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Comment by fooker | Hacker News Reader

There’s another more fundamental reason to use Kelvin here, linearity.

100K is twice as hot as 50K, while the idea of twice as hot is meaningless in C or F.

Isn’t it the exact opposite? It you talk to people about something being “twice as warm” or “half as warm” people will assume you are talking about a scale in celcius or something closely related? Because it doesn’t make sense to say “the bedroom is freezing it’s 3/100th colder than the living room!” And no one saying “the bedroom is half as warm as the living room” will be interpreted to be saying that it’s -127 degrees celcius.

No I mean this in a physics sense, not ‘feelings’ sense.

If there is a physical phenomenon that depends on temperature, you can’t use C or F in that calculation unless the temperature parameters somehow cancel out.

So, if y = Tx, twice the temperature means y is twice if x is constant. But only if it’s in Kelvin.

In a “physics sense” there is no such thing as warm or cold those are language constructs not physical properties of materials. In physics there is temperature. You don’t say “the metal bar is 20 warm” you say “temperature is 20 degrees celcius” something having “twice the temperature” isn’t the same as being twice as warm or twice as cold.

I'm not sure if you got the point but I'll repeat. I am not talking about language.

40C is not twice the temperature as 20C, but 40K is twice the temperature as 20K.

You are using language and you seem to make an equivalence of temperature to warm/cold which doesn’t work. Now your saying that it only makes sense to use kelvin because it’s the only scale that doubles when you double it (which is actually also false they all do that). When in fact the concept of “twice as warm” is a fuzzy language construct which matches better to celcius. Which isn’t surprising as both the language and celcius scale are designed around our subjective experience.

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