[alancalverd]

You narrowed down the scope of your physics to a level to be simpler than high school text books.

AFAIK  high school physics still deals with ideal pendulums. I don't recall the chemical and crystallographic aspects of vacuum tribology being part of the syllabus, though some of my contemporaries did study it for their PhDs and as of this week it remains an important topic for electron microscopists in a well-known laboratory down the road from here.

[Bored chemist]

Pick one.

Antenna temperature is well defined.

Antenna Temperature is a measure of the noise generated by an antenna in a given environment,... This is not the physical temperature of the antenna itself; rather, it depends on ....

Then tell me, is the temperature of the electrons going up and down, the same as that of the electrons going side to side?

Do you realise that a noise temperature or antenna temperature isn't a real temperature of anything?
e.g.

"C-band LNB
Here is an example of a North American C-band LNB:

Local oscillator: 5.15 GHz
Frequency: 3.40?4.20 GHz
Noise temperature: 25?100 kelvins"

From
https://en.wikipedia.org/wiki/Low-noise_block_downconverter#C-band_LNB

[alancalverd]

The Boltzmann equation actually derives from considerations of thermal noise in a conductor. This is an entirely reasonable derivation and is borne out in practice: as you increase the temperature of a resistive element, so you see more "grass" on the voltage across it. The inverse process, ascribing a "temperature" to an antenna that is receiving incoming signals, doesn't appear at first sight to generate a particularly useful parameter.     

[Bored chemist]

The Boltzmann equation actually derives from considerations of thermal noise in a conductor.

This was particularly clever of him since he derived  the eqn in 1872 and the electron was not discovered until 1897.

[alancalverd]

It is the mark of vacuous vanity to put your name on a bankrupt university, hotel or golf course.

It is the mark of greatness that people name things for you after you are dead. 

IIRC Einstein currently holds the record for posthumous nomenclature in physics and chemistry, including  an element and a derived unit among other things, but Boltzmann's constant  and distribution are more widely used in engineering.


PS only two people have colleges named after them in both Oxford and Cambridge. Good pub quiz question! 

[Bored chemist]

I guess the "trick question" ones are Queens and Kings.
Jesus (AKA Corpus Christi) and
Mary Magdalen
each have a college.

Are there two Saints Catherine and two Saints  John?

[alancalverd]

There are subtle differences between Catherine/Catharine and Magdalen/Magdalene. Likewise Queen's and Queens, King's and Kings. Lord knows how many different St Johns may have blessed academe, with or without apostrophes.

Meanwhile, here's an old chestnut:

Tourist in Cambridge: Hey, buddy, where's "Cayus"?
Student: It's pronounced "Keys" and on your map it is spelled "Gon...."

(note for mystified non-Brits:   Gonville and Caius College, usually referred to Caius , was founded in 1348 by Edmund Gonville, ran out of money, and was refounded in 1557 by John Caius.)

[hamdani yusuf (OP)]

AFAIK  high school physics still deals with ideal pendulums. I don't recall the chemical and crystallographic aspects of vacuum tribology being part of the syllabus, though some of my contemporaries did study it for their PhDs and as of this week it remains an important topic for electron microscopists in a well-known laboratory down the road from here.

Some textbooks have advanced sections or more detailed problems addressing damped pendulums or other oscillatory motions like vibrating mass on a spring or a bouncing ball. They show how energy is lost due to non-ideal conditions.

[hamdani yusuf (OP)]

Then tell me, is the temperature of the electrons going up and down, the same as that of the electrons going side to side?

It depends on how it's measured. If the antenna is diagonally polarized, or circularly polarized, they can be the same.
Although the values can be different, they are still well defined.

[hamdani yusuf (OP)]

Do you realise that a noise temperature or antenna temperature isn't a real temperature of anything?

How do you define real temperature?
How do you measure it?

[Bored chemist]

There are subtle differences between Catherine/Catharine

So subtle that both colleges have crests featuring Catherine wheels.

and Magdalen/Magdalene.

Again, the difference is spelling.
Both refer to Mary.

[alancalverd]

The answer is Jesus and Wolfson. No question about spelling, or "which Jesus".

[Bored chemist]

In what alphabet do you think Mary Magdalen would have spelled her own name?

:-)

How many Saints Catherine was the firework named after?


Anyway...
Back to the less important matter of reminding HY of stuff he's already been told...

How do you define real temperature?

The temperature corresponds to the average energy in the various forms available to the system.
If there isn't one- as in this case for example

It depends on how it's measured.

then there isn't a real temperature.

Temperature is important if you are looking at things in thermal equilibrium. But if they are not even at equilibrium with themselves, that's not going to work.

How do you measure it?

With a thermometer that is at equilibrium with the thing you are measuring, which it can't be if the things is not, in itself, at equilibrium.

[hamdani yusuf (OP)]

The temperature corresponds to the average energy in the various forms available to the system.

This might be necessary, but inadequate to distinguish temperature from other forms of energy.

[Bored chemist]

Anyway...
Back to the less important matter of reminding HY of stuff he's already been told...

The energy of a moving object like a car isn't thermal energy for two reasons.
1) there's only 1 car and temperature is defined for an ensemble of particles.
2) the various forms of energy within the car (rotation, vibration, translation, electronic, etc) are not all in equilibrium.

[hamdani yusuf (OP)]

Temperature is important if you are looking at things in thermal equilibrium. But if they are not even at equilibrium with themselves, that's not going to work.

Temperature in water column of the ocean, or atmospheric air column, or water being boiled are not in equilibrium. But their temperature can be measured.

[hamdani yusuf (OP)]

With a thermometer that is at equilibrium with the thing you are measuring, which it can't be if the things is not, in itself, at equilibrium.

What kind of thermometer is the most accurate to measure the real temperature? What makes it better than the others?

[Bored chemist]

Temperature is important if you are looking at things in thermal equilibrium. But if they are not even at equilibrium with themselves, that's not going to work.

Temperature in water column of the ocean, or atmospheric air column, or water being boiled are not in equilibrium. But their temperature can be measured.

OK, so we can start with water being boiled. That, by definition, is the temperature at which the liquid and gas phases are at equilibrium at the local external pressure.
It really is at equilibrium.

The water column etc have average temperatures.
But the temperature of the bottom is different to that at the top.
So what?

What kind of thermometer is the most accurate to measure the real temperature? What makes it better than the others?

It depends, and it depends.

[hamdani yusuf (OP)]

OK, so we can start with water being boiled. That, by definition, is the temperature at which the liquid and gas phases are at equilibrium at the local external pressure.
It really is at equilibrium.

At equilibrium with what?

[hamdani yusuf (OP)]

ChatGPT's answer to my question,
When were the term temperature defined in scientific community?

The concept of temperature has been studied and refined over centuries, with its formal scientific definition taking shape in the 17th and 18th centuries as thermodynamics and kinetic theory developed.

Key Milestones in the Definition of Temperature:

1. Ancient Roots (Pre-17th Century):

Early cultures understood the qualitative idea of "hot" and "cold" but had no precise measurement.

Ancient Greek philosophers like Aristotle (4th century BCE) described temperature in terms of the "qualities" of heat and cold, but these ideas were purely philosophical.



2. Invention of Temperature Scales (17th Century):

Galileo Galilei (1593): Invented a rudimentary thermoscope to measure temperature changes qualitatively.

Fahrenheit Scale (1724): Gabriel Fahrenheit developed a mercury-in-glass thermometer and defined a temperature scale.

Celsius Scale (1742): Anders Celsius introduced a scale based on the freezing and boiling points of water.



3. Thermodynamic Definition (19th Century):

The scientific definition of temperature was linked to energy and the motion of particles.

William Thomson (Lord Kelvin, 1848): Proposed the absolute temperature scale, now called the Kelvin scale, rooted in thermodynamic principles.

Kelvin defined temperature based on the second law of thermodynamics, making it independent of the properties of specific substances.



4. Kinetic Theory (19th Century):

James Clerk Maxwell and Ludwig Boltzmann connected temperature to the average kinetic energy of particles in a system:




T ~ < KE >

Summary:

Pre-1600s: Temperature understood qualitatively.

17th?18th Century: Development of temperature scales and thermometers.

19th Century: Temperature defined scientifically in terms of thermodynamics and particle motion.


Today, temperature is formally defined as a measure of the average kinetic energy of particles in a system, with the Kelvin being the SI unit.