Hear me out. There's nothing wrong with setting the 0 temperature for the relative temperature scale to the freezing point of water. It is a convenience after all. However there is no reason to arbitrarily assign the boiling point of water the value of 100 degrees. I propose that a better system would be to base the unit of temperature on other already existing units. One degree of this system would be the temperature change corresponding to 1 joule of heat being added to 1 kg of water. There is no reason to have the heat capacity of water be 4.184 when it could easily be 1.