To make small note on Kelvins, it is a popular mistake to say "grades of Kelvin", similarly to "grades of Celsius" etc. Kelvin is a unit, like meter, moreover it is, so to say, absolute. i do somehow extrapolate that physics in IB went the same way in thinking about use of ye third thermodynamic law to express temperature. the table thus should look:
- 0 K = absolute zero
- 163.89 K = melting point of water
- 223.89 K = boiling point of water at 1 atmosphere
my two groats as bloody scientist Jan II. 23:24, 12 June 2007 (PDT)
- You certainly have a valid point to make regarding *here*'s temperature scales. Chalk it up to one of those minor differences between *here* and *there*. As far as *here*'s Kelvin is concerned, it has to be kept as a unit per se (that is, the unit is "kelvin", not "degree" on the kelvin scale) because all metric units can be divided and multiplied: you can have millikelvins and megakelvins the same way you can have millimetres and megameters. The SI is different in IB because it is simply the normal system of measures (the traditional units), standardised and universially defined.
- Thus, there can't be a "kelvin" unit, because the traditional and standard unit is the "degree". What the kelvin is in IB is one of the temperature scales.
- It should be noted that, historically, the "kelvin" was a degree scale. Lord Kelvin himself proposed the scale as denoted in "degrees" and until the 1950s, "degree Kelvin" was the standard use. I'm not using this as a justification for IB's usage, just noting that our modern usage of plain "kelvin" is fairly new. Given that both world's SI measures were defined in the mid to late 19th century, it would make sense that IB's kelvin scale would be denoted in degrees rather than kelvins.
- Elemtilas 06:31, 13 June 2007 (PDT)