Climate change in a shoebox: Right result, wrong physics
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From: Just A Guy on 4 May 2010 23:49 Climate change in a shoebox: Right result, wrong physics American Journal of Physics -- May 2010 -- Volume 78, Issue 5, pp. 536-540 Paul Wagoner TERC, Cambridge, Massachusetts 02140 Chunhua Liu Department of Education, Tufts University, Medford, Massachusetts 02155 R. G. Tobin Department of Physics and Astronomy, Tufts University, Medford, Massachusetts 02155 Classroom experiments that purport to demonstrate the role of carbon dioxide's far-infrared absorption in global climate change are more subtle than is commonly appreciated. We show, using both experimental results and theoretical analysis, that one such experiment demonstrates an entirely different phenomenon: The greater density of carbon dioxide compared to air reduces heat transfer by suppressing convective mixing with the ambient air. Other related experiments are subject to similar concerns. Argon, which has a density close to that of carbon dioxide but no infrared absorption, provides a valuable experimental control for separating radiative from convective effects. A simple analytical model for estimating the magnitude of the radiative greenhouse effect is presented, and the effect is shown to be very small for most tabletop experiments.
From: Benj on 5 May 2010 01:53 On May 4, 11:49 pm, Just A Guy <Jus...(a)hushmail.com> wrote: > Climate change in a shoebox: Right result, wrong physics > American Journal of Physics -- May 2010 -- Volume 78, Issue 5, pp. > 536-540 > > Paul Wagoner > TERC, Cambridge, Massachusetts 02140 > > Chunhua Liu > Department of Education, Tufts University, Medford, Massachusetts > 02155 > > R. G. Tobin > Department of Physics and Astronomy, Tufts University, Medford, > Massachusetts 02155 > > Classroom experiments that purport to demonstrate the role of carbon > dioxide's far-infrared absorption in global climate change are more > subtle than is commonly appreciated. We show, using both experimental > results and theoretical analysis, that one such experiment > demonstrates an entirely different phenomenon: The greater density of > carbon dioxide compared to air reduces heat transfer by suppressing > convective mixing with the ambient air. Other related experiments are > subject to similar concerns. Argon, which has a density close to that > of carbon dioxide but no infrared absorption, provides a valuable > experimental control for separating radiative from convective effects. > A simple analytical model for estimating the magnitude of the > radiative greenhouse effect is presented, and the effect is shown to > be very small for most tabletop experiments. Oh here we go "Wormley"! A REAL peer-reviewed scientific paper (unlike your propaganda organization press releases that you always post) that shows that yes, CO2 is a greenhouse gas, and NO, it isn't capable of causing anything but insignificant climate change even without considering what a minor fraction of that is man-made. As Usual: "Sam Wormley" = idiot AGW shill. Oh that's right. It doesn't matter what is true, it only matters what you can convince the public is true!
From: Roving rabbit on 5 May 2010 02:05 On 5-5-2010 7:53, Benj wrote: > On May 4, 11:49 pm, Just A Guy <Jus...(a)hushmail.com> wrote: >> Climate change in a shoebox: Right result, wrong physics >> American Journal of Physics -- May 2010 -- Volume 78, Issue 5, pp. >> 536-540 >> >> Paul Wagoner >> TERC, Cambridge, Massachusetts 02140 >> >> Chunhua Liu >> Department of Education, Tufts University, Medford, Massachusetts >> 02155 >> >> R. G. Tobin >> Department of Physics and Astronomy, Tufts University, Medford, >> Massachusetts 02155 >> >> Classroom experiments that purport to demonstrate the role of carbon >> dioxide's far-infrared absorption in global climate change are more >> subtle than is commonly appreciated. We show, using both experimental >> results and theoretical analysis, that one such experiment >> demonstrates an entirely different phenomenon: The greater density of >> carbon dioxide compared to air reduces heat transfer by suppressing >> convective mixing with the ambient air. Other related experiments are >> subject to similar concerns. Argon, which has a density close to that >> of carbon dioxide but no infrared absorption, provides a valuable >> experimental control for separating radiative from convective effects. >> A simple analytical model for estimating the magnitude of the >> radiative greenhouse effect is presented, and the effect is shown to >> be very small for most tabletop experiments. > > Oh here we go "Wormley"! A REAL peer-reviewed scientific paper > (unlike your propaganda organization press releases that you always > post) that shows that yes, CO2 is a greenhouse gas, and NO, it isn't > capable of causing anything but insignificant climate change even > without considering what a minor fraction of that is man-made. > > As Usual: "Sam Wormley" = idiot AGW shill. > > Oh that's right. It doesn't matter what is true, it only matters what > you can convince the public is true! As usual Benj is fantasizing ad hominem. Q -- Who is general failure and why does he need my attention?
From: spudnik on 6 May 2010 01:07
the actual problem was in 1895, when Svente Ahrrhenius didn't bother to model an actual glass house at a particular lattitude ... and neither did anyone who had a computer in the climate lab. on the other hand, he probably didn't get the first Nobel for *that*, any way, thus: you mean, F"L"T is easy for the Sophie Germaine primes? thus: in contrast to Magadin's assertion, below, the reality is that n=4 is the only case that is truly special, which Fermat apparently didn't notice, when he wrote the marginal note. (may be, that's what blew him off, when I noted it in another item .-) Fermat apparently did not have to prove n=3, 5 etc., nor any other composite power (the "easy lemma" in all elementary treatments of numbertheory with F"L"T .-) thus: .... but, he did see one key (old) result, that Fermat's "last" theorem is the same, when applied to rational numbers, as pairs of coordinates on the unit circle (or the associated Fermat curves, for powers greater than two. well, it's quite trivial, as they say, but it is a good way to attempt the problem, a la Ribet, Frey etc. through to Wiles' Secret Attic Project. there's a really good expository book on the stuff around Wiles "proof," _Fearless Symmetry_. thus: since Fermat made no mistakes, at all, including in withdrawing his assertion about the Fermat primes (letter to Frenicle), all -- as I've posted in this item, plenty -- of the evidence suggests that the "miracle" was just a key to his ne'er-revealed method, and one of his very first proofs. (and, I wonder, if Gauss was attracted to the problem of constructbility, after reading of the primes.) --Light: A History! http://wlym.TAKEtheGOOGOLout.com |