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There are no ideal gases.
Quote from: Bored chemist on 01/10/2022 17:08:24But the heat capacity is not actually a constantWhat makes it change?
But the heat capacity is not actually a constant
I was going to query how such a simple question could expand to 38 pages and still appear to be alive.
Go and read the thread again.
Sort of, because the energy levels are quantised.For a cold diatomic gas like nitrogen there's not enough to excite vibrations and so the only contributions to the heat capacity are translation and rotation.That's 3 translational degrees and 2 rotational ones (rotation about the axis between the centres of the two atoms doesn't count) making 5 in totalWhen the gas is hot there is enough energy to get the molecules vibrating and that adds some more degrees of freedom into which energy can be placed.That adds another degree of freedom , making 6 in total.So the calculated heat capacities under those conditions are 2.5kT and 3 kT But, at an intermediate temperature some, but not all, of the molecules will have enough energy to induce vibrations.And under those conditions the average number of degrees of freedom will be somewhere between 5 and 6.
I was going to query how such a simple question could expand to 38 pages and still appear to be alive. However having scanned a number of pages I do see education at work, albeit at a snail's pace. I have one small addition from the early pages: the op referenced Jean Piere Robitaille, this guy is a notorious crank and not a scientist. He is a medic of some description, an anaesthetist as far as I remember.
https://medicine.osu.edu/find-faculty/clinical/radiology/pierre-marie-robitaille-phdPierre Marie Robitaille, PhDProfessor, Department of RadiologyBackgroundI joined the Department of Radiology in 1989. At the time, my research centered on spectroscopic methods, with a focus on the experimental and theoretical aspects of nuclear magnetic resonance and magnetic resonance imaging (MRI). I devoted considerable attention to NIH-funded spectroscopic analysis of in-vivo cardiac metabolism in the normal and failing heart, using both 13C- and 31P- NMR methods. I also focused on the development of new instrumentation for MRI. This included the design and assembly of the first torque compensated asymmetric gradient coil.From 1995-2000, I was responsible for conceiving and assembling, at Ohio State, the world's first ultra high field clinical MRI system. This 8 Tesla/80cm MRI system was utilized to acquire many of the highest resolution images in existence. At the same time, early results with this instrument prompted a reconsideration of RF power requirements in MRI and of signal to noise. In turning my attention to these problems, I initially sought to consider NMR is a "thermal" process. In the early days of this modality, the T1 relaxation time was also known as the "thermal" relaxation time. This would lead to a detailed study of Kirchhoff's Law of Thermal Emission, a topic on which I have subsequently published extensively.Kirchhoff's Law stands at the very heart of spectroscopic analysis, not only in medicine, but also in fields as seemingly remote as astronomy. For me, revisiting Kirchhoff's Law of Thermal Emission has resulted in questioning many established ideas in astronomy, including the origin of the microwave background and, most importantly, the nature of the sun itself. That is because the standard model of the sun, relies on the validity of Kirchhoff's Law, in order to justify a gaseous state. Conversely, if Kirchhoff's Law is not valid, then the sun cannot be a gaseous in nature. Along these lines, I have recently advanced forty lines of evidence that the sun is comprised of condensed matter.
What determines the required energy to excite vibrations?
He recently published a new video here, called "Responding to Loose Ends!"
When you discuss a topic and everyone agrees, the conversation often dies out quickly. But when you disagree, you're putting yourself in opposition to what was said, and the discussion continues. Paul Graham, a computer engineer, therefore proposed a “Hierarchy of Disagreement” in 2008. Learn at which level you are able to articulate your disagreement. Hopefully it’s not just name-calling or responding to tone.CHAPTER00:00 Opening quotes and statement00:52 Introduction01:19 Graham's hierarchy of disagreement01:32 Level 1: Name-calling01:48 Level 2: Ad hominem02:14 Level 3: Responding to tone02:41 Level 4: Contradiction03:08 Level 5: Counterargument03:41 Level 6: Refutation04:13 Level 7: Refuting the central point05:05 Benefit of knowing the form of argument06:06 What do you think?06:58 Patrons credits07:07 Ending
it would be helpful to identify the level of our disagreement.
Quote from: hamdani yusuf on 31/10/2022 12:10:29it would be helpful to identify the level of our disagreement.So... do you need me to point out that I posted a refutation of his point, or can you work that out for yourself?
Quote from: Bored chemist on 31/10/2022 18:07:25Quote from: hamdani yusuf on 31/10/2022 12:10:29it would be helpful to identify the level of our disagreement.So... do you need me to point out that I posted a refutation of his point, or can you work that out for yourself?Feel free to write down your reasoning here.
do you need me to point out that I posted a refutation of his point,
"Conversely, if Kirchhoff's Law is not valid, then the sun cannot be a gaseous in nature"But we know it is a gas, so we know the law is valid.This is a surprise to nobody except cranks because Kirchhoff's radiation law is just a special case of the conservation of energy.
Feel free to answer my question.
Feel free to write down your reasoning here.
How do you know that it's a gas?
At over 5000C what else could it be?
But my point is that anyone who doubts Kirchhoff's law is doubting the conservation of energy and thus not trustworthy.
There must be some reasons to accept or reject an assertion if we want to make our beliefs reasonable.