# If its 0 degrees centigrade...

Thread Starter

Join Date: May 2004

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**If its 0 degrees centigrade...**

then how cold would it be if it were twice as cold?

(this was on Brainiac and I never saw the answer - could go into Faranheit and Kelvin temperatures etc but I cant be f**ked trying to figure it out)

(this was on Brainiac and I never saw the answer - could go into Faranheit and Kelvin temperatures etc but I cant be f**ked trying to figure it out)

Self Loathing Froggy

Join Date: Jun 2002

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The only temperature scales for which multiplication makes sense are the Kelvin or Rankine scales as they are both absolute, i.e. they originate at the absolute zero.

If you double the absolute temperature of a given mass of ideal gas at constant volume, the pressure doubles.

If you double the absolute temperature of a given mass of ideal gas at constant volume, the pressure doubles.

Thread Starter

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So do you suggest I find out the kelvin value of 0 degrees centigrade, halve that value, then convert that figure back to centigrade?

(in all honesty not that I really care, nor was I expecting a proper answer out of jetblast )

(in all honesty not that I really care, nor was I expecting a proper answer out of jetblast )

*Fabulous Flyblue*

*Bleu SuperModerateur*Join Date: Nov 2000

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It depends on which scale you are using, if Celsius, Farenheit or Kelvin, since "zero" is a different concept. Celsius "zero" is between -273,17° (absolute zero) and the positive temperatures, Farenheit "absolute zero" is - 459 while on Kelvin "zero" would be what is called "absolute zero" on Celsius and Farenheit= the coldest temperature possible. So I'd say it's not possible to have twice as cold as Kelvin zero, while on C and F it can be discussed (halve it?? ) .

Self Loathing Froggy

Join Date: Jun 2002

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So do you suggest I find out the kelvin value of 0 degrees centigrade, halve that value, then convert that figure back to centigrade?

My guess would be 273.15 / 2 = 136.575 K or -136.575 deg C

*Signora Flyblue*
Celsius "zero" is between -273,17° (absolute zero) and the positive temperatures

There is only one absolute zero. As temperature is related to atomic or particular motion, it is the temperature at which everyting stops moving, even the tiniest particles. incidentally, you would need an inifite amount of energy to reach it. Lowest temperatures achieved are in the microK range (one millionth).

Initially the Celsius scale was defined as 0 = freezing water, 100 = boiling water at atmospheric pressure.

Nowadays the definition of absolute temperature is the following : the triple point of water (liquid/solid/vapour equilibrium) is at 273.16 K (K stands for Kelvin - there is no such thing as a degree Kelvin). As it is an absolute scale, the origin is at the absolute zero.

The Celsius scale is a relative scale and is defined by 1 degree Celsius = 1 K and the origin of the Celsius scale is at 273.15 K

hence :

TK = Tc + 273.15

Tc = TK - 273.15

Farenheit is a bit more complicated :

initially 0 degrees F = ice/salt brine, 100 degrees F = Farenheit's body temperature (BTW he was a bit feverish)

Nowadays Tc = (5/9)*(Tf-32), Tf = (9/5)*Tc+32

0 deg C = 32 deg F, 0 deg F = -18 deg C, etc

Rankine is an absolute scale where 1 R = 1 degree F = 5/9 K

Absolute zero is indeed at -459 F

Resident insomniac

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Twice as cold? Do they mean half as hot?

Twice as anything implies an initial separation from 'the norm' (and then doubling it). AFAICT the attempts at calculation using Absolute temperatures are relying on the separation of 0 deg C from Absolute Zero (which cannot in any way be considered a 'norm' IMHO).

If you were to consider STP (Standard Temperature and Pressure),

"Definition: Standard temperature and pressure. The standard conditions used as a basis for calculations involving quantities that vary with temperature and pressure. These conditions are used when comparing the properties of gases. They are 273.15 K (or 0°C) and 101325 Pa (or 760 mmHg)."

Then there IS no separation from 0 degC, therefore twice (or half) the separation is zero, so the answer is the figure that you first thought of (sort of).

No?

If you want to measure 0 deg C from the average norm ambient temperature, then the world is your lobster . . .

BTW -40 deg F is also -40 deg C (but you knew that anyway . . . )

Twice as anything implies an initial separation from 'the norm' (and then doubling it). AFAICT the attempts at calculation using Absolute temperatures are relying on the separation of 0 deg C from Absolute Zero (which cannot in any way be considered a 'norm' IMHO).

If you were to consider STP (Standard Temperature and Pressure),

"Definition: Standard temperature and pressure. The standard conditions used as a basis for calculations involving quantities that vary with temperature and pressure. These conditions are used when comparing the properties of gases. They are 273.15 K (or 0°C) and 101325 Pa (or 760 mmHg)."

Then there IS no separation from 0 degC, therefore twice (or half) the separation is zero, so the answer is the figure that you first thought of (sort of).

No?

If you want to measure 0 deg C from the average norm ambient temperature, then the world is your lobster . . .

BTW -40 deg F is also -40 deg C (but you knew that anyway . . . )

Chief Tardis Technician

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G-Cptn

Was going to say some thing along those lines.

English is a strange language, in that you try to multiply some thing to result in a smaller result.

Does twise as cold mean 1/2 the temperaure, is is the sensation of cold measured on a logerithmic scale?

20 Deg C is warm, 15 is cold, 25 is getting nice (or a heat wave in England) 30 uncomfortable 32 hot 40 dont think about that.

Its all too hard for a Saturday morning, and I'm only on my second coffee.

Was going to say some thing along those lines.

English is a strange language, in that you try to multiply some thing to result in a smaller result.

Does twise as cold mean 1/2 the temperaure, is is the sensation of cold measured on a logerithmic scale?

20 Deg C is warm, 15 is cold, 25 is getting nice (or a heat wave in England) 30 uncomfortable 32 hot 40 dont think about that.

Its all too hard for a Saturday morning, and I'm only on my second coffee.

*Fabulous Flyblue*

*Bleu SuperModerateur*Join Date: Nov 2000

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Spent more time looking at the physics teacher's eyes than at the blackboard, haven't you

**Mr Bre**, I avoided looking too much at my Physics teacher to avoid nightmares at night so I'm sure I was looking at the blackboard allright when he taught us that in Celsius "absolute zero" was -273,15 and that the negative temperatures went up to 0°, the temperature of water freezing into ice.

Now Physics might have changed since I was in High School, it's true we didn't know about Matrix and the like during the Eighties