Zero Temperature

[leedsgurl]

If it is zero degrees today, and then it's twice as cold tomorrow, what will the temperature be?

[eezablade]

depends. Zero degrees celsius or farenheit?

zero degrees C is 32 degrees F. Twice as cold is -8.8 degrees
zero degrees F is -17.78 degrees C. Twice as cold is -35 degrees C which is -31 degrees f.

I think.

[leedsgurl]

Thanx! So we can only work it out because there are 2 ways of measuring temperature? ... What if there was only 1 way?

[gen2]

There IS only one way of truly measuring relative temperatures, and that is the Absolute scale (or Kelvin). With all other temperature scales with arbitrary zero points, terms like twice as hot or half as hot don't relate to the numbers on the scale.

Ice at 273 Kelvin is twice as hot as a substance at 136.5K

[brachiopod]

There is no such thing as 'cold' only a lack of heat (or thermodynamic energy) so, using tonyted's suggestion of it being 'half as hot - If it's 0�C today, then it will be a little under -136�C, or -213.8�F tomorrow.

This is based on the absolute temperature scale, or Kelvin scale. This is the lowest temperature you can achieve, where (in theory), all atomic movement ceases and matter contains no heat energy.

This is called absolute zero or 0 K (note there is no '' � " (degree) symbol - and is equivalent (by agreement) to -273.15�C or about -459.7�F.

The Farenheit and Centigrade (Celsius) scales are arbitrary in where the zero lies on there respective scales. By quoting the equivalent values on the absolute scale is the only way you will get a meaningful answer to this question.

[brachiopod]

Sorry, gen, cross-post !

[stevie21]

Do you think all weather reporters should be giving us the temperature in Kelvin then? I might finally have a grasp of how hot or cold different numbers represent.

[Space]

I don't know whether eezablade was serious or joking... but his answer doesn't make any sense at all, I hope you don't take it seriously.
Multiplying or dividing temperatures in Celcius or Farenheight doesn't make any sense.
"twice as cold as 1 C " would be nearly the same temperature ( 0.5 C ) but in Farenheight it would be very different. These calculations mean nothing and neither do the results.

To answer the question, "twice as cold" only means something if you're doing thermodynamics.