[hamdani yusuf (OP)]

And the result is still crap. See above.

It reflects current understanding of mainstream science.

[Bored chemist]

It reflects current understanding of mainstream science.

Whose?

What question did you ask it?

[hamdani yusuf (OP)]

What question did you ask it?

Is molecular motion frictionless ?

[alancalverd]

The question is similar to asking whether the motion of the moon is caused by tides.

See reply #1055 above for an explanation.

[Bored chemist]

What question did you ask it?

Is molecular motion frictionless ?

So... you missed out the important bit.
Why did you ignore the fact tat I was talking about zpe?

If you ask a better question, you get a better answer. (Even with Chatgpt.)

ZPE.JPG (37.46 kB . 805x236 - viewed 396 times)

[hamdani yusuf (OP)]

What question did you ask it?

Is molecular motion frictionless ?

So... you missed out the important bit.
Why did you ignore the fact tat I was talking about zpe?

If you ask a better question, you get a better answer. (Even with Chatgpt.)

ZPE.JPG (37.46 kB . 805x236 - viewed 396 times)

So, it's OK to use ChatGPT now?

[hamdani yusuf (OP)]

The question is similar to asking whether the motion of the moon is caused by tides.

See reply #1055 above for an explanation.

No. It's like asking whether the motion of the moon is frictionless.

[Bored chemist]

So, it's OK to use ChatGPT now?

If you are using it to explain why it's not much use, yes.

Did you forget to answer my question?
Why did you ignore the fact that I was talking about zpe?

[hamdani yusuf (OP)]

Why did you ignore the fact that I was talking about zpe?

Because it's irrelevant to my respond to Alan's assertion.
Why did you bring out ZPE into discussion?

Physics is about ideal gases, weightless strings, etc. So you can assume your pendulum is swinging in a vacuum, suspended from a frictionless pivot.

It depends on the level of complexity. High school physics already takes friction into account.

[hamdani yusuf (OP)]

... and since  Kinetic+potential is a constant, you don't need to average it.

Only in ideal case.

The "ideal" case where energy is conserved.
LOL

It's where the system doesn't exchange energy with the outside. It can happen through friction or radiation.

[Bored chemist]

The total energy of the ZPE of a spring (or a pendulum) is constant.
That's true whether the energy is kinetic or potential.
There are no losses.
So, if you wanted to ask a bot about the energy losses from ZPE, you need to tell it that's what you are referring to.

A better question might be why did Alan bring friction into it?

[hamdani yusuf (OP)]

Average kinetic energy alone isn't enough to describe temperature, a concept that's supposed to predict heat flow when two objects are allowed to exchange heat. The missing ingredients are what I was trying to identify.

Modern study for temperature was developed during early industrial revolution to optimize steam engines. Its measurements were mostly based on conductive heat transfer from the measured objects to the thermometer.
Here's a temperature measurement based on energy transfer through radiation.

Antenna Part 13. How to Calculate Antenna Noise Temperature. How Ant Temp Affects the Noise Floor.

Antenna Temperature is a measure of the noise generated by an antenna in a given environment, also referred to as Antenna Noise Temperature. This is not the physical temperature of the antenna itself; rather, it depends on the antenna's gain, radiation pattern and the noise picked up from the surrounding environment.

To define the environment (and thus provide a complete definition of antenna temperature), we will introduce a temperature distribution, which represents the temperature in every direction away from the antenna in spherical coordinates. For example, the temperature of the night sky is approximately 4 Kelvin, while the temperature in the direction of the Earth's surface corresponds to the physical temperature of the ground.

This equation shows that the antenna temperature is calculated by integrating over the entire sphere, based on the radiation pattern of the antenna and the temperature distribution of the antenna.

This states that the temperature surrounding the antenna is integrated over the entire sphere and weighted by the antenna's radiation pattern. Thus, an isotropic antenna would have a noise temperature that represents the average of all temperatures around it. For a perfectly directional antenna (such as one with a pencil beam), the antenna temperature will depend only on the temperature in the direction it is "pointing." Consequently, an antenna's temperature will vary depending on whether it is directional and aimed into space or directed toward the sun.

Here?s how antenna temperature works and is calculated:

Measurement in Kelvin: Antenna temperature is usually measured in Kelvin (K), where a higher temperature indicates more power from the radiation field being received.

Power Relation: The antenna temperature (Ta​) is proportional to the power density received by the antenna. The total received power Pr​ is calculated as:

     Pr = k TA B
where:
k is the Boltzmann constant, k = 1.38 X 10-23 J/K
TA​ is the antenna temperature in Kelvin,
B is the bandwidth in Hz.

The receiver has a temperature TR & total system temperature (antenna plus receiver) has a combined temperature given by Tsys = TA + TR.

A parameter often encountered in antenna specification sheets for operation in certain environments is the ratio of the antenna gain to the antenna temperature (or system temperature, if a receiver is specified). This parameter is denoted as G/T and has units of dB/Kelvin [dB/K].

Additionally, many RF engineers use the term Noise Figure (or Noise Factor, NF) to describe system performance. Noise Figure is the ratio of the input SNR (signal-to-noise ratio) to the output SNR. Essentially, all RF devices (such as mixers and amplifiers) introduce some noise. However, antenna temperature is not directly related to Noise Figure, as the power level of the signal input can vary significantly depending on the desired signal's direction of arrival, while the noise contribution remains constant.

In summary, antenna temperature is a key concept in understanding the amount of radiation an antenna receives, which can represent either signal or noise, depending on the application. It helps quantify the effective power of this radiation by linking it to the temperature concept, facilitating better analysis and system design in both astronomy and communications.

[alancalverd]

A better question might be why did Alan bring friction into it?

I don't recall doing so. I did point out that friction between mesoscopic objects has a strong chemical (i.e. molecular) component, but, being a physicist, all my pendulums are of course point masses on weightless strings in vacuo. Or, if you really insist, uniform rigid bars suspended on frictioness pivots.

[hamdani yusuf (OP)]

A better question might be why did Alan bring friction into it?

I don't recall doing so. I did point out that friction between mesoscopic objects has a strong chemical (i.e. molecular) component, but, being a physicist, all my pendulums are of course point masses on weightless strings in vacuo. Or, if you really insist, uniform rigid bars suspended on frictioness pivots.

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

[hamdani yusuf (OP)]

Modern study for temperature was developed during early industrial revolution to optimize steam engines. Its measurements were mostly based on conductive heat transfer from the measured objects to the thermometer.
Here's a temperature measurement based on energy transfer through radiation.

In both cases, temperature determines the direction of energy transfer when two systems are allowed to exchange energy. They are also related to kinetic energy of each system, as well as entropy, which is shown by the Boltzmann constant in the equations.

[Bored chemist]

Here's a temperature measurement based on energy transfer through radiation.

The purpose of antennae is not that they produce black body radiation.

It's obviously very far from equilibrium and does not have a well defined temperature. (For example, if you consider a simple dipole antenna, the electrons going "up and down" are not in equilibrium with the electros going "side to side")
Why did you bring it up?

[Bored chemist]

A better question might be why did Alan bring friction into it?

I don't recall doing so. I did point out that friction between mesoscopic objects has a strong chemical (i.e. molecular) component, but, being a physicist, all my pendulums are of course point masses on weightless strings in vacuo. Or, if you really insist, uniform rigid bars suspended on frictioness pivots.

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

That's entirely reasonable when communicating with someone who does not understand high school physics.

[hamdani yusuf (OP)]

The purpose of antennae is not that they produce black body radiation.

Who says it is?

[Bored chemist]

The purpose of antennae is not that they produce black body radiation.

Who says it is?

OK, so what antennae do is nothing to do with temperature.

[hamdani yusuf (OP)]

It's obviously very far from equilibrium and does not have a well defined temperature. (For example, if you consider a simple dipole antenna, the electrons going "up and down" are not in equilibrium with the electros going "side to side")
Why did you bring it up?

Antenna temperature is well defined.

Power Relation: The antenna temperature (Ta​) is proportional to the power density received by the antenna. The total received power Pr​ is calculated as:

     Pr = k TA B
where:
k is the Boltzmann constant, k = 1.38 X 10-23 J/K
TA​ is the antenna temperature in Kelvin,
B is the bandwidth in Hz.