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Comment on Week in review by jim2

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The difference is that air molecules can release their energy to space via radiation. If there were no Sun and you suddenly created the atmosphere at 30 C, it would radiate until the temperature was near absolute zero.

Ultimately, it is the Sun that keeps the atmosphere a gas and suspended above the surface.


Comment on Week in review by jim2

Comment on Week in review by PA

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Tamino doesn’t appear to have a new post since July.

Did he say all he had to say about climate and move on to something else?

Comment on Ethics of communicating scientific uncertainty by Rob Ellison

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‘It is important to note that the average kinetic energy used here is limited to the translational kinetic energy of the molecules. That is, they are treated as point masses and no account is made of internal degrees of freedom such as molecular rotation and vibration. This distinction becomes quite important when you deal with subjects like the specific heats of gases. When you try to assess specific heat, you must account for all the energy possessed by the molecules, and the temperature as ordinarily measured does not account for molecular rotation and vibration.’ http://hyperphysics.phy-astr.gsu.edu/hbase/kinetic/kintem.html

Comment on Myths and realities of renewable energy by AK

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I was surprised at the low cost of module-level inverters. Call it 30¢/watt in quantity. If we assume that within, say, 5 years utility customers could get very sophisticated control (phase, voltage, etc.) technology built in at the same price (via Moore’s “Law”), solar PV would have to come down to around a dollar a watt before inversion becomes a major expense.

Comment on Ethics of communicating scientific uncertainty by Rob Ellison

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Again you confuse molecular dynamics with kinetic theory.

It is hard enough to wade through the extreme verbiage at the best of times – this is not it. It seems not to mean anything at all..

Comment on Ethics of communicating scientific uncertainty by Rob Ellison

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Utotal = Utrans + Urot + Uvib

Temperature measures the first.

Comment on Week in review by Jim D

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He makes the point in contrast that GWPF is the only skeptic organization, but has only UKP 300k and 3 people. If that was such a good idea, why so poorly supported? Makes you think. Also lobbying money is not quite the same as paying politicians in the UK. That is a fine art in the US through election-campaign money, which has no UK equivalent. Lobbying can only make a case to the politicians and public, and the politicians can think for themselves what to do without financial penalty.


Comment on Ethics of communicating scientific uncertainty by Pierre-Normand

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“When you try to assess specific heat, you must account for all the energy possessed by the molecules, and the temperature as ordinarily measured does not account for molecular rotation and vibration.”

And this is precisely why, as I had explained, in every case where f>3 (for diatomic and polyatomic gases) I insisted to write KEavg = (3/2)kT and Uavg = f*(1/2)*kT. While you used to incorrectly write KEavg = f*(1/2)*kT, which is only correct for monatomic gases. And you also used to write KEavg = Total_U/N, which also only is correct for monatomic gases where f=3, since for all other gases only part of the internal energy is kinetic, while the rest is merely internal. When f = 5, for instance, KEavg only makes up 3/5 of Uavg, since the other 2/3 is rotational.

Comment on Ethics of communicating scientific uncertainty by Pierre-Normand

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“Again you confuse molecular dynamics with kinetic theory.”

Are you suggesting that kinetic theory doesn’t apply to real molecules, even to a good approximation? Why are the predictions of kinetic theory so very good for predicting Uavg and heat capacities of very many real gases (He, H2, O2, etc.) on the basis of the application of the Boltsmann distibution to translational and rotational energies? Why would it succeed there and fail when gravitation is involved? In any case it succeeds spectacularly, since the application of the Boltzmann distribution to m*g*z for individual molecules immediately yield the barometric pressure and density gradients that match experience for boxes of any size.

Comment on Week in review by Jim D

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I wonder how many of the skeptics realize that the models underdid the warming from 1984-1998 by as much as they overdid it after 1998, and whether they can think of a reason why that may be. Natural variability perhaps? 1998 being an exceptional El Nino perhaps? Concentrating on post 1998 is just half the issue, especially given what 1998 was in terms of natural variability.

Comment on Week in review by A fan of *MORE* discourse

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BREAKING Climate Etc NEWS
Prominent Skeptic Moves Toward the Consensus

Rob Ellison announces …

“There is the other big news — in which the structure of the atmosphere is modelled by bouncing balls [i.e., a hard-sphere model] with a Boltzmann velocity distribution at a few degrees above absolute zero.

[see Bouncing Balls and the Boltzmann Distribution]

Which can entirely be described by –

\text{Total energy} = mgh + mv^2/2

There is an  intuitively  rigorously *proven* corollary — the FOMD corollary — that kinetic energy is constant at every height.”

Now yer grasping it, Rob Ellison!

Exercise  Now imagine that the internal radioactivity of the earth has been turned-off, and the sun’s radiation has been turned off, and furthermore the temperature of the interstellar black-body radiation has adjusted upwards from 4K to 50K (to match the now-vanished solar constant).

Remark  To a good approximation, the velocity and rotation of the earth can be left as-is (that is, Doppler and relativistic effects are neglected).

Then we have:

The FOMD Corollary  The equilibrium temperature distribution of of the atmosphere is isothermal — that is, the Loschmidt gravito-thermal effect is utterly absent.

Needless to say, on this boring planet there is no wind and no weather … `cuz nothing of thermodynamical consequence ever happens at all.

It has been a pleasure to assist your thermodynamical understanding, Rob Ellison.

Kudos to astrophysicist Dominic Ford for a magnificent hard-sphere scattering simulation that concretely illustrates these key thermodynamical principles!

\scriptstyle\rule[2.25ex]{0.01pt}{0.01pt}\,\boldsymbol{\overset{\scriptstyle\circ\wedge\circ}{\smile}\,\heartsuit\,{\displaystyle\text{\bfseries!!!}}\,\heartsuit\,\overset{\scriptstyle\circ\wedge\circ}{\smile}}\ \rule[-0.25ex]{0.01pt}{0.01pt}

Comment on Ethics of communicating scientific uncertainty by Pierre-Normand

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Rob Ellison wrote: “Utotal = Utrans + Urot + Uvib

Temperature measures the first.”

I agree with this. This is why if we have a diatomic molecule, and the temperature is low enough not to excite vibrational modes significantly, we have f = 5 and

Utotal = Utrans + Urot = EK + Erot = N(3/2)kT + N(2/2)kT

However this means that Utransl_avg = EKavg = (3/2)kT.

In any case, for monatomic molecules Utotal = EKtotal.

Do you agree with my paraphrase of your position for the case of monatomic molecules? Do you also believe that when C1 and C2 are filled with helium at the same temperature and 1atm vs 2atm, then EKavg is only half as large in the second container? Or are you beginning to see your error?

Comment on Week in review by markus

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Eric, according to HADCRUT4 Feb 1878 was warmer than Feb 2014.

How is that explained by CO2?”

Some questions are so stupid they don’t deserve an actual response.

Comment on Week in review by markus

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The faint sun pertains to early earth – two to four billion years ago. The Eemian interglacial (120k years or so ago) is generally accepted to have been warmer”

No it isn’t.


Comment on Week in review by markus

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“You climate cultists do not have a cogent theory of climate. All you have are a bunch of self-contradictory and non-quantitative talking points”

Why not use your brain?

If the Sun was fainter in the past then having more CO2 doesn’t automatically mean the Earth would be warmer.

Comment on Week in review by captdallas2 0.8 +/- 0.2

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If abstinence has such a great health benefit why is it so poorly supported? If the perfect diet is vegan, why is it so poorly supported?

Comment on Week in review by markus

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Lets drop the lie that those 30,000 on the list are “scientists” shall we.

That might work on joe public but I am a bit more educated about the “list” you are talking about.

Comment on Ethics of communicating scientific uncertainty by Rob Ellison

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‘KEavg only makes up 3/5 of Uavg, since the other 2/3 is rotational.’

So 60% is translational and 66% is rotational?

‘According to the equipartition principle the total energy of a mole of water vapor is

Utotal = Utrans + Urot + Uvib = 3/2 RT + 3/2 RT + 3RT = 6RT.

It is important to recognize that the equipartition principle is a classical idea that fails to correctly account for the true quantum energies of molecules, with particularly poor applicability to vibrations.’

http://www.fordham.edu/academics/programs_at_fordham_/chemistry/courses/physical_chemistry_i1/lectures/equipartition_6542.asp

Comment on Ethics of communicating scientific uncertainty by captdallas2 0.8 +/- 0.2

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Boy Y’all got some stamina! Let’s say you have two identical containers. In one container you capture air at 25 C and 1 atmosphere. In the other container you capture air at 25C and 0.5 atmospheres. The two containers would have the same temperature but different energy components. So you store both samples for a while at the same location which happens to be at 25 C. Which box contains more potential energy? The one with the most mass or the one with the lower pressure?

Or how about capturing a 10 km tall column of air one horizontal and one vertical at the same average temperature and pressure under gravity. In order to compare the two you either have to stand one up or lay one down which would involve work external to the samples, but both would have the same temperature and pressure provided the containment was perfect. Then, provided they both contain the same number of molecules in the same mixture ratio they would be the same, but why would you expect your samples to be the same in a real environment?

If they were the same though, standing vertically under gravity the bottom would have a higher measured temperature than the top due to the force of gravity but the potential temperature difference isn’t useful until you invent an anti gravity device provided of course you have access to the perfect container. Since you found some means to stand up a perfect container 10 km tall, perhaps you should patent that instead :)

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