[time-nuts] Obscure terms
Magnus Danielson
magnus at rubidium.dyndns.org
Thu Aug 20 10:06:49 UTC 2009
Neville Michie wrote:
>
>> One of the more interesting units used in the air conditioning
>> industry in USA in the past was
> a measure of wall insulation which was tons per square foot per inch
> per degree Fahrenheit.
> That is the number of tons of ice per 24 hour period that must melt to
> sustain a temperature difference
> of one degree F per square foot of wall one inch thick.
> Not far off furlongs per cubic fortnight.
It is clear that inventing new measures which hopefully was logical in
their original context has never been discouraged.
Some of them has ceased to exist while others has been refined and is
now part of the SI units.
I am still supprised that optical people talk about wavelength rather
than frequency, it's like they haven't grasped the effects of different
wave propagation speeds (which changes the actual length of the wave,
but not the frequency).
Cheers,
Magnus
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