This thread debates the Miskolczi semi-transparent atmosphere model.
The link with the easiest introduction to the subject is http://hps.elte.hu/zagoni/Proofs_of_the_Miskolczi_theory.htm
This thread debates the Miskolczi semi-transparent atmosphere model.
The link with the easiest introduction to the subject is http://hps.elte.hu/zagoni/Proofs_of_the_Miskolczi_theory.htm
Alex Harvey writes:
“A First Course in Atmospheric Radiation” is a physics textbook, son.
Not by anyone competent in the field, they’re not.
Try this: Don’t use the number of hits of web pages to prove scientific points. Sturgeon’s Law applies to the internet, you know.
Yes, Kirchhoff’s laws are used to relate absorption and emission if you set the problem up that way. But that is NOT the same as saying Kirchhoff’s Law says absorption must equal emission, which is wrong. You’ve got three quantities related here:
temperature
emissivity (or absorptivity)
emission (or absorption)
For example, if a body, let’s say a patch of gas, is at a temperature of T = 270 K, and has a graybody emissivity of 0.2, its emission will be ε σ T4, or about 60 watts per square meter. Kirchhoff’s law tells you the absorptivity, 0.2, must be the same as the emissivity. But it does NOT tell you the absorption will be the same as the emission! Without intelligence and sufficient technology to hand, an object can’t decide how much energy is falling on it. If our patch of gas has 1,366 watts per square meter falling on it (it’s at noon on the equator, let’s say), it will absorb 0.2 x 1366 or 273 watts per square meter — more than four times what it’s emitting. The absorptivity and emissivity will be the same, but the absorption and the emission will not be the same.
BPL:
That’s right, I didn’t understand. I’m a computer programmer. You’re a science fiction writer; Miskolczi is a specialist in radiative transfer with 30 years experience, many of those as a research scientist with Langley. He has a long publishing history of at least 15 peer-reviewed papers since the late 1980s; his specialisation is in radiative transfer. You want me to believe that a man hired & retained for many years by NASA as a research scientist doesn’t understand the ABC’s of theoretical physics. Indeed, you want me to believe that his NASA colleague, Martin G. Mlynczak, likewise makes these sorts of “freshman” errors.
Interestingly, have a look at this article about Dr. Mlynczak:
http://www.nasa.gov/centers/langley/news/researchernews/rn_mylnczak.html
And it’s not just these two. There are plenty of posts out there on the blogosphere from people saying, “er, actually, I don’t see a problem with this part of Miskolczi’s paper actually.”
Now apologies for the polemics but I would prefer a response that goes a little deeper than, “I could tell you, but you wouldn’t understand.”
Eq (2.76) is an equation relating absorptivity & emissivity, is it BPL. Look on p. 28 & read the words, “Kirchhoff’s deductions were as follows [some conditions and then] … (b) the source function is equal to the intensity.”
That is, absorption=emission.
Question 1: Do you want to dispute my reading of Goody & Yung pp. 28, 39? If so please don’t return the mantra about LTE, absorptivity & emissivity. Can you explain what it is that I’m missing? In particular, the bit that says the source function is equal to the intensity.
Question 2: Since the textbook is not wrong, can you explain which part of “Since clouds, ground, and atmosphere do not differ greatly in temperature, it follows from Kirchhoff’s laws that emission and absorption are approximately equal to each other. Terrestrial radiation is therefore passed from layer to layer in the atmosphere” I did not understand?
Alex Harvey:
– I didn’t catch where BPL was impugning Dr. Mlynczak. Where was that?
Neal, nowhere directly. I doubt that anyone has thought this through, but it is implied: if Miskolczi doesn’t understand Kirchhoff’s Law, then Mlynczak obviously doesn’t either since Miskolczi & Mlynczak (2004) uses Kirchhoff’s law in exactly the same way as Miskolczi (2007):
p. 229:
p. 232:
If Dr. Mlynczak doesn’t agree with what I’ve written here, it’s about time someone from NASA breaks this silence. How is it that no one at NASA ever pointed out to poor Dr. Miskolczi that he misunderstood Kirchhoff’s Law? Most likely, because they knew he didn’t. I’m sorry, this is NASA research. Someone needs to explain this contradiction.
Alex Harvey:
OK, you’re talking about M&M (2004). I haven’t focused much on that, as it doesn’t seem relevant to the questions I have.
As I’ve said before, I don’t have any particular beef with equation (4), whether or not it comes from Kirchhoff’s law.
But I have lots of other beefs with M (2007).
I guess if you’re really curious about Mlynczak’s point of view, why not just send him a note asking what he thinks about M (2007)?
Alex, I have tried my damnedest to walk you through this issue. I’ve cited sources and worked examples. You are just completely unwilling to learn. To anyone who knows radiation physics, you come off like the kind of buffoon who thinks he can prove that the Moon landings were faked or that Velikovsky was right about astronomy.
Ignorance can be cured. Stupidity can’t be. Militant ignorance of your sort is a kind of stupidity.
Wait a minute here!
Velikovsky was wrong?
Now my entire world is in upheaval.
BPL,
You are being rude.
This is not necessary.
Let’s keep things to a higher level.
BPL:
I don’t think I can prove anything. I’m just asking questions, and I’m noticing that right now I’ve asked the same question several times & you’re refusing to answer. Is G&Y’s eq. (2.76) an equation that relates absorptivity & emissivity or isn’t it? I’m not asking for a lot of your time here. “Yes” or “no” will suffice. It’s not about intelligence. Your CV suggests you win the IQ contest. There’s no need for the insults. It looks to me that you’ve just said something that’s wrong & are refusing to admit this. But I’m quite happy to be corrected. Thanks.
BPL:
From http://www.ssec.wisc.edu/library/coursefiles/03_abs_emiss_ref.pdf
Compare again with Miskolczi’s statement:
Alex Harvey:
I would agree that “two systems in thermal equilibrium exchange energy by absorption and emission in equal amounts” and “the thermal energy of either system cannot be changed”. If anything else were happening, these two wouldn’t be in thermal equilibrium.
But I don’t know if there is much point in dragging Kirchhoff’s law into this.
Alex writes:
I have answered your question at great length, and in detail. You simply refused to believe anything I said. There is nothing more I can say to you; you’re immune to evidence. There’s really no point continuing to talk to you at all.
Neal:
– I don’t think it matters whether we call it Kirchhoff’s law or something else. Miskolczi is calling it Kirchhoff’s law because others have called it Kirchhoff’s law. You seem to be in disagreement with BPL who finds eq (4) to be completely unjustifiable. You have read his responses & you seem to be standing to your position that there is no problem with eq (4). Since he won’t answer my questions about the apparent contradictions, perhaps you can explain what he’s missing?
– On another point I re-read MM2004 section 4 last night whilst trying to understand the argument from the minimum energy principle. If you really have no objection to M2007, eq (4), may I implore you to read MM2004, section 4, pp. 233-248. None of the virial arguments are used at all yet MM arrive at much of the same result.
Consider this, MM2004, p. 241:
I’m feeling very puzzled as to how Martin Mlynczak’s name got onto this paper! I did send him an email as you suggested; I hope he responds.
“IIgnorance can be cured. Stupidity can’t be. Militant ignorance of your sort is a kind of stupidity.”
Arthur Miller differentiated dumb (lacking ability) and stupid (knowing but choosing otherwise).
My dumb question, regarding radiate and thermal equilibrium. The two are different, averaged concepts, but result in same temperature. If not, perpetual motion, here we come.
Consider the letter C, conductive, but radiate at the gap.
Any way to massage the statistics, (smoke and one way mirrors, prisms, diffraction gratings oscillating, pulsed microwave transmitters with antennas mechanically modulated, magnetically aligned molecules) You can filter in time, frequency, space direction, etc., but to no avail ? How do optical depth and thermal kinetics, freedom degrees, balance it, making perpetual, always ,stupid wrong ?
Alex Harvey:
– I took a look last night at the later discussion on Kirchhoff’s law, and as far as I can tell, the main objection to eqn.(4) is just the claim that it comes from KL. I don’t see that anyone (even BPL) has made a strong objection eqn.(4) in itself. As I said, my point of view is that I don’t find eqn.(4) a problem; but I also don’t see that it really has much to do with KL. Maybe that’s not so different from what BPL is saying, except that I’m not getting too excited about the wording Miskolczi employs around eqn.(4). I only care about whether his equations string together, and for me, the train doesn’t come to a screeching halt until just before eqn.(7).
– OK, I will look at that section of M&M. However, I don’t know that I will be able to come to any conclusion: If it depends on real familiarity with the field and the data, as opposed to ability to follow and interpret a logical & physical argument, it might be out of my scope.
– Well, Mlynczac signed the 2004 paper, but not the 2007. Does that indicate anything? Let me know what he says.
Alex Harvey:
Sorry, I don’t get anything out of M&M, pp. 233 onward:
– In eqns (1)-(2), I don’t have a copy of Goody & Yung (as I mentioned earlier), so I don’t know the context of this equation: What is it about, what is the problem being addressed, what kind of tools are they using? In order to understand (not just quote), I have to have that context.
– Confusingly, they say under eqn.(4), “We should note, that the terrestrial graybody optical thickness is not an accurate measure of the atmospheric absorption and cannot be used in Eqs. (1) and (2).” But then, despite some disclaimers, they seem to go on to use it in their further equations.
– I don’t know where eqn.(5) comes from, they just state it. Maybe it’s the output from the “relatively simple computation” that they do not present.
– Under eqn.(6), they say, “The data points in these figures represent only about 10% of the total 230 profiles. Only those cases were selected for these plots, where the simulated and theoretically predicted OLRs agreed within less than 0.5%.” I can’t quite make out what this means: Is this selectivity a valid method of filtering out cases that don’t fit into the scope of investigation, or is it cherry-picking the points you like? I can’t tell.
I could go on, but you see the problem: I don’t really know where they’re coming from or where they’re going. This may not be their fault. But it means I don’t have anything particularly useful to say about M&M.
M (2007) is another matter: He starts out with something well-defined, and at least for the first ten pages I can make sense of what he is trying to do (although, as extensively documented by now, there are several of his steps that I do not agree with).
Sorry, Alex, this is the most I can do.
Neal:
The reason I asked you to look at MM2004 is that if you really want to understand the argument from the principle of minimum energy, it is spelt out in far greater detail in this earlier paper. And, as I said, it doesn’t depend on the virial arguments.
– On your first point I suppose yes; the authors are supposing that the reader knows Goody & Yung.
– On your second point I think you are confusing terrestrial graybody optical thickness (τ_T) & atmospheric graybody optical thickness (τ_A). They don’t use (τ_T) in the subsequent equations.
– Not sure about eq (5).
– the 10% of profiles were selected because they were the ones that were in radiative equilibrium in their own right.
At any rate, if you really want to understand where M2007 is going, I think that MM2004 helps. Of course, you may feel that there’s no point continuing unless Dr. Miskolczi responds, which I’d agree is valid. I will probably give up in that event too. 🙂
Alex Harvey:
What I can tell you, after trying, is that M&M doesn’t help me.
Alex posts:
He’s wrong, of course, and if this is what Miskolczi is saying there’s another mistake by the latter. There’s no distinction between “terrestrial graybody optical thickness” and “atmospheric graybody optical thickness.” What is the first phrase supposed to refer to – something other than the atmosphere? On a planetary scale, only an atmosphere or an ocean can have any optical thickness. An opaque object, like the solid Earth, doesn’t transmit any light.
BPL,
I was thinking along similar lines; but my real purpose was to emphasize that M&M don’t provide enough help to put me over any threshold to understanding the intent of M (2007).
Alex, you are grasping at straws. It is not your duty to fight to the last quibble for the sacred honor of Miskolczi’s paper: That is his job, and realistically you cannot do it for him.
I have sent him a list of questions (http://landshape.org/stats/wp-content/uploads/2008/07/m_questions-3.pdf) that are:
– focused & specific
– unanswered (to my satisfaction and to that of at least several participants) in any blog discussion or posting of which I’m aware (and I’ve been watching and participating in 4 of them)
– courteous
I cannot believe that anyone who could write the article M (2007) would have any difficulty understanding these questions, or why they should be answered.
Whether he wants to take the trouble to do so is, of course, his business. Even in this mini-world of Miskolczi analysis, I do not consider myself a very important person. But part of science is explaining things, so most scientists find pleasure in explaining ideas to other people – especially their own ideas.
BPL:
Yes, but have you ever actually tried to measure the earth’s optical depth yourself? That’s fine; neither have I. Anyway, if you read the paper I’m sure you would understand why it’s necessary to distinguish a τ_A and τ_T (and indeed quite a few other τs).
Any chance you’re going to clear up this confusion about Kirchhoff’s laws? My two questions remain unanswered. At least one person has read what you’re saying above & supposed that your only issue with Miskolczi’s eq (4) is that you feel very strongly that he shouldn’t have called it the “Kirchhoff law.”
The system has been blocking the URL to my set of questions.
Alex Harvey:
I don’t think you understand what BPL is saying: The straightforward interpretation of the words “the Earth’s optical depth” has to do with transmission of light through the Earth.
If you’ve never done this before, here is a quick approach:
1) Stand in an open field.
2) Look down.
3) Ask yourself, “Do I see the hot molten core of the Earth below me?”
4) If the answer is “Yes”, then you have untimely gone to an unjust reward. Please take it up with “higher authorities”; and in the meantime, I’d rather you didn’t stay in touch, thank you.
5) If not, you have just done a very crude measurement of the optical depth of the Earth. The answer is, “Just about infinite.”
6) This was a measurement at optical frequencies. The answer will not differ significantly for the infrared.
BPL:
That was my question.
I don’t really have a particular beef with eqn.(4) as such.
I’m not sure it makes sense to attribute it to Kirchhoff’s laws, however.
How does your view differ from mine?
P.S. There is something funny happening with the posting times: I keep having my postings come AFTER Alex Harvey’s, even when I post earlier.
Neal:
– terrestrial vs atmospheric optical thickness: It’s not about defending the sacred honour of Miskolczi’s paper. I’m just responding to the silly suggestion that I’ve misread the paper when BPL hasn’t read the paper at all. How about we have a “why Miskolczi & Mlynczak (2004) are wrong” page as well? The MM2004 is just as interesting & just as controversial (and I’m sure most will want to say just as wrong) as M2007. MM arive at different measures of the same quantities by using different procedures. To get “atmospheric flux transmittance” they use Tr_A =1 – A. To get “terrestrial flux transmittance” they use Tr_T=OLR/S_U. Since graybody optical thickness is the negative logarithm of atmospheric flux transmittance, they end up with two different quantities, τ_A & τ_T.
– earth’s optical thickness, yes that’s infinity; agreed. But I think deep down you knew I was talking about the earth-ATMOSPHERE’s optical thickness? 🙂