.wikipedia.org/wiki/Fahrenheit

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4 points

Neither will kill you (usually) but both suck.

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5 points
*

Yeah, this gets repeated (by Americans) every time a discussion about temperature measuring systems comes up, but it is complete nonsense. The vast majority of Earth’s population are completely fine with measuring how hot they feel in celsius, it is only people who are unaccustomed to that system who thinks it is somehow unqualified to do that.

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1 point

American who lives in a country that uses C now.

20=frickin cold 30=swampy ass 40=nope

Not enough degrees of separation

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3 points

20 isn’t cold at all, it’s perfectly warm.

10 is nippy, but you still warm up quick after a few minutes walking, and get sweaty if you’re working on something.

0 is cold enough for a couple layers. Jumper + jacket so you can take one off if you warm up too much.

-10 doesn’t feel that much different to 0.

-20 is time to put on a thicker coat over the jumper.

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1 point

I lived for a third of my life in a country that uses Celsius, and the switch to Fahrenheit was not only seamless, it made much more sense to me intuitively. Whereas I was fine using Celsius, I don’t really want to go back.

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1 point

Downvote my experience all you want, bitches

It’s not gonna change

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49 points

Celcius is the logical choice. The others are just crazy.

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-21 points

Because aligning to the temperature at which water boils is the objectively correct choice?

“Hey, how hot is it going to be today?”

“Well water is about 1/3rd the way to boiling, so about 30 degrees”

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12 points

The fact that 99.5% of the global population uses it makes it the objectively correct choice.

The remaining .5% can keep bashing their heads against a wall if they like though

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-8 points

Most people like pop music. Does that make it the best?

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1 point

Not arguing for either unit here - use what you’re comfortable with and don’t be smug about it - but Americans are ~4-5% of the world and even if not all Americans use Fahrenheit, people in other countries (e.g. mine) still do.

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5 points

Maybe ecause everyone uses it? Just so you know nobody even knows how fahrenhiet was defined first, everyone in the scientific community uses kelvin which is celsius but shifted so absolute zero is zero on it and the us actually uses si they just convert it to imperial so conversion between them is easier. There is point to imperial units other than its hard to switch between systems.

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-12 points
*

the Celsius nerds are mad at you, I guess. I love it when you see someone make a good point and the downvotes just pile on.

never change, reddit.

edit: they’re here! lol. hey guys! have fun with your storming the castle to defeat the evil Fahrenheit! make sure to prepare your spells, you don’t wanna get caught out when the negative values come out. 💕

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1 point
*

Check which temperature scale the device you posted your garbage reply with uses for its sensors.

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4 points

It is so funny seeing Americans thinking that only nerds uses celsius, because they can’t fathom it themselves. It is like when you call 24 hour time “military time”, even though the majority of Earths civilian population uses it.

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10 points

the Celsius nerds are mad at you

You mean most of the world? Defending a backwards options never looks like a rational choice.

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4 points

The temperature of water is very intuitive in nature. Dip ur hand in ice water. That’s almost 0C. Dip ur finger in boiling water (very quickly). That’s 100C. Dip ur finger in coffee whose temperature is fit for consumption: that’s around 75-80C. Ur hot water shower is likely between 37 and 41C…

Everything is tied quite well to water. Now compare that to F. What’s 0F? What’s 100F?

Forget the intuitiveness of celsius. It’s also much easier to calculate using celsius. When I say “My coffee was worth 80 calories”, I’m referring to a measure called “KCal”, which is the amount of energy required to raise the temperature of 1 litre, or 1 Kg of water by 1C. So if u ate something worth 100Kcal, you consumed enough energy to heat 1L/1Kg of water from 0C (ice) to 100C (steam). The average human requires around 2500 KCal everyday. Which is equivalent to 2.5 liters of water. Pretty cool, huh…

Just a quick sidenote: KCal is still not an “SI” unit. “Joules” are what we use here, but that’s another story.

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16 points

True, we should be using a temperature scale that was defined on how cold it was in Gdańsk, Poland in the winter of 1708, something the average man is more familiar with than water temperature, right?

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12 points

We used water to decide a lot of measurements. 1ml of water is = 1 gram. A gram of water is also equal to 1 cm^3. It’s a beautiful system in that way. Water surrounds us and gives us life, it has chemically interesting properties that make this planet function. Why shouldn’t we just base everything off of this one substance?

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2 points

Not using metric is so much more fun:

  • water freezes at 32, boils at 212
  • 16 cups in 1 gallon (both standard units of measurement)
  • 1 (US) cup of water is 8 (US) oz
  • 1 (US) cup of water is 14.4375in^3

Makes your maths so much more exciting!!

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11 points
*

When it’s “freezing cold” or “ice cold” outside, what do you think is freezing? When something is “boiling hot”, what is boiling exactly?

We use water to describe temperature even without using Celsius, because it’s everywhere around us, and we are literally made of this stuff. It’s also one of the only materials that goes through three different states in our usual temperature range, so using those as a reference point to measure temperature makes perfect sense imo.

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4 points

You can get used to any scale

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45 points

Kelvin and Celsius are the same, just offset onto absolute zero or the water freezing point

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18 points

Yeah, often it is just way more convenient to use the Kelvin scale without any negative temperatures for some calculations and formulas then Celsius

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3 points

Than* Celsius.

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73 points

Based on human perception, based on water chemistry, based on physics.

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10 points

Zero Fahrenheit is the freezing point of brine (of a certain concentration). That’s water chemistry.

Originally, 90F was based on the average human body temperature, but that later changed to 96F, which just goes to show how arbitrary that scale is.

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9 points

It’s all arbitrary. Someone just decided to base a scale off of something and that something isn’t fixed from the start. The meter used to be based off the measurement of the earth, but now it’s based off of light.

It’s just some random semi-useful starting point that we all agree on so we’re using the same language.

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8 points

The meter did not change, science has merely defined it more precisely and reliably over time. It is a measure of length, still one 40 millionth of the circumference of the earth through the poles. Other definitions like the speed of light definition will give you the same result. These newer definitions have reduced uncertainty and added ways to reproduce its length by natural means. But it’s not like the ‘original’ meter was shorter or longer than today’s meter, at least not by any noticeable margin.

Shifting the top end of a temperature scale by over five percent of the scale is a bit more arbitrary than that.

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11 points

Nah Kelvin is just on hydrogen perspective

(Kelvin and Celsius are the same scale just with different 0)

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6 points

So, Kelvin in Physics, Celsius in daily usage and Fahrenheit…?

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You’ll be shocked to learn that the distance in Kelvin is also adjusted to water “chemistry”, albeit changing the aggregate state seems more physics to me, since no molceules are reacting with each other.

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0 points

You can’t change the aggregate state of a single molecule, or how do you mean that? Excluding plasma.

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you can of a lot of molecules though. and tgat is classically “physics” rather than “chemistry”. Classical chemistry is reactiona between atoms or molecules to form new ones.

If you get deeper into it, the lines between chemistry and physics blur anyways.

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11 points

Thankfully that has been redefined using the Boltzmann constant, so now anyone in the universe can agree on °C and K without needing to measure any Vienna standard ocean water.

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6 points

I was going to make a joke about how Austria is landlocked, how did we come up with the idea of making an ocean water standard.

Apparently the IAEA which is headquartered here set that standard, for anyone else curious.

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55 points

Since when is 0°C “fairly cold” it’s literally freezing.

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0 points

We’re not made out of water.

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4 points

You’re failing at pretending to be human. We’re literally made of water. About 80% of us is water.

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0 points

I knew someone would say this. We don’t freeze solid at 0 Celsius however.

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27 points

I’ve been in -37C snow shoveling. Since then 0C doesn’t even register as cold to me

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19 points

Yep, and I’ve been in 110C in sauna. It’s pretty fucking hot but not death

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1 point

I’m pretty sure you mean 110°F, don’t you?

110°C = 230°F
110°F = 43°C

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10 points

I think more that if it’s 100c outside the planet is basically dead.

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0 points

Everything about -10 is warm.

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47 points
*

0°C is completely fine with jeans and a thick jacket, especially when it’s sunny and there isn’t much wind. It’s cold, but there’s probably not much ice or snow, if anything, probably mostly slush.

Compared to say -20 C where you should have a good ski jacket and ski pants, warm shoes and socks, generally multiple layers everywhere, winter gloves and so on.

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0 points

Humidity. I’m guessing you don’t live in a humid place because freezing temps are horrifically cold here. You will need a winter coat and multiple layers of your going to be outside for a while. I layer long Johns under my pants and wear my parka and a light jacket as well as 2 layers of socks. Everytime a northerner comes here they are shocked at the cold/heat. That’s because the air here is full of water to the point that you will actually get wet just from the humidity, not even sweating.

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3 points

But so is 100°F completely fine with a shirt and shorts and some shade.

So basically: |0°F| > |100°F|, where | is the mathematical absolute operator.

0°F is really cold, while 100°F is merely somewhat hot.

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19 points

It can be -20 C and you can be still fine with jeans and a jacket if it isn’t windy.

What I’m saying is temperature alone doesn’t tell you the whole story.

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3 points
*

Many places in the US, particularly in the East and Midwest, experience average temperatures at or below freezing (32°F) in the winter, so while it’s definitely cold, it’s often not considered really cold. It’s not until you move further towards 0 and the negatives that most people in that area feel really cold (like weather advisory levels). Of course the further north you go, the more normal those temps are. Likewise, it’s definitely not unheard of for temps to hit 100°F (37°C) in the Southwest, but it would be considered pretty hot for much of the country, and even Texas suffers at sustained temps like that.

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1 point

Freezing temps here are definitely considered very cold. Cold enough that you need multiple layers and you should be wrapping your pipes to prevent freezing. It’s very humid here. Our freezing is insanely cold. Like chills you to your bones cold. Our hot here is insanely hot as well.

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1 point

I dunno, man. I usually only wear a sweatshirt when it’s 32. You get used to the cold fast.

There was an article recently that said the researchers in Antarctica were wearing shorts because it was so warm (14F).

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16 points

The northern half of the US laughs

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6 points

The temperature that water freezes at is only fairly cold weather by a lot of people’s perception.
I’d call it “chilly”. No jacket for running to the mailbox, or if I’ll be outside for half an hour or so. Light jacket otherwise. I don’t expect it to snow, since it’s not actually cold enough usually, and there won’t be ice on the ground unless it’s just warmed up.

So it might be “freezing”, but that doesn’t make it cold.

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3 points

In Aus we say it’s fucking freezing

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8 points

It’s almost like being ‘fairly cold for humans’ is a wide range, and subjective, therefore useless as a baseline.

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1 point

True, but that’s also not super relevant to the merits of a temperature scale. Fahrenheit isn’t actually based off of human subjective temperature perception, it just coincidentally lines up a bit closer with the comfortable range for people in northern temperate climates.

Before it’s redefinition in terms of Celsius, fahrenheit was defined by a particular temperature stable brine solution (easy to replicate for calibration), and with the freezing and boiling points of water set to be 180 degrees apart, because of the relationship with a circle.

People decided we liked base10 adherence more than trigonometry, and then everyone adopted Celsius, so we should use Celsius. Doesn’t make fahrenheit some sort of random scale, just deprecated.

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1 point

Well I’d say that’s why op chose the adverb “fairly”, it gets across that it’s a wide range and lacks specificity.

Not completely useless as a baseline, but fairly general.

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It is also literally melting.

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2 points

I would put it at a 3/10

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3 points

100° outside is dead

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2 points

True, you can be in 100’C indoors and be fine (sauna). Though I’ve heard some people think you’ll boil alive there lol

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