There is a book called "Slaying the Sky Dragon" based on the concept that all of climate science is completely wrong from the git-go. A whole book! Do you think I am making this up? Well, here's a key argument from that book, which is popping up here and there, via Jennifer Marohasy, who also propagates an amazingly fictitious history of climate science that I don't recommend without the requisite head-vise.
One person was overheard proclaiming "I am more dumb for having read this", but there is a cure to that sort of thing: make the dumbth explicit.
It won't be hard to just find a refutation of the general misunderstanding somewhere and link to it, but this is getting enough play as to deserve a custom demolition. Your mission is to explain in very clear terms what is wrong with this picture. The best answer, not the first answer, gets an OIIFTG No-Prize.
Anyway, here it is. You'll see variants of it all over the place.
‘There is an important point that was missed in your article about the Stefan-Boltzmann equation. Applying the argument to the “greenhouse gas” theory is quite simple: there can be no “back radiation” from the colder atmosphere to the warmer earth’s surface. It violates the 2nd Law of Thermodynamics as it applies to radiative transfer…’Follow the link to Hertzberg's biography; you will find an even more stupefying argument that the CO2 rise is not anthropogenic.
More following from Dr. Martin Hertzberg, a coauthor of “Slaying the Sky Dragon-Death of the Greenhouse Gas Theory”…
‘Consider two flat, parallel surfaces each with unit emissivity facing each other. One surface is maintained at a higher temperature, Th while the other surface is maintained at a lower temperature Tc . If the hotter surface were facing a complete void or surroundings at 0 K, the flux of radiant energy that it would emit and that the void would receive is sTh4.
‘Similarly, if the colder surface were facing a complete void or surroundings at 0 K, the flux of radiant energy that it would emit and that the void would receive is sTc4. But neither of the surfaces is facing a void: they are facing each other, and accordingly the net flux of radiant energy in the field between them is:
I (net) = s (Th4 – Tc4 ) ,
and is always from the hotter surface to the colder surface as required by the 2nd Law of Thermodynamics.
‘Nowhere in the radiation field between the two surfaces is the flux of radiant energy equal to what either of the surfaces would emit if they were facing a complete void at 0 K! Thus, the simple use of the Stefan-Boltzmann equation to characterize the emission from a source of radiation as though it depends only on the temperature of the source without considering the temperature of the surroundings that are receiving the radiation, is a misuse of the equation, and the notion that a colder source can transfer radiant energy to a warmer object involves not only a misuse of the Stefan-Boltzmann equation but also a violation of the 2nd Law.
‘The situation is analogous to a simple problem in mechanics. A 1 Kg mass is sitting on a frictionless table and is subjected to a force of 10 Newtons from left to right and simultaneously subjected to a force of 7 Newtons from right to left. Now you are free to calculate what the motion would be if only the 10 Newton force acted on the mass, or if you prefer, you can calculate what the motion would be if only the 7 Newton mass operated on it. But, of course, neither of those calculations describes the real motion, which is that of a 3 Newton force acting from left to right. There is no motion to the left from the weaker force.
‘Thus it should be quite clear that the simple use of the Stefan-Boltzmann equation as though it can characterize the radiant energy being transferred from a source to its surroundings without any reference to the conditions of the surroundings that are receiving that radiant energy, is a misuse of the equation.’
Dr. Martin Hertzberg coauthor of Slaying the Sky Dragon-Death of the Greenhouse Gas Theory
Proving yet again that a PhD doesn't actually prove you know what you are talking about.
Contest closes in a week, which is noon, March 12, Texas time.
Bug report: "there can be no 'back radiation” from the colder atmosphere to the warmer earth’s surface' returns an error.
ReplyDeleteSeverity: Critical
Classification: Blocker
Steps to reproduce:
1 put a 100W bulb in a vacuum chamber
2 measure its surface temperature very precisely
3 remove
4 put a 60W bulb in the same chamber
5 measure its surface temperature very precisely
6 remove
7 put both bulbs in the chamber
8 compare the surface temperature of the 100W bulb to the measurement in step 2
Reproducibility: 100%
Michael. I'm surprised that your post on "Slaying the Climate Dragon" doesn't mention the three posts at Judith Curry's Climate Etc that addressed this.
ReplyDeleteThe first post "Slaying a Greenhouse Dragon" was posted on 31 January this year and attracted 1200 comments. The second and third posts were posted on 4 February and attracted respectively 272 and 328 comments.
Judith was quite critical of much of the book, as were many of the commenters.
Another amusing thing to do is to think about what it would mean if Slaying the Sky Dragon were true.
ReplyDeleteI can't imagine anyone keeping up with everything on Curry's. It's a relief to hear that she still has a few standards.
ReplyDeleteScience of Doom has covered these issues.
ReplyDelete"Do Trenberth and Kiehl understand the First Law of Thermodynamics?" Part Three and a Half – The Creation of Energy?
http://scienceofdoom.com/2010/12/04/do-trenberth-and-kiehl-understand-the-first-law-of-thermodynamics-part-three-and-a-half-%e2%80%93-the-creation-of-energy/
"The Real Second Law of Thermodynamics"
http://scienceofdoom.com/2010/09/27/the-real-second-law-of-thermodynamics/
"Absorption of Radiation from Different Temperature Sources"
http://scienceofdoom.com/2010/10/02/absorption-of-radiation-from-different-temperature-sources/
So, the colder blanket (compared to my body temperature) I wrap myself in during these cold Atlantic Canadian nights is violating the second law of thermodynamics? I guess it must be cosmic rays and sun spots, or maybe my body is naturally varying in it's temperature regulation. The blanket is a spurious correlation then!
ReplyDeleteThe Stefan–Boltzmann law: the total energy radiated per unit surface area of a black body per unit time is directly proportional to the fourth power of the black body's absolute temperature T.
ReplyDeleteHertzberg apparently does not believe this; rather, he believes that when a cold surface sees a warm surface, it will inhibit its own emission of radiation.
Insofar as is possible, not mentioning or linking to Curry or her site is a good thing, even if it's a putatively non-crazy bit. SoD's explanations are great, but over-thorough for general purposes. Elevator speeches, more or less what Michael has requested, are good to have.
ReplyDeleteI'm not going to try to write a response, but I will say that what I find most amazing about Hertzberg is that he seems to imagine that the flux from the cold object does nothing when it reaches the hot one. Implied is some sort of transition from having no effect to having one if one were to heat up the cold object.
Similarly, he seems to expect that the radiation from a colder emitter nearby will have a different effect that that from a hotter one positioned farther away such that the flux is the same at the target surface. Standing under a night sky, one would need to argue that the light from e.g. Mars warms not at all while the light from Venus does. Loyal offspring, the well-behaved photons remember their momma!
For that matter, how do we see objects colder than ourselves if their very photons somehow must flee from our retinas? I have a very high skin temperature, so most other people should be invisible to me!
Thinking back to Einstein's thought experiments, I have to say it's a little depressing that he and Hertzberg are members of the same species.
For Hertzberg or any advocate of his theories - what specific quantitative difference to you believe there to be between your way of thinking about this problem and the standard approach?
ReplyDeleteFor example, suppose we create a small hole in the warmer surface at time t = 0, over a time interval delta t which is much less than the time it takes light to go between the surfaces (delta t << L/c where L = their separation, c = speed of light).
At what time T is the radiative flux observed through the small hole from the void on the other side equal to sigma T_c^4? What is the observed flux between t = 0 and T?
Let's see some quantitative predictions from these folks rather than hand-waving about meanings and definitions.
Roy Spencer tried valiantly to fight the good fight on this issue nearly two years ago. It seems he made no progress. (See http://www.drroyspencer.com/2009/04/in-defense-of-the-greenhouse-effect/)
ReplyDeleteI would be willing to bet that if one traveled back in time far enough you could find cavemen denying that others had figured out how to start fires, insisting that only the Sky Gods could do so. Looking at some of these discussions about back radiation that keep popping up, it's not hard to imagine who among us are the descendants of those Australopithecus denierissimus individuals.
PhD in what?
ReplyDeleteFolk songs?
[Disclaimer: I like folk songs but those songs contain rather minimal physics.]
The Second Law relates to work done by “heat engines”. It does not apply to to interactions between photons and matter. For example,some lasers can burn holes through steel without the laser ever going above room temperature.
ReplyDeleteThe Second Law requires that there be a heat source or heat sink. The Earth's atmosphere is heated by the sun and can lose heat to space. Thus, even if the Second Law applied, it would merely limit the work done (heating the atmosphere) to the total heat available from the sun and other stars.
Interactions between the photons emitted by the sun, and absorbed by CO2 (and other greenhouse gases in the Earth's atmosphere) is quantitatively described by quantum mechanics.
Dr. M. Hertzberg invoked the wrong branch of physics. And, his understanding of the law that he did invoke, was wrong. This makes me think that a person without science training is using his name.
David,
ReplyDeletePhysical Chemistry!?
He was in fire and safety work related to COAL mines. It is not a glamorous field, but it is challenging physics.
He seems not to have been active for a while, then Bang! a paper on climate in _&_ , and a book, and a tour.
Youtube: http://www.youtube.com/watch?v=SiQkjmujkdw
I have to admit that I don't have what is required to understand all the physics and math happening here but when I first heard of this tome I knew I would have to reconsider my attitude towards book burning.
ReplyDeleteFirstly, it was scraped together under the aegis of one John O'sullivan who bills himself as the most popular writer on Global Warming on the web and who has been breathlessly wanking on about 'Climategate' from the very first..a sort of poor man's Moncton.
Secondly, it looks - with it's overwrought gothic/high tech cover and title (Slaying the Sky Dragon..puleez!) - like the latest in the Harry Potter series. It fairly screams - 'don't take this seriously'...
As well...what Scruffy Dan said.
Earthshine is an example that people can see which disproves the argument that a colder object cannot radiate energy to a warmer object.
ReplyDeletehttp://www.google.com.au/images?hl=en&q=earthshine&um=1&ie=UTF-8&source=og&sa=N&tab=wi&biw=1440&bih=805
If you want an IR example, how can we see the rings of Saturn with IR camera if they are -160 degrees C and our camera is say +20 degrees.
Hertzberg writes:
ReplyDelete"The situation is analogous to a simple problem in mechanics. A 1 Kg mass is sitting on a frictionless table and is subjected to a force of 10 Newtons from left to right and simultaneously subjected to a force of 7 Newtons from right to left. Now you are free to calculate what the motion would be if only the 10 Newton force acted on the mass, or if you prefer, you can calculate what the motion would be if only the 7 Newton mass operated on it. But, of course, neither of those calculations describes the real motion, which is that of a 3 Newton force acting from left to right. There is no motion to the left from the weaker force."
No the situation is analogous to Hertzberg claiming that the smaller opposing force violates Newtons second law.
Hertzberg is confusing net heat flow with emitted and absorbed radiation.
ReplyDeleteHe and Gerlich are stuck in 1850 when we had the second law, but did not understand electromagnetic radiation.
As far as Curry, she is shoving the Overton window as far towards stupid as she can, and frankly, Eli welcomes all the crap that flies through it onto her desk.
Is Mr. Ash being intentionally obtuse in comment #1? Surely he realizes the Sky Dragon argument pertains to the case where the 100W bulb is powered and the 60W bulb is not. Mr. Ash does not state this implicitly, but implies that both lamps are powered during the final test.
ReplyDeleteThe question is, how much does that passive lamp "back-radiate" to make the active lamp hotter? Can this "back-radiation" effect be isolated, quantified and measured? Will the passive bulb ever make the active bulb hotter in either peak temperature or average temperature?
If not, then you guys have a little problem with your "greenhouse gas" theory, don't you?
Intentionally obtuse... Marvelous...
ReplyDeleteThis would all be so much more amusing if it weren't important, but then, if it weren't important, people would not be so quick to confuse themselves.
MT, should you wish to apply a Label (aka Category) to your spot-the-bug posts, it would make them easier to locate in future...
ReplyDelete(if you've done so here, I am not seeing it)
Ken Coffman ask:
ReplyDeleteThe question is, how much does that passive lamp "back-radiate" to make the active lamp hotter? Can this "back-radiation" effect be isolated, quantified and measured? Will the passive bulb ever make the active bulb hotter in either peak temperature or average temperature?
RP has relevant answers
http://geosci.uchicago.edu/~rtp1/papers/PhysTodayRT2011.pdf
H/T Eli.
If Ken wants the back radiation from a 'passive' to an 'active' light light-bulb he only need a thermometer and a physics textbook.
Ken Coffman ask:
ReplyDeleteThe question is, how much does that passive lamp "back-radiate" to make the active lamp hotter? Can this "back-radiation" effect be isolated, quantified and measured? Will the passive bulb ever make the active bulb hotter in either peak temperature or average temperature?
RP has relevant answers
http://geosci.uchicago.edu/~rtp1/papers/PhysTodayRT2011.pdf
H/T Eli.
If Ken wants the back radiation from a 'passive' to an 'active' light light-bulb he only needs a thermometer and a physics textbook.
No argument with the second law of thermodynamics here, that one seems to be on pretty solid ground! But the train of logic above has a subtle problem in its over statement of the constraints this law places on energy flow. Given a warmer and a cooler body exchanging energy either through convection or through radiation, the fact is, energy is constantly being exchanged in both directions. The second law of thermodynamics does not apply to individual photons, it applies to the net flow of energy in the entire system. How could it be otherwise?
ReplyDeleteWhen an excited molecule of CO2 releases a photon, it does not somehow "know" which way to send it. It can not aim it towards a cooler body. It is simply released in a random direction. In the case of CO2 in the atmosphere, having absorbed some of the energy radiating towards space from the surface of the earth, this random choice of direction means that, roughly speaking, half of that energy is sent back. An individual molecule is not influenced at all by the temperature of the earth's surface, be it warmer or cooler.
Where the second law does apply is in the net flow of heat, and this happens because a warmer body will send out more energy overall than it is receiving from the cooler one. Lots of energy going back and foth, but on balance more is leaving the warmer body.
From here.
Is this Terra or Wonderland?
ReplyDeleteKen, it doesn't matter. Try and figure it out, you might learn something. Hope is eternal.
ReplyDeleteThe dumbest argument by proponents of the greenhouse gas theory is that such gases "act like a blanket" to keep the Earth warmer than it otherwise would.
ReplyDeleteWell, guys, just try this simple thought experiment: sit yourself down in an armchair in front of a burning hearth fire. You feel the radiant heat to the front of your body while the back of your chair remains cool. Now hang a blanket halfway between you and the fire. Are you feeling warmer or cooler?
Your "blanket" is now blocking radiation from the fire so you become cool again like the back of your chair!
Junk scientists tell us CO2 "traps" inbound solar energy restricting it from leaving Earth's surface; yet have an intellectual blindspot in that the very same "trapping" mechanism would have also been obstructing solar radiation inbound to the Earth from the sun. So the inward and outward "trapping" mechanism must be balanced and thus neutral in the overall equation. CO2 'trapping' is thus NOT operating like a one way valve!
O dear!
ReplyDeleteHere is a better mechanical analogy, involving a mass but also a spring. The mass is attached to the spring.
Now there is a pulling force of 10N working on the mass in a direction parallel with the spring. This force corresponds to energy from the sun. The mass starts moving, and the displacement of the mass corresponds to temperature. As the mass moves the spring extends and creates a counter-force which after lets say 10 cm is 10N, so the system has reached an equilibrum and the mass stops moving. This counterforce corresponds to the blackbody radiation. Now add another 3N to the 10N force (corresponding to backradiation from GHGs). The mass moves and the spring extends another 3cm until its counterforce has reached 13N and a new equilibrum has been reached.
Note that the mass moves in spite of there being a 10N counter-force, because that counter-force is balanced by the original 10N pulling force.
Well, arguing by metaphor is always a risky business, but I can't explain the Second law as well as Steve (scienceofdoom) Carson. Believers seem to like real-world-seeming examples, so I brought out my vacuum chamber and a couple of old incandescents.
ReplyDeleteI had a long-sleeved shirt on when I woke up. I was cool, so I turned the heat on. The thermostat now says 60° and I switched to a T-shirt.
My skin is warmer than the air surrounding it. So did I just violate the Second Law, or am I being unintentionally obtuse? It seems that if home heating doesn't actually work, I could save a lot of money next winter...
johnosullivan, the atmosphere is, um, largely transparent to the visible. This is why you can see and feel the sun.
ReplyDeleteWhat this means, in practice, is that it is heated from below.
Evidence for this can be seen in the structure of cumulus clouds, which are one of the mechanisms by which heat is exported upward from the surface.
So, in fact, the heat source is on the same side of the blanket as you are.
How long have you been thinking about this? If it's a day or two, that is an insightful question. If it's much longer, you are being stubborn. Surely somebody has tried to explain this before.
I see Mr. O'Sullivan has appeared in the digital 'flesh' to provide us with first hand evidence that his book "Slaying the Sky Dragon" is a waste of trees. (If he's published a hard copy, that is.)
ReplyDeleteI'm pretty sure he has been contemplating the 'blanket between you and the fire' analogy for a long time.
Oh my. Yes, I see he is a coauthor.
ReplyDeletePerhaps it is a different John O'Sullivan. One can hope.
> Curry ... Overton Window
ReplyDeleteYeah, while she did sort of debunk the 'Sky Dragon' nonsense, she's encouraged them to go on at great length about it in a hospitable way.
If you keep your mind completely open, you'll find that nature abhors a vacuum.
I think the quote is "keep an open mind, but not so open that your brain falls out"
ReplyDeleteIt appear that this guy is a co-author, of at least one edition, as well.
ReplyDelete"Truth is victorious"
Can I contribute a bit of an intelligence test? It’s our right to think about the words of others and decide for ourselves who provides useful ideas and wisdom...and who does not.
ReplyDeleteDistributed uniformly over the mass of the planet the absorbed energy would raise the Earth’s temperature to nearly 800,000K after a billion years, if Earth had no way of getting rid of it.
—Raymond T. Pierrehumbert
People think about geothermal energy—when they think about it at all—in terms of the hot water bubbling up in some places, but two kilometers or so down in most places there are these incredibly hot rocks, ‘cause the interior of the earth is extremely hot, several million degrees, and the crust of the earth is hot…
—Albert Arnold Gore
As there is no glass roof on the earth to trap the excess heat, it escapes upward into space.
—John O’Sullivan
Recent commentary has shown we are in Wonderland.
ReplyDelete"Nohting but a pack of cards..."
Fascinating discussion indeed, but few entries for the prize so far...
ReplyDeleteWhat's wrong with the picture?
In simple terms, Hertberg is tricks himself by being inconsistent. He starts out by claiming there can be no “back radiation” from the colder atmosphere to the warmer earth’s surface. It violates the 2nd Law of Thermodynamics as it applies to radiative transfer. Then he switches from his claim of no “back radiation” to discussing net-radiation (“net flux of radiant energy”). But why do we need the term “net” if there is no back radiation?
ReplyDeleteHe then spends his energy debating a straw man of “net radiation” flows, and avoiding the issue of back radiation.
As I’ve said, back radiation from a cooler object is evident in ‘earthshine’ where we receive light from the otherwise dark side of the moon which is lit up (to our receivers -being our eyes) with back radiation of the radiation the moon gets via the earth.
Herzberg essentially proves what he sets out to disprove.
ReplyDeleteHere is the crux: “But neither of the surfaces is facing a void: they are facing each other, and accordingly the NET (my emphasis) flux of radiant energy in the field between them is:
I (net) = s (Th4 – Tc4 ) ,
and is always from the hotter surface to the colder surface as required by the 2nd Law of Thermodynamics.”
Yes, the 2nd law says that the NET flux will always be from warmer to colder but to consider a calculation of NET flux, one must acknowledge the possibility of some flux from cold to hot. (Here Herzberg clearly gives the non-zero, cold flux determined by the cold surface temperature “maintained” [sic] at Tc.)
Therefore, Herzberg, having invoked a NET energy flux, CANNOT validly hold true the basis of his attempted refutation, that is, “the notion that a colder source can transfer radiant energy to a warmer object involves .... a violation of the 2nd Law.”
As to his “clarifying” example. He states: “There is no motion to the left from the weaker force.” Absolutely true but there must remain in effect the 7 Newton, right-left (weaker) force to keep the observed motion consistent with a (net) “3 Newton force acting from left to right.”
For Herzberg, somehow, the physical entities represented by the “small/lower/weaker” component of his “net” calculations vaporize after the calculation is complete.
It’s like “tax cuts” in our current political situation. As soon as they are made, their effect on the rest of the system cannot be acknowledged, much less discussed and, therefore, simply does not exist.
John Puma
Michael Tobis --- The answer, of course, is to be found in R.T Pierrehumbert's Principles of Planetary Climate; indeed, in the first half.
ReplyDeleteThus, the simple use of the Stefan-Boltzmann equation to characterize the emission from a source of radiation as though it depends only on the temperature of the source without considering the temperature of the surroundings that are receiving the radiation, is a misuse of the equation, non sequitur and the notion that a colder source can transfer radiant energy to a warmer object involves not only a misuse of the Stefan-Boltzmann equation but also a violation of the 2nd Law non sequitur.
ReplyDeleteDavid Benson, some songs are about physics. Meet Gilberto Gil.
Aaron, note the punchline.
Pete,
ReplyDeleteStated as “Entropy increases in defined and bounded systems”, thermodynamics holds. However, Hertzberg (or more likely a speech writer) invokes the “Second Law of Thermodynamics” which harkens back to cyclical heat engines working on fluids. As a rhetorical device it is clever. Everyone has heard of the law, but few understand it. Then, the speechwriter can violate the definitions and boundaries of the system.
The Second Law of Thermodynamics demands a closed system, while Hertzberg's example requires outside energy to maintain the temperatures of the two plates. What the Second Law of Thermodynamics (SLT) says is that if you shut off whatever is keeping one plate hotter than the other plate, they will both come to the same temperature. As long as, something outside the defined and bounded system is affecting the temperature inside the defined system, the SLT does not apply.
The example does not work as an analogy for the Sun/Earth system because the example has a “void” between the plates, while the Sun/Earth system has a mixture of gases (Earth's atmosphere) between them. Global warming is all about the details of photons (from the sun) interacting with those gases. What SLT says about this, is that heat tends to move from the hotter Sun toward the cooler Earth, and from Earth to space. SLT does not address the details of interactions between matter and photons.
If Hertzberg defines the system to include then sun, then the SLT argument falls apart because he has the huge source of heat warming the atmosphere. If Hertzberg defines the sun out of his system, then the SLT cannot be applied because his system has an outside source of energy.
Pete --- I prefer Tom Lehrer.
ReplyDeleteHertzberg's problem is mental. He blocks out of his mind the radiation going in both directions.
ReplyDeleteBut Aaron, I have not heard of the second law of thermodynamics (2lot) not applying to anything. The 2lot has many equivalent formulations both verbal and mathematical. For instance google the expression "no process is possible whose sole result." One has to be careful in recognizing the full process and full result. The 2lot (entropy formulation) has much to do with understanding radiation. See here for example. The 2lot does not come with any "void where prohibited" fine print.
I will plagiarize John Denker for the most general and correct modern statement of the 2nd law, to wit: entropy obeys a local paraconservation law. That is, entropy is nearly conserved. Change(entropy inside a boundary) >= - change(entropy outside the boundary). Entropy can decrease inside a boundary but only with an equal or (almost always) greater increase in entropy outside the boundary. This law is completely general and applies without exception in all circumstances short of intervention by God. He hasn't told me yet whether He obeys it. Downward long wave radiation certainly obeys this law and yet exists and is measurable (and measured).
ReplyDelete