Re: First snow

John W Kennedy
The Fahrenheit scale was adjusted (centuries ago) to
make 32?F and 212?F the exact temperatures of
freezing and boiling, with a nice, even 180?F
between them (which is why the 9/5C+32 and
5/9(F-32), or, as some prefer, 9/5(C+40)-40 and
5/9(F+40)-40 formulas work exactly).

Alma Hromic Deckert
And didn't someone mention "the lowest point he could
get in his lab"? And interesting variations like salt
water?

Yes, but they found those were difficult to reproduce,
while boiling and freezing water were easy to reproduce
- so they repinned the Fahrenheit scale to pure water
at atmospheric pressure.

Similarly, the meter was originally set to a forty
millionth of the circumference of the earth. When they
realized that they could not measure the earth all that
accurately, and the circumference was apt to change from
time to time, they repinned the meter to two marks on a
metal bar, and then they discovered that metal tended to
wear and warp, and repinned the meter as the distance
light travels in a rather small fraction of a second.
Then they discovered that they could not measure that
distance all that accurately, and somewhat furtively
redefined it as a certain number of wavelengths of an
iodine-stabilised helium-neon laser.

And now it has been discovered that atomic fountains are
inherently more stable and reproducible than the
iodine-stabilised helium-neon laser and so they are
working their way back towards the previous definition
as the distance light travels in a rather small
fraction of a second.



.

Relevant Pages

  • Re: Typing in Ada
    ... Celsius, at standard pressure, between freezing and boiling of water. ... strict EPA system may consider "overfilling" the tank to be an exception ...
    (comp.lang.ada)
  • Re: tossing pancakes
    ... 100F is SUPPOSED to be human body temperature. ... I think the common conception is that Fahrenheit is also based on freezing and boiling of fresh water, but that Herr Fahrenheit wanted those to temperatures to be positive. ...
    (rec.arts.sf.composition)
  • Re: GRidlock - How far has RTD gone?
    ... How about 0 to 100 based on the boiling and freezing points ... heat distilled water above 100 C under 1 Atm without it boiling. ... brine at one end and human blood at the other). ...
    (rec.arts.drwho)
  • Re: GRidlock - How far has RTD gone?
    ... You're against the metric system because computers tend to use it more ... let's think of a really rational scale of measuring ... How about 0 to 100 based on the boiling and freezing points of ...
    (rec.arts.drwho)
Loading