Sunday, February 24, 2008

An example of why


Ethon flew in using the Way Back Machine attachment. Since the big guy is kinda slow, he has taken to doing the red-eye, followed by a quick spin in the time shifter however, you never know what will turn up in the ash can of history slot and, of course, it is Eli's job to clean up. Recently it was the text of a speech by Gerhard Gerlich of Gerlich and Tscheuschner fame at the Theodor-Heuss-Akademie, in Gummersbach, Germany on 20. 2. 2005.

Now some bunnies say that there has been enough, enough! on the other hand Gerlich and friend, have been, let us say not very friendly to the Rabett Run locals while being very aggressive about holding the one true second law, an attitude they are proselytizing throughout the deny-o-sphere. Their oh we am physicists and we know it all attitude is wearing, especially since they have not a clue. Anyhow, here is an example GG imposed on the Theodor-Huess-Akademic in Gummersbach to show that there is no greenhouse effect. The answer to the puzzler is given after the jump.

Gegenbeispiel 1:
Ein Wassertopf auf der Herdplatte. Ohne Wasser wird der Topfboden rotglühend. Wasser absorbiert die Infrarotstrahlung hervorragend und läßt das sichtbare Licht weitgehendunbehindert durch. Mit Wasser wird aber der Boden nicht rotglühend, also ist mit Wasser bei gleicher Heizleistung der Boden wesentlich kälter.
oK, it was in German, which translates as
Counter example 1:
A pot of water on the (electric) stove. Without water the bottom of the heating plate pot glows red. Water is great at absorbing the infrared radiation and lets visible light pass pretty much straight through. When you put the water on the heater the plate bottom of the pot doesn't glow red, so with water using the same heating power the electric stove plate bottom of the pot is a lot colder.

(Thanks to Martin for the correction on Boden)
So little ones - what did friend Gerlich miss? Here is a hint: make yourself a tea.



Water boils. Before it boils it evaporates, the heat loss is called latent heat, and is a major way in which the surface loses energy to the atmosphere (convection and radiation are the other two). Without a pot of water, the electric heater loses heat by convection and radiation. Put a pot of water on, and first the water is heated by conduction from the heating plate (this cools the plate as it is an additional heat loss mechanism), then evaporative losses move heat from the water to the atmosphere, and this large heat loss cools the electric plate.

Of course, if you boil all the water away, that electric heater glows red again because there is no loss of latent heat by evaporation (boiling being rapid evaporation). Difficult to know what G means by this example, a counterexample for the atmospheric greenhouse effect it is not, a difficult problem to understand, it is not. What does Gerlich think this shows?

It is not simple for laymen to find the cause of physical effects. A model of effect requires both a cause and an explanation. Both must be there. Even the Neanderthals used skins to reduce convectional cooling. You don't need any "physical explanation" for that. Thus, you don't find the "normal" greenhouse effect (auto or greenhouse) in any physics textbook. You also don't find the atmospheric CO2 greenhouse effect described in any theoretical physics textbook. That, taken together with these counterexamples shows every layman that this effect does not exist physically because the "physical explanation" is false.
Friend Gerlich is quite proud. At the beginning of this opus he mentions with due modesty:
Ich lege großen Wert darauf, daß ich kein Klimawissenschaftler bin, erst recht kein selbsternannter, sondern ein theoretischer Physiker. Auf jeden Fall verstehe ich von den physikalischen Grundlagen der fiktiven atmosphärischen Treibhauseffekte mehr als alle Klimatologen zusammengenommen, was naturgemäß gar nicht so schwer sein kann.
or
I am proud that I am not a climate scientist, even a self described one, but a theoretical physicist. In amy case, I understand the physical basis of the fictional greenhouse effect more as all the climatologists taken together, which, naturally can't be so difficult.
Better he should take a beginners course in atmospheric science and after that, perhaps something more complex. Oh yes, Dr. Gerlich will cheerfully send you a copy of his 1996 opus.
G. Gerlich: "Die physikalischen Grundlagen des Treibhauseffekts und fiktiver Treibhauseffekte", in: "Treibhaus-Kontroverse und Ozon-Problem", Europäische Akademie für Umweltfragen (1996), S. 115-147).
The Rabett shudders.

20 comments:

Chris Colose said...

I don't want to go on a rant on the first comment, but next time you go camping you can pour water in one of those little cups and put it on the fireplace-- it won't burn.

Anonymous said...

Translation nit: Topfboden / Boden refers to the bottom of the vessel, not the heating plate of the stove.

- Martin

Anonymous said...

The bottom of the pot never gets red with water in it because of conduction, convection and the fact that it takes some 539 cal at 212 degrees F (@ sea level pressure) to vaporize water. It has little to do with radiation. The fact that Gerlich “missed” this should be reason enough to conclude that either: 1) He is not technically qualified to author a paper about thermal properties, or 2) He is intentionally trying to mislead his audience concerning well established thermal properties and as such is not morally qualified to author a paper on thermal properties particularly when it has grave sociopolitical consequences for the future.

Arch Stanton

Anonymous said...

Hi Eli,
thank you for your comments on Gerlich!
Do you know this paper?
http://www.ing-buero-ebel.de/Treib/Hauptseite.pdf

A german physicist commented the whole G&Ts paper (in german). That must have been a lot of work!

Anonymous said...

If you look into the Theodor-Heuss Akademie, it appears to be a creature of the Friedrich Naumann Stiftelse (Foundation). And their website promotes a host of small l "liberal" causes of the 19th century idea of liberal. And then you find their Hall of Fame page...Hayek, von Mises (calm down, anonymice) Ayn Rand, and....Mary Wollstonecraft Shelley of Frankenstein fame. So, the German Cato institute? What else goes on at the Akademie?

Just Sayin'

Holly Stick said...

So you are saying that the pot's heat is partly absorbed by the water; whereas if there is no water the pot gets much hotter faster? Which would explain why my plastic vegetable steamer melted when I forgot to put water in the pot before turning on the stove.

Dan said...

G and T made the same argument in their ArXiV paper, section 3.8.3 "In the kitchen: Physics-obsessed housewife versus IPCC".

John Mashey said...

Well, all this is well-explained by the Dunning-Kruger Effect, which certainly applies to Deutschland as well as other places.

Chris Colose said...

Believe it or not, a greenhouse gas is also a "gas." Just in case anyone forgot.

raypierre said...

Arch Stanton had basically the right answer, but with a few concepts mis-stated. It's all a matter of latent heat. When the saturation vapor pressure exceeds atmospheric pressure, you can form bubbles in the interior (boiling) and at that point the conversion of liquid to vapor is so efficient that all energy goes into the latent heat of vaporization until the water is exhausted. Since you have to get up to temperatures of a few thousand degrees before there is visible red glow, and since boiling is 373.15K at sea level, the dry pot can get red hot but not the wet pot. All basic high school thermodynamics. The fact that G&T don't know this, and think it has something to do with radiation, shows that they are fools (as if more evidence of that were needed).

Now, they forgot to mention that their "housewife" has to live at Earth sea level pressure. If you have high enough atmospheric pressure then you can indeed get red hot before you boil. I leave it as an exercise to the reader to discuss how high the pressure has to be for this to happen, and to discuss how the result interacts with the critical point of water.

Chris Colose said...

//"The fact that G&T don't know this, and think it has something to do with radiation, shows that they are fools"//

Do you actually think they don't know this? MY guess is that they are in someone's pocket. I would even go so far as to say they know their entire piece is nonsense. Like people in Ch. 4 GGWS.

For the quiz, if you reduce the pressure of the surrounding air, then the saturation vapor pressure will equal the surrounding pressure at a lower temperature. So you lower the boiling point if you reduce the pressure, raise it if you enhance the pressure. This is why deep, deep ocean water that is over sea leve boiling point (by sitting next to hydrothermal vents) does not boil. Vapor Pressure also increases with T by Clausius-Clapyron. I'll leave the quantification for the next poster :-)

John Mashey said...

Chris:

1) "Never ascribe to malice, that which can be explained by incompetence" - Napoleon Bonaparte.

2) And really, see Dunning-Kruger:
http://en.wikipedia.org/wiki/Dunning-Kruger_effect

There are enough absolutely-sure-of-themselves incompetents running around, that incompetence is usually a better bet.

Really, someone has to have exhibited serious competence, and *then* show such behavior to guess the other explanation.

Chris Colose said...

Hmmm...given the creationist lecture I attended today, who knows.

Meanwhile, yours truly will stand against one of the Inhofe 400 in a community college setting (just as an audience member), but I will judge from the quality of arguments where this one fellow stands between the two options. Let me not be too hasty. For a taste of what I expect, see
http://chriscolose.wordpress.com/2008/02/25/i-walk-the-line/

Anonymous said...

Lest anyone think that raypierre is talking thousands of kelvin before a (steel) pot turns red with the heat, he's momentarily lapsed to those ancient beasties called Fahrenheit (~1000 to ~2000°F for various shades of red to orange), otherwise your pot would be a puddle.

Hank Roberts said...

What's most astonishing is, if the past is the way the most fervent believers want it to be --- a worldwide medieval warming --- then the past says we are going to be in great trouble if that's repeating itself:

http://cel.isiknowledge.com/CEL/CIW.cgi

Chris Colose said...

I would take a MWP over a doubling of CO2 anyday. There have been civilization declines related to slight changes in cliamte (like the Mayans, the viking had trouble with the LIA) but nothing has been experienced like what you'd get from 2x CO2 since the last ice age, and analogs for what will happen based on ice ages is not very productive because people weren't in cities and planting crops, and huge populations on the coast, billions in infrastructure, etc. We're going into unknown territory, and the best scholarship agrees that business-as-usual out for several decades to 2100 will be worse than the medieval times or LIA.

raypierre said...

Regarding the comment by anonymous re. melting pots, to be honest I did mean a few thousand Kelvin in what I wrote, based on a quick mental estimate from the Wien-Botzman law and also the number I happened to remember (the photosphere temperature of M-dwarfs). Quite true that you don't need to get that hot to be visibly red rather than brilliant red, since the eye has logarithmic sensitivity and you only need to radiate a fraction of a watt in the red spectrum in order for something to look visibly red. So call it a thousand kelvin for red hot. That won't melt a steel pot but will do bad things to aluminum, zinc, tin or lead pots.

Anonymous said...

raypierre, that person was me.

I should have been a bit more precise, instead of trying for the faintly amusing as well.

If, indeed, you had kelvin in mind (and perhaps I should have guessed you really meant kelvin given your background), then your iron or steel pots would indeed be puddles at a "few thousand degrees" (long past red emission of course).

I'm confident on the temperatures I gave for the range of reds (which should be approximately valid for carbon/stainless steels and cast irons), since I once was capable of "fairly accurate" visual gauging of temperatures for steel heat treatments -- when I used to be a metallurgist.

Stainless steels for cookware, e.g. a 20Cr/10Ni (type 304), will melt at ~1400-1450°C (~1700-1750 K). Ancient history now (i.e. poor memory recall), but I think you can also get cheap carbon-steel pots; there will be a liquid component at ~1500°C (~1800 K) and they will be fully puddles at ~1530°C (~1830 K).

Cast iron pots will have liquid components at ~1120°C (~1420K; the eutectic) and be fully melted in, say, another 100°C (K), depending on actual composition.

If the heating is done in any of the common gas/air fuel mixtures, then all these temperatures are easily achievable. However, if the heating is done on an electric hotplate, then the maximum temperature achievable is more likely to be on the order of ~900°C (~1200 K), or maybe ~100°C (K) more before it likely burns itself out (or has some sort of thermal cutout employed).

The aluminium pots, as you say, will long be puddles before the emission gets to the red wavelengths.

Of course, if you put water in your pots, then this all becomes academic ... which brings us back on topic.

Cymraeg llygoden

Anonymous said...

Raypierre, Thank you for clarifying my misstated concepts.

Chris Colouse, I agree with you; I don’t see how they could not know it.

Arch Stanton

Anonymous said...

Perhaps someone can exoplain how a cool troposphere is supposed to radiate "half down" (Smith's term page 8 in his refutation) or "downward ratiate" (IPCC term) or "back radiate" to a warmer earth surface ?

Cool bodies cannot radiate to hot bodies ... 2nd Law.

Therefore, no greenhouse !