tlhIngan-Hol Archive: Sat Feb 18 08:59:45 2006

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Re: bIrqu'choH

Terrence Donnelly ([email protected]) [KLI Member] 


--- [email protected] wrote:
> > 
> 
> If the boiling point equals 100%, then what is it
> 100% of?  I would expect it 
> to be 100% of the total heat content, which would
> then be about 373 kelvins 
> and each percentage of that would be 3.73 kelvins
> and 0% would be absolute zero.
> 

But that's not how they did it.  As it was explained
to me, the deviser of the Celsius/centigrade scale 
picked two universal physical markers, the boiling 
point and the freezing point of water, and arbitrarily

labelled the latter 0 and the former 100, then it 
was a simple matter to mark each degree between 
these, since it was a simple percentage of 100.  There

is no such natural marker for temperatures below 
freezing (except, as you note, absolute zero), so they

just extended the same system in the opposite
direction.

So (just as an example) if a column of mercury is
150 mm high at the freezing point, and is 250 mm high
at the boiling point, then each degree above freezing
is represented by a 1 mm change in the column;
therefore, degrees below 0 also change the height of
the
column by 1 mm in the opposite direction.  So a
column of mercury 50 mm high would correspond to a
Celsius temperature of -100 (or, in my "Klingon"
scale, lacking 100% of the freezing point), but
-100 C doesn't correspond to any particular physical
state, at least none involving water.  The degrees
below 0 are simply measured by analogy with their
positive counterparts.

(BTW, I don't really like the centigrade scale, in
part because it falls into negative values too 
readily.  You can read my rant against it at
http://other.tdonnelly.org/fahren.html , if you
are interested. But it does make it easy to
describe temperature in terms of percents!)

-- ter'eS

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