h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Entry: Fahrenheit and Celsius - A1026532
Author: Whisky :- Consultant retro-phrenologist - U180644

Another boring one

Believe it or not I couldn't find an entry telling our colonial friends the other side of the atlantic how to use 'civilised' temperature scales...


(Diplomacy never was my strong point)

Go ahead and do your worst


Whisky

Nice -- just three things:

Celsius himself defined 100°C to be the freezing point and 0°C the boiling point. Later other people (sorry don't know the names) inverted it. Fortunately.

You may link to A471476. It contains the complete set of temperature conversion formulae.

Maybe you could say a few words about Fahrenheit and Celsius.

Nice stuff

How about a nod in the direction of Lord Kelvin (A356889) and his scale.

Good Entry

I agree with GreyDesk, although degrees in Kelvin are rarely used outside of scientific circles, it would be useful to provide links to Lord Kelvin and also directly to the more apposite A291034 Absolute Zero

Pimms

I suppose there is also the Réaumur scale to consider.

I recall when I was very young my school bought a whole load of thermometers for science lessons, and when we used them to look at the boiling point of water, we all faithfully reported that water boiled at 80 degrees. The poor old teacher blew his top, first at us for getting it 'wrong', and then at the supplies people for providing the wrong equipment

You are aware of what's already said in A471476?

As I've already said, I would put more emphasis on the people and stories behind these things. I know that at least Celsius was a pretty erm ... weird person.

Yes yes yes Cefpret. It is a great entry , but a bit wide in scope and long for researchers looking for the bitesize info on Temperature. 'For further info on Units of Measurement' link maybe, but definitely also room in the Guide for this entry too (but maybe that's what you meant)

I guess the question is how much surrounding info is included in the currently concise entry on extant and practical temperature measurement?

Pimms

Boring?
Not at all!

Nice entry, Whisky

There's a full stop missing at the end of the first paragraph.

I agree about linking to the other edited entries and here's another for you:
A273179 - water

AGB

*bookmarks unusual example of Whisky doing something useful with his time on h2g2*

2 things:

"The temperature of a mixture of equal proportions of ice and salt"

This is a bit silly, isn't it, because equal proportions of ice and salt could be 0 degrees _or anything less_. I would suggest something a bit like the following, deliberately trying to avoid any scientific jargon:

"The freezing point of a solution of 1 part (by mass) salt in 1 part water"

On a more fun note, are you going to mention that Mr. Fahrenheit actually intended the temperature of the human body on his scale to be 100 degrees, but right royally buggered up his calculations (I think he did the whole experiment up a mountain or something, rather than at sea level), hence also why the freezing point of water came out as 32 degrees rather than 30.

B

Why not add a section on kelvin (it doesn't have to be that long) and rename the article "Temperature Scales". Otherwise someone will need to do a more complete article later, and there will be a big overlap, something that would be best avoided.

Over than that, great article! (with the few changes suggested already, that is)

Tango

I'll just add another vote for Kelvin and keepe quiet about this otherwise fine entry...


- Jimi X

Nice concise entry.

It might be worth mentioning a quirk of the relationship between the two scales is that -40C is -40F and both are equally bloody cold.

Good point Gordon the Scout.

Master B, I always thought that ice below freezing became "dry ice" but don't quote me on that...

...or is it the salt that stops it freezing?

"Dry ice" is a term commonly used for the solid form of carbon dioxide. It's called "dry" because it reverts to gaseous form via sublimation, avoiding a liquid stage (ie: it doesn't melt).

Salt doesn't stop the water from freezing, it just lowers the freezing point of the water.

I'm a bit concerned over one bit: I read ages ago that the boiling point of a certain organic substance (methanol, ethanol, ?) was used as 100 F. Can you please check that this isn't the case.

Also, the wonderfully batty William Hague suggested, in a paroxysm of anti-Europeanism, that kids in UK schools should go back to using the imperial system of measurements. I'm sure that Farenheit was mentioned at one point. He *obviously* never studied physics otherwise he'd realise what a stupid suggestion he'd made.

Hi,

Did Fahrenheit think that 0, on his scale, was the coldest anything could ever get?


There's a joke that the use of Celsius in Canada keeps out the Americans. They look at a weather map, see that it's a comfortable 70 in Buffalo, but 50 degrees lower in neighbouring Ontario.

Awu.

I always seem to forget which measurment is lower: 0 Farenheit or 0 Celsius. Which is it?

Hazz.

As Finn I just have to correct you this much. -18C or 0F is not cold by any standard . Following relative temperature scaling has actually nothing to do with this otherwise nice and usefull entry.

(Following temperatures in Celsius)

+15
Spaniards start looking for winter clothing
Finns lay on beaches and crowd their parks
+5
Italian cars won't start anymore
Finns put on shirts while having barbaque parties
0
Pure water freezes
Greeks declare national catastrophe
Finns enjoy exceptionally mild weather
-15
EU south of Denmark collapses due to cold weather
Mild weather cancels Finland's army's winter exercise
-30
Finns start army's winter exercise
-45
Finns start to stay indoors more
-75
Finns admit that it is actually quite cold
-273
Absolute zero, movement of atoms stops
-300
Hell freezes over and Finland wins its first ever Eurovision song contest.

Wow... I go away for the weekend and it gets busy around here...

Thanks folks, I've had a quick glance throught the thread and a lot of it makes a lot of sense... I'll try and have a go at addressing all of these points at lunchtime and get back to you all...



Whisky

0 Fahrenheit is colder than 0 C.
0 Fahrenheit is about -17C.

If I can't remember, I draw two thermometers side by side. Make 0 on the C align with 32 on the F. And 100 with the 212. You have 0-100 C degrees corresponding to 32-212 (or 180 degrees) F. That's a ratio of 100/180 or 5/9. Then you just have to figure out whether to subtract the 32 first or add it on after doing the division.

The table and the formula in the entry do just that. But this lets you reconstruct it any time.

Awu.