Absolute zero

[alex36]

Main Question or Discussion Point

Why absolute zero of temperature doesn't depend upon properties of substance?

 

[phinds]

I don't understand what you mean, can you clarify your question?

If you heat a piece of metal to 100 degrees how is that temperature any different than heating a piece of glass to 100 degrees, or a piece of wood ?

And by the way, "absolute zero" is not believed to be achievable in reality.

 

[alex36]

I don't understand what you mean, can you clarify your question?

If you heat a piece of metal to 100 degrees how is that temperature any different than heating a piece of glass to 100 degrees, or a piece of wood ?

And by the way, "absolute zero" is not believed to be achievable in reality.

In my syllabus its written "understand that there is an absolute scale of temperature that does not depend on the property of any particular substance"

 

[drvrm]

Why absolute zero of temperature doesn't depend upon properties of substance?

do you wish to say that temperature of a body is not absolute and is defined with respect to material/substances?
do you say 50 degree of water or hydrogen.... or you have scale of measurements including thermodynamic scale.

 

[alex36]

do you wish to say that temperature of a body is not absolute and is defined with respect to material/substances?
do you say 50 degree of water or hydrogen.... or you have scale of measurements including thermodynamic scale.

-273K is called absolute 0 temperature where there is no any kinetic energy in molecule . Practically it doesn't exist but theoretically it does . So, my question is why absolute zero temperature doesnot depend upon property of particular substance.

 

[phinds]

In my syllabus its written "understand that there is an absolute scale of temperature that does not depend on the property of any particular substance"

Exactly. Just as there is a scale of length that does not depend on what you are measuring.

 

[phinds]

-273K is called absolute 0 temperature where there is no any kinetic energy in molecule . Practically it doesn't exist but theoretically it does . So, my question is why absolute zero temperature doesnot depend upon property of particular substance.

See post #2

 

[alex36]

Exactly. Just as there is a scale of length that does not depend on what you are measuring.

That was too easy ! thanks man

 

[Khashishi]

Maybe it's easiest to understand in contrast to the Celsius scale. 0 degrees C was once defined as the freezing point of water at one atmosphere. You don't need water to have something at 0 degrees C, but people originally agreed to build the scale around properties of water. The 0 point of Kelvin does not depend on any special substance. It is a universal property.

 

[sophiecentaur]

In my syllabus its written "understand that there is an absolute scale of temperature that does not depend on the property of any particular substance"

I think what the syllabus statement means is that the various practical types of thermometer will give different temperature scales that, when extrapolated downwards, will not coincide at the bottom end. The Kelvin Scale of temperatures is based on a more basic (thermodynamic) idea that ignores the deviations that you get with 'real' thermometers e.g Platinum Resistance, Gas, Mercury in Glass, Alcohol which are based on different physical properties of substances.