It was invented by some scottish guy long before we had the means to measure things that would need it, and ever since that multibillion-dollar satellite thing fell to pieces even American scientists use metric units, we learn them in every grade level’s science class and our scientific community has this understandable atmosphere of regret that Congress was too lazy to completely kill off imperial units when they had the chance
Fahrenheit is actually a base-ten system, where 0° was the freezing temperature of a salt/water mixture used in laboratories in the 18th century, and 100° was supposed to be a human’s blood temperature. Another convenient perk of the fahrenheit system is that most European weather occurs inside it’s 0-100 range.
Eventually Fahrenheit saw the scientific need to know the freezing and boiling point of plain water, but instead of adjusting his system, he just found those values within his system.
The story I heard, and I don’t know if this is true or not, is that 100 isn’t just a human’s blood temperature, but specifically Mrs. Fahrenheit’s blood temperature.
I’m assuming this is because the concept of absolute zero did not exist when most of these temperature scales were defined, whereas zero distance and zero weight were easily observable
I guess in terms of an actual weightless object… Not… But if you have 2 equal weight items, call their combined weight 1 weight unit, take one away, that’s half a weight unit, take two away, that’s zero weight units.
The Rankine scale is generally measured in degrees. That’s because it’s defined in terms of the Fahrenheit scale, which is also measured in degrees. i.e. 1 Rankine degree = 1 Fahrenheit degree.
This is not the case for the Kelvin scale, which is defined directly in terms of thermal energy: 1 Kelvin ≈ 1.38*10^-23 J. Coincidentally (but not really of course) this amount of thermal energy is such that an increase of 1 Kelvin corresponds to 1 degree Celsius.
This is rather pedantic, as you could easily define Rankine in terms of thermal energy as well. Some people do this and don’t say “degrees” in front of Rankine. Or, you could define the Kelvin in terms of the Celsius, and measure it in degrees.
tl:dr Rankine has degrees, but for mainly historical reasons.
P.S.: Kelvin actually also had degrees until 1968!
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