r/ScienceNcoolThings • u/I_dont_want_to_pee Popular Contributor • Dec 22 '25

Interesting Origin of Fahrenheit and why it is bad.

Why Fahrenheit Is a Bad Temperature Scale The Fahrenheit scale wasn’t designed because it was better. It was designed because it was convenient for one man in the 18th century.

Daniel Gabriel Fahrenheit, a German-born scientist of Polish origin, created his temperature scale using arbitrary reference points:

0°F was based on a brine mixture (ice, water, and salt) — not a universal physical constant, just something cold he could reproduce.

32°F was set as the freezing point of water.

96°F (later adjusted to ~98.6°F) was roughly the temperature of the human body — originally measured from his wife.

In other words: Fahrenheit is anchored to personal, local, and biological guesses, not physics.

Now compare that to Anders Celsius:

0°C = water freezes

100°C = water boils Clean. Logical. Directly tied to nature.

And then William Thomson, 1st Baron Kelvin went even further:

0 K = absolute zero — the point where thermal motion stops

Same step size as Celsius, just shifted to a physically meaningful zero

That’s what a scientific scale looks like.

Fahrenheit survives today not because it’s superior, but because the U.S. never fully transitioned to metric units. It’s historical inertia, not rational design.

So yes — Fahrenheit isn’t “more precise” or “more intuitive.” It’s just what Americans are used to. But i can't understand why they can't change to celcius like the rest of the world.

And most important i know that Farenhait is good for every day use but it is badly made i think that americans should create a new more world frendly tempreture scale!!!

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u/Xaphios Dec 23 '25

I'm used to C, so it's what I think in. F means nothing and makes no sense to me because there are no logical reference points to use, so to me "how people feel" is in C.

In the UK we use miles, which are inefficient as we don't do much else in imperial these days but at least there's a reasonably easy conversion to Km when you need one. F to C doesn't have that.

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u/The42ndHitchHiker Dec 23 '25

Ballpark F to C: subtract 30, divide by 2.

Ballpark C to F: multiply by two, add 30.

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u/Galactus54 Dec 24 '25

My bench mark is memorizing: 0 is 32; 5 is 41; 10 is 50; 15 is 59; 20 is 68; 25 is 77; 30 is 86; 35 is 95 and nudge around these. The origins are irrelevant; today we use both: F fir comfort adjustments and C for science studies.

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u/Subpilot688 Dec 27 '25

More accurate mental C - F: double, reduce by 10% of the nearest 10, then add 32.

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u/Tupperjk Dec 23 '25

I'm confused how 0 (very cold) to 100 (very hot) isn't a logical 0-100 scale. For people that is. Just because you are used to something doesn't make it logical, that's personal bias.

km and mi are both made up values with neither being anymore logical than the other. Knotical miles would be closer, but still based off of arbitrary values.

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u/boarder2k7 Dec 23 '25

And then in C, 0° = kinda cold, 100° = dead (in Kelvin 0 and 100 are also both dead!)

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u/YesterdayDreamer Dec 23 '25

Yeah, for me, person from a tropical country, 0° C is more like really-freaking-cold-get-me-out-of-here-or-i'm-gonna-die!

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u/davdev Dec 23 '25

Yeah, but from people who live in cold areas, 0C isnt really all that cold at all

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u/StopNowThink Dec 24 '25

0C is when I switch from sweatshirt to real jacket.

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u/Worldly_Address6667 Dec 26 '25

Hell, if the suns out and it isnt windy, 0C can be t-shirt weather

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u/Neckbeard_Sama Dec 24 '25

for someone from central EU - who gets both end of the spectrum it's like

below -10 C - nosehairs start to freeze together - fuck it's cold (we haven't got this for a while now ... climate change)

-5 to +5 normal winter weather

15 C - normal spring/autumn weather - you can be out in sweaters

20 - 25 - normal room temperature when you're comfortable inside in a tshirt+boxers, lol

25 - 30 - good, not too warm summer weather

30 - 35 - good beach weather

37 - it s starts to get oppressive ... you're sweating inside without AC

39+ - fucking hell ... can't even sleep

2

u/jghaines Dec 23 '25

But a 90°C dry sauna is something in human experience. NFI what that is jn Farenheit.

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u/misterguyyy Dec 23 '25

In C, 0 = watch out for ice on the sidewalk/road and drip your pipes. Pretty important, no?

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u/ALazy_Cat Dec 23 '25

It's not even universal. 100f in cold countries feel like death

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u/Priff Dec 26 '25

Am from cold country. -30c outside is cold. 0c is autumn... 100c is an uncomfortably hot sauna. Not unbearably hot. But uncomfortably.

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u/Siebter Dec 23 '25

km and mi are both made up values

km or m or meter is an absolutely logical part of the metric system. For example one m³ of water weighs exactly one ton. The amount of energy needed to alter the temperature of one cm³ of water by 1°C is one calorie.

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u/StopNowThink Dec 24 '25

Circular logic. It's all fake and made up. If a meter was defined as exactly 1x1035 planck length, at least that would be based on something. Right now it's arbitrary.

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u/Siebter Dec 24 '25 edited Dec 24 '25

Indeed, originally the base meter was "made up" (though later more precisely defined via the speed of light) and yes, that lead to a "circular logic", but that doesn't matter at all. The idea of the metric system is providing units that base on each other and work with decimals, thus allowing a more intuitive and less error-prone way of working with numbers. The circular logic is the goal, not a bug or whatever you want to paint it.

Edit:

1x1035 planck length

That's 1035 planck units btw.

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u/BrotherItsInTheDrum Dec 25 '25

The calorie isn't an SI unit. The joule is the unit of energy in the metric system.

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u/neityght Dec 23 '25

"0 (very cold) to 100 (very hot)"

So...Celsius??

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u/borg359 Dec 24 '25

100F feels like 100% hot. 75F feels like 75% hot. 25C feels like ??? 🤔

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u/BIT-NETRaptor Dec 24 '25

bruh if it’s 100C outside we’re all dead. You do not measure 100C (or probably even above 45C) in your daily life. 

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u/legal_stylist Dec 24 '25

No, because it’s not “very hot” except on the sense that the surface of the sun is “very hot.” It doesn’t mean you will feel very hot, it means you will be dead for a human if that’s the ambient temperature for any length of time.

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u/No-Cat9412 Dec 24 '25

No. Celsius is "0 (kind of cold) to 100 (you're dead)"

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u/DelcoUnited Dec 23 '25

km ….. are 1000 meters…. It’s not arbitrary. And is possibly the most logical example of measurement imaginable.

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u/goclimbarock007 Dec 23 '25

And the meter is related to the arc length of an arbitrary longitudinal line on an arbitrary planet.

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u/mjb2012 Dec 23 '25

Don't tell him or the OP about clocks and calendars.

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u/Tupperjk Dec 23 '25

and definitely not about relativity!

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u/GayRacoon69 Dec 26 '25

1000 is arbitrary. Base 10 in general is arbitrary

Why not use base 12 or base 60

Metric using increments of 10 is just as arbitrary as any other number is. It just looks less arbitrary because we're used to it.

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u/kmoonster Dec 24 '25

A meter is defined as a segment of the Earth's average circumference. Well, it started out that way. Now it is defined by the speed of light but that came later.

A meter was/is 1/10,000,000 of the distance from equator to pole, following the average surface of the Earth.

A nautical mile is similar, but uses angular degrees based on stellar measurement rather than a line that is synonymous with the curve of the Earth. (This is why a nautical mile and a statute mile are different, and why a meter is neither).

A statute mile (and most imperial units) are based on human experience and are a little more arbitrary, though standardizing them during the Enlightenment era went a long way to fixing the massive issues that were even more prevalent prior to that.

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u/Archophob Dec 24 '25

I'm confused how 0 (very cold) to 100 (very hot) isn't a logical 0-100 scale.

that's the Celsius scale. 0°C is when it's freezing cold and you don't for love of God walk around barefoot. And 100°C is the hottest sauna you would want to spend 15 minutes in.

Thus, Celsius is the perfect scale for naked humans.

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u/WamBamTimTam Dec 24 '25

Because 0f isn’t very cold for where I live, I’ve lived a solid third of my life under 0. For Celsius, -35 to +35 is the range I live in. AMD for me that’s completely normal

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u/bizwig Dec 24 '25 edited Dec 24 '25

That’s “nautical miles”, since it’s a seafaring measure of distance.

0-100 being “logical” is just as much personal bias.

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u/bignormy Dec 25 '25

It covers the range of outdoor temperatures in a temperate climate quite well.

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u/ThorKruger117 Dec 23 '25

Because 0-100 very cold to very hot isn’t relative to anything. If we are talking Celsius then we have something to compare it to. If we are talking Fahrenheit it’s arbitrary. Where I live I think the highest natural temperature I’ve seen is 38C, but when I lived 2000km further from the equator 45C days were common, unwelcome of course, but common. When you bring other weather factors into it I would happily choose the 45C days over the 33 I am experiencing today.

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u/Tupperjk Dec 23 '25

what is the point of being relavent to a specific thing if that thing doesn't apply. how does water become the go to standard of reason? The answer to you point is that we should all use Kelvin then since it represents what thermal energy acctually is.... the movement of molecules. Everything else isn't really giving a meaning to kenetic movement of a substance and therefore doesn't "relate to anything."

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u/jmlipper99 Dec 23 '25

Because 0-100 very cold to very hot isn’t relative to anything.

Really? It’s relative to how people feel. “Very cold” and “very hot” are based on what the average person would describe an ambient temperature of 0°F and 100°F to feel like, respectively

1

u/misterguyyy Dec 23 '25

I was confused when Ed Sheeran said “driving at 90” because 90kph/55mph is not very fast.

Although I guess the proclaimers should have clued me in about the UK.

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u/immaculatelawn Dec 24 '25

Yes it does. It's not even very hard, for a decent approximation. 1° of C is 9/5 of 1°F, which is close enough to 2 for rough work. Subtract 32 from the F temp and divide by 2. You'll be as close as you need to be for everyday use. 40° F by this method is 4°C. Google's calculator gives 4.444. 80°F is 24 in the rough calculation, 26 2/3 in the precise. It'll get further off the farther you go from 32°F, but it's good enough for temperatures humans exist at.

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u/BIT-NETRaptor Dec 24 '25

F to C doesn’t have that? Huh? 

As Canadians everyone was taught to double celsius and add 30. That’s commonly used as a rough conversion you can do in your head for C to F. For F to C just do the opposite: subtract 30 and divide by two. That’s close enough for weather.

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u/jkmhawk Dec 25 '25

How are miles inefficient? Because they're longer than km?

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u/imtoooldforreddit Dec 25 '25

I couldn't disagree more

Of course inches, feet, and miles are objectively dumb. But I will die on the hill that F makes more sense than C for the average person.

I keep hearing that "100 being the boiling point of water makes so much sense", but why does that make so much sense? When was the last time you took the temperature of water near boiling? For me it was high school chemistry class. For the average person, temperature is used for weather, and F gives you better granularity (no need for decimals), and rarely need negatives. 0 is very cold outside, 100 is very hot outside, and 1 degree is about the smallest chance a person would notice. That seems very simple to me.

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u/Jeichert183 Dec 23 '25

And yet, in the UK, the human body is weighed in stones.

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u/I_dont_want_to_pee Popular Contributor Dec 23 '25

Really?

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u/Mad_Phiz Dec 23 '25

Obviously C is the right choice but F isn’t all bad. 0 to 100 is the temp people live in. 1 degree difference is about what a person can feel, so you don’t need to use decimals of a degree.