P-N, Apologies, that should have been no lapse rate. The main point was the “exactly” cancels. Since the average velocity in the +z only direction decreases with altitude. For a layer near the top, the average velocity would still be determined by the Kinetic temperature and as long as there is elastic collision, the M-B distribution would not change since it is not dependent on the direction of the velocities. The average -z velocity of the layer would be slightly higher than average. Given enough time and pressure the system will try to reach an isothermal equilibrium, but the velocity distribution in z is skewed toward -z. The density is skewed toward -z. So the heat capacity is skewed toward -z. To say it “exactly” cancels is a stretch in my opinion.
Comment on Gravito-thermal discussion thread by captdallas2 0.8 +/- 0.2
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Comment on Gravito-thermal discussion thread by Stephen Wilde
“putting an atmosphere on top of a water surface would enable it to reach its heat IN/OUT balance point at a lower steady state temperature than without such an atmosphere.”
The heavier an atmosphere the warmer the water has to become to supply the necessary latent heat of vaporisation to fuel evaporation.
The amount of energy required to effect the phase change is pressure related. If there were zero atmospheric pressure the oceans would evaporate instantly, freeze and fall to the ground as a solid.
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Comment on Gravito-thermal discussion thread by Rob Ellison
FOMBS was armwaving about the symplectic manifold of the Hamiltonian – somehow in connection to a Wikipedia cartoon of a box of ideal gas molecules. A fantastic and improbable juxtaposition with the symplectic manifold seeming to have only a symbolic significance. A talisman of cargo cult science.
For my sins – I introduced the Fronsdal paper as an example of a Hamiltonian of the atmosphere – that – intriguingly – suggested a gravito-thermal effect.
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Comment on Gravito-thermal discussion thread by captdallas2 0.8 +/- 0.2
Rob, “For my sins – I introduced the Fronsdal paper as an example of a Hamiltonian of the atmosphere – that – intriguingly – suggested a gravito-thermal effect.”
Yep, it is all your fault.
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Comment on Gravito-thermal discussion thread by David L. Hagen
Pekka
Graeff’s “engine” is insignificant power wise. However I encourage you to review Graeff’s experimental data and show where they are off. I see how they could be improved 10x or more, but the base case with no circulation looks interesting.
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Comment on Gravito-thermal discussion thread by Rob Ellison
‘It is important to ask to what extent the observed polytropic relations are to be attributed to the intrinsic properties of the gas or to radiation. Although the question is somewhat academic, since it does not directly affect the main applications, it is natural to ask: what are the natural configurations of an isolated atmosphere, one that is not exposed to radiation? Our understanding of atmospheres will not be complete without an answer to this question.
The statement that any two thermodynamic systems, each in a state of equilibrium with a well defined temperature, and in thermal equilibrium with each other, must have the same temperature is a central tenet of thermodynamics. A natural generalization is that the temperature, in an extended, but closed system in a state of equilibrium, that must be uniform, and there is a wide spread opinion that this remains true in the presence of gravitational fields. This is important for the understanding of terrestrial and stellar atmospheres, where the gravitational forces create a non-uniform density distribution.’
http://www.mdpi.com/1099-4300/16/3/1515
So this is the question being investigated by Christian Frønsdal with his ‘action principle’. It is a very old question with very little in the way of convincing exposition either way. In a sense – it is merely academic. It may or not underlie radiation and convection processes in the real atmosphere – which are likely far more significant. Indeed as the original protagonists – Loschmidt and Boltzmann – concluded long ago.
I propose two corollaries:
1. That silly little thought experiments resolve nothing of any significance.
2. That it is hugely unnecessary to take a position on each and every point of contention. Science advances by observation and experiment – see proposition 1.
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Comment on Gravito-thermal discussion thread by Pekka Pirilä
The most important reason that makes the experiment extremely difficult is that the mechanism that brings the system to the isothermal state according to standard physics is conduction. Conduction in gas is a really weak process, but the experiment tells nothing unless all other heat fluxes combined are guaranteed to be weaker than internal conduction in the gas volume. Very weak heating or cooling of the walls of the enclosure are likely to lead to larger heat fluxes and to convective flows that produce the lapse rate inside the volume.
For an experiment to have any value it must be shown by reliable measurements and calculations that no external influence affects the outcome. I have looked at the papers of Graeff and found that he does not present such analysis. I have also observed that he has not done the experiment with such care that there were a change that he ends up with valid measurements.
This is a deceptive experiment. Most errors in the execution of the experiment lead towards the same wrong result. Only extremely careful work has any change of avoiding on error of that type. He is looking at an issue, where the standard physical understanding predicts that he finds a “confirmation” of his “theory” even when he is wrong, because he is unlikely able to avoid conductive fluxes inside his apparatus.
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Comment on Gravito-thermal discussion thread by Kristian
Stephen,
Indeed. But first we have to get Pierre-Normand and his kind to understand that radiation is not some divine entity that operates completely independent from all other physical processes in this universe, like for instance other heat loss mechanisms for a warm object (radiation is, after all, simply one of several heat loss mechanisms).
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Comment on Gravito-thermal discussion thread by Pekka Pirilä
As we discussed with P-N in the previous thread his approach lacks exactly those mechanisms that lead to the correct isothermal solution. I cannot be absolutely certain that we found the correct reason for his strange results, but the explanation seems to be as follows.
His hydrodynamical equations (Euler’s equations) do not include viscosity. He doesn’t even mention the word in his paper. He does discuss thermal conduction at one point in the introductory discussion, but he does not include that in his theory, as far as I can see. Thus his theory lacks both dissipative mechanisms that are always present in real gases. Without dissipation he can maintain convection indefinitely long without any input of energy. His equations allow the non-equilibrium states persist for ever, and he cannot describe the approach to equilibrium. Therefore he gets wrong results.
Furthermore he proposes the centrifuge experiment using erroneous arguments that he just assumes without presenting any support for them beyond a few words that just state the wrong argument.
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Comment on The legacy of Climategate: 5 years later by ClimateGate, Five Years Later | Transterrestrial Musings
[…] Thoughts from Judith Curry on the legacy: […]
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Comment on The legacy of Climategate: 5 years later by cwon14
An important event to be sure but the signs of political indoctrination and corruption were known from the inception of the AGW agenda. Harping about Climategate is a sign of incoherence to the overriding factors found in leftist academic pseudoscience, the cabal of like minded media and government agenda. Dr. Curry always appears out of touch in the general demeanor regarding the event as if 25 years and more of green activism and fanaticism weren’t obvious before Climategate. I could understand if she were in a different field or from another planet but as an insider it’s obtuse.
The details about Climategate just weren’t that surprising to those paying attention to the “agenda” anytime before it. It looks and feels like a low information discussion if people claim it as decisively informative or significant.
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Comment on Open thread: Thanksgiving edition by David Springer
The easy way to think of it is as an ocean of kinetic energy in the atmosphere and the earth’s gravity simply pulls it slightly in one direction much like the moon’s gravity causes tides in the ocean.
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Comment on Gravito-thermal discussion thread by Pekka Pirilä
It’s a very long time since I used the Action Principle for anything. Thus I had to refresh my knowledge on that. A suitable source seems to be here
http://www.scholarpedia.org/article/Principle_of_least_action
One thing that we can learn from this presentation is that the Action Principle cannot be used for dissipative processes (with some exceptions). For that reason the principle is not at all suitable for the study of the thermodynamic equilibrium. It can describe only isentropic processes, but the approach to equilibrium is fundamentally not isentropic, but dependent on the rise of entropy towards its maximal value.
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Comment on The legacy of Climategate: 5 years later by fulltimetumbleweed
“First they tell you that you’re wrong, and they can prove it.
Then they tell you you’re right, but it’s not important.
Then they tell you it’s important, but they’ve known it for years.”
CF Kettering, Time Magazine July 11, 1969, pg 54.
I started following your blog a while back and I was delighted to find what seemed to me a voice of carefully reasoned rationality and clear scientific thinking. My opinion has not changed over time, rather it has been reinforced. Thank you for this excellent post. You are probably better off not miring yourself in administration because as satisfying as it may be to solve other people’s problems, those who do so almost invariably stop publishing on their own.
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Comment on The legacy of Climategate: 5 years later by Stephen Murgatroyd
Judith – an excellent, reflective and insightful piece. Your journey is a signal to many that there is life beyond the cartel of climate science..
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Comment on The legacy of Climategate: 5 years later by A fan of *MORE* discourse
Every year, during the Holiday Season, thoughtful citizens reflect upon a world in which the sea-level is rising, the ocean-water is heating and acidifying, the polar ice is melting, record heat-waves become more likely, droughts are deepening, and CO2 levels are increasing …
… all without pause or evident human-lifetime limit.
Most folks regard these realities as *FAR* more serious than leaked (and boring!) emails, eh Climate Etc readers?
That’s why more-and-more folks are reflecting soberly upon
the cognitive traits of confidently ignorant denialism, which include:
• ignorance that feels like knowledge, and
• bluster that feel like confidence, and
• denial that feels like skepticism, and
• prejudice that feels like conviction, and
• cherry-picking that feels like data, and
• nut-jobbery that feels like creative genius, and
• short-sightedness that masquerades as pragmatism, and
• market-failures that masquerade as efficiency
These cognitive traits are distressingly common, eh Climate Etc readers?
Still we can be optimistic that the prevalence of these traits is diminishing, as the “pause” ends and the science strengthens!
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Comment on The legacy of Climategate: 5 years later by Curious George
Thank you very much for helping to debunk this religion masquerading as science. As a poor science.
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Comment on The legacy of Climategate: 5 years later by Paul Matthews
A fascinating and thoughtful piece. Lots to agree with here, such as the lower level of political polarisation in the UK.. The only point I would slightly disagree with is on the blogosphere, where I think that some of the sceptic blogs have quietened down also, eg climate audit and the air vent.
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Comment on Gravito-thermal discussion thread by A fan of *MORE* discourse
Rob Ellison perceives a “symplectic manifold seeming to have only a symbolic significance”
Confident ignorance by Rob Ellison, well-regarded dynamics textbook by the celebrated mathematician Vladimir Arnold!
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Comment on The legacy of Climategate: 5 years later by Bad Andrew
People behave badly. Climategate is just a drop in the bucket.
The real crime here is the lousy pile of dung that passes for Climate Science™.
Andrew
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