Fahrenheit was set to 0 on the lowest temperature someone could achieve at time. And 100 was set to the body temperature of the human body. Totally two comparable points of measurement.
It’s not the coldest someone could achieve at the time. It was chosen because it’s a reliable low temperature that will consistently be produced by a particular brine solution.
Celsius uses the melting point of water as 0.and then uses, revolutionary, the same water when it changes its state from liquid to gas.
That doesn’t really make it better, does it? How does that make it better? It sounds like it makes it better, but functionally what’s better about it? What functionally is made superior by defining it as two stages of one thing rather than stages of different things? As long as the temperatures are reliably reproduced, it’s functionally the same. Sure, being a measure of water does make it more useful when you care about water (at sea level, and only at sea level), as I said before. It doesn’t generally make it better though.






You didn’t answer why that makes it better. What functionality does it give us that we don’t have if we use two reference points from different things. I’m pretty confident there aren’t any. This is proven especially true because that’s not how Celsius is defined anymore, and it didn’t lose any functionality. It sounds more “pure”, or whatever, but that doesn’t make it better. Do you have an actual reason that it improves its functionality?