• hperrin@lemmy.ca
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    1 day ago

    The original Fahrenheit system was actually pretty clever. It set 0° at the temperature of brine and 96° at internal body temperature. That made marking a thermometer really easy. Like, ridiculously easy. 96 is divisible by two many times before reaching a decimal.

    Because the freezing temperature of water was really close to 32°, the later Fahrenheit system set that as the lower temperature and 212° as the boiling point instead of using body temperature. That made marking a thermometer more difficult, and basically took away Fahrenheit’s only advantage. It was more consistent though. Now Fahrenheit is formally defined based on Kelvin.

    Centigrade was originally marked as 100° at the freezing temperature, going down as temperature increases to 0° at the boiling temperature. Obviously that didn’t last long. The downside is that marking a Celsius thermometer depended on atmospheric pressure. Now Celsius is defined based on Kelvin by -273.15° being absolute zero and a degree corresponding to a very specific amount of heat energy increase.

    So yeah, Fahrenheit hasn’t made any sense for many many years.

        • Th4tGuyII@fedia.io
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          1 day ago

          Yeah, of course that is the case now that most definitions have been updated to be tied to physical constants rather than observations that rely on specific conditions…

          But the same wiki article you linked literally says otherwise. The Kelvin’s magnitude was based on the magnitude of Celcius because of Charle’s Law.

          I.e. the volumes of gases under the ideal gas law scaled linearly with degrees celcius by about 1/273rd between 0-100C - which led to the prediction that the lowest possible temperature a gas could be was -273C (because that would be the point where it theoretically would have absolutely zero volume).

          Which is a long-winded way of saying stop being a smartass. The guy you replied to was just as technically correct as you were, given they said 1k stemmed from 1C.

          • NoneOfUrBusiness@fedia.io
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            18 hours ago

            I.e. the volumes of gases under the ideal gas law scaled linearly with degrees celcius by about 1/273rd between 0-100C - which led to the prediction that the lowest possible temperature a gas could be was -273C (because that would be the point where it theoretically would have absolutely zero volume).

            No horse in this race, but this is cool as fuck. So that’s how the first tries at measuring absolute zero were made.

          • hperrin@lemmy.ca
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            1 day ago

            But they didn’t say “stemmed”. They said “stemming”. But sure, they’re technically correct in a historical context. I wanted to be more precise about the current definition. Under that current definition, it’s actually degree Celsius that stems from Kelvin.