[Bored chemist]

Is there some reason why you don't just learn the science?
https://en.wikipedia.org/wiki/Partition_function_(statistical_mechanics)

[Eternal Student]

Hi.

   This thread has got quite unpleasant, hasn't it?  It's not my forum and there's no reason my opinion is worth writing down or reading.   However, I don't think I'll be following this thread anymore.  My apologies if I don't reply to someone who has quoted or tagged me  ( @Eternal Student )   etc.

Best Wishes.
   

[alancalverd]

 As it happens I don't think there is a good theoretical model for porridge.  As such Goldilocks probably can't determine the temperature of her porridge on the modern (post 2019) kelvin scale.   That temperature is simply "unknown" or "undetermined" at this time.

Things aren't quite that bad. She may not find it easy to calculate, but it's very easy to measure with a thermometer calibrated in K.

[Rodneyhhernandez]

Depending on the temperature molecules move faster or slower?
Do I understand?

[Bored chemist]

Depending on the temperature molecules move faster or slower?
Do I understand?

Yes.
Hotter molecules move faster.
But, as is often the case, the detail is more complicated than that

[hamdani yusuf (OP)]

Things aren't quite that bad. She may not find it easy to calculate, but it's very easy to measure with a thermometer calibrated in K.

Different types of thermometers have their limits in range and linearities. How would you calibrate them against each other, if temperature is not well defined in standardized definition?

[Bored chemist]

How would you calibrate them against each other,

Practically speaking, like this.
https://en.wikipedia.org/wiki/International_Temperature_Scale_of_1990

Theoretically, like this
https://en.wikipedia.org/wiki/2019_redefinition_of_the_SI_base_units#Kelvin

[Origin]

Different types of thermometers have their limits in range and linearities. How would you calibrate them against each other, if temperature is not well defined in standardized definition?

After 16 pages you sound more confused about temperature than when you started.   

[alancalverd]

Things aren't quite that bad. She may not find it easy to calculate, but it's very easy to measure with a thermometer calibrated in K.

Different types of thermometers have their limits in range and linearities. How would you calibrate them against each other, if temperature is not well defined in standardized definition?

Temperature is fully defined, and the fixed points on the Celsius scale are entirely adequate for determining the temperature of porridge since it consists mostly of liquid water.

[hamdani yusuf (OP)]

After 16 pages you sound more confused about temperature than when you started.   

So, what's your answer to this question : what is temperature?

[hamdani yusuf (OP)]

How would you calibrate them against each other,

Practically speaking, like this.
https://en.wikipedia.org/wiki/International_Temperature_Scale_of_1990

Theoretically, like this
https://en.wikipedia.org/wiki/2019_redefinition_of_the_SI_base_units#Kelvin

How can we make sure that those defining points conform to the definition of temperature?

https://en.wikipedia.org/wiki/International_Temperature_Scale_of_1990#Defining_points
Substance and its state   Defining point (range)
K   °C   °R   °F
Triple point of hydrogen   13.8033   −259.3467   24.8459   −434.8241
Triple point of neon   24.5561   −248.5939   44.2010   −415.4690
Triple point of oxygen   54.3584   −218.7916   97.8451   −361.8249
Triple point of argon   83.8058   −189.3442   150.8504   −308.8196
Triple point of mercury   234.3156   −38.8344   421.7681   −37.9019
Triple point of water[note 1]   273.16   0.01   491.69   32.02
Melting point[note 2] of gallium   302.9146   29.7646   545.2463   85.5763
Freezing point[note 2] of indium   429.7485   156.5985   773.5473   313.8773
Freezing point[note 2] of tin   505.078   231.928   909.140   449.470
Freezing point[note 2] of zinc   692.677   419.527   1,246.819   787.149
Freezing point[note 2] of aluminium   933.473   660.323   1,680.251   1,220.581
Freezing point[note 2] of silver   1,234.93   961.78   2,222.87   1,763.20
Freezing point[note 2] of gold   1,337.33   1,064.18   2,407.19   1,947.52
Freezing point[note 2] of copper   1,357.77   1,084.62   2,443.99   1,984.32

[Bored chemist]

How can we make sure that those defining points conform to the definition of temperature?

By doing science.
You should try it some time.

[hamdani yusuf (OP)]

How can we make sure that those defining points conform to the definition of temperature?

By doing science.
You should try it some time.

Are they necessary to be defined besides of practical purpose?
Can they be derived purely theoretically?
How do you calibrate temperature far from those defining points, such as 1 milli Kelvin, or 1 million Kelvin?

[Spring Theory]

I think you guys are getting very unproductive.  My elegant description of temperature in the form of concentration of photons gives the concept.  In statistical mechanics temperature is defined starting with Entropy (setting Boltzmann's constant to 1):



Where T is temperature, E is the energy of the system and S is the entropy of the system. 

Temperature is the amount of energy required to change the entropy by one bit.

[hamdani yusuf (OP)]

I think you guys are getting very unproductive.  My elegant description of temperature in the form of concentration of photons gives the concept.  In statistical mechanics temperature is defined starting with Entropy (setting Boltzmann's constant to 1):




Where T is temperature, E is the energy of the system and S is the entropy of the system. 

Temperature is the amount of energy required to change the entropy by one bit.

What does the log2 mean? Is it a constant?
How do you explain that melting ice doesn't change its temperature while absorbing heat energy?

[Bored chemist]

My elegant description of temperature

It may be elegant, but it isn't much use.
Do you think that you can clearly explain the concept of entropy changes without using temperature in your explanation?

[alancalverd]

Temperature is the amount of energy required to change the entropy by one bit.

So the entropy of an object at constant temperature is continually changing?  Welcome to the world of Hamdani Yusuf!

[alancalverd]

So, what's your answer to this question : what is temperature?

A measure of the internal kinetic energy of a body.

[alancalverd]

How do you calibrate temperature far from those defining points, such as 1 milli Kelvin, or 1 million Kelvin?

You can only calibrate an instrument at the agreed fixed points. You can interpolate or extrapolate other values.

I measured microdegfree temperature changes with a thermistor, whilst my good buddy (also named Alan)  in the next lab measured plasma temperatures of 100 MK by studying the electron resonance spectrum. Herr Boltzmann's Konstant was very helpful in both cases.

[Spring Theory]

I think you guys are getting very unproductive.  My elegant description of temperature in the form of concentration of photons gives the concept.  In statistical mechanics temperature is defined starting with Entropy (setting Boltzmann's constant to 1):




Where T is temperature, E is the energy of the system and S is the entropy of the system. 

Temperature is the amount of energy required to change the entropy by one bit.

What does the log2 mean? Is it a constant?
How do you explain that melting ice doesn't change its temperature while absorbing heat energy?

Yes log2 is one bit, a constant.

Melting ice is doing work on the molecular structure.