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.

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.

0°F is literally freezing outside too

32°C is 90°F

90°F is a very hot day. Extremely hot is 100°F (38°C).

50°F is where you’d slowly die being naked.

75°F is room temperature

25°F water is definitely frozen

Hot tubs are 100°F

Saunas are 200°F

-20°C to 40°C

Or

0°F to 100°F

10°C is about 50°F

20°C is about 75°F

-20,(-10), 0, 10, 20, (30), 40

Or

0, (14), 25, 50, 75, (86), 100

They are both easy once you know the scale

-40° is where they both line up.

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.