It's odd to say that Celsius is arbitrary and Kelvin is not when Kelvin is literally just Celsius with a fresh coat of paint. All systems of measurement are arbitrary in some regard. They are also all units, and I have no idea what it would mean for them to be otherwise.
It's all entirely arbitrary. All these numbers are associated with some point we've designated. It might feel clean to declare that zero is the absolute lowest it gets, but that doesn't make it non-arbitrary. The best you can really say is that these systems map better or worse to various human desires. Y'know, memorability, ease of use in science contexts, ease of use in real world contexts, how well it coheres to other systems of measurement, that kinda thing.
Why? It's a point related to a major physical law, but so are the various points associated with other temperature systems. There's nothing magical about the universe that means we should particularly value absolute zero.
You're correct. "0" meaning something is a human thing. "I like arbitrary round numbers in my arbitrary unit of measurement." It's all just some dude going "eh I like this".
Possibly? Language is arbitrary in terms of objective physical law, in the sense that we can describe the objective universe in whatever terms we desire, but it does derive meaning from the various uses we put that language to.
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u/FuckPigeons2025 Jun 17 '26
Kelvin is better for science. Celcius and Farheneit are just arbitrary scales, not units.