So to carry on from another thread:
Syobon wrote:
Uh, explain to me how it could have been made more metric. They made it like that so it's easy to convert, in the vain hope everybody would switch to it. Setting it so that for example 100K=water freezing would have been pointless, as you've pointed out (also, it's dependent on pressure as well, making it even more useless).
The issue with the easily convertible system is that Kelvin probably wouldn't have been adopted ever, since Celsius provides a nice range that anyone can understand and that encompasses the range most people are going to deal with. And we'd be talking about temperatures within a range of 233 and 322 K (-40 to 120 F and -40-49 C) which aren't attractive numbers to laymen (plus they're big enough that differences between the numbers seem negligible). So accessibility shouldn't have been an issue, so the individual degree scale should have followed the same reasoning for what the bottom end of the scale was based on (absolute zero, or lack of heat energy).
Degrees in Celsius were determined by taking the heat energy needed to boil water (in certain conditions, like being at sea level with one atmosphere of pressure) subtracting the heat energy water would need to freeze and dividing the resulting difference by 100 to make a scale. It looks metric because you have a nice even number to deal with, but with Kelvin being based on heat energy, not heat energy relative to an abundant molecule that can have its freezing and boiling point easily determined. The degree scale should have set a scale based on overall heat energy (This substance has one [unit of heat energy], so it is 1 degree Kelvin). You'd still have decimal places (assuming you aren't using the smallest unit of heat energy (which would be stupid, that would be like talking about how tall a building is in nanometers (yes I know there's units smaller than that)).
The degrees wouldn't be based on anything arbitrary (like Fahrenheit) or made from a scale with both extremes based on a specific substance, it has a lower bound and just extends upward indefinitely, with a consistent scale based on the amount of heat energy X contains/produces/etc.
-K-