The Rabett writes:
Universitaets Prof. i.R. Dr. Jürgen U. Keller (another one gone emeritus)
Universität Siegen
FB11-Maschinenbau
Institut für Fluid- und Thermodynamik
Paul-Bonatz-Str. 9-11
57072 Siegen (Spent a year there one night)
Dear Prof. Keller,
Recently some (resident fireflies) have brought to our attention (tried to shove down our throats is more like it) a paper by Essex (clueless about climate), McKitrick (an economist who can't tell the difference between degrees and radians and gets off on odd interpolations) and Andresen (who happens to be on your editorial board, something we recommend you change right quick) that appeared in the February issue of the Journal of Non-Equilibrium Thermodynamics (the manga edition. Please include more nude scientists for the ladies), entitled "Does a Global Temperature Exist?" (floated a real air biscuit there Jürgen)
After a careful reading (two days later we were able to stop laughing long enough to take pen in hand) it is our considered opinion (even the damn mice cracked up) that arguments advanced (couldn't float a chickenwire canoe on a dry lake) are either irrelevant or incorrect (be kind, be kind...). While others will be writing (to the IgNobel Prize Committee, although the competition in category is strong) about technical matters (did ANYONE stay awake through the seminar?) we restrict ourselves here to basic issues (which establish that you should be convicted of criminal electron waste, there being no paper edition of your fishwrap).
The paper tries (and fails miserably) on all points. You are referred first (clearly if you had read the thing you would have circular filed it) to 3.1.2 where EMA attempt (and do a cannonball splatter) to show the results of averaging the temperature when a glass of ice water@ 2 oC and a cup of coffee at 33 oC cool separately in a 20 oC room. (proportional to T^4 following the Stefan-Boltzmann law). They claim to plot the predictions of the arithmetic average, the harmonic, the RMS and what they call radiation (proportional to T^4 following the Stefan-Boltzmann law). I have also shown the temperatures of the coffee and the ice waterThe only one they get right is the arithmetic average (see below).
Essex and McKitrick then riff about how the radiation curve is higher than the RMS, and the arithmetic average, and the harmonic is lower 
Unfortunately, (a shooting foul in thermo) the authors (silly bunnies) fail to use the appropriate temperature scale. Thermodynamics demands the use of the Kelvin temperature scale (students fail for not doing this). To make their point, the authors (very silly bunnies) use Celsius. To assert that radiative emission is proportional to the fourth power of the temperature in Celsius, (is a clusterfuck of the order of invading Iraq to deal with 9/11 and) is a spectacular error (world class in a Journal claiming to be about thermodynamics), but the authors make it (shows what happens when a math and an eco guy get together at the faculty bar and write a paper). In a few cases, one can use Celsius to calculate thermodynamic quantities, an average temperature being one, this is only the case when the function varies linearly with temperature, and even there, not always. For example, the average energy of an ideal gas is 3/2 nRT where T must be in Kelvin.
The dotted brown line next to the arithmetic average shows the result for the "radiation" average if Kelvin is used (makes you kind of want to zot the paper Juergen?). As a matter of fact, if one uses Kelvin for all the other averages
the differences by which the authors set great store vanish.
Is there anything that sets the arithmetic average apart? (Why yes, happy that you asked.) If you had first equilibrated the ice water and the coffee, and then let them warm up to room temperature you would get the blue dots which overlay the arithmetic average. That is a fine physical reason for preferring the arithmetic average. Then, the energy of the liquids pretty much depends on mCT, where m is the mass, C the specific heat and T the absolute temperature (true C(T) has a weak dependence on T, but the difference is small).
More tomorrow, Eli must resnark.....
Friday, March 16, 2007
Subscribe to:
Post Comments (Atom)
Posts
18 comments:
As Stefan and Boltzmann are proud you spelled their respectively Slavic and German names correctly, so Anders Celsius asks for the same courtesy. So don't post this, just fix the spelling!
Eli got the important spelling (and physics) right: Kelvin.
Perhaps the editors of the "Journal for Dis-equilibrated Thermodynamicists" should have worried far less about irrelevant spelling -- and irrelevant physics -- and more about real physics.
Ever wonder why it's Eli RABETT? Long story.
Hey, at least the authors were right on one thing (and one thing only): you get a different answer if you use different ways of averaging: right vs wrong.
These guys are not even not even wrong. They are just plain wrong.
OK, spelling aside, some time in the future, when carbon dioxide concentrations are greater than 2.5 Pielkes ( a new unit i just invented--a Pielke is the pre-industrial level; really simplifies writing if not orthography) at a time when mitigation was too late and adaptatation has paled in comparision with the immediacy of crisis-a-week, some one is going to have a lot of fun writing the history of denialism. And this paper will be a great case study. You sure there isn't another one in the works in the Journal of Irreproducible Results?
The results of McKitrick, Essex and Andresen are reproducible.
It's just that only a 4th grader could do it without cringing -- and simultaneously cracking up.
OK, now that I've finished laughing, I have one minor complaint. If you're gonna include a link tagged 'nude scientists' can you at least link it to a site that shows us some nude scientists? This alone would be at least as substantive as their analysis, and much more interesting. There's gotta be SOMETHING worthwhile come out of the McKitrick et al idiocy.
yes, the anonymice want nude scientists (or pictures at least), and preferably not named Fred.
Is Siegen University real? or is it a fig newton of someone's imagination?
Because when I click on departments on their purported home page all I get is an error "Fehler 404".
Try this
http://www.uni-siegen.de/fb11/thv/personen/?lang=de
There is a press release from the University of Copenhagen, quoted in EurekAlert and ScienceDaily, about the EMA article.
In the press release the coffee is sold out, now there are two glasses of water (0° and 100°). There is an example number 2 where "The calculation is done in degrees Kelvin which are then converted back to degrees Celsius".
My, my how quickly your criticsm got adressed Eli.
No wonder John A did would not comment on the Celsius vs Kelvin MFU.
He was waiting for the "new, improved" paper -- so he did not have to address the problem here or elsewhere.
We must await the graph, of course, which will tell us if they really did the calculation in Kelvin.
(shows what happens when a math and an eco guy get together at the faculty bar and write a paper)
Now wait a cotton-pickin' MINUTE, mister. I'm an eco guy. We don't make these mistakes. ECON guys make these mistakes.
All the cute and useful critters that reside in ecosystems demand you retract your hasty generalization immediately, lest the fungi and molds coming out on the Front Range infest your mucous membranes and cause you allergic distress. Oh, wait: too late. Um...lest the fungi...erm...
Ahem.
Best,
D
This has got to be one of the worst "scientific" papers I have ever read (and I've read lots of them over the years).
It's bad enough that they are speaking in such broad generalities about the utility of averaging, but when they imply things about the physical world that are clearly false -- ie, that air at the surface of the earth is not in thermodynamic equilibrium for all intents and purposes (and that temperature measurements on this air are therefore essentially meaningless -- they have gone way over the line demarcating what is permissible in a scientific paper.
What they are writing is unadulterated nonsense. It's gibberish sand I'm really amazed that none one on the editorial board of the journal has yet recognized it.
Eli, again, you're hilarious! Great work! You had me ROFLMAO! :P
-Stephen Berg
Just curious, I don't know if somebody has also noticed that they are plain wrong when they interpret the meaning of their averages. According to their paper, R-1 "... also appears in connection with average resistance in a parallel circuit...".
Plain wrong. The logical interpretation of the "average" would presumably be the "equivalent" resistance that would be equal to the two resistances in parallel in the circuit, and it is (R1*R2)/(R1+R2), NOT their equation 9.
Similar arguments can be used with the spring (R2) or R4. The problem here is that they always insist in computing averages using a 1/2 factor which, clearly, does not apply when computing the "average (i. e. equivalent) displacement" of a spring or the "average (i. e. equivalent) temperature" of a blackbody, interpreting the word "equivalent" as the displacement which would cause the same potential energy or the temperature which would cause the same irradiance in the black-body example (of course, the spectral characteristics of the energy can not be made equivalent, but that is another story..)
Funny paper. Who were the reviewers?
hi, i'd like to cite some of your posts in an article i'm writing about falacies of climate change denial, what name should i write? rabett?
kind regards,
Sara
Post a Comment