• Dale@lemmy.world
      link
      fedilink
      English
      arrow-up
      21
      arrow-down
      2
      ·
      2 days ago

      And a Fahrenheit is 1/100 the temperature difference between frozen salt brine and Mrs Fahrenheit’s armpit. Also the answer to how hot it is outside on a scale from 0-100.

      • Sludgeyy@lemmy.world
        link
        fedilink
        arrow-up
        12
        arrow-down
        5
        ·
        1 day ago

        Daniel Fahrenheit invented the mercury thermometer.

        He wanted 0°F to be as cold as he could create and duplicate. Frozen salt brine.

        100°F just happened to be very close to body temperature.

        Celcius came after and just stated that at 100°C water froze at 1 atmosphere. 0°C was boiling.

        Since then, it’s been changed to 0°C being the freezing point.

        Also, Celcius is now based on Kelvin. 0K is -273.15°C

        They are both outdated systems

        Kelvin is the true system

        Fahrenheit and Celsius are just still being used by people because they know it.

        People who know Celsius think it’s easy, people who know Fahrenheit think it’s easy.

        273.15K for the freezing point of water isn’t hard.

        Temperature outside ranges from 250K to 310k

        Room temperature is about 295K

        F has 30° between 70° and 100°

        C has 20° between 20° and 40°

        K has 15 between 295 and 310

        They are all just numbers on different scales that help represent an idea. One isn’t necessarily easier than another. 295K as room temperature would scare people, though.

        • Dale@lemmy.world
          link
          fedilink
          English
          arrow-up
          7
          ·
          1 day ago

          Kelvin is great for math and science. But daily life? Dude. The weather does not need to be reported relative to absolute zero just like the speed of your car doesn’t need to be reported relative to the sun. Also Fahrenheit did famously use his wife’s armpit for the 100 mark that’s why it’s “close to body temperature”.

          Another fun fact human body temperature has not always been 98.6 and has been getting lower.

          • Sludgeyy@lemmy.world
            link
            fedilink
            arrow-up
            2
            ·
            20 hours ago

            I didn’t know about the arm pit thing.

            To create a scale you have to start somewhere.

            To think he measured his wife arm pit to be 100°F and then said, let me make a salt brine mix to get to 0°F. Seems completely backwards.

            They had no idea about absolute 0 back then. Coldest thing you can create in a lab consistently at the time was a reasonable 0°

            But that’s where the scale starts and everything is based on.

            Could he have created a colder one but wanted 100° to be close to body temperature. Maybe. But that’s not weird. 0 and 100 are important numbers. Most people have an armpit and a way to calibrate their thermometer in a pinch. Axillary method, armpit, is a legit way to take someone temperature.

            Fahrenheit has 2° compared to 1° of Celsius. 98, 99, 100, 101. (37, 37, 38, 38). Being 1° off in F isn’t as much of an error as being 1° off in C.

            You can’t just boil water and say, that’s 100°C! Pressure matters. To boil water at standard pressure was difficult to recreate at the time. Same for freezing.

          • Sludgeyy@lemmy.world
            link
            fedilink
            arrow-up
            1
            ·
            20 hours ago

            That’s the whole point of using Celsius or Fahrenheit. They are both just different representations of Kelvin. But Kelvin is absolute.

            If you want your weather scale to go -20 to 40 or 0 to 100. Is debatable.

            0°F to 100°F is better for weather

            0°C to 100°C is better for water temperature

            If you know C, there’s no need to learn F for the weather.

            If you know F, there’s no reason to learn C for the weather.

            You don’t need to know F or C to read a thermometer. 375°F or 190°C are just numbers you might bake cookies at. No one knows how 375°F or 190°C “feels like”

            Things you need to know is if 90°F or 32°C water is safe to get in. Over 100°F is getting dangerous, Over 40°C is getting dangerous.

            Normal house hot water is 50°C or 120°F.

            Time to cause burns:

            120°F or 50°C More than 5 minutes

            130°F or 55°C About 30 seconds

            140°F or 60°C Less than 5 seconds

            150°F or 65°C About 1.5 seconds

            160°F or 70°C About 1/2 a second

            Aslong as you know a system, you’re fine. Fahrenheit isn’t like the other US customary units. It is based on the exact same thing Celsius is, Kelvin. Just shown in different numbers. Something like a quart to gallon is a completely made-up measurement and horrible.

        • untorquer@lemmy.world
          link
          fedilink
          arrow-up
          4
          arrow-down
          1
          ·
          1 day ago

          I put my pizza in the oven at 250k with convection. How long until the crust is brown and the cheese melted?

        • JLock17@lemmy.world
          link
          fedilink
          English
          arrow-up
          2
          arrow-down
          2
          ·
          1 day ago

          Chad Kelvin poster. It really is a better system. 0 K is the absolute absence of energy in a system, and is a reasonable starting point to define energy and temperature.

        • Pup Biru@aussie.zone
          link
          fedilink
          English
          arrow-up
          2
          ·
          edit-2
          1 day ago

          the answer to that question is the same as whether a foot as any foot or only king henry’s……. arm