Heh. In response to a ridiculous claim making the rounds (I get comment bombed at WUWT daily with that nonsense) which I debunked here: A misinterpreted claim about a NASA press release, CO2, solar flares, and the thermosphere is making the rounds
Dr. Roy Spencer employs some power visual satire, that has truth in it. He writes:
How Can Home Insulation Keep Your House Warmer, When It Cools Your House?!
<sarc> There is an obvious conspiracy from the HVAC and home repair industry, who for years have been telling us to add more insulation to our homes to keep them warmer in winter.
But we all know, from basic thermodynamics, that since insulation conducts heat from the warm interior to the cold outside, it actually COOLS the house.
Go read his entire essay here. <Sarc> on, Roy!
UPDATE: Even Monckton thinks these ideas promoted by slayers/principia/O’Sullivan are ridiculous:
Reply to John O’Sullivan:
One John O’Sullivan has written me a confused and scientifically illiterate “open letter” in which he describes me as a “greenhouse gas promoter”. I do not promote greenhouse gases.
He says I have “carefully styled [my]self ‘science adviser’ to Margaret Thatcher. Others, not I, have used that term. For four years I advised the Prime Minister on various policy matters, including science.
He says I was wrong to say in 1986 that added CO2 in the air would cause some warming. Since 1986 there has been some warming. Some of it may have been caused by CO2.
He says a paper by me admits the “tell-tale greenhouse-effect ‘hot spot’ in the atmosphere isn’t there”. The “hot spot”, which I named, ought to be there whatever the cause of the warming. The IPCC was wrong to assert that it would only arise from greenhouse warming. Its absence indicates either that there has been no warming (confirming the past two decades’ temperature records) or that tropical surface temperatures are inadequately measured.
He misrepresents Professor Richard Lindzen and Dr. Roy Spencer by a series of crude over-simplifications. If he has concerns about their results, he should address his concerns to them, not to me.
He invites me to “throw out” my “shredded blanket effect” of greenhouse gases that “traps” heat. It is Al Gore, not I, who talks of a “blanket” that “traps” heat. Interaction of greenhouse gases with photons at certain absorption wavelengths induces a quantum resonance in the gas molecules, emitting heat directly. It is more like turning on a tiny radiator than trapping heat with a blanket. Therefore, he is wrong to describe CO2 as a “coolant” with respect to global temperature.
He invites me to explain why Al Gore faked a televised experiment. That is a question for Mr. Gore.
He says I am wrong to assert that blackbodies have albedo. Here, he confuses two distinct methods of radiative transfer at a surface: absorption/emission (in which the Earth is a near-blackbody, displacing incoming radiance to the near-infrared in accordance with Wien’s law), and reflection (by which clouds and ice reflect the Sun’s radiance without displacing its incoming wavelengths).
He implicitly attributes Margaret Thatcher’s 1988 speech to the Royal Society about global warming to me. I had ceased to work with her in 1986.
He says that if I checked my history I should discover that it was not until 1981 that scientists were seriously considering CO2’s impact on climate. However, Joseph Fourier had posited the greenhouse effect some 200 years previously; Tyndale had measured the greenhouse effect of various gases at the Royal Institution in London in 1859; Arrhenius had predicted in 1896 that a doubling of CO2 concentration would cause 4-8 K warming, and had revised this estimate to 1.6 K in 1906; Callender had sounded a strong note of alarm in 1938; and numerous scientists, including Manabe&Wetherald (1976) had attempted to determine climate sensitivity before Hansen’s 1981 paper.
He says, with characteristic snide offensiveness, that I “crassly” attribute the “heat-trapping properties of latent heat to a trace gas that is a perfect energy emitter”. On the contrary: in its absorption bands, CO2 absorbs the energy of a photon and emits heat by quantum resonance.
He says the American Meteorological Society found in 1951 that all the long-wave radiation that might otherwise have been absorbed by CO2 was “already absorbed by water vapor”. It is now known that, though that is largely true for the lower troposphere, it is often false for the upper.
The series of elementary errors he here perpetrates, delivered with an unbecoming, cranky arrogance, indicates the need for considerable elementary education on his part. I refer him to Dr. Spencer’s excellent plain-English account of how we know there is a greenhouse effect.
The Viscount Monckton of Brenchley (April 18, 2013)
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Mr. Folkerts says: “For centuries, nature was “emitting 34 units” and “absorbing 34 units” of CO2 in a pretty steady balance, not varying much from 280 ppm total.”
Assuming this to be true, which I do not, what then explains the Holocene Optimum temperature being so much higher than today?
tjfolkerts:
Thankyou for your post at April 30, 2013 at 11:18 am which asks me
I thought – and still think – I explained that in the context in which I stated it.
And I expanded on that explanation in my post at April 30, 2013 at 4:23 am where I wrote
Simply, it is a very small variation in emission which could have been expected to have happened previously but did NOT have catastrophic effects. The change to the emission is a trivial alteration to the climate system.
The argument broke out because Phil. (he says deliberately) changed my statement so it ignored the putative climate effects and switched the subject to the carbon cycle (i.e. “sinks”) then said I was “disingenuous” because I stated what I wanted to say instead of what he wanted said.
Your post I am answering also discusses the possible effect on the climate system.
OK. I will briefly answer that. But it is not relevant to this thread and it is not what I was talking about: it is what Phil. said he preferred me to talk about..
You assume the ice core data indicates a stable ~280 ppmv atmospheric CO2 concentration prior to industrialisation. That is a dubious indication for several reasons, most importantly that the temporal resolution of the ice cores cannot show it. Also, the stomata data do not agree it. There are reasons to doubt both the ice core and the stomata data and it is pure prejudice to rely on either one then to ignore the other.
Ferdinand asserts that the seasonal variation in atmospheric CO2 should be ignored. But our investigation of the carbon cycle indicates it is very informative.
(ref. Rorsch A, Courtney RS & Thoenes D, ‘The Interaction of Climate Change and the Carbon Dioxide Cycle’ E&E v16no2 (2005) )
The dynamics of the seasonal variation indicate that the natural sequestration processes can easily sequester ALL the CO2 emission (n.b. both natural and anthropogenic) of each year. But the annual increase indicates that the sequestration processes don’t sequester all of the emissions.
Furthermore, the considerations of seasonal variation and all other available data strongly suggest that the anthropogenic emissions of CO2 will have no significant effect on atmospheric CO2 concentration. The main reason is that the rate of increase of the anthropogenic production of CO2 is very much smaller that the observed maximum rate of increase of the natural consumption of CO2. Indeed, the dynamics of the seasonal sequestration show it is more than two orders of magnitude smaller.
So, the question is why don’t the natural sequestration processes sequester all the emissions (both natural and anthropogenic) when it is clear that they can?
The answer has to be that the equilbrium of the carbon cycle has changed and the system is adjusting to the new equilibrium. Some of the rate constants in the system are years and decades so the system takes decades to adjust to a new equilibrium. And the rate of adjustment is not constant because it is affected by variations e.g. of temperature.
There are many possible causes of such an alteration to the equilibrium. One possibility is the anthropogenic emission, but there are several natural possibilities. A few hours ago on another thread I stated one natural possibility to Phil.. It is here
http://wattsupwiththat.com/2013/04/30/usa-todays-breathless-co2-announcement-not-quite-there-yet/#comment-1292546
Richard
mkelly,
1) I was basing my conclusion on the graph I referenced (and various comments I have heard in the past). Of course, all measurements are subject to some uncertainties (and potentially to biases of the person presenting the data). All in all, I have pretty good confidence in ice cores, but it would have been really nice if plant stomata had been in better agreement. I guess we need one MORE technique to help judge between the two.
2) I don’t know the origins of the Holocene warming! It is clear that there are drivers of the climate besides CO2 that are important. For one thing, precession changed the seasonal input of light significantly over the last ~ 10,000 years, which could have had an impact. (It is an eternal challenge in climate studies that the only REALLY good data we have covers only the last ~50 years. That makes it tough to come to firm conclusions, esp[especially among those of us (me included) who don’t have the luxury of lots of free time to become experts on all the dat aand all the techniques). )
The dynamics of the seasonal variation indicate that the natural sequestration processes can easily sequester ALL the CO2 emission (n.b. both natural and anthropogenic) of each year.
The net result of each year over the past 50 years is that the natural sequestration processes don’t sequester all CO2 emissions (whatever the source). That is the fundamental error in your reasoning. Each year there is a residual increase in the atmosphere which is about halve the human emissions in quantity.
Thus while the quantities involved are huge, the seasonal exchange is limited in quantity, depending on temperature changes over the seasons. But that temperature dependency is not more than 5 ppmv/°C. This results in a natural variability not more than halve the human emissions as can be seen in the trend over the past 50+ years.
Thus the human emissions are highly relevant to the increase in the atmosphere.
Ferdinand:
I stated why the seasonal CO2 variation is – in my view and that of some others – very important.
You have stated why the seasonal CO2 variation is – in your view and that of some others – not important.
I suggest that on this thread we leave discussion of the carbon cycle at that. We are discussing carbon cycle issues on another thread where it is relevant to the thread.
Richard
joeldshore says, April 28, 2013 at 11:02 am:
“Now that I have provided conclusive evidence that your “not ‘belief’” was completely wrong, you’ve decided these are “the same tired old arguments from assertion” or “arguments from authority”.
It’s not something I have ‘decided’. They ARE tired old arguments from assertion and assumption. Nothing is being shown, quantified or substantiated at all about the claimed effect. It is just asserted as real. Like an incantation.
No, when I stated that what I’m arguing for on this thread is in agreement with what basic physics and physics textbooks are saying, I was specifically NOT referring to the kind of slapdash twaddle you decided to present, but to the actual PHYSICS that these textbooks actually handle. Like basic thermodynamics.
“So, basically, you won’t accept our attempts to explain to you the basic concept of conservation of energy (…)”
Sigh. You people are utterly entrenched in your belief that the sphere and the shell is and should be treated as ONE thermodynamic system. Hence your wildly confused idea that the heat loss from the SHELL has to balance the heat gain to the SPHERE at dynamic equilibrium. This is your entire argument: The sphere needs to heat up so that the shell can put out a flux to equal the sphere’s input. Completely ridiculous! And you try to lecture me on the concept of conservation of energy. You evidently don’t even know what the 1st law of thermodynamics is actually saying and what it refers to!
tjfolkerts says, April 28, 2013 at 11:51 am:
“The problem, Kristian, is that even when I *do* provide exactly what you are asking for and walk you through the steps, you invent objections like “you are treating it as one system” even though I was following exactly your arguments (often evening using your notation).
Point to ONE SPECIFIC equation that you object to in my post. Explain why you think it is wrong.”
Good grief!
No. You specifically did NOT follow my argument. You dropped the outward J1 and ended up with the heat loss for the sphere as being J – J1. That is, right there and then you jumped back to treating the sphere and the shell as ONE thermodynamic system. You didn’t follow my argument at all. I explained it to you quite carefully in that very post what would happen if you treat the sphere and shell as two separate systems. But you simply chose to ignore it. As you tend to do …
I already pointed to ONE SPECIFIC equation in your post, Tim. The one where you claimed you ‘found’ my error, when the error in fact was all yours.
tjfolkerts says, April 28, 2013 at 1:42 pm:
“Wherever you got “3,8 x 10^-24 W/m^2″, it is not even close to right.”
This is only getting better and better!
I distinctly stated: “According to your logic with the back-adding of energy and the need for the heat loss from the outermost layer to space to exactly match the original input to the instruments inside, ideally, if you let the energy input run constantly (let’s say 400 W/m^2 from within to the surface of the instruments), then 4-5 such layers only would be enough to melt the device long before equilibration. With 20 such layers, the steady input to maintain the interior instrument temperature of 290K (400 W/m^2) would only need to be 3,8 x 10^-24 W/m^2!”
I did not set out to portray a real scenario. I set out to represent YOUR scenario, drawn from your specific arithmetical logic used to explain why the planet in the infamous planet/shell model would have to warm up with the shell surrounding it.
The first BB shell cuts the outward flux in half (1/2). The second shell in turn cuts this half flux in half (1/2 * 1/2). The outward flux is now down to one quarter of the original. The third shell then cuts this flux in half again (1/4 * 1/2). And so forth and so on …
With a highly reflective layer/shell, about 90% of the flux from the sphere is reflected back, so only 10% is absorbed. Of the 10%, 5% is ideally reradiated inwards and 5% outwards. That means, only 5% of the original flux from the sphere passes through even the first layer. That’s 1/20. So with two such layers, you have a reduction of the original flux of 1/400, three layers give 1/8000 the outward flux. And so on and so forth …
That’s how I came to the fantastic 3.8 * 10^-24 W/m^2 for the input to maintain a steady interior temperature of 290K and a flux to space from the outermost sheet of the MLI of … yes, 3.8 * 10^-24 W/m^2.
Absurd? Yes, indeed! But the original logic is yours, not mine.
Or, could you please tell me in what way this is a misrepresentation of your planet/shell logic? Can you explain to me the reasoning behind your 1/2, 1/3, 1/4 … succession? As per the planet/shell model.
– – –
“And why do they do that? Exactly for the reason we are talking about! The heat loss is decreased dramatically!”
Yes, indeed! The heat loss to space is reduced by the MLI. The temperature of the interior instruments providing the original flux does NOT need to rise as a result.
Ferdinand Engelbeen says, April 28, 2013 at 1:43 pm:
“The incoming energy for the sphere is J + J1.”
This is a fundamental mistake you make here.
Yes, I know this is what is claimed in the upside-down world of the radiative GHE.
But you see, J1 is not incoming energy. It is part of the outgoing energy flux J from the sphere. All it can do is REDUCE the outgoing. It cannot INCREASE the incoming.
Incoming is heat gain. Outgoing is heat loss. ‘Back radiation’ (J1) can only reduce radiative heat loss. It can not increase the heat gain.
And I’ve specifically accounted for the reduction in Q’ by virtue of the ‘back-radiated’ J1. You cannot then also add J1 to J in the next step. J1 is not HEAT.
The expression is right there for the sphere:
J = (J – J1) + J1 = (400 – 200) + 200 = 400 W/m^2
I don’t see what’s not to understand here …
Kristian says:
That makes no sense. The textbooks I am referring to are using this as an example applying the basic concepts of thermodynamics (and electromagnetic radiation). Why would they have a clearly incorrect application of physics (as you seem to think this is) as one of their basic examples? Look, what you have is a bizarre religious conviction that violates the laws of physics but you are going to refuse to drop it no matter what evidence we present because you are wedded to your religious convictions.
Yes, because by the setup of the problem, the shell is the only one that is emitting to the surroundings and the sphere is the only one receiving thermal energy from its surroundings (or from conversion from other forms of energy if you want to imagine a sphere being heated by internal processes). Usually, one attacks an argument by explaining what it wrong with it and by explaining how your notions obey conservation of energy. You have done neither.
Considered as two separate systems, each one also has to obey energy conservation and doing that calculation yields the exact same result.
Gary Hladik says, April 28, 2013 at 11:19 pm:
“Kristian says (April 28, 2013 at 6:15 am): “Can anyone here provide me with a single physics textbook example (or better yet, an actual account of a controlled experiment conducted in a vacuum chamber) where it is shown, or even remotely discussed, that supplied with a constant energy input, the central sphere will heat up beyond the original input energy temperature with the shell in place around it?”
Such examples seem to be few and far between (…)”
Such examples seem to be nonexistent, Gary. And why do you think that is? Doesn’t that fact make you even just a little bit discomforted in your self-assured position?
“(…) but after a short search I found one that seems to come close (problem 7.12 on page 245):”
I’m sorry to tell you this, Gary, but it does not come close. Here is what it says:
“Initially, the sphere is at 200K and is suddenly irradiated with a laser providing an irradiation of 100W (normal to beam) to raise its temperature rapidly to its melting point (2741K). Determine the time required to reach the melting point.”
This is about heating rates (the other side of ‘cooling rates’). The sphere is heated by the laser input and nothing else. It is specifically not mentioned anywhere that the surrounding shell adds to the input from the laser to make the final temperature of the sphere hotter than it would have been with only the laser and the sphere present. All it says is the following:
“A spherical aluminum shield (with a circular cutout) is placed around the sphere as shown, to reduce heat loss from the sphere.”
Yes, all the shell does and can do is expedite the heating rate of the sphere so that we get to the final temperature in less time.
As soon as the sphere were to be no longer heating (or, as in other cases, cooling), the shell could not do anything further. It could not (and can not) increase the temperature of the sphere beyond the source input.
– – –
“(…) I’m not clear how Kristian views the ability of a reflection to heat its source.”
Gary, it wouldn’t surprise me in the least if you actually walk around thinking that reflected light (like from a mirror) can indeed heat its source.
Then switch on a flashlight and seal it in a thermos bottle and watch the whole thing melt down (or explode, whatever your preference) in no time!
The humanity …
So, no one was able to come up with a single real-world experiment or even a physics or engineering textbook example that theoretically deals with the heating of a sealed source of constant power beyond the input from its heat source … The only one even making an attempt was Gary Hladik.
I wonder why.
But cocksure and patronising they remain! Nothing new in that department. Even though their pet hypothesis is fundamentally based on no real, observed, theoretically quantified physical mechanism at all. Only assertions and assumptions of an alleged effect somewhere …
Kristian says:
When designing a spacecraft, why would one care about reducing the total power radiated to the surroundings if one isn’t concerned with temperature control of the object inside? Are we worried about satellites causing warming to outer space?
JPL says ( http://www2.jpl.nasa.gov/basics/bsf11-4.php ):
Are they misguided in thinking that their insulation prevents too much cooling?
Kristian says:
I’ve given you examples of discussions of exactly that…and for the specific case of the greenhouse effect in case there was any ambiguity…in both of the major textbooks that we teach with here at RIT. Why should we waste our time trying to find still more examples when it is clear that your point-of-view has nothing to do with any evidence that we can provide?
At some point, you can’t force people to abandon ignorance when they are too invested in remaining ignorant.
Kristian
Its quite possible that some post year 2000 physics textbooks are now including some AGW pseudoscience.
Its a shameful episode.
This is due to commercial pressures because of the vast army of students of Climate Nonsense now at University and also the Jesuit like activities of fanatics like Joel with the new Green Inquisition.
I mentioned the howling mistakes (even from an IPCC perspective) in the previous textbook cited by Joel.
Its also worth noting that Joel appears to know about the Popper test of falsification for eligibility of a scientific theory.
Yet Joel cannot apply this test to CO2 driven catastrophic AGW.
Come on Joel give some test that could falsify this theory or agree with me that it is pseudoscience.
joeldshore says, May 1, 2013 at 12:03 pm:
“Yes, because by the setup of the problem, the shell is the only one that is emitting to the surroundings and the sphere is the only one receiving thermal energy from its surroundings (or from conversion from other forms of energy if you want to imagine a sphere being heated by internal processes).”
And this precisely goes to show that you simply cannot grasp the very basic concept of thermodynamic systems, their surroundings and the total of fluxes entering and leaving their boundaries. This is scary coming from a working physicist.
“Considered as two separate systems, each one also has to obey energy conservation and doing that calculation yields the exact same result.”
I’ve already shown upthread how this works out perfectly. But you apparently ignore or refuse to take in what opposing arguments to yours are actually about. What they are and are not saying. So then it’s hard to keep up a factual, rational discussion.
Frankly, I’m getting quite fed up with your bluster … That seems to be all you’ve got.
joeldshore says, May 1, 2013 at 6:30 pm:
“I’ve given you examples of discussions of exactly that…and for the specific case of the greenhouse effect in case there was any ambiguity…in both of the major textbooks that we teach with here at RIT. Why should we waste our time trying to find still more examples when it is clear that your point-of-view has nothing to do with any evidence that we can provide?”
Uh, you’ve done no such thing. You’ve given me exactly ZERO examples of what I was ACTUALLY asking for. You’ve only tried your best to divert. Read my post and my request one more time, Joel! It’s not that hard.
Oh…Kristian and Bryan: You can also add what is probably the most popular textbook for a first upper-level undergraduate course in thermal physics / statistical mechanics for physics majors (“Thermal Physics” by Kittel and Kroemer) to your list of banned textbooks. They have committed the heresy of also including a simple discussion of the greenhouse effect: http://books.google.com/books?id=c0R79nyOoNMC&pg=115#v=onepage&q&f=false
I guess teaching physics in a way approved by Bryan and Kristian is going to become as difficult as teaching biology in a way approved by Jerry Falwell & Pat Robertson!
Kristian says (May 1, 2013 at 12:07 pm): “So, no one was able to come up with a single real-world experiment or even a physics or engineering textbook example that theoretically deals with the heating of a sealed source of constant power beyond the input from its heat source … The only one even making an attempt was Gary Hladik.”
Well, let’s be very clear on what I didn’t find. I didn’t find fully-computed textbook examples of problem 1023 aka “steel greenhouse” that supported either “Spencer-type” physics or “Kristian-type” physics. Kristian is of course free to link experiments or computed textbook examples that support his view (good luck).
What I did find is pretty close to problem 1023, and I only hope the differences won’t confuse Kristian. To start, look at this discussion of thermocouples:
http://eyrie.shef.ac.uk/eee/cpe630/comfun2.html
You’ll see (near Figure 1.2), “The greatest problem with measuring gas temperatures is combatting radiation loss. This cannot be ignored and should always be estimated to make sure the difference is not excessive. There are a number of commonly used methods. The simplest is to reduce the size of the thermocouple…
The next simplest method is to surround the probe with a radiation shield [see Fig 1.2] The gas is free to pass through the shield and the shield and thermocouple are heated. The thermocouple bead radiates to the shield which is much hotter than the surrounding walls. Thus the radiative loss and hence temperature error is significantly reduced.” (Thanks to “Phil.” who provided this link in an earlier thread at WUWT.)
Here’s a computed textbook example, showing thermocouple temps before and after a radiation shield is added (the topic starts on page 297, example 9.25 is on page 298):
http://books.google.com/books?id=eQ6yfl3cUKsC&pg=PA298&dq=radiative+heat+transfer+thermocouple+shield&hl=en&sa=X&ei=1f6BUd_pLOPHiwLj2YGoCg&ved=0CDsQ6AEwAA#v=onepage&q=radiative%20heat%20transfer%20thermocouple%20shield&f=false
The same example is also in the 2011 edition, but the preview excludes part of the solution.
Note that the bead temperature is higher after the radiation shield is added, even though the steady-state conductive heat flow to the bead is lower because of the smaller temperature difference between bead and gas stream. The difference is the “back radiation” from the cooler shield, which Kristian claims should have no effect on the warmer bead.
This is also textbook confirmation of Dr. Spencer’s comment (April 24, 2013 at 1:37 pm): “Temperature is a function of BOTH energy input (typically not temperature dependent) AND energy loss…”, which Kristian has disputed (April 25, 2013 at 2:35 pm).
A second computed example (Problem 12-089) is from this book:
http://www.amazon.com/Heat-Transfer-Practical-Yunus-Cengel/dp/0072458933/ref=sr_1_26?s=books&ie=UTF8&qid=1367520360&sr=1-26&keywords=Yunus+Cengel
The solution is here:
http://www.belgeler.com/blg/1k20/heat-chap-12-088
This one is tricky, because when the shield is removed the gas temp is raised to keep the thermocouple reading constant. However, it’s clear that the shield keeps the thermocouple closer to the gas temp.
Now these examples aren’t experiments, but thermocouples manufactured according textbook principles are used in any number of practical applications, e.g. jet engine design. If Kristian thinks the textbooks are wrong, I suggest he refrain from flying. 🙂
I don’t expect Kristian to accept these examples (by now he’s dug in so deep he’s tap dancing in Lucifer’s attic), but he certainly can’t claim any longer that he’s in accordance with accepted physics. If he still thinks he is, Kristian should be able to find computed textbook examples that
support his view (again, good luck).
Kristian, the ball’s in your court.
Konrad asks: “Can you explain to me the reasoning behind your 1/2, 1/3, 1/4 … succession?”
Clearly I cannot. I have tried once already. Joel has tried. I linked to the wikipedia article for MLI that discusses the problem. There are lots of places on the internet that explain this problem (this one looks good — http://cybele.bu.edu/courses/gg612fall99/gg612lab/lab1.html). The fact that you can’t even understand the physics of a single layer is further proof that I cannot explain this to you in a way that you understand what I am saying.
But at least readers will see what people on “both sides” of this issue think and will hopefully be able to decide for themselves what is correct.
tjfolkerts says (May 2, 2013 at 12:59 pm): “There are lots of places on the internet that explain this problem …”
For example Leonard Weinstein at The Air Vent:
https://noconsensus.wordpress.com/2012/07/20/why-back-radiation-is-not-a-source-of-surface-heating/
where he derives equation 8: T’/To=(N+1)^0.25
T’ is temperature of sphere with shell(s)
To is sphere temp without shell(s)
N is number of shells
For people who dislike the term “back radiation”, Weinstein explicitly does not attribute “heating” of the sphere to “back radiation”, although in the comment thread we see the distinction, while perhaps scientifically rigourous, is basically semantic for us laymen.
This article also explains why Kristian’s comment (May 1, 2013 at 11:52 am) about multiple shells is merely demolishing a straw man. Kristian, when disputing someone’s calculations, you should at least understand how the disputed calculation is being done.
Kristian says (May 1, 2013 at 11:56 am): [snip]
Summarizing, Ferdinand Engelbeen writes (April 28, 2013 at 1:43 pm): “The incoming energy for the sphere is J + J1.”
Kristian writes: “This is a fundamental mistake you make here… But you see, J1 is not incoming energy. It is part of the outgoing energy flux J from the sphere. All it can do is REDUCE the outgoing. It cannot INCREASE the incoming.”
It just occurred to me that Kristian’s claim is analogous to matter/anti-matter annihilation. You see, half the sphere’s outgoing energy per second (half of 400 watts = 200 watts) is “annihilated” by the “anti-energy” radiated by the inner surface of the shell. The outer shell surface of course radiates “normal” energy at 200 watts, but the inner surface of the same shell radiates “anti-energy”.
Of course the difference between “anti-energy” and anti-matter is that matter/anti-matter annihilation yields energy equivalent to the original reactants, whereas energy/”anti-energy” annihilation yields…nothing. This is potentially a great way to reduce the cooling requirements of, say, a nuclear power plant. 400 watts of waste heat in a pipe, add a shell–presto!–only 200 watts to the cooling tower! Add enough shells and you could cool the plant with a garden hose! We’ll call it the “Kristian Kooler!” 🙂
Kristian says (May 1, 2013 at 12:04 pm): “Gary, it wouldn’t surprise me in the least if you actually walk around thinking that reflected light (like from a mirror) can indeed heat its source.”
Thanks for the clarification. So if I have an incadescent light bulb with constant power input and surround it with a perfectly reflecting shell, i.e. none of the energy going into the bulb escapes the shell, I could pour power into the bulb until Doomsday and the temperature inside the shell would not increase? Am I understanding you correctly?
Kristian says:
So, let’s say the instruments were generating 100 W initially. Now, because of our heat shield, only 10 W is escaping to space. What happens to the other 90 W? Does it just disappear into the ether?
Kristian says: I don’t see what’s not to understand here …
The arithmetic, of course, has no flaws. The problem comes from your lack of clear definitions of the terms you use and what the equations mean.
Most specifically you say:
“J1 is not incoming energy. ….
‘Back radiation’ (J1) … ”
So what is “J1”?. Because “back radiation” IS EXACTLY “incoming IR energy ” from the sphere (or the atmosphere for earth). You can’t have “back radiation” that is not “incoming energy”.
And what is “J” for that matter? It seems that it represents both “IR flux from the surface” and “heat input from the heaters” in your equations. While these might be the same, there is no a priori reason that these two very different quantities must be the same. That is something that must be proven. (And in this case, the somewhat surprising answer is that the surface radiates TWICE as much IR as the heaters directly provide.)
Joel Shore says
“You can also add what is probably the most popular textbook for a first upper-level undergraduate course in thermal physics / statistical mechanics for physics majors (“Thermal Physics” by Kittel and Kroemer ) ”
1980 edition?
Joel your link does not give any indication of the conclusion of the discussion.
Please outline relevant details.
My old school textbook A Level Physics by Nelkon & Parker 1973
(pitched about first year American University Standard);
also discuss the Greenhouse Effect.
But dismiss it as being falsified by R W Wood.
By the way what has happened to the falsification test for CO2 driven catastrophic greenhouse effect?
You might as well admit that you hold a belief similar to a religious conviction that is however not subject to scientific scrutiny.