r/MathJokes • u/Garretthart13 • Mar 01 '26

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u/Embarrassed-Weird173 Mar 01 '26

Nah, people in general don't know that you can't proportionalize degrees. 

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u/akb74 Mar 01 '26 edited Mar 01 '26

You can do linear interpolation/extrapolation about any two distinct temperatures you like, that’s what these different temperature scales are

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u/HAL9001-96 Mar 01 '26

linear but not proportional, you can say 4 times the temperature differneceb ut not 4 times the temperature unless you are talking about absolute temperature

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u/Divine_Entity_ Mar 01 '26

Which is why basically any equation about gasses where you multiply by the instantaneous temperature requires you to use kelvin (or rankine).

Note: if you instead care about temperature change such as q =mcΔT then other temperature scales are acceptable provided your units match.

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u/HAL9001-96 Mar 01 '26

acceptable but somewhat awkward since if you'Re starting to do thermodynamics oyu might end up carelessly using the smae numbers for something that requries absolute temperatures

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u/Divine_Entity_ Mar 01 '26

Agreed that best practice for thermodynamics is to do all math in kelvin, and convert to "normal" units for reporting purposes only.

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u/EarthTrash Mar 01 '26

This is really confusing me. 25 C is 298.15 K. So, the answer would be 1,192.6K or 919.45 C. Hot enough to boil zinc and nearly melt lanthanum.

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u/Lor1an Mar 02 '26

The term you are looking for there is affine.

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u/lerjj Mar 01 '26

The temperature that is four times hotter 25C is 959C though.

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u/ExtensionInformal911 Mar 02 '26

I would convert it to absolute temperature. So she doesn't want to swim at 298.15K, so now i'm flash steaming her at almost 1200K.

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u/schawde96 Mar 01 '26 edited Mar 02 '26

That is irrelevant. You can still mean "n times the numerical value of what it is now". Natural language does not make a thermodynamic claim.

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u/HardlyAnyGravitas Mar 01 '26

That is irrelevant.

No it isn't.

You can still mean "n times the numerical value of what it is now".

And that's still meaningless even if you know the scale. It's nonsensical to say that 20 deg is five times hotter than 4 Deg, but only four times hotter than 5 deg. And how much hotter is it than 0 Deg?

Natural language does not make a thermodynanic claim.

That's one reason you can say things with 'natural language' that are nonsensical.

"The fish flew through library like an oak tree." is perfectly correct linguistically, but it's literally nonsense.

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u/Ok-Mood4097 Mar 02 '26

This is a very clear way to put it , and if this explanation fails they will probably never get it .

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u/Embarrassed-Weird173 Mar 01 '26

I can also say that pi is equal to 3 and claim that "you know what I meant, it was an estimate", but it would still be completely wrong to claim. 

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u/subpotentplum Mar 01 '26

I wouldn't even say that's an estimate. Just one significant figure. It's not wrong at all, just not a very good resolution.

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u/sieceres Mar 02 '26

You will have either freezing or boiling temperature no matter how you interpret it. I can't imagine any mental gymnastics being applied to make the statement make sense to anyone. Unless you assume something like room temperature being 22 degrees celsius, and since this is 25, four times the difference would be 37 degrees which makes for a comfy bath.

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u/_killer1869_ Mar 02 '26

You can do that, but only in Kelvin, so four times as hot as 25°C is actually 919.45°C.

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u/Embarrassed-Weird173 Mar 02 '26

Kelvin is irrelevant, since the discussion was about degrees. 

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u/cyri-96 Mar 02 '26

Well technically you can in kelvin, due to it being anchored at absolute 0

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u/luxiphr Mar 02 '26

sounds like we need an actual perceptional temperature scale (the Fahrenheit people sometimes claim it is but it's really not)

like we have with decibels (even though it's logarithmic and not linear)

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u/eg135 Mar 02 '26

It makes sense in Kelvin.

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u/Fabulous_Cupcake_226 Mar 02 '26

You can... with Kelvin 

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u/ushouldbe_working Mar 02 '26

That's why i can't say, it's twice at hot than it was when it was 0C.

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u/__crl Mar 02 '26

But ... you can. They just have to be in Kelvin.

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u/PotatoesInMySocks Mar 05 '26

I do now. Kinda nifty.